[PATCH V2] input synaptics-rmi4: Bug fixes to ATTN GPIO handling.

[Christopher Heiny <cheiny@synaptics.com>]

This patch fixes some bugs in handling of the RMI4 attention line GPIO.

1) in enable_sensor(), eliminate the complicated check on ATTN and just 
call process_interrupt_requests().  This will have minimal overhead if ATTN
is not asserted, and clears the state of the RMI4 device in any case.

2) Correctly free the GPIO in rmi_driver_remove().

3) in rmi_driver_probe()
    - declare the name of the attention gpio (GPIO_LABEL)
    - use gpio_request_one() to get the gpio and export it.
    - simplify conditional gpio acquisition logic and combine with interrupt
      setup

4) use gpio_is_valid() instead of comparing to 0.

Signed-off-by: Christopher Heiny <cheiny@synaptics.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

 drivers/input/rmi4/rmi_driver.c | 43 ++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
index a30c7d3..9b02358 100644
--- a/drivers/input/rmi4/rmi_driver.c
+++ b/drivers/input/rmi4/rmi_driver.c
@@ -140,7 +140,6 @@ static int enable_sensor(struct rmi_device *rmi_dev)
 	struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
 	struct rmi_phys_device *rmi_phys;
 	int retval = 0;
-	struct rmi_device_platform_data *pdata = to_rmi_platform_data(rmi_dev);
 
 	if (data->enabled)
 		return 0;
@@ -169,11 +168,7 @@ static int enable_sensor(struct rmi_device *rmi_dev)
 
 	data->enabled = true;
 
-	if (!pdata->level_triggered &&
-		    gpio_get_value(pdata->attn_gpio) == pdata->attn_polarity)
-		retval = process_interrupt_requests(rmi_dev);
-
-	return retval;
+	return process_interrupt_requests(rmi_dev);
 }
 
 static void rmi_free_function_list(struct rmi_device *rmi_dev)
@@ -800,13 +795,20 @@ static SIMPLE_DEV_PM_OPS(rmi_driver_pm, rmi_driver_suspend, rmi_driver_resume);
 static int rmi_driver_remove(struct device *dev)
 {
 	struct rmi_device *rmi_dev = to_rmi_device(dev);
+	const struct rmi_device_platform_data *pdata =
+					to_rmi_platform_data(rmi_dev);
 
 	disable_sensor(rmi_dev);
 	rmi_free_function_list(rmi_dev);
 
+	if (gpio_is_valid(pdata->attn_gpio))
+		gpio_free(pdata->attn_gpio);
+
 	return 0;
 }
 
+static const char GPIO_LABEL[] = "attn";
+
 static int rmi_driver_probe(struct device *dev)
 {
 	struct rmi_driver *rmi_driver;
@@ -937,7 +939,7 @@ static int rmi_driver_probe(struct device *dev)
 		mutex_init(&data->suspend_mutex);
 	}
 
-	if (pdata->attn_gpio) {
+	if (gpio_is_valid(pdata->attn_gpio)) {
 		data->irq = gpio_to_irq(pdata->attn_gpio);
 		if (pdata->level_triggered) {
 			data->irq_flags = IRQF_ONESHOT |
@@ -948,24 +950,17 @@ static int rmi_driver_probe(struct device *dev)
 				(pdata->attn_polarity == RMI_ATTN_ACTIVE_HIGH)
 				? IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
 		}
-	} else
-		data->poll_interval = ktime_set(0,
-			(pdata->poll_interval_ms ? pdata->poll_interval_ms :
-			DEFAULT_POLL_INTERVAL_MS) * 1000 * 1000);
-
-	if (data->f01_container->dev.driver) {
-		/* Driver already bound, so enable ATTN now. */
-		enable_sensor(rmi_dev);
-	}
 
-	if (IS_ENABLED(CONFIG_RMI4_DEV) && pdata->attn_gpio) {
-		retval = gpio_export(pdata->attn_gpio, false);
+		retval = gpio_request_one(pdata->attn_gpio,
+					  GPIOF_EXPORT | GPIOF_DIR_IN,
+					  GPIO_LABEL);
 		if (retval) {
-			dev_warn(dev, "WARNING: Failed to export ATTN gpio!\n");
+			dev_warn(dev, "WARNING: Failed to request ATTN gpio %d, code=%d.\n",
+				 pdata->attn_gpio, retval);
 			retval = 0;
 		} else {
 			retval = gpio_export_link(dev,
-						  "attn", pdata->attn_gpio);
+						  GPIO_LABEL, pdata->attn_gpio);
 			if (retval) {
 				dev_warn(dev,
 					"WARNING: Failed to symlink ATTN gpio!\n");
@@ -975,6 +970,14 @@ static int rmi_driver_probe(struct device *dev)
 					pdata->attn_gpio);
 			}
 		}
+	} else
+		data->poll_interval = ktime_set(0,
+			(pdata->poll_interval_ms ? pdata->poll_interval_ms :
+			DEFAULT_POLL_INTERVAL_MS) * 1000 * 1000);
+
+	if (data->f01_container->dev.driver) {
+		/* Driver already bound, so enable ATTN now. */
+		enable_sensor(rmi_dev);
 	}
 
 	return 0;