staging:Removed i2c errors during resume of Synaptics RMI4 touchpad

Removed i2c errors during resume of Synaptics RMI4 touchpad due to
decrease in delay of i2c transfers.

ST-Ericsson Id: ER 280566

Change-Id: I4dc6930fc6f5721f10fe60091968aa0a2ac5e5be
Signed-off-by: Naveen Kumar Gaddipati <naveen.gaddipati@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/9212
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>

1 files changed, 31 insertions, 2 deletions

diff --git a/drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c b/drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c
index 5f4300edd4a..df258321022 100644
--- a/drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c
+++ b/drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c
@@ -5,7 +5,7 @@
  *
  * Author: Js HA <js.ha@stericsson.com> for ST-Ericsson
  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
- * Copyright 2010 (c) ST-Ericsson AB
+ * Copyright 2010 (c) ST-Ericsson SA
  */
 /*
  * This file is licensed under the GPL2 license.
@@ -27,6 +27,7 @@
 
 #include <linux/input.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/regulator/consumer.h>
@@ -45,6 +46,7 @@
 #define BUF_LEN			37
 #define QUERY_LEN		9
 #define DATA_LEN		12
+#define RESUME_DELAY		100 /* msecs */
 #define HAS_TAP			0x01
 #define HAS_PALMDETECT		0x01
 #define HAS_ROTATE		0x02
@@ -165,6 +167,7 @@ struct synaptics_rmi4_device_info {
  * @wait: wait queue structure variable
  * @touch_stopped: flag to stop the thread function
  * @enable: flag to enable/disable the driver event.
+ * @resume_wq_handler: work queue for resume the device
  *
  * This structure gives the device data information.
  */
@@ -186,6 +189,7 @@ struct synaptics_rmi4_data {
 	wait_queue_head_t	wait;
 	bool			touch_stopped;
 	bool			enable;
+	struct work_struct	resume_wq_handler;
 };
 
 /**
@@ -308,6 +312,7 @@ static int synaptics_rmi4_enable(struct synaptics_rmi4_data *pdata)
 	enable_irq(pdata->board->irq_number);
 	pdata->touch_stopped = false;
 
+	msleep(RESUME_DELAY);
 	retval = synaptics_rmi4_i2c_block_read(pdata,
 					pdata->fn01_data_base_addr + 1,
 					&intr_status,
@@ -1009,6 +1014,24 @@ static int synaptics_rmi4_i2c_query_device(struct synaptics_rmi4_data *pdata)
 }
 
 /**
+ * synaptics_rmi4_resume_handler() - work queue for resume handler
+ * @work:work_struct structure pointer
+ *
+ * This work queue handler used to resume the device and returns none
+ */
+static void synaptics_rmi4_resume_handler(struct work_struct *work)
+{
+	struct synaptics_rmi4_data *prmi4_data = container_of(work,
+				struct synaptics_rmi4_data, resume_wq_handler);
+	struct i2c_client *client = prmi4_data->i2c_client;
+	int retval;
+
+	retval = synaptics_rmi4_enable(prmi4_data);
+	if (retval < 0)
+		dev_err(&client->dev, "%s: resume failed\n", __func__);
+}
+
+/**
  * synaptics_rmi4_probe() - Initialze the i2c-client touchscreen driver
  * @i2c: i2c client structure pointer
  * @id:i2c device id pointer
@@ -1137,6 +1160,8 @@ static int __devinit synaptics_rmi4_probe
 		goto err_request_irq;
 	}
 
+	INIT_WORK(&rmi4_data->resume_wq_handler, synaptics_rmi4_resume_handler);
+
 	/* sysfs implementation for dynamic enable/disable the input event */
 	retval = sysfs_create_group(&client->dev.kobj,
 					&synaptics_rmi4_attr_group);
@@ -1148,6 +1173,7 @@ static int __devinit synaptics_rmi4_probe
 	return retval;
 
 err_sysfs:
+	cancel_work_sync(&rmi4_data->resume_wq_handler);
 err_request_irq:
 	free_irq(platformdata->irq_number, rmi4_data);
 	input_unregister_device(rmi4_data->input_dev);
@@ -1181,6 +1207,7 @@ static int __devexit synaptics_rmi4_remove(struct i2c_client *client)
 	sysfs_remove_group(&client->dev.kobj, &synaptics_rmi4_attr_group);
 	rmi4_data->touch_stopped = true;
 	wake_up(&rmi4_data->wait);
+	cancel_work_sync(&rmi4_data->resume_wq_handler);
 	free_irq(pdata->irq_number, rmi4_data);
 	input_unregister_device(rmi4_data->input_dev);
 	if (pdata->regulator_en) {
@@ -1219,7 +1246,9 @@ static int synaptics_rmi4_resume(struct device *dev)
 {
 	struct synaptics_rmi4_data *rmi4_data = dev_get_drvdata(dev);
 
-	return synaptics_rmi4_enable(rmi4_data);
+	schedule_work(&rmi4_data->resume_wq_handler);
+
+	return 0;
 }
 
 static const struct dev_pm_ops synaptics_rmi4_dev_pm_ops = {