diff options
| -rw-r--r-- | drivers/iio/adc/ti_am335x_adc.c | 64 | ||||
| -rw-r--r-- | drivers/mfd/ti_am335x_tscadc.c | 63 | ||||
| -rw-r--r-- | include/linux/mfd/ti_am335x_tscadc.h | 4 |
3 files changed, 103 insertions, 28 deletions
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index e0dc2d0e7590..dff7343405e2 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -60,6 +60,24 @@ static u32 get_adc_step_mask(struct tiadc_device *adc_dev) return step_en; } +static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev, + struct iio_chan_spec const *chan) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) { + if (chan->channel == adc_dev->channel_line[i]) { + u32 step; + + step = adc_dev->channel_step[i]; + /* +1 for the charger */ + return 1 << (step + 1); + } + } + WARN_ON(1); + return 0; +} + static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan) { return 1 << adc_dev->channel_step[chan]; @@ -326,34 +344,43 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, unsigned int fifo1count, read, stepid; bool found = false; u32 step_en; - unsigned long timeout = jiffies + usecs_to_jiffies - (IDLE_TIMEOUT * adc_dev->channels); + unsigned long timeout; if (iio_buffer_enabled(indio_dev)) return -EBUSY; - step_en = get_adc_step_mask(adc_dev); + step_en = get_adc_chan_step_mask(adc_dev, chan); + if (!step_en) + return -EINVAL; + + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); + while (fifo1count--) + tiadc_readl(adc_dev, REG_FIFO1); + am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en); - /* Wait for ADC sequencer to complete sampling */ - while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) { - if (time_after(jiffies, timeout)) + timeout = jiffies + usecs_to_jiffies + (IDLE_TIMEOUT * adc_dev->channels); + /* Wait for Fifo threshold interrupt */ + while (1) { + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); + if (fifo1count) + break; + + if (time_after(jiffies, timeout)) { + am335x_tsc_se_adc_done(adc_dev->mfd_tscadc); return -EAGAIN; + } } map_val = chan->channel + TOTAL_CHANNELS; /* - * When the sub-system is first enabled, - * the sequencer will always start with the - * lowest step (1) and continue until step (16). - * For ex: If we have enabled 4 ADC channels and - * currently use only 1 out of them, the - * sequencer still configures all the 4 steps, - * leading to 3 unwanted data. - * Hence we need to flush out this data. + * We check the complete FIFO. We programmed just one entry but in case + * something went wrong we left empty handed (-EAGAIN previously) and + * then the value apeared somehow in the FIFO we would have two entries. + * Therefore we read every item and keep only the latest version of the + * requested channel. */ - - fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); for (i = 0; i < fifo1count; i++) { read = tiadc_readl(adc_dev, REG_FIFO1); stepid = read & FIFOREAD_CHNLID_MASK; @@ -365,6 +392,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, *val = (u16) read; } } + am335x_tsc_se_adc_done(adc_dev->mfd_tscadc); if (found == false) return -EBUSY; @@ -492,8 +520,8 @@ static int tiadc_resume(struct device *dev) tiadc_writel(adc_dev, REG_CTRL, restore); tiadc_step_config(indio_dev); - am335x_tsc_se_set(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps); - + am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, + adc_dev->buffer_en_ch_steps); return 0; } diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c index 157f5699a33c..d4e860413bb5 100644 --- a/drivers/mfd/ti_am335x_tscadc.c +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -24,6 +24,7 @@ #include <linux/pm_runtime.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/sched.h> #include <linux/mfd/ti_am335x_tscadc.h> @@ -48,31 +49,71 @@ static const struct regmap_config tscadc_regmap_config = { .val_bits = 32, }; -static void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc) -{ - tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); -} - void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val) { unsigned long flags; spin_lock_irqsave(&tsadc->reg_lock, flags); - tsadc->reg_se_cache |= val; - am335x_tsc_se_update(tsadc); + tsadc->reg_se_cache = val; + if (tsadc->adc_waiting) + wake_up(&tsadc->reg_se_wait); + else if (!tsadc->adc_in_use) + tscadc_writel(tsadc, REG_SE, val); + spin_unlock_irqrestore(&tsadc->reg_lock, flags); } EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache); +static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc) +{ + DEFINE_WAIT(wait); + u32 reg; + + /* + * disable TSC steps so it does not run while the ADC is using it. If + * write 0 while it is running (it just started or was already running) + * then it completes all steps that were enabled and stops then. + */ + tscadc_writel(tsadc, REG_SE, 0); + reg = tscadc_readl(tsadc, REG_ADCFSM); + if (reg & SEQ_STATUS) { + tsadc->adc_waiting = true; + prepare_to_wait(&tsadc->reg_se_wait, &wait, + TASK_UNINTERRUPTIBLE); + spin_unlock_irq(&tsadc->reg_lock); + + schedule(); + + spin_lock_irq(&tsadc->reg_lock); + finish_wait(&tsadc->reg_se_wait, &wait); + + reg = tscadc_readl(tsadc, REG_ADCFSM); + WARN_ON(reg & SEQ_STATUS); + tsadc->adc_waiting = false; + } + tsadc->adc_in_use = true; +} + void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val) { + spin_lock_irq(&tsadc->reg_lock); + am335x_tscadc_need_adc(tsadc); + + tscadc_writel(tsadc, REG_SE, val); + spin_unlock_irq(&tsadc->reg_lock); +} +EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); + +void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc) +{ unsigned long flags; spin_lock_irqsave(&tsadc->reg_lock, flags); - tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache | val); + tsadc->adc_in_use = false; + tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); spin_unlock_irqrestore(&tsadc->reg_lock, flags); } -EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); +EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done); void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val) { @@ -80,7 +121,7 @@ void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val) spin_lock_irqsave(&tsadc->reg_lock, flags); tsadc->reg_se_cache &= ~val; - am335x_tsc_se_update(tsadc); + tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); spin_unlock_irqrestore(&tsadc->reg_lock, flags); } EXPORT_SYMBOL_GPL(am335x_tsc_se_clr); @@ -188,6 +229,8 @@ static int ti_tscadc_probe(struct platform_device *pdev) } spin_lock_init(&tscadc->reg_lock); + init_waitqueue_head(&tscadc->reg_se_wait); + pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index 2fa9c0613da4..fb96c84dada5 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -159,6 +159,9 @@ struct ti_tscadc_dev { int adc_cell; /* -1 if not used */ struct mfd_cell cells[TSCADC_CELLS]; u32 reg_se_cache; + bool adc_waiting; + bool adc_in_use; + wait_queue_head_t reg_se_wait; spinlock_t reg_lock; unsigned int clk_div; @@ -179,5 +182,6 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p) void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val); void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val); void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val); +void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc); #endif |