drivers: Replace DEV_OK by 0

This patch replaces all occurences of the macro DEV_OK by the actual
value 0 at the driver level. So this patch touch the files under
drivers/, include/ and samples/drivers/.

This patch is part of the effort to transition from DEV_* codes to
errno.h codes.

Change-Id: I69980ecb9755f2fb026de5668ae9c21a4ae62d1e
Signed-off-by: Andre Guedes <andre.guedes@intel.com>

71 files changed, 302 insertions, 302 deletions

diff --git a/drivers/802.15.4/cc2520.c b/drivers/802.15.4/cc2520.c
index e5a968829..d20ee4989 100644
--- a/drivers/802.15.4/cc2520.c
+++ b/drivers/802.15.4/cc2520.c
@@ -1265,7 +1265,7 @@ static int cc2520_init(struct device *dev)
 		return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(cc2520, CONFIG_CC2520_DRV_NAME,
diff --git a/drivers/802.15.4/cc2520_arch.h b/drivers/802.15.4/cc2520_arch.h
index 343554c2a..04844ae1b 100644
--- a/drivers/802.15.4/cc2520_arch.h
+++ b/drivers/802.15.4/cc2520_arch.h
@@ -107,7 +107,7 @@ static inline bool spi_transfer(struct device *dev,
 	spi_slave_select(dev, CC2520_SPI_SLAVE());
 	ret = spi_transceive(dev, data_out, out_len, data_in, in_len);
 
-	return (ret == DEV_OK);
+	return (ret == 0);
 }
 
 static inline bool cc2520_read_fifo_buf(uint8_t *buffer, uint32_t count)
diff --git a/drivers/adc/adc_qmsi.c b/drivers/adc/adc_qmsi.c
index b22c331e2..567f0cb8c 100644
--- a/drivers/adc/adc_qmsi.c
+++ b/drivers/adc/adc_qmsi.c
@@ -106,7 +106,7 @@ static void adc_qmsi_disable(struct device *dev)
 #if (CONFIG_ADC_QMSI_POLL)
 static int adc_qmsi_read(struct device *dev, struct adc_seq_table *seq_tbl)
 {
-	int i, ret = DEV_OK;
+	int i, ret = 0;
 	qm_adc_xfer_t xfer;
 	qm_adc_config_t cfg;
 
@@ -161,7 +161,7 @@ static int adc_qmsi_read(struct device *dev, struct adc_seq_table *seq_tbl)
 #else
 static int adc_qmsi_read(struct device *dev, struct adc_seq_table *seq_tbl)
 {
-	int i, ret = DEV_OK;
+	int i, ret = 0;
 	qm_adc_xfer_t xfer;
 	qm_adc_config_t cfg;
 
@@ -263,7 +263,7 @@ int adc_qmsi_init(struct device *dev)
 
 	adc_config_irq();
 
-	return DEV_OK;
+	return 0;
 }
 
 struct adc_info adc_info_dev;
diff --git a/drivers/adc/adc_ti_adc108s102.c b/drivers/adc/adc_ti_adc108s102.c
index f2b90f73b..7c7fcc3dd 100644
--- a/drivers/adc/adc_ti_adc108s102.c
+++ b/drivers/adc/adc_ti_adc108s102.c
@@ -162,7 +162,7 @@ static int ti_adc108s102_read(struct device *dev,
 	struct spi_config spi_conf;
 	uint32_t data[2] = {0, 0};
 	struct nano_timer timer;
-	int ret = DEV_OK;
+	int ret = 0;
 	int32_t delay;
 
 	spi_conf.config = config->spi_config_flags;
@@ -198,7 +198,7 @@ static int ti_adc108s102_read(struct device *dev,
 		nano_task_timer_test(&timer, TICKS_UNLIMITED);
 
 		ret = _ti_adc108s102_sampling(dev);
-		if (ret != DEV_OK) {
+		if (ret != 0) {
 			break;
 		}
 
@@ -228,7 +228,7 @@ int ti_adc108s102_init(struct device *dev)
 
 	dev->driver_api = &ti_adc108s102_api;
 
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_ADC_TI_ADC108S102
diff --git a/drivers/aio/aio_dw_comparator.c b/drivers/aio/aio_dw_comparator.c
index e579d9af6..e6bddf750 100644
--- a/drivers/aio/aio_dw_comparator.c
+++ b/drivers/aio/aio_dw_comparator.c
@@ -46,7 +46,7 @@ static int dw_aio_cmp_disable(struct device *dev, uint8_t index)
 	/* Disable power in comparator <index> */
 	regs->pwr &= ~(1 << index);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int dw_aio_cmp_configure(struct device *dev, uint8_t index,
@@ -116,7 +116,7 @@ static int dw_aio_cmp_configure(struct device *dev, uint8_t index,
 	/* Enable interrupt to host */
 	SCSS_INTERRUPT->int_comparators_host_mask &= ~(1 << index);
 
-	return DEV_OK;
+	return 0;
 }
 
 void dw_aio_cmp_isr(struct device *dev)
@@ -166,7 +166,7 @@ int dw_aio_cmp_init(struct device *dev)
 
 	if (config->config_func) {
 		i =  config->config_func(dev);
-		if (i != DEV_OK)
+		if (i != 0)
 			return i;
 	}
 
@@ -192,7 +192,7 @@ int dw_aio_cmp_init(struct device *dev)
 
 	irq_enable(config->interrupt_num);
 
-	return DEV_OK;
+	return 0;
 }
 
 struct dw_aio_cmp_dev_cfg_t dw_aio_cmp_dev_config = {
@@ -216,5 +216,5 @@ static int dw_aio_cmp_config(struct device *dev)
 	IRQ_CONNECT(INT_AIO_CMP_IRQ, CONFIG_AIO_DW_COMPARATOR_IRQ_PRI,
 		    dw_aio_cmp_isr,
 		    DEVICE_GET(dw_aio_cmp), 0);
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/aio/aio_qmsi_comparator.c b/drivers/aio/aio_qmsi_comparator.c
index ea72643d1..b0ac7abc2 100644
--- a/drivers/aio/aio_qmsi_comparator.c
+++ b/drivers/aio/aio_qmsi_comparator.c
@@ -63,7 +63,7 @@ static int aio_qmsi_cmp_disable(struct device *dev, uint8_t index)
 		return DEV_INVALID_CONF;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int aio_qmsi_cmp_configure(struct device *dev, uint8_t index,
@@ -113,7 +113,7 @@ static int aio_qmsi_cmp_configure(struct device *dev, uint8_t index,
 	/* Enable Interrupts to host for an specific comparator */
 	QM_SCSS_INT->int_comparators_host_mask &= ~(1 << index);
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct aio_cmp_driver_api aio_cmp_funcs = {
@@ -147,7 +147,7 @@ int aio_qmsi_cmp_init(struct device *dev)
 
 	irq_enable(INT_AIO_CMP_IRQ);
 
-	return DEV_OK;
+	return 0;
 }
 
 void aio_qmsi_cmp_isr(struct device *dev)
@@ -186,5 +186,5 @@ static int aio_cmp_config(struct device *dev)
 	IRQ_CONNECT(INT_AIO_CMP_IRQ, CONFIG_AIO_COMPARATOR_IRQ_PRI,
 		    aio_qmsi_cmp_isr, DEVICE_GET(aio_qmsi_cmp), 0);
 
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/bluetooth/h4.c b/drivers/bluetooth/h4.c
index 0fc3abdc6..b4b50e759 100644
--- a/drivers/bluetooth/h4.c
+++ b/drivers/bluetooth/h4.c
@@ -254,7 +254,7 @@ static int _bt_uart_init(struct device *unused)
 
 	bt_driver_register(&drv);
 
-	return DEV_OK;
+	return 0;
 }
 
 SYS_INIT(_bt_uart_init, NANOKERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);
diff --git a/drivers/bluetooth/h5.c b/drivers/bluetooth/h5.c
index 562b0e7a6..44ccbccbd 100644
--- a/drivers/bluetooth/h5.c
+++ b/drivers/bluetooth/h5.c
@@ -781,7 +781,7 @@ static int _bt_uart_init(struct device *unused)
 
 	bt_driver_register(&drv);
 
-	return DEV_OK;
+	return 0;
 }
 
 SYS_INIT(_bt_uart_init, NANOKERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);
diff --git a/drivers/clock_control/quark_se_clock_control.c b/drivers/clock_control/quark_se_clock_control.c
index bcef87f38..7d618a1e9 100644
--- a/drivers/clock_control/quark_se_clock_control.c
+++ b/drivers/clock_control/quark_se_clock_control.c
@@ -55,7 +55,7 @@ static inline int quark_se_clock_control_on(struct device *dev,
 		DBG("Enabling all clock gates on dev %p\n", dev);
 		sys_write32(0xffffffff, info->base_address);
 
-		return DEV_OK;
+		return 0;
 	}
 
 	DBG("Enabling clock gate on dev %p subsystem %u\n", dev, subsys);
@@ -73,7 +73,7 @@ static inline int quark_se_clock_control_off(struct device *dev,
 		DBG("Disabling all clock gates on dev %p\n", dev);
 		sys_write32(0x00000000, info->base_address);
 
-		return DEV_OK;
+		return 0;
 	}
 
 	DBG("clock gate on dev %p subsystem %u\n", dev, subsys);
@@ -93,7 +93,7 @@ int quark_se_clock_control_init(struct device *dev)
 
 	DBG("Quark Se clock controller driver initialized on device: %p\n",
 									dev);
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_CLOCK_CONTROL_QUARK_SE_PERIPHERAL
diff --git a/drivers/clock_control/stm32f10x_clock.c b/drivers/clock_control/stm32f10x_clock.c
index ecd64de09..954d39dc6 100644
--- a/drivers/clock_control/stm32f10x_clock.c
+++ b/drivers/clock_control/stm32f10x_clock.c
@@ -50,7 +50,7 @@ static inline int stm32f10x_clock_control_on(struct device *dev,
 	} else {
 		rcc->apb1enr |= subsys;
 	}
-	return DEV_OK;
+	return 0;
 }
 
 static inline int stm32f10x_clock_control_off(struct device *dev,
@@ -67,7 +67,7 @@ static inline int stm32f10x_clock_control_off(struct device *dev,
 	} else {
 		rcc->apb1enr &= ~subsys;
 	}
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -187,7 +187,7 @@ static int stm32f10x_clock_control_get_subsys_rate(struct device *clock,
 
 	*rate = __get_apb_clock(ahb_clock, prescaler);
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct clock_control_driver_api stm32f10x_clock_control_api = {
@@ -257,7 +257,7 @@ int stm32f10x_clock_control_init(struct device *dev)
 	}
 
 	dev->driver_api = &stm32f10x_clock_control_api;
-	return DEV_OK;
+	return 0;
 }
 
 static struct stm32f10x_rcc_data stm32f10x_rcc_data = {
diff --git a/drivers/console/ipm_console_receiver.c b/drivers/console/ipm_console_receiver.c
index 4b3ed237f..43333c053 100644
--- a/drivers/console/ipm_console_receiver.c
+++ b/drivers/console/ipm_console_receiver.c
@@ -122,6 +122,6 @@ int ipm_console_receiver_init(struct device *d)
 			 IPM_CONSOLE_PRI, 0);
 	ipm_set_enabled(ipm, 1);
 
-	return DEV_OK;
+	return 0;
 }
 
diff --git a/drivers/console/ipm_console_sender.c b/drivers/console/ipm_console_sender.c
index 376642a4c..9cc200016 100644
--- a/drivers/console/ipm_console_sender.c
+++ b/drivers/console/ipm_console_sender.c
@@ -61,6 +61,6 @@ int ipm_console_sender_init(struct device *d)
 		__printk_hook_install(consoleOut);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
diff --git a/drivers/console/ram_console.c b/drivers/console/ram_console.c
index b7a61a1f8..90b1f858d 100644
--- a/drivers/console/ram_console.c
+++ b/drivers/console/ram_console.c
@@ -42,7 +42,7 @@ static int ram_console_init(struct device *d)
 	__printk_hook_install(ram_console_out);
 	__stdout_hook_install(ram_console_out);
 
-	return DEV_OK;
+	return 0;
 }
 
 SYS_INIT(ram_console_init, PRIMARY, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
diff --git a/drivers/console/uart_console.c b/drivers/console/uart_console.c
index 72c563112..49858864b 100644
--- a/drivers/console/uart_console.c
+++ b/drivers/console/uart_console.c
@@ -417,7 +417,7 @@ void uart_console_hook_install(void)
  *
  * @brief Initialize one UART as the console/debug port
  *
- * @return DEV_OK if successful, otherwise failed.
+ * @return 0 if successful, otherwise failed.
  */
 static int uart_console_init(struct device *arg)
 {
@@ -427,7 +427,7 @@ static int uart_console_init(struct device *arg)
 
 	uart_console_hook_install();
 
-	return DEV_OK;
+	return 0;
 }
 
 /* UART consloe initializes after the UART device itself */
diff --git a/drivers/flash/spi_flash_w25qxxdv.c b/drivers/flash/spi_flash_w25qxxdv.c
index c564e370e..db0365deb 100644
--- a/drivers/flash/spi_flash_w25qxxdv.c
+++ b/drivers/flash/spi_flash_w25qxxdv.c
@@ -30,7 +30,7 @@ static inline int spi_flash_wb_id(struct device *dev)
 	buf[0] = W25QXXDV_CMD_RDID;
 
 	if (spi_transceive(driver_data->spi, buf, W25QXXDV_LEN_CMD_AND_ID,
-			   buf, W25QXXDV_LEN_CMD_AND_ID) != DEV_OK) {
+			   buf, W25QXXDV_LEN_CMD_AND_ID) != 0) {
 		return DEV_FAIL;
 	}
 
@@ -42,7 +42,7 @@ static inline int spi_flash_wb_id(struct device *dev)
 		return DEV_NO_SUPPORT;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_flash_wb_config(struct device *dev)
@@ -56,11 +56,11 @@ static int spi_flash_wb_config(struct device *dev)
 
 	if (spi_slave_select(driver_data->spi,
 			     CONFIG_SPI_FLASH_W25QXXDV_SPI_SLAVE) !=
-			     DEV_OK) {
+			     0) {
 		return DEV_FAIL;
 	}
 
-	if (spi_configure(driver_data->spi, &config) != DEV_OK) {
+	if (spi_configure(driver_data->spi, &config) != 0) {
 		return DEV_FAIL;
 	}
 
@@ -72,13 +72,13 @@ static int spi_flash_wb_reg_read(struct device *dev, uint8_t *data)
 	struct spi_flash_data *const driver_data = dev->driver_data;
 	uint8_t buf[2];
 
-	if (spi_transceive(driver_data->spi, data, 2, buf, 2) != DEV_OK) {
+	if (spi_transceive(driver_data->spi, data, 2, buf, 2) != 0) {
 		return DEV_FAIL;
 	}
 
 	memcpy(data, buf, 2);
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline void wait_for_flash_idle(struct device *dev)
@@ -102,11 +102,11 @@ static int spi_flash_wb_reg_write(struct device *dev, uint8_t *data)
 	wait_for_flash_idle(dev);
 
 	if (spi_transceive(driver_data->spi, data, 1,
-			   &buf /*dummy */, 1) != DEV_OK) {
+			   &buf /*dummy */, 1) != 0) {
 		return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_flash_wb_read(struct device *dev, off_t offset, void *data,
@@ -121,7 +121,7 @@ static int spi_flash_wb_read(struct device *dev, off_t offset, void *data,
 
 	nano_sem_take(&driver_data->sem, TICKS_UNLIMITED);
 
-	if (spi_flash_wb_config(dev) != DEV_OK) {
+	if (spi_flash_wb_config(dev) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
@@ -136,7 +136,7 @@ static int spi_flash_wb_read(struct device *dev, off_t offset, void *data,
 	memset(buf + W25QXXDV_LEN_CMD_ADDRESS, 0, len);
 
 	if (spi_transceive(driver_data->spi, buf, len + W25QXXDV_LEN_CMD_ADDRESS,
-			   buf, len + W25QXXDV_LEN_CMD_ADDRESS) != DEV_OK) {
+			   buf, len + W25QXXDV_LEN_CMD_ADDRESS) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
@@ -145,7 +145,7 @@ static int spi_flash_wb_read(struct device *dev, off_t offset, void *data,
 
 	nano_sem_give(&driver_data->sem);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_flash_wb_write(struct device *dev, off_t offset,
@@ -160,7 +160,7 @@ static int spi_flash_wb_write(struct device *dev, off_t offset,
 
 	nano_sem_take(&driver_data->sem, TICKS_UNLIMITED);
 
-	if (spi_flash_wb_config(dev) != DEV_OK) {
+	if (spi_flash_wb_config(dev) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
@@ -184,14 +184,14 @@ static int spi_flash_wb_write(struct device *dev, off_t offset,
 
 	memcpy(buf + W25QXXDV_LEN_CMD_ADDRESS, data, len);
 
-	if (spi_write(driver_data->spi, buf, len + W25QXXDV_LEN_CMD_ADDRESS) != DEV_OK) {
+	if (spi_write(driver_data->spi, buf, len + W25QXXDV_LEN_CMD_ADDRESS) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
 
 	nano_sem_give(&driver_data->sem);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_flash_wb_write_protection_set(struct device *dev, bool enable)
@@ -201,7 +201,7 @@ static int spi_flash_wb_write_protection_set(struct device *dev, bool enable)
 
 	nano_sem_take(&driver_data->sem, TICKS_UNLIMITED);
 
-	if (spi_flash_wb_config(dev) != DEV_OK) {
+	if (spi_flash_wb_config(dev) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
@@ -214,14 +214,14 @@ static int spi_flash_wb_write_protection_set(struct device *dev, bool enable)
 		buf = W25QXXDV_CMD_WREN;
 	}
 
-	if (spi_flash_wb_reg_write(dev, &buf) != DEV_OK) {
+	if (spi_flash_wb_reg_write(dev, &buf) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
 
 	nano_sem_give(&driver_data->sem);
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int spi_flash_wb_erase_internal(struct device *dev,
@@ -278,7 +278,7 @@ static int spi_flash_wb_erase(struct device *dev, off_t offset, size_t size)
 {
 	struct spi_flash_data *const driver_data = dev->driver_data;
 	uint8_t *buf = driver_data->buf;
-	int ret = DEV_OK;
+	int ret = 0;
 	uint32_t new_offset = offset;
 	uint32_t size_remaining = size;
 
@@ -290,7 +290,7 @@ static int spi_flash_wb_erase(struct device *dev, off_t offset, size_t size)
 
 	nano_sem_take(&driver_data->sem, TICKS_UNLIMITED);
 
-	if (spi_flash_wb_config(dev) != DEV_OK) {
+	if (spi_flash_wb_config(dev) != 0) {
 		nano_sem_give(&driver_data->sem);
 		return DEV_FAIL;
 	}
@@ -303,7 +303,7 @@ static int spi_flash_wb_erase(struct device *dev, off_t offset, size_t size)
 		return DEV_FAIL;
 	}
 
-	while ((size_remaining >= W25QXXDV_SECTOR_SIZE) && (ret == DEV_OK)) {
+	while ((size_remaining >= W25QXXDV_SECTOR_SIZE) && (ret == 0)) {
 		if (size_remaining == CONFIG_SPI_FLASH_W25QXXDV_FLASH_SIZE) {
 			ret = spi_flash_wb_erase_internal(dev, offset, size);
 			break;
diff --git a/drivers/gpio/gpio_atmel_sam3.c b/drivers/gpio/gpio_atmel_sam3.c
index 02c3416df..3f63048a0 100644
--- a/drivers/gpio/gpio_atmel_sam3.c
+++ b/drivers/gpio/gpio_atmel_sam3.c
@@ -108,7 +108,7 @@ static void _config(struct device *dev, uint32_t mask, int flags)
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_sam3_config(struct device *dev, int access_op,
 			    uint32_t pin, int flags)
@@ -124,7 +124,7 @@ static int gpio_sam3_config(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -135,7 +135,7 @@ static int gpio_sam3_config(struct device *dev, int access_op,
  * @param pin The pin number
  * @param value Value to set (0 or 1)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_sam3_write(struct device *dev, int access_op,
 			   uint32_t pin, uint32_t value)
@@ -165,7 +165,7 @@ static int gpio_sam3_write(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -176,7 +176,7 @@ static int gpio_sam3_write(struct device *dev, int access_op,
  * @param pin The pin number
  * @param value Value of input pin(s)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_sam3_read(struct device *dev, int access_op,
 				       uint32_t pin, uint32_t *value)
@@ -195,7 +195,7 @@ static int gpio_sam3_read(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static void gpio_sam3_isr(void *arg)
@@ -233,7 +233,7 @@ static int gpio_sam3_set_callback(struct device *dev,
 
 	cfg->cb = callback;
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sam3_enable_callback(struct device *dev,
@@ -256,7 +256,7 @@ static int gpio_sam3_enable_callback(struct device *dev,
 	cfg->enabled_cb |= mask;
 	cfg->port->ier |= mask;
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sam3_disable_callback(struct device *dev,
@@ -279,7 +279,7 @@ static int gpio_sam3_disable_callback(struct device *dev,
 	cfg->enabled_cb &= ~mask;
 	cfg->port->idr |= mask;
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sam3_suspend_port(struct device *dev)
@@ -311,7 +311,7 @@ static struct gpio_driver_api gpio_sam3_drv_api_funcs = {
  * @brief Initialization function of MMIO
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int gpio_sam3_init(struct device *dev)
 {
@@ -321,7 +321,7 @@ int gpio_sam3_init(struct device *dev)
 
 	cfg->config_func(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Port A */
diff --git a/drivers/gpio/gpio_k64.c b/drivers/gpio/gpio_k64.c
index 2d6a355a3..0956aeb5e 100644
--- a/drivers/gpio/gpio_k64.c
+++ b/drivers/gpio/gpio_k64.c
@@ -153,7 +153,7 @@ static int gpio_k64_config(struct device *dev, int access_op,
 		}
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -178,7 +178,7 @@ static int gpio_k64_write(struct device *dev, int access_op,
 
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -195,7 +195,7 @@ static int gpio_k64_read(struct device *dev, int access_op,
 
 	/* nothing more to do for GPIO_ACCESS_BY_PORT */
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -205,7 +205,7 @@ static int gpio_k64_set_callback(struct device *dev, gpio_callback_t callback)
 
 	data->callback_func = callback;
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -220,7 +220,7 @@ static int gpio_k64_enable_callback(struct device *dev, int access_op,
 		data->port_callback_enable = 1;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -235,7 +235,7 @@ static int gpio_k64_disable_callback(struct device *dev, int access_op,
 		data->port_callback_enable = 0;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -325,13 +325,13 @@ static struct gpio_driver_api gpio_k64_drv_api_funcs = {
  * @brief Initialization function of Freescale K64-based GPIO port
  *
  * @param dev Device structure pointer
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int gpio_k64_init(struct device *dev)
 {
 	dev->driver_api = &gpio_k64_drv_api_funcs;
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for Port A */
diff --git a/drivers/gpio/gpio_mmio.c b/drivers/gpio/gpio_mmio.c
index 32546e57b..5ae43efba 100644
--- a/drivers/gpio/gpio_mmio.c
+++ b/drivers/gpio/gpio_mmio.c
@@ -98,7 +98,7 @@ static uint32_t _io_write(uint32_t addr, uint32_t bit, uint32_t value)
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_mmio_config(struct device *dev, int access_op,
 					 uint32_t pin, int flags)
@@ -153,7 +153,7 @@ static int gpio_mmio_config(struct device *dev, int access_op,
 	 */
 
 	if (!cfg->reg.en) {
-		return DEV_OK;
+		return 0;
 	}
 
 	if (cfg->cfg_flags & GPIO_MMIO_CFG_EN_MASK) {
@@ -175,7 +175,7 @@ static int gpio_mmio_config(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -186,7 +186,7 @@ static int gpio_mmio_config(struct device *dev, int access_op,
  * @param pin The pin number
  * @param value Value to set (0 or 1)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_mmio_write(struct device *dev, int access_op,
 			   uint32_t pin, uint32_t value)
@@ -209,7 +209,7 @@ static int gpio_mmio_write(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -220,7 +220,7 @@ static int gpio_mmio_write(struct device *dev, int access_op,
  * @param pin The pin number
  * @param value Value of input pin(s)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_mmio_read(struct device *dev, int access_op,
 				       uint32_t pin, uint32_t *value)
@@ -244,7 +244,7 @@ static int gpio_mmio_read(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_mmio_set_callback(struct device *dev,
@@ -305,13 +305,13 @@ static struct gpio_driver_api gpio_mmio_drv_api_funcs = {
  * @brief Initialization function of MMIO
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int gpio_mmio_init(struct device *dev)
 {
 	dev->driver_api = &gpio_mmio_drv_api_funcs;
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for MMIO_0 */
diff --git a/drivers/gpio/gpio_mmio.h b/drivers/gpio/gpio_mmio.h
index f94c63b51..4e03889c2 100644
--- a/drivers/gpio/gpio_mmio.h
+++ b/drivers/gpio/gpio_mmio.h
@@ -49,7 +49,7 @@ extern "C" {
  * @brief Initialization function for GPIO driver
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 extern int gpio_mmio_init(struct device *dev);
 
diff --git a/drivers/gpio/gpio_pcal9535a.c b/drivers/gpio/gpio_pcal9535a.c
index 53d3c9fb1..3930c2078 100644
--- a/drivers/gpio/gpio_pcal9535a.c
+++ b/drivers/gpio/gpio_pcal9535a.c
@@ -89,7 +89,7 @@ static inline int _has_i2c_master(struct device *dev)
  * @param reg Register to read (the PORT0 of the pair of registers).
  * @param buf Buffer to read data into.
  *
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 static int _read_port_regs(struct device *dev, uint8_t reg,
 			   union gpio_pcal9535a_port_data *buf)
@@ -135,7 +135,7 @@ error:
  * @param reg Register to write into (the PORT0 of the pair of registers).
  * @param buf Buffer to write data from.
  *
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 static int _write_port_regs(struct device *dev, uint8_t reg,
 			    union gpio_pcal9535a_port_data *buf)
@@ -169,7 +169,7 @@ static int _write_port_regs(struct device *dev, uint8_t reg,
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int _setup_pin_dir(struct device *dev, int access_op,
 			  uint32_t pin, int flags)
@@ -221,7 +221,7 @@ done:
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int _setup_pin_pullupdown(struct device *dev, int access_op,
 				 uint32_t pin, int flags)
@@ -314,7 +314,7 @@ done:
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int _setup_pin_polarity(struct device *dev, int access_op,
 			       uint32_t pin, int flags)
@@ -369,7 +369,7 @@ done:
  * @param pin The pin number
  * @param flags Flags of pin or port
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_pcal9535a_config(struct device *dev, int access_op,
 				 uint32_t pin, int flags)
@@ -419,7 +419,7 @@ done:
  * @param pin The pin number
  * @param value Value to set (0 or 1)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_pcal9535a_write(struct device *dev, int access_op,
 				uint32_t pin, uint32_t value)
@@ -479,7 +479,7 @@ done:
  * @param pin The pin number
  * @param value Value of input pin(s)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int gpio_pcal9535a_read(struct device *dev, int access_op,
 			       uint32_t pin, uint32_t *value)
@@ -492,7 +492,7 @@ static int gpio_pcal9535a_read(struct device *dev, int access_op,
 	}
 
 	ret = _read_port_regs(dev, REG_INPUT_PORT0, &buf);
-	if (ret != DEV_OK) {
+	if (ret != 0) {
 		goto done;
 	}
 
@@ -574,7 +574,7 @@ static struct gpio_driver_api gpio_pcal9535a_drv_api_funcs = {
  * @brief Initialization function of PCAL9535A
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int gpio_pcal9535a_init(struct device *dev)
 {
@@ -595,7 +595,7 @@ int gpio_pcal9535a_init(struct device *dev)
 
 	nano_timer_init(&drv_data->timer, (void *) 0);
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for PCAL9535A_0 */
diff --git a/drivers/gpio/gpio_pcal9535a.h b/drivers/gpio/gpio_pcal9535a.h
index 2b55447e0..c1c0b2da7 100644
--- a/drivers/gpio/gpio_pcal9535a.h
+++ b/drivers/gpio/gpio_pcal9535a.h
@@ -34,7 +34,7 @@ extern "C" {
  * @brief Initialization function for PCAL9535A
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 extern int gpio_pcal9535a_init(struct device *dev);
 
diff --git a/drivers/gpio/gpio_qmsi.c b/drivers/gpio/gpio_qmsi.c
index 275d31326..a92990bd5 100644
--- a/drivers/gpio/gpio_qmsi.c
+++ b/drivers/gpio/gpio_qmsi.c
@@ -189,7 +189,7 @@ static inline int gpio_qmsi_config(struct device *port, int access_op,
 	} else {
 		qmsi_port_config(port, flags);
 	}
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_write(struct device *port, int access_op,
@@ -208,7 +208,7 @@ static inline int gpio_qmsi_write(struct device *port, int access_op,
 		qm_gpio_write_port(gpio, value);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_read(struct device *port, int access_op,
@@ -223,7 +223,7 @@ static inline int gpio_qmsi_read(struct device *port, int access_op,
 		*value = qm_gpio_read_port(gpio);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_set_callback(struct device *port,
@@ -233,7 +233,7 @@ static inline int gpio_qmsi_set_callback(struct device *port,
 
 	context->callback = callback;
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_enable_callback(struct device *port, int access_op,
@@ -247,7 +247,7 @@ static inline int gpio_qmsi_enable_callback(struct device *port, int access_op,
 		context->port_callback = 1;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_disable_callback(struct device *port, int access_op,
@@ -261,7 +261,7 @@ static inline int gpio_qmsi_disable_callback(struct device *port, int access_op,
 		context->port_callback = 0;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline int gpio_qmsi_suspend_port(struct device *port)
@@ -316,5 +316,5 @@ int gpio_qmsi_init(struct device *port)
 	}
 
 	port->driver_api = &api_funcs;
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/gpio/gpio_sch.c b/drivers/gpio/gpio_sch.c
index 7316e94b5..a1652762c 100644
--- a/drivers/gpio/gpio_sch.c
+++ b/drivers/gpio/gpio_sch.c
@@ -149,7 +149,7 @@ static int gpio_sch_config(struct device *dev,
 		_gpio_port_config(dev, flags);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_write(struct device *dev,
@@ -167,7 +167,7 @@ static int gpio_sch_write(struct device *dev,
 		_write_glvl(info->regs, value);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_read(struct device *dev,
@@ -185,7 +185,7 @@ static int gpio_sch_read(struct device *dev,
 		*value = !!(*value & BIT(pin));
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static void _gpio_sch_poll_status(int data, int unused)
@@ -259,7 +259,7 @@ static int gpio_sch_set_callback(struct device *dev,
 		gpio->poll = 0;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_enable_callback(struct device *dev,
@@ -287,7 +287,7 @@ static int gpio_sch_enable_callback(struct device *dev,
 
 	gpio_sch_set_callback(dev, gpio->callback);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_disable_callback(struct device *dev,
@@ -313,17 +313,17 @@ static int gpio_sch_disable_callback(struct device *dev,
 
 	gpio_sch_set_callback(dev, gpio->callback);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_suspend(struct device *dev)
 {
-	return DEV_OK;
+	return 0;
 }
 
 static int gpio_sch_resume(struct device *dev)
 {
-	return DEV_OK;
+	return 0;
 }
 
 static struct gpio_driver_api gpio_sch_api = {
@@ -347,7 +347,7 @@ int gpio_sch_init(struct device *dev)
 
 	DBG("SCH GPIO Intel Driver initialized on device: %p\n", dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 #if CONFIG_GPIO_SCH_0
diff --git a/drivers/grove/lcd_rgb.c b/drivers/grove/lcd_rgb.c
index 58b86c524..cb23daeff 100644
--- a/drivers/grove/lcd_rgb.c
+++ b/drivers/grove/lcd_rgb.c
@@ -339,7 +339,7 @@ int glcd_initialize(struct device *port)
 	_rgb_reg_set(dev->i2c, REGISTER_G, color_define[GROVE_RGB_WHITE][1]);
 	_rgb_reg_set(dev->i2c, REGISTER_B, color_define[GROVE_RGB_WHITE][2]);
 
-	return DEV_OK;
+	return 0;
 }
 
 struct glcd_driver grove_lcd_config = {
diff --git a/drivers/i2c/i2c_atmel_sam3.c b/drivers/i2c/i2c_atmel_sam3.c
index cefdda9b0..0c3f026b6 100644
--- a/drivers/i2c/i2c_atmel_sam3.c
+++ b/drivers/i2c/i2c_atmel_sam3.c
@@ -229,7 +229,7 @@ static int i2c_sam3_runtime_configure(struct device *dev, uint32_t config)
 	/* Setup clock wavefore generator */
 	cfg->port->cwgr = clk;
 
-	return DEV_OK;
+	return 0;
 }
 
 static void i2c_sam3_isr(void *arg)
@@ -475,7 +475,7 @@ static int i2c_sam3_transfer(struct device *dev,
 	struct i2c_msg *cur_msg = msgs;
 	uint8_t msg_left = num_msgs;
 	uint32_t pflags = 0;
-	int ret = DEV_OK;
+	int ret = 0;
 	int xfr_ret;
 
 	/* Why bother processing no messages */
@@ -592,13 +592,13 @@ done:
 static int i2c_sam3_suspend(struct device *dev)
 {
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 static int i2c_sam3_resume(struct device *dev)
 {
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 static struct i2c_driver_api api_funcs = {
@@ -623,13 +623,13 @@ static int i2c_sam3_init(struct device *dev)
 	cfg->config_func(dev);
 
 	if (i2c_sam3_runtime_configure(dev, dev_data->dev_config.raw)
-	    != DEV_OK) {
+	    != 0) {
 		DBG("I2C: Cannot set default configuration 0x%x\n",
 		    dev_data->dev_config.raw);
 		return DEV_INVALID_CONF;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_I2C_ATMEL_SAM3_0
diff --git a/drivers/i2c/i2c_dw.c b/drivers/i2c/i2c_dw.c
index 9d5e37743..bd3769c93 100644
--- a/drivers/i2c/i2c_dw.c
+++ b/drivers/i2c/i2c_dw.c
@@ -156,7 +156,7 @@ static int _i2c_dw_data_send(struct device *dev)
 
 		dw->state &= ~I2C_DW_CMD_SEND;
 
-		return DEV_OK;
+		return 0;
 	}
 
 	while (regs->ic_status.bits.tfnf && (dw->xfr_len > 0)) {
@@ -184,7 +184,7 @@ static int _i2c_dw_data_send(struct device *dev)
 		}
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline void _i2c_dw_transfer_complete(struct device *dev)
@@ -208,7 +208,7 @@ void i2c_dw_isr(struct device *port)
 	struct i2c_dw_dev_config * const dw = port->driver_data;
 	union ic_interrupt_register intr_stat;
 	uint32_t value;
-	int ret = DEV_OK;
+	int ret = 0;
 
 	volatile struct i2c_dw_registers * const regs =
 		(struct i2c_dw_registers *)rom->base_address;
@@ -275,7 +275,7 @@ void i2c_dw_isr(struct device *port)
 			 */
 			if (((dw->xfr_len == 0)
 			     && !(dw->xfr_flags & I2C_MSG_STOP))
-			    || (ret != DEV_OK)) {
+			    || (ret != 0)) {
 				goto done;
 			}
 		}
@@ -421,7 +421,7 @@ static int _i2c_dw_setup(struct device *dev, uint16_t slave_address)
 		regs->ic_sar.bits.ic_sar = slave_address;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int i2c_dw_transfer(struct device *dev,
@@ -527,7 +527,7 @@ static int i2c_dw_runtime_configure(struct device *dev, uint32_t config)
 	struct i2c_dw_rom_config const * const rom = dev->config->config_info;
 	struct i2c_dw_dev_config * const dw = dev->driver_data;
 	uint32_t	value = 0;
-	uint32_t	rc = DEV_OK;
+	uint32_t	rc = 0;
 
 	volatile struct i2c_dw_registers * const regs =
 		(struct i2c_dw_registers *)rom->base_address;
@@ -632,7 +632,7 @@ static int i2c_dw_suspend(struct device *dev)
 {
 	DBG("I2C: suspend called - function not yet implemented\n");
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -640,7 +640,7 @@ static int i2c_dw_resume(struct device *dev)
 {
 	DBG("I2C: resume called - function not yet implemented\n");
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -718,7 +718,7 @@ int i2c_dw_initialize(struct device *port)
 
 	rom->config_func(port);
 
-	if (i2c_dw_runtime_configure(port, dev->app_config.raw) != DEV_OK) {
+	if (i2c_dw_runtime_configure(port, dev->app_config.raw) != 0) {
 		DBG("I2C: Cannot set default configuration 0x%x\n",
 		    dev->app_config.raw);
 		return DEV_NOT_CONFIG;
@@ -726,7 +726,7 @@ int i2c_dw_initialize(struct device *port)
 
 	dev->state = I2C_DW_STATE_READY;
 
-	return DEV_OK;
+	return 0;
 }
 
 #if defined(CONFIG_IOAPIC)
diff --git a/drivers/i2c/i2c_qmsi.c b/drivers/i2c/i2c_qmsi.c
index 5a1825c3c..33dfcd620 100644
--- a/drivers/i2c/i2c_qmsi.c
+++ b/drivers/i2c/i2c_qmsi.c
@@ -97,7 +97,7 @@ static int i2c_qmsi_configure(struct device *dev, uint32_t config)
 	if (qm_i2c_set_config(instance, &qm_cfg) != QM_RC_OK)
 		return DEV_FAIL;
 
-	return DEV_OK;
+	return 0;
 }
 
 static void transfer_complete(uint32_t id, qm_rc_t status)
@@ -180,7 +180,7 @@ static int i2c_qmsi_transfer(struct device *dev, struct i2c_msg *msgs,
 			return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int i2c_qmsi_suspend(struct device *dev)
@@ -238,5 +238,5 @@ static int i2c_qmsi_init(struct device *dev)
 	device_sync_call_init(&driver_data->sync);
 
 	dev->driver_api = &api;
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/i2c/i2c_quark_se_ss.c b/drivers/i2c/i2c_quark_se_ss.c
index 103eec6d1..4bcf15c32 100644
--- a/drivers/i2c/i2c_quark_se_ss.c
+++ b/drivers/i2c/i2c_quark_se_ss.c
@@ -230,7 +230,7 @@ static int _i2c_qse_ss_data_send(struct device *dev)
 
 		dw->state &= ~I2C_QSE_SS_CMD_SEND;
 
-		return DEV_OK;
+		return 0;
 	}
 
 	while (_i2c_qse_ss_is_tfnf(dev) && (dw->xfr_len > 0)) {
@@ -259,7 +259,7 @@ static int _i2c_qse_ss_data_send(struct device *dev)
 
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static inline void _i2c_qse_ss_transfer_complete(struct device *dev)
@@ -279,7 +279,7 @@ void i2c_qse_ss_isr(void *arg)
 	struct device *dev = (struct device *)arg;
 	struct i2c_qse_ss_dev_config * const dw = dev->driver_data;
 	uint32_t ic_intr_stat;
-	int ret = DEV_OK;
+	int ret = 0;
 
 	/*
 	 * Causes of an intterrupts:
@@ -328,7 +328,7 @@ void i2c_qse_ss_isr(void *arg)
 		 */
 		if (((dw->xfr_len == 0)
 		     && !(dw->xfr_flags & I2C_MSG_STOP))
-		    || (ret != DEV_OK)) {
+		    || (ret != 0)) {
 			goto done;
 		}
 	}
@@ -349,7 +349,7 @@ static int _i2c_qse_ss_setup(struct device *dev, uint16_t addr)
 {
 	struct i2c_qse_ss_dev_config * const dw = dev->driver_data;
 	uint32_t ic_con;
-	int rc = DEV_OK;
+	int rc = 0;
 
 	/* Disable the device controller but enable clock
 	 * so we can setup the controller.
@@ -518,7 +518,7 @@ static int i2c_qse_ss_runtime_configure(struct device *dev, uint32_t config)
 {
 	struct i2c_qse_ss_dev_config * const dw = dev->driver_data;
 	uint32_t	value = 0;
-	uint32_t	rc = DEV_OK;
+	uint32_t	rc = 0;
 	uint32_t	ic_con;
 	uint32_t	spklen;
 
@@ -598,14 +598,14 @@ static int i2c_qse_ss_suspend(struct device *dev)
 {
 	DBG("I2C_SS: suspend called - function not yet implemented\n");
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 static int i2c_qse_ss_resume(struct device *dev)
 {
 	DBG("I2C_SS: resume called - function not yet implemented\n");
 	/* TODO - add this code */
-	return DEV_OK;
+	return 0;
 }
 
 static struct i2c_driver_api ss_funcs = {
@@ -631,7 +631,7 @@ int i2c_qse_ss_initialize(struct device *dev)
 
 	device_sync_call_init(&dw->sync);
 
-	if (i2c_qse_ss_runtime_configure(dev, dw->app_config.raw) != DEV_OK) {
+	if (i2c_qse_ss_runtime_configure(dev, dw->app_config.raw) != 0) {
 		DBG("I2C_SS: Cannot set default configuration 0x%x\n",
 		    dw->app_config.raw);
 		return DEV_NOT_CONFIG;
@@ -639,7 +639,7 @@ int i2c_qse_ss_initialize(struct device *dev)
 
 	dw->state = I2C_QSE_SS_STATE_READY;
 
-	return DEV_OK;
+	return 0;
 }
 
 #if CONFIG_I2C_QUARK_SE_SS_0
diff --git a/drivers/ipm/ipm_quark_se.c b/drivers/ipm/ipm_quark_se.c
index 146759547..94029ea32 100644
--- a/drivers/ipm/ipm_quark_se.c
+++ b/drivers/ipm/ipm_quark_se.c
@@ -215,7 +215,7 @@ int quark_se_ipm_controller_initialize(struct device *d)
 	if (config->controller_init) {
 		return config->controller_init();
 	}
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -229,7 +229,7 @@ int quark_se_ipm_initialize(struct device *d)
 		inbound_channels |= (0x3 << (config->channel * 2));
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
diff --git a/drivers/nble/uart.c b/drivers/nble/uart.c
index 378c580b3..a61e9e71a 100644
--- a/drivers/nble/uart.c
+++ b/drivers/nble/uart.c
@@ -232,7 +232,7 @@ static int _bt_nble_init(struct device *unused)
 	net_buf_pool_init(rx_pool);
 	net_buf_pool_init(tx_pool);
 
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(bt_nble, "", _bt_nble_init, NULL, NULL, NANOKERNEL,
diff --git a/drivers/pinmux/pinmux_k64.c b/drivers/pinmux/pinmux_k64.c
index 49d774012..3e45a4fb6 100644
--- a/drivers/pinmux/pinmux_k64.c
+++ b/drivers/pinmux/pinmux_k64.c
@@ -47,7 +47,7 @@ struct fsl_k64_data {
 static inline int config_port_a(mem_addr_t *addr)
 {
 	*addr = CONFIG_PORT_K64_A_BASE_ADDR;
-	return DEV_OK;
+	return 0;
 }
 #else
 #define config_port_a(addr) DEV_NO_ACCESS
@@ -57,7 +57,7 @@ static inline int config_port_a(mem_addr_t *addr)
 static inline int config_port_b(mem_addr_t *addr)
 {
 	*addr = CONFIG_PORT_K64_B_BASE_ADDR;
-	return DEV_OK;
+	return 0;
 }
 #else
 #define config_port_b(addr) DEV_NO_ACCESS
@@ -67,7 +67,7 @@ static inline int config_port_b(mem_addr_t *addr)
 static inline int config_port_c(mem_addr_t *addr)
 {
 	*addr = CONFIG_PORT_K64_C_BASE_ADDR;
-	return DEV_OK;
+	return 0;
 }
 #else
 #define config_port_c(addr) DEV_NO_ACCESS
@@ -77,7 +77,7 @@ static inline int config_port_c(mem_addr_t *addr)
 static inline int config_port_d(mem_addr_t *addr)
 {
 	*addr = CONFIG_PORT_K64_D_BASE_ADDR;
-	return DEV_OK;
+	return 0;
 }
 #else
 #define config_port_d(addr) DEV_NO_ACCESS
@@ -87,7 +87,7 @@ static inline int config_port_d(mem_addr_t *addr)
 static inline int config_port_e(mem_addr_t *addr)
 {
 	*addr = CONFIG_PORT_K64_E_BASE_ADDR;
-	return DEV_OK;
+	return 0;
 }
 #else
 #define config_port_e(addr) DEV_NO_ACCESS
@@ -151,7 +151,7 @@ static int _fsl_k64_get_gpio_dev(struct device *dev,
 		return DEV_NO_ACCESS;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -179,7 +179,7 @@ static int _fsl_k64_set_pin(struct device *dev,
 
 	status = _fsl_k64_get_port_addr(pin_id, &port_base_addr);
 
-	if (status != DEV_OK) {
+	if (status != 0) {
 		return status;
 	}
 
@@ -193,7 +193,7 @@ static int _fsl_k64_set_pin(struct device *dev,
 
 		status = _fsl_k64_get_gpio_dev(dev, port_base_addr, &gpio_dev);
 
-		if (status != DEV_OK) {
+		if (status != 0) {
 			return status;
 		} else if (gpio_dev == NULL) {
 			return DEV_NOT_CONFIG;
@@ -207,7 +207,7 @@ static int _fsl_k64_set_pin(struct device *dev,
 
 		status = gpio_pin_configure(gpio_dev, port_pin, gpio_setting);
 
-		if (status != DEV_OK) {
+		if (status != 0) {
 			return status;
 		}
 
@@ -220,7 +220,7 @@ static int _fsl_k64_set_pin(struct device *dev,
 
 	sys_write32(func, port_base_addr + K64_PINMUX_CTRL_OFFSET(port_pin));
 
-	return DEV_OK;
+	return 0;
 }
 
 static int _fsl_k64_get_pin(struct device *dev,
@@ -242,7 +242,7 @@ static int _fsl_k64_get_pin(struct device *dev,
 
 	status = _fsl_k64_get_port_addr(pin_id, &port_base_addr);
 
-	if (status != DEV_OK) {
+	if (status != 0) {
 		return status;
 	}
 
@@ -260,7 +260,7 @@ static int _fsl_k64_get_pin(struct device *dev,
 
 		status = _fsl_k64_get_gpio_dev(dev, port_base_addr, &gpio_dev);
 
-		if (status != DEV_OK) {
+		if (status != 0) {
 			return status;
 		} else if (gpio_dev == NULL) {
 			return DEV_NOT_CONFIG;
@@ -275,7 +275,7 @@ static int _fsl_k64_get_pin(struct device *dev,
 		}
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int fsl_k64_dev_set(struct device *dev,
@@ -340,7 +340,7 @@ int pinmux_fsl_k64_initialize(struct device *port)
 	}
 #endif
 
-	return DEV_OK;
+	return 0;
 }
 
 
diff --git a/drivers/pwm/pwm_dw.c b/drivers/pwm/pwm_dw.c
index 83f1e27c8..465caee43 100644
--- a/drivers/pwm/pwm_dw.c
+++ b/drivers/pwm/pwm_dw.c
@@ -112,7 +112,7 @@ static int pwm_dw_configure(struct device *dev, int access_op,
 	ARG_UNUSED(pwm);
 	ARG_UNUSED(flags);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int __set_one_port(struct device *dev, uint32_t pwm,
@@ -127,7 +127,7 @@ static int __set_one_port(struct device *dev, uint32_t pwm,
 
 	if ((off == 0) || (on == 0)) {
 		/* stop PWM if so specified */
-		return DEV_OK;
+		return 0;
 	}
 
 	/* write timer for pin to stay low */
@@ -139,7 +139,7 @@ static int __set_one_port(struct device *dev, uint32_t pwm,
 	/* Enable timer so it starts running and counting */
 	sys_write32((TIMER_INIT_CTRL | 0x01), (reg_addr + REG_TMR_CTRL));
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -158,7 +158,7 @@ static int __set_one_port(struct device *dev, uint32_t pwm,
  * @param on Duration for pin to stay high (must be >= 2)
  * @param off Duration for pin to stay low (must be >= 2)
  *
- * @return DEV_OK
+ * @return 0
  */
 static int pwm_dw_set_values(struct device *dev, int access_op,
 				  uint32_t pwm, uint32_t on, uint32_t off)
@@ -180,7 +180,7 @@ static int pwm_dw_set_values(struct device *dev, int access_op,
 			__set_one_port(dev, i, on, off);
 		}
 
-		return DEV_OK;
+		return 0;
 	}
 
 	return DEV_INVALID_OP;
@@ -227,13 +227,13 @@ static struct pwm_driver_api pwm_dw_drv_api_funcs = {
  * @brief Initialization function of PCA9685
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int pwm_dw_init(struct device *dev)
 {
 	dev->driver_api = &pwm_dw_drv_api_funcs;
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for PWM_DW */
diff --git a/drivers/pwm/pwm_k64_ftm.c b/drivers/pwm/pwm_k64_ftm.c
index 70dddfa51..3db3000d3 100644
--- a/drivers/pwm/pwm_k64_ftm.c
+++ b/drivers/pwm/pwm_k64_ftm.c
@@ -80,7 +80,7 @@
  *
  * @param ftm_num index indicating which FTM
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_clk_enable(uint8_t ftm_num)
@@ -99,7 +99,7 @@ static int pwm_ftm_clk_enable(uint8_t ftm_num)
 
 	sim->scgc6 |= 1 << (24 + ftm_num);
 
-	return DEV_OK;
+	return 0;
 }
 
 
@@ -114,13 +114,13 @@ static int pwm_ftm_clk_enable(uint8_t ftm_num)
  * @param channel The pwm channel number
  * @param flags Device flags (unused)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_configure(struct device *dev, int access_op,
 			     uint32_t channel, int flags)
 {
-	int return_val = DEV_OK;
+	int return_val = 0;
 
 	uint32_t clock_source;
 	uint32_t prescale;
@@ -274,7 +274,7 @@ static int pwm_ftm_configure(struct device *dev, int access_op,
  *            signal will be off (low if positive polarity) for the rest of
  *            the cycle.
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_set_values(struct device *dev, int access_op,
@@ -440,7 +440,7 @@ static int pwm_ftm_set_values(struct device *dev, int access_op,
 
 	DBG("pwm_ftm_set_values done.\n");
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -453,7 +453,7 @@ static int pwm_ftm_set_values(struct device *dev, int access_op,
  * @param channel The pwm channel number
  * @param duty Percentage of time signal is on (value between 0 and 100)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_set_duty_cycle(struct device *dev, int access_op,
@@ -549,7 +549,7 @@ static int pwm_ftm_set_duty_cycle(struct device *dev, int access_op,
  * @param channel The pwm channel number
  * @param phase Clock ticks of delay before start of the pulse (must be 0)
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_set_phase(struct device *dev, int access_op,
@@ -601,7 +601,7 @@ static int pwm_ftm_set_phase(struct device *dev, int access_op,
 
 	DBG("pwm_ftm_set_phase done.\n");
 
-	return DEV_OK;
+	return 0;
 #else /*COMBINE_MODE_SUPPORT*/
 
 	ARG_UNUSED(dev);
@@ -623,7 +623,7 @@ static int pwm_ftm_set_phase(struct device *dev, int access_op,
  *
  * @param dev Device struct
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_suspend(struct device *dev)
@@ -647,7 +647,7 @@ static int pwm_ftm_suspend(struct device *dev)
 
 	DBG("pwm_ftm_suspend done.\n");
 
-	return DEV_OK;
+	return 0;
 
 }
 
@@ -660,7 +660,7 @@ static int pwm_ftm_suspend(struct device *dev)
  *
  * @param dev Device struct
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 
 static int pwm_ftm_resume(struct device *dev)
@@ -688,7 +688,7 @@ static int pwm_ftm_resume(struct device *dev)
 
 	DBG("pwm_ftm_resume done.\n");
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct pwm_driver_api pwm_ftm_drv_api_funcs = {
@@ -704,7 +704,7 @@ static struct pwm_driver_api pwm_ftm_drv_api_funcs = {
  * @brief Initialization function of FTM
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int pwm_ftm_init(struct device *dev)
 {
@@ -713,7 +713,7 @@ int pwm_ftm_init(struct device *dev)
 
 	dev->driver_api = &pwm_ftm_drv_api_funcs;
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for PWM_K64_FTM_0 */
diff --git a/drivers/pwm/pwm_k64_ftm.h b/drivers/pwm/pwm_k64_ftm.h
index 25fa41d8c..c164e98c4 100644
--- a/drivers/pwm/pwm_k64_ftm.h
+++ b/drivers/pwm/pwm_k64_ftm.h
@@ -147,7 +147,7 @@
  * @brief Initialization function for FlexTimer Module FTM (PWM mode)
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 extern int pwm_ftm_init(struct device *dev);
 
diff --git a/drivers/pwm/pwm_pca9685.c b/drivers/pwm/pwm_pca9685.c
index 74b11382b..f5660f233 100644
--- a/drivers/pwm/pwm_pca9685.c
+++ b/drivers/pwm/pwm_pca9685.c
@@ -71,7 +71,7 @@ static int pwm_pca9685_configure(struct device *dev, int access_op,
 	ARG_UNUSED(pwm);
 	ARG_UNUSED(flags);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int pwm_pca9685_set_values(struct device *dev, int access_op,
@@ -184,7 +184,7 @@ static struct pwm_driver_api pwm_pca9685_drv_api_funcs = {
  * @brief Initialization function of PCA9685
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise.
+ * @return 0 if successful, failed otherwise.
  */
 int pwm_pca9685_init(struct device *dev)
 {
@@ -211,11 +211,11 @@ int pwm_pca9685_init(struct device *dev)
 	buf[1] = (1 << 5); /* register addr auto increment */
 
 	ret = i2c_write(i2c_master, buf, 2, config->i2c_slave_addr);
-	if (ret != DEV_OK) {
+	if (ret != 0) {
 		return DEV_NOT_CONFIG;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /* Initialization for PWM_PCA9685_0 */
diff --git a/drivers/pwm/pwm_pca9685.h b/drivers/pwm/pwm_pca9685.h
index fb56b3a1d..085458601 100644
--- a/drivers/pwm/pwm_pca9685.h
+++ b/drivers/pwm/pwm_pca9685.h
@@ -32,7 +32,7 @@ extern "C" {
  * @brief Initialization function for PCA9685
  *
  * @param dev Device struct
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 extern int pwm_pca9685_init(struct device *dev);
 
diff --git a/drivers/pwm/pwm_qmsi.c b/drivers/pwm/pwm_qmsi.c
index 1b34472cf..f3ce762ad 100644
--- a/drivers/pwm/pwm_qmsi.c
+++ b/drivers/pwm/pwm_qmsi.c
@@ -30,7 +30,7 @@ static int pwm_qmsi_configure(struct device *dev, int access_op,
 	ARG_UNUSED(pwm);
 	ARG_UNUSED(flags);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int __set_one_port(qm_pwm_t id, uint32_t pwm, uint32_t on, uint32_t off)
@@ -42,7 +42,7 @@ static int __set_one_port(qm_pwm_t id, uint32_t pwm, uint32_t on, uint32_t off)
 
 	if ((off == 0) || (on == 0)) {
 		/* stop PWM if so specified */
-		return DEV_OK;
+		return 0;
 	}
 
 	/* PWM mode, user-defined count mode, timer disabled */
@@ -62,7 +62,7 @@ static int __set_one_port(qm_pwm_t id, uint32_t pwm, uint32_t on, uint32_t off)
 	/* Enable timer so it starts running and counting */
 	qm_pwm_start(id, pwm);
 
-	return DEV_OK;
+	return 0;
 }
 
 /*
@@ -82,7 +82,7 @@ static int __set_one_port(qm_pwm_t id, uint32_t pwm, uint32_t on, uint32_t off)
  * on: Duration for pin to stay high (must be >= 2)
  * off: Duration for pin to stay low (must be >= 2)
  *
- * return DEV_OK, DEV_INVALID_OP
+ * return 0, DEV_INVALID_OP
  */
 static int pwm_qmsi_set_values(struct device *dev, int access_op,
 				  uint32_t pwm, uint32_t on, uint32_t off)
@@ -106,7 +106,7 @@ static int pwm_qmsi_set_values(struct device *dev, int access_op,
 		return DEV_INVALID_OP;
 	}
 
-	return DEV_OK;
+	return 0;
 
 }
 
@@ -167,7 +167,7 @@ static int pwm_qmsi_init(struct device *dev)
 {
 	dev->driver_api = &pwm_qmsi_drv_api_funcs;
 	clk_periph_enable(CLK_PERIPH_PWM_REGISTER | CLK_PERIPH_CLK);
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(pwm_qmsi_0, CONFIG_PWM_QMSI_DEV_NAME, pwm_qmsi_init,
diff --git a/drivers/rtc/rtc_dw.c b/drivers/rtc/rtc_dw.c
index 6694456da..74185cd11 100644
--- a/drivers/rtc/rtc_dw.c
+++ b/drivers/rtc/rtc_dw.c
@@ -138,7 +138,7 @@ static int rtc_dw_set_alarm(struct device *dev, const uint32_t alarm_val)
 
 	sys_write32(alarm_val, rtc_dev->base_address + RTC_CMR);
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -167,7 +167,7 @@ static int rtc_dw_set_config(struct device *dev, struct rtc_config *config)
 		sys_clear_bit(rtc_dev->base_address + RTC_CCR, 0);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -216,6 +216,6 @@ int rtc_dw_init(struct device *dev)
 
 	dev->driver_api = &funcs;
 
-	return DEV_OK;
+	return 0;
 }
 
diff --git a/drivers/rtc/rtc_qmsi.c b/drivers/rtc/rtc_qmsi.c
index 59690d98f..e54fc7444 100644
--- a/drivers/rtc/rtc_qmsi.c
+++ b/drivers/rtc/rtc_qmsi.c
@@ -56,12 +56,12 @@ static int rtc_qmsi_set_config(struct device *dev, struct rtc_config *cfg)
 	if (qm_rtc_set_config(QM_RTC_0, &qm_cfg) != QM_RC_OK)
 		return DEV_FAIL;
 
-	return DEV_OK;
+	return 0;
 }
 
 static int rtc_qmsi_set_alarm(struct device *dev, const uint32_t alarm_val)
 {
-	return qm_rtc_set_alarm(QM_RTC_0, alarm_val) == QM_RC_OK ? DEV_OK : DEV_FAIL;
+	return qm_rtc_set_alarm(QM_RTC_0, alarm_val) == QM_RC_OK ? 0 : DEV_FAIL;
 }
 
 static uint32_t rtc_qmsi_read(struct device *dev)
@@ -89,7 +89,7 @@ static int rtc_qmsi_init(struct device *dev)
 	QM_SCSS_INT->int_rtc_mask &= ~BIT(0);
 
 	dev->driver_api = &api;
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(rtc, CONFIG_RTC_DRV_NAME, &rtc_qmsi_init,
diff --git a/drivers/sensor/sensor.c b/drivers/sensor/sensor.c
index 46b55a28d..2421f16c1 100644
--- a/drivers/sensor/sensor.c
+++ b/drivers/sensor/sensor.c
@@ -51,7 +51,7 @@ static int sensor_init(struct device *dev)
 			  sensor_fiber_main, 0, 0,
 			  CONFIG_SENSOR_DELAYED_WORK_PRIORITY, 0);
 
-	return DEV_OK;
+	return 0;
 }
 
 SYS_INIT(sensor_init, PRIMARY, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
diff --git a/drivers/sensor/sensor_mcp9808.c b/drivers/sensor/sensor_mcp9808.c
index 0a4dc9fef..e1ccded54 100644
--- a/drivers/sensor/sensor_mcp9808.c
+++ b/drivers/sensor/sensor_mcp9808.c
@@ -48,7 +48,7 @@ int mcp9808_reg_read(struct mcp9808_data *data, uint8_t reg, uint16_t *val)
 
 	*val = sys_be16_to_cpu(*val);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int mcp9808_sample_fetch(struct device *dev)
@@ -80,7 +80,7 @@ static int mcp9808_channel_get(struct device *dev,
 		val->val1 -= 256;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct sensor_driver_api mcp9808_api_funcs = {
@@ -107,7 +107,7 @@ int mcp9808_init(struct device *dev)
 
 	mcp9808_setup_interrupt(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(mcp9808, CONFIG_MCP9808_DEV_NAME, mcp9808_init, &mcp9808_data,
diff --git a/drivers/sensor/sensor_mcp9808_trigger.c b/drivers/sensor/sensor_mcp9808_trigger.c
index dda4d098e..9fbcd0c47 100644
--- a/drivers/sensor/sensor_mcp9808_trigger.c
+++ b/drivers/sensor/sensor_mcp9808_trigger.c
@@ -59,7 +59,7 @@ static int mcp9808_reg_update(struct mcp9808_data *data, uint8_t reg,
 	new_val |= val;
 
 	if (new_val == old_val) {
-		return DEV_OK;
+		return 0;
 	}
 
 	return mcp9808_reg_write(data, reg, new_val);
diff --git a/drivers/sensor/sensor_sx9500.c b/drivers/sensor/sensor_sx9500.c
index c63ffb9c0..28edb9fd7 100644
--- a/drivers/sensor/sensor_sx9500.c
+++ b/drivers/sensor/sensor_sx9500.c
@@ -87,7 +87,7 @@ int sx9500_update_bits(struct sx9500_data *data, uint8_t reg,
 	new_val = (old_val & ~mask) | (val & mask);
 
 	if (new_val == old_val) {
-		return DEV_OK;
+		return 0;
 	}
 
 	return sx9500_reg_write(data, reg, new_val);
@@ -116,7 +116,7 @@ static int sx9500_channel_get(struct device *dev,
 	val->val1 = !!(data->prox_stat &
 		       (1 << (4 + CONFIG_SX9500_PROX_CHANNEL)));
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct sensor_driver_api sx9500_api_funcs = {
@@ -185,7 +185,7 @@ int sx9500_init(struct device *dev)
 		return ret;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 DEVICE_INIT(sx9500, CONFIG_SX9500_DEV_NAME, sx9500_init, &sx9500_data,
diff --git a/drivers/sensor/sensor_sx9500.h b/drivers/sensor/sensor_sx9500.h
index 998ebcc80..53a71d308 100644
--- a/drivers/sensor/sensor_sx9500.h
+++ b/drivers/sensor/sensor_sx9500.h
@@ -76,7 +76,7 @@ int sx9500_trigger_set(struct device *dev,
 #else
 static inline int sx9500_setup_interrupt(struct device *dev)
 {
-	return DEV_OK;
+	return 0;
 }
 #endif
 
diff --git a/drivers/sensor/sensor_sx9500_trigger.c b/drivers/sensor/sensor_sx9500_trigger.c
index 73ba250f8..055f64756 100644
--- a/drivers/sensor/sensor_sx9500_trigger.c
+++ b/drivers/sensor/sensor_sx9500_trigger.c
@@ -59,7 +59,7 @@ int sx9500_trigger_set(struct device *dev,
 		return DEV_INVALID_CONF;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_SX9500_TRIGGER_OWN_FIBER
@@ -160,5 +160,5 @@ int sx9500_setup_interrupt(struct device *dev)
 			  CONFIG_SX9500_FIBER_PRIORITY, 0);
 #endif
 
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/serial/uart_atmel_sam3.c b/drivers/serial/uart_atmel_sam3.c
index 8bd942e42..0036e038c 100644
--- a/drivers/serial/uart_atmel_sam3.c
+++ b/drivers/serial/uart_atmel_sam3.c
@@ -164,7 +164,7 @@ static void baudrate_set(struct device *dev,
  *
  * @param dev UART device struct
  *
- * @return DEV_OK
+ * @return 0
  */
 static int uart_sam3_init(struct device *dev)
 {
@@ -195,7 +195,7 @@ static int uart_sam3_init(struct device *dev)
 
 	dev->driver_api = &uart_sam3_driver_api;
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
diff --git a/drivers/serial/uart_k20.c b/drivers/serial/uart_k20.c
index 5c261f058..44eca7290 100644
--- a/drivers/serial/uart_k20.c
+++ b/drivers/serial/uart_k20.c
@@ -62,7 +62,7 @@ static struct uart_driver_api uart_k20_driver_api;
  *
  * @param dev UART device struct
  *
- * @return DEV_OK
+ * @return 0
  */
 static int uart_k20_init(struct device *dev)
 {
@@ -101,7 +101,7 @@ static int uart_k20_init(struct device *dev)
 
 	dev->driver_api = &uart_k20_driver_api;
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
diff --git a/drivers/serial/uart_ns16550.c b/drivers/serial/uart_ns16550.c
index f6b0b2e13..71d1afc25 100644
--- a/drivers/serial/uart_ns16550.c
+++ b/drivers/serial/uart_ns16550.c
@@ -287,7 +287,7 @@ static inline int ns16550_pci_uart_scan(struct device *dev)
  *
  * @param dev UART device struct
  *
- * @return DEV_OK if successful, failed othersie
+ * @return 0 if successful, failed othersie
  */
 static int uart_ns16550_init(struct device *dev)
 {
@@ -343,7 +343,7 @@ static int uart_ns16550_init(struct device *dev)
 
 	dev->driver_api = &uart_ns16550_driver_api;
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -627,7 +627,7 @@ static void uart_ns16550_isr(void *arg)
  * @param ctrl The line control to be manipulated
  * @param val Value to set the line control
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int uart_ns16550_line_ctrl_set(struct device *dev,
 				      uint32_t ctrl, uint32_t val)
@@ -637,7 +637,7 @@ static int uart_ns16550_line_ctrl_set(struct device *dev,
 	switch (ctrl) {
 	case LINE_CTRL_BAUD_RATE:
 		set_baud_rate(dev, val);
-		return DEV_OK;
+		return 0;
 
 	case LINE_CTRL_RTS:
 	case LINE_CTRL_DTR:
@@ -655,7 +655,7 @@ static int uart_ns16550_line_ctrl_set(struct device *dev,
 			mdc &= ~(chg);
 		}
 		OUTBYTE(MDC(dev), mdc);
-		return DEV_OK;
+		return 0;
 	}
 
 	return DEV_INVALID_OP;
@@ -672,7 +672,7 @@ static int uart_ns16550_line_ctrl_set(struct device *dev,
  * @param cmd Command to driver
  * @param p Parameter to the command
  *
- * @return DEV_OK if successful, failed otherwise
+ * @return 0 if successful, failed otherwise
  */
 static int uart_ns16550_drv_cmd(struct device *dev, uint32_t cmd, uint32_t p)
 {
@@ -681,7 +681,7 @@ static int uart_ns16550_drv_cmd(struct device *dev, uint32_t cmd, uint32_t p)
 #ifdef CONFIG_UART_NS16550_DLF
 	case CMD_SET_DLF:
 		set_dlf(dev, p);
-		return DEV_OK;
+		return 0;
 #endif
 
 	}
diff --git a/drivers/serial/uart_nsim.c b/drivers/serial/uart_nsim.c
index 9b4e85e83..1a3ea7e25 100644
--- a/drivers/serial/uart_nsim.c
+++ b/drivers/serial/uart_nsim.c
@@ -43,13 +43,13 @@ static struct uart_driver_api uart_nsim_driver_api;
  *
  * @param dev UART device struct
  *
- * @return DEV_OK
+ * @return 0
  */
 static int uart_nsim_init(struct device *dev)
 {
 	ARG_UNUSED(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 /*
diff --git a/drivers/serial/uart_qmsi.c b/drivers/serial/uart_qmsi.c
index c331f6299..646c39572 100644
--- a/drivers/serial/uart_qmsi.c
+++ b/drivers/serial/uart_qmsi.c
@@ -315,7 +315,7 @@ static int uart_qmsi_line_ctrl_set(struct device *dev, uint32_t ctrl, uint32_t v
 		return DEV_NO_SUPPORT;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 #endif /* CONFIG_UART_LINE_CTRL */
 
@@ -377,5 +377,5 @@ static int uart_qmsi_init(struct device *dev)
 
 	dev->driver_api = &api;
 
-	return DEV_OK;
+	return 0;
 }
diff --git a/drivers/serial/uart_stellaris.c b/drivers/serial/uart_stellaris.c
index eaaa10e05..ceeb55537 100644
--- a/drivers/serial/uart_stellaris.c
+++ b/drivers/serial/uart_stellaris.c
@@ -267,7 +267,7 @@ static inline void line_control_defaults_set(struct device *dev)
  *
  * @param dev UART device struct
  *
- * @return DEV_OK
+ * @return 0
  */
 static int uart_stellaris_init(struct device *dev)
 {
@@ -283,7 +283,7 @@ static int uart_stellaris_init(struct device *dev)
 
 	dev->driver_api = &uart_stellaris_driver_api;
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
diff --git a/drivers/shared_irq/shared_irq.c b/drivers/shared_irq/shared_irq.c
index 2ff756790..181186d9e 100644
--- a/drivers/shared_irq/shared_irq.c
+++ b/drivers/shared_irq/shared_irq.c
@@ -42,7 +42,7 @@ static int isr_register(struct device *dev, isr_t isr_func,
 		if (!clients->client[i].isr_dev) {
 			clients->client[i].isr_dev = isr_dev;
 			clients->client[i].isr_func = isr_func;
-			return DEV_OK;
+			return 0;
 		}
 	}
 	return DEV_FAIL;
@@ -63,7 +63,7 @@ static inline int enable(struct device *dev, struct device *isr_dev)
 		if (clients->client[i].isr_dev == isr_dev) {
 			clients->client[i].enabled = 1;
 			irq_enable(config->irq_num);
-			return DEV_OK;
+			return 0;
 		}
 	}
 	return DEV_FAIL;
@@ -97,7 +97,7 @@ static inline int disable(struct device *dev, struct device *isr_dev)
 			if (last_enabled_isr(clients, config->client_count)) {
 				irq_disable(config->irq_num);
 			}
-			return DEV_OK;
+			return 0;
 		}
 	}
 	return DEV_FAIL;
diff --git a/drivers/spi/spi_dw.c b/drivers/spi/spi_dw.c
index d52014da1..a1fc73bf7 100644
--- a/drivers/spi/spi_dw.c
+++ b/drivers/spi/spi_dw.c
@@ -238,7 +238,7 @@ static int spi_dw_configure(struct device *dev,
 	/* Configuring the rate */
 	write_baudr(config->max_sys_freq, info->regs);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_dw_slave_select(struct device *dev, uint32_t slave)
@@ -253,7 +253,7 @@ static int spi_dw_slave_select(struct device *dev, uint32_t slave)
 
 	spi->slave = 1 << (slave - 1);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_dw_transceive(struct device *dev,
@@ -310,7 +310,7 @@ static int spi_dw_transceive(struct device *dev,
 		return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_dw_suspend(struct device *dev)
@@ -319,7 +319,7 @@ static int spi_dw_suspend(struct device *dev)
 
 	_clock_off(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_dw_resume(struct device *dev)
@@ -328,7 +328,7 @@ static int spi_dw_resume(struct device *dev)
 
 	_clock_on(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 void spi_dw_isr(void *arg)
@@ -398,7 +398,7 @@ int spi_dw_init(struct device *dev)
 
 	DBG("Designware SPI driver initialized on device: %p\n", dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 #if defined(CONFIG_IOAPIC) || defined(CONFIG_MVIC)
diff --git a/drivers/spi/spi_intel.c b/drivers/spi/spi_intel.c
index 57596d63b..b5500fee4 100644
--- a/drivers/spi/spi_intel.c
+++ b/drivers/spi/spi_intel.c
@@ -259,7 +259,7 @@ static int spi_intel_configure(struct device *dev,
 	/* Configuring the rate */
 	write_dds_rate(INTEL_SPI_DSS_RATE(config->max_sys_freq), info->regs);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_intel_transceive(struct device *dev,
@@ -303,7 +303,7 @@ static int spi_intel_transceive(struct device *dev,
 		return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_intel_suspend(struct device *dev)
@@ -315,7 +315,7 @@ static int spi_intel_suspend(struct device *dev)
 	clear_bit_sscr0_sse(info->regs);
 	irq_disable(info->irq);
 
-	return DEV_OK;
+	return 0;
 }
 
 static int spi_intel_resume(struct device *dev)
@@ -327,7 +327,7 @@ static int spi_intel_resume(struct device *dev)
 	set_bit_sscr0_sse(info->regs);
 	irq_enable(info->irq);
 
-	return DEV_OK;
+	return 0;
 }
 
 void spi_intel_isr(void *arg)
@@ -417,7 +417,7 @@ int spi_intel_init(struct device *dev)
 
 	DBG("SPI Intel Driver initialized on device: %p\n", dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_IOAPIC
diff --git a/drivers/spi/spi_k64.c b/drivers/spi/spi_k64.c
index de9d85aa4..34e95a256 100644
--- a/drivers/spi/spi_k64.c
+++ b/drivers/spi/spi_k64.c
@@ -425,7 +425,7 @@ static uint32_t spi_k64_set_delay(enum spi_k64_delay_id delay_id,
  * @param dev Pointer to the device structure for the driver instance
  * @param config Pointer to the application provided configuration
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static int spi_k64_configure(struct device *dev, struct spi_config *config)
 {
@@ -528,7 +528,7 @@ static int spi_k64_configure(struct device *dev, struct spi_config *config)
 
 	spi_data->cont_pcs_sel = SPI_CONT_PCS_GET(flags);
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -543,7 +543,7 @@ static int spi_k64_configure(struct device *dev, struct spi_config *config)
  * Select inactive state setting, MCR[PCSIS], determined by the configuration
  * data parameter to spi_configure()/spi_k64_configure().
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static int spi_k64_slave_select(struct device *dev, uint32_t slave)
 {
@@ -562,7 +562,7 @@ static int spi_k64_slave_select(struct device *dev, uint32_t slave)
 
 	spi_data->pcs = (uint8_t)slave;
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -574,7 +574,7 @@ static int spi_k64_slave_select(struct device *dev, uint32_t slave)
  * @param rx_buf Memory buffer that data should be transferred to
  * @param rx_buf_len Size of the memory buffer available for writing to
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static int spi_k64_transceive(struct device *dev,
 				const void *tx_buf, uint32_t tx_buf_len,
@@ -645,13 +645,13 @@ static int spi_k64_transceive(struct device *dev,
 		return DEV_FAIL;
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
  * @brief Suspend SPI host controller operations.
  * @param dev Pointer to the device structure for the driver instance
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static int spi_k64_suspend(struct device *dev)
 {
@@ -669,13 +669,13 @@ static int spi_k64_suspend(struct device *dev)
 		DBG("SPI Controller dev %p is running.  Waiting to stop.\n", dev);
 	}
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
  * @brief Resume SPI host controller operations.
  * @param dev Pointer to the device structure for the driver instance
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static int spi_k64_resume(struct device *dev)
 {
@@ -689,7 +689,7 @@ static int spi_k64_resume(struct device *dev)
 
 	irq_enable(info->irq);
 
-	return DEV_OK;
+	return 0;
 }
 
 /**
@@ -1027,7 +1027,7 @@ int spi_k64_init(struct device *dev)
 
 	/* operation remains disabled (MCR[HALT] = 1)*/
 
-	return DEV_OK;
+	return 0;
 }
 
 /* system bindings */
diff --git a/drivers/spi/spi_qmsi.c b/drivers/spi/spi_qmsi.c
index 341621cde..09e185df4 100644
--- a/drivers/spi/spi_qmsi.c
+++ b/drivers/spi/spi_qmsi.c
@@ -87,7 +87,7 @@ static int spi_qmsi_configure(struct device *dev,
 	cfg->clk_divider = config->max_sys_freq;
 
 	/* Will set the configuration before the transfer starts */
-	return DEV_OK;
+	return 0;
 }
 
 static void pending_transfer_complete(uint32_t id, qm_rc_t rc)
@@ -139,7 +139,7 @@ static int spi_qmsi_slave_select(struct device *dev, uint32_t slave)
 	struct spi_qmsi_config *spi_config = dev->config->config_info;
 	qm_spi_t spi = spi_config->spi;
 
-	return qm_spi_slave_select(spi, 1 << (slave - 1)) ? DEV_FAIL : DEV_OK;
+	return qm_spi_slave_select(spi, 1 << (slave - 1)) ? DEV_FAIL : 0;
 }
 
 static inline uint8_t frame_size_to_dfs(qm_spi_frame_size_t frame_size)
@@ -210,7 +210,7 @@ static int spi_qmsi_transceive(struct device *dev,
 
 	device_sync_call_wait(&context->sync);
 
-	return context->rc ? DEV_FAIL : DEV_OK;
+	return context->rc ? DEV_FAIL : 0;
 }
 
 static int spi_qmsi_suspend(struct device *dev)
@@ -286,7 +286,7 @@ static int spi_qmsi_init(struct device *dev)
 
 	device_sync_call_init(&context->sync);
 
-	return DEV_OK;
+	return 0;
 }
 
 #ifdef CONFIG_SPI_QMSI_PORT_0
diff --git a/drivers/watchdog/wdt_dw.c b/drivers/watchdog/wdt_dw.c
index 09ea11220..c129981c9 100644
--- a/drivers/watchdog/wdt_dw.c
+++ b/drivers/watchdog/wdt_dw.c
@@ -138,7 +138,7 @@ static int wdt_dw_set_config(struct device *dev, struct wdt_config *config)
 
 	wdt_dw_reload(dev);
 
-	return DEV_OK;
+	return 0;
 }
 
 static struct wdt_driver_api wdt_dw_funcs = {
diff --git a/drivers/watchdog/wdt_qmsi.c b/drivers/watchdog/wdt_qmsi.c
index 3368c656c..9b9375599 100644
--- a/drivers/watchdog/wdt_qmsi.c
+++ b/drivers/watchdog/wdt_qmsi.c
@@ -52,7 +52,7 @@ static int set_config(struct device *dev, struct wdt_config *cfg)
 	qm_wdt_set_config(QM_WDT_0, &qm_cfg);
 	qm_wdt_start(QM_WDT_0);
 
-	return DEV_OK;
+	return 0;
 }
 
 static void reload(struct device *dev)
diff --git a/include/adc.h b/include/adc.h
index 5a44c8cb5..a3570e6d0 100644
--- a/include/adc.h
+++ b/include/adc.h
@@ -137,7 +137,7 @@ static inline void adc_disable(struct device *dev)
  * @param dev Pointer to the device structure for the driver instance.
  * @param seq_table Pointer to the structure representing the sequence table.
  *
- * @retval DEV_OK On success
+ * @retval 0 On success
  * @retval else Otherwise.
  */
 static inline int adc_read(struct device *dev, struct adc_seq_table *seq_table)
diff --git a/include/display/grove_lcd.h b/include/display/grove_lcd.h
index 24abf8d50..45137d620 100644
--- a/include/display/grove_lcd.h
+++ b/include/display/grove_lcd.h
@@ -162,7 +162,7 @@ void glcd_color_set(struct device *port, uint8_t r, uint8_t g, uint8_t b);
  *
  *  @param port Pointer to device structure for driver instance.
  *
- *  @return Returns DEV_OK if all passes
+ *  @return Returns 0 if all passes
  */
 int glcd_initialize(struct device *port);
 
diff --git a/include/flash.h b/include/flash.h
index d56bc6df1..abb8c0f90 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -60,7 +60,7 @@ struct flash_driver_api {
  *  @param  data            : Buffer to store read data
  *  @param  len             : Number of bytes to read.
  *
- *  @return  DEV_OK on success else DEV_* code
+ *  @return  0 on success else DEV_* code
  */
 static inline int flash_read(struct device *dev, off_t offset, void *data,
 			     size_t len)
@@ -78,7 +78,7 @@ static inline int flash_read(struct device *dev, off_t offset, void *data,
  *  @param  data            : data to write
  *  @param  len             : Number of bytes to write
  *
- *  @return  DEV_OK on success else DEV_* code
+ *  @return  0 on success else DEV_* code
  */
 static inline int flash_write(struct device *dev, off_t offset,
 			      const void *data, size_t len)
@@ -98,7 +98,7 @@ static inline int flash_write(struct device *dev, off_t offset,
  *  @param  offset          : erase area starting offset
  *  @param  size            : size of area to be erased
  *
- *  @return  DEV_OK on success else DEV_* code
+ *  @return  0 on success else DEV_* code
  */
 static inline int flash_erase(struct device *dev, off_t offset, size_t size)
 {
@@ -113,7 +113,7 @@ static inline int flash_erase(struct device *dev, off_t offset, size_t size)
  *  @param  dev             : flash device
  *  @param  enable          : enable or disable flash write protection
  *
- *  @return  DEV_OK on success else DEV_* code
+ *  @return  0 on success else DEV_* code
  */
 static inline int flash_write_protection_set(struct device *dev, bool enable)
 {
diff --git a/include/i2c.h b/include/i2c.h
index 2cc3deb8d..72673466e 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -148,7 +148,7 @@ struct i2c_driver_api {
  * @param dev_config Bit-packed 32-bit value to the device runtime configuration
  * for the I2C controller.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* code otherwise.
  */
 static inline int i2c_configure(struct device *dev, uint32_t dev_config)
@@ -169,7 +169,7 @@ static inline int i2c_configure(struct device *dev, uint32_t dev_config)
  * @param len Size of the memory pool available for reading.
  * @param addr Address to the target I2C device for writing.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* code otherwise.
  */
 static inline int i2c_write(struct device *dev, uint8_t *buf,
@@ -196,7 +196,7 @@ static inline int i2c_write(struct device *dev, uint8_t *buf,
  * @param len Size of the memory pool available for writing.
  * @param addr Address of the I2C device being read.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* code otherwise.
  */
 static inline int i2c_read(struct device *dev, uint8_t *buf,
@@ -225,7 +225,7 @@ static inline int i2c_read(struct device *dev, uint8_t *buf,
  * @param num_msgs Number of messages to transfer.
  * @param addr Address of the I2C target device.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* code otherwise.
  */
 static inline int i2c_transfer(struct device *dev,
@@ -242,7 +242,7 @@ static inline int i2c_transfer(struct device *dev,
  * @brief Suspend an I2C driver.
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  */
 static inline int i2c_suspend(struct device *dev)
 {
@@ -256,7 +256,7 @@ static inline int i2c_suspend(struct device *dev)
  * @brief Resume an I2C driver.
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  */
 static inline int i2c_resume(struct device *dev)
 {
diff --git a/include/pwm.h b/include/pwm.h
index 02f436eba..1c3be6e7a 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -68,7 +68,7 @@ struct pwm_driver_api {
  * @param pwm PWM output.
  * @param flags PWM configuration flags.
  *
- * @retval DEV_OK If successful,
+ * @retval 0 If successful,
  * @retval failed Otherwise.
  */
 static inline int pwm_pin_configure(struct device *dev, uint8_t pwm,
@@ -88,7 +88,7 @@ static inline int pwm_pin_configure(struct device *dev, uint8_t pwm,
  * @param on ON value set to the PWM.
  * @param off OFF value set to the PWM.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_pin_set_values(struct device *dev, uint32_t pwm,
@@ -110,7 +110,7 @@ static inline int pwm_pin_set_values(struct device *dev, uint32_t pwm,
  * @param duty Duty cycle to set to the PWM in %, for example,
  *        50 sets to 50%.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_pin_set_duty_cycle(struct device *dev, uint32_t pwm,
@@ -131,7 +131,7 @@ static inline int pwm_pin_set_duty_cycle(struct device *dev, uint32_t pwm,
  * @param pwm PWM output.
  * @param phase The number of clock ticks to delay before the start of pulses.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_pin_set_phase(struct device *dev, uint32_t pwm,
@@ -154,7 +154,7 @@ static inline int pwm_pin_set_phase(struct device *dev, uint32_t pwm,
  * @param dev Pointer to the device structure for the driver instance.
  * @param flags PWM configuration flags.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_all_configure(struct device *dev, int flags)
@@ -172,7 +172,7 @@ static inline int pwm_all_configure(struct device *dev, int flags)
  * @param on ON value set to the PWM.
  * @param off OFF value set to the PWM.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_all_set_values(struct device *dev,
@@ -193,7 +193,7 @@ static inline int pwm_all_set_values(struct device *dev,
  * @param duty Duty cycle to set to the PWM in %, for example,
  *        50 sets to 50%.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_all_set_duty_cycle(struct device *dev, uint8_t duty)
@@ -213,7 +213,7 @@ static inline int pwm_all_set_duty_cycle(struct device *dev, uint8_t duty)
  * @param pwm PWM output.
  * @param phase The number of clock ticks to delay before the start of pulses.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_all_set_phase(struct device *dev, uint8_t phase)
@@ -235,7 +235,7 @@ static inline int pwm_all_set_phase(struct device *dev, uint8_t phase)
  *
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_suspend(struct device *dev)
@@ -251,7 +251,7 @@ static inline int pwm_suspend(struct device *dev)
  *
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int pwm_resume(struct device *dev)
diff --git a/include/sensor.h b/include/sensor.h
index 8339468ec..9dfe059bb 100644
--- a/include/sensor.h
+++ b/include/sensor.h
@@ -190,7 +190,7 @@ struct sensor_driver_api {
  * @param attr The attribute to set
  * @param val The value to set the attribute to
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static inline int sensor_attr_set(struct device *dev,
 				  enum sensor_channel chan,
@@ -220,7 +220,7 @@ static inline int sensor_attr_set(struct device *dev,
  * @param handler The function that should be called when the trigger
  * fires
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static inline int sensor_trigger_set(struct device *dev,
 				     struct sensor_trigger *trig,
@@ -250,7 +250,7 @@ static inline int sensor_trigger_set(struct device *dev,
  *
  * @param dev Pointer to the sensor device
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static inline int sensor_sample_fetch(struct device *dev)
 {
@@ -275,7 +275,7 @@ static inline int sensor_sample_fetch(struct device *dev)
  * @param chan The channel to read
  * @param val Where to store the value
  *
- * @return DEV_OK if successful, another DEV_* code otherwise.
+ * @return 0 if successful, another DEV_* code otherwise.
  */
 static inline int sensor_channel_get(struct device *dev,
 				     enum sensor_channel chan,
diff --git a/include/spi.h b/include/spi.h
index 640011e85..4c7e321aa 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -98,7 +98,7 @@ struct spi_driver_api {
  * @param dev Pointer to the device structure for the driver instance.
  * @param config Pointer to the configuration provided by the application.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_configure(struct device *dev,
@@ -120,7 +120,7 @@ static inline int spi_configure(struct device *dev,
  * @param dev Pointer to the device structure for the driver instance
  * @param slave An integer identifying the slave
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_slave_select(struct device *dev, uint32_t slave)
@@ -128,7 +128,7 @@ static inline int spi_slave_select(struct device *dev, uint32_t slave)
 	struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;
 
 	if (!api->slave_select) {
-		return DEV_OK;
+		return 0;
 	}
 
 	return api->slave_select(dev, slave);
@@ -140,7 +140,7 @@ static inline int spi_slave_select(struct device *dev, uint32_t slave)
  * @param buf Memory buffer where data will be transferred.
  * @param len Size of the memory buffer available for writing.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_read(struct device *dev, void *buf, uint32_t len)
@@ -156,7 +156,7 @@ static inline int spi_read(struct device *dev, void *buf, uint32_t len)
  * @param buf Memory buffer from where data is transferred.
  * @param len Size of the memory buffer available for reading.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_write(struct device *dev, const void *buf, uint32_t len)
@@ -177,7 +177,7 @@ static inline int spi_write(struct device *dev, const void *buf, uint32_t len)
  * @param rx_buf Memory buffer where data is transferred.
  * @param rx_buf_len Size of the memory buffer available for writing.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_transceive(struct device *dev,
@@ -193,7 +193,7 @@ static inline int spi_transceive(struct device *dev,
  * @brief Suspend the SPI host controller operations.
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_suspend(struct device *dev)
@@ -207,7 +207,7 @@ static inline int spi_suspend(struct device *dev)
  * @brief Resume the SPI host controller operations.
  * @param dev Pointer to the device structure for the driver instance.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval DEV_* Code otherwise.
  */
 static inline int spi_resume(struct device *dev)
diff --git a/include/uart.h b/include/uart.h
index cba33c392..2efb4c553 100644
--- a/include/uart.h
+++ b/include/uart.h
@@ -568,7 +568,7 @@ static inline void uart_irq_callback_set(struct device *dev,
  * @param ctrl The line control to manipulate.
  * @param val Value to set to the line control.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int uart_line_ctrl_set(struct device *dev,
@@ -599,7 +599,7 @@ static inline int uart_line_ctrl_set(struct device *dev,
  * @param cmd Command to driver.
  * @param p Parameter to the command.
  *
- * @retval DEV_OK If successful.
+ * @retval 0 If successful.
  * @retval failed Otherwise.
  */
 static inline int uart_drv_cmd(struct device *dev, uint32_t cmd, uint32_t p)
diff --git a/samples/drivers/adc/src/adc.c b/samples/drivers/adc/src/adc.c
index a82242b36..e47b277f6 100644
--- a/samples/drivers/adc/src/adc.c
+++ b/samples/drivers/adc/src/adc.c
@@ -91,7 +91,7 @@ void main(void)
 	nano_timer_init(&timer, data);
 	adc_enable(adc);
 	while (1) {
-		if (adc_read(adc, &table) != DEV_OK) {
+		if (adc_read(adc, &table) != 0) {
 			DBG("Sampling could not proceed, an error occurred\n");
 		} else {
 			DBG("Sampling is done\n");
diff --git a/samples/drivers/i2c_fujitsu_fram/src/main.c b/samples/drivers/i2c_fujitsu_fram/src/main.c
index d36b6903f..fb8af313c 100644
--- a/samples/drivers/i2c_fujitsu_fram/src/main.c
+++ b/samples/drivers/i2c_fujitsu_fram/src/main.c
@@ -148,7 +148,7 @@ void main(void)
 		printk("Read %d bytes from address 0x00.\n", sizeof(data));
 	}
 
-	ret = DEV_OK;
+	ret = 0;
 	for (i = 0; i < sizeof(cmp_data); i++) {
 		/* uncomment below if you want to see all the bytes */
 		/* printk("0x%X ?= 0x%X\n", cmp_data[i], data[i]); */
@@ -157,7 +157,7 @@ void main(void)
 			ret = DEV_FAIL;
 		}
 	}
-	if (ret == DEV_OK) {
+	if (ret == 0) {
 		printk("Data comparison successful.\n");
 	}
 }
diff --git a/samples/drivers/i2c_lsm9ds0/src/main.c b/samples/drivers/i2c_lsm9ds0/src/main.c
index d2b011e14..66a59edd9 100644
--- a/samples/drivers/i2c_lsm9ds0/src/main.c
+++ b/samples/drivers/i2c_lsm9ds0/src/main.c
@@ -29,13 +29,13 @@ static void read_who_am_i(struct device *dev)
 	uint8_t data;
 
 	data = WHO_AM_I_REG;
-	if (i2c_write(dev, &data, sizeof(data), GYRO_I2C_ADDR) != DEV_OK) {
+	if (i2c_write(dev, &data, sizeof(data), GYRO_I2C_ADDR) != 0) {
 		printk("Error on i2c_write()\n");
 		return;
 	}
 
 	data = 0;
-	if (i2c_read(dev, &data, sizeof(data), GYRO_I2C_ADDR) != DEV_OK) {
+	if (i2c_read(dev, &data, sizeof(data), GYRO_I2C_ADDR) != 0) {
 		printk("Error on i2c_read()\n");
 		return;
 	}
@@ -60,7 +60,7 @@ static void read_who_am_i_by_transfer(struct device *dev)
 	msg[1].buf = &read_data;
 	msg[1].len = sizeof(read_data);
 
-	if (i2c_transfer(dev, msg, 2, GYRO_I2C_ADDR) != DEV_OK) {
+	if (i2c_transfer(dev, msg, 2, GYRO_I2C_ADDR) != 0) {
 		printk("Error on i2c_transfer()\n");
 		return;
 	}
@@ -89,7 +89,7 @@ void main(void)
 		return;
 	}
 
-	if (i2c_configure(dev, cfg.raw) != DEV_OK) {
+	if (i2c_configure(dev, cfg.raw) != 0) {
 		printk("Error on i2c_configure()\n");
 		return;
 	}
diff --git a/samples/drivers/i2c_stts751/src/main.c b/samples/drivers/i2c_stts751/src/main.c
index 67c2ddb4d..1491e0b3c 100644
--- a/samples/drivers/i2c_stts751/src/main.c
+++ b/samples/drivers/i2c_stts751/src/main.c
@@ -29,13 +29,13 @@ static void read_temperature(struct device *dev)
 	uint8_t data;
 
 	data = TEMP_VAL_HIGH_REG_ADDR;
-	if (i2c_write(dev, &data, sizeof(data), STTS751_I2C_ADDR) != DEV_OK) {
+	if (i2c_write(dev, &data, sizeof(data), STTS751_I2C_ADDR) != 0) {
 		printk("Error on i2c_write()\n");
 		return;
 	}
 
 	data = 0;
-	if (i2c_read(dev, &data, sizeof(data), STTS751_I2C_ADDR) != DEV_OK) {
+	if (i2c_read(dev, &data, sizeof(data), STTS751_I2C_ADDR) != 0) {
 		printk("Error on i2c_read()\n");
 		return;
 	}
@@ -57,7 +57,7 @@ static void read_temperature_by_transfer(struct device *dev)
 	msg[1].buf = &read_data;
 	msg[1].len = sizeof(read_data);
 
-	if (i2c_transfer(dev, msg, 2, STTS751_I2C_ADDR) != DEV_OK) {
+	if (i2c_transfer(dev, msg, 2, STTS751_I2C_ADDR) != 0) {
 		printk("Error on i2c_transfer()\n");
 		return;
 	}
@@ -83,7 +83,7 @@ void main(void)
 		return;
 	}
 
-	if (i2c_configure(dev, cfg.raw) != DEV_OK) {
+	if (i2c_configure(dev, cfg.raw) != 0) {
 		printk("Error on i2c_configure()\n");
 		return;
 	}
diff --git a/samples/drivers/w25q80bl/src/main.c b/samples/drivers/w25q80bl/src/main.c
index eb1ebd3d4..539eda433 100644
--- a/samples/drivers/w25q80bl/src/main.c
+++ b/samples/drivers/w25q80bl/src/main.c
@@ -87,5 +87,5 @@ int main(void)
 	printk("SPI Flash Manufacturer %x Device Id %x\n", manufacturer,
 	       device_id);
 
-	return DEV_OK;
+	return 0;
 }