linux-kernel - [PATCH] ads7846: do not ignore pendown-gpio flags

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Message-ID: <20150520072620.GA8930@fifteen>
Date:	Wed, 20 May 2015 10:26:20 +0300
From:	Evgeniy Dushistov <dushistov@...l.ru>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Daniel Mack <zonque@...il.com>
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] ads7846: do not ignore pendown-gpio flags

At current state ads7846 driver ignore GPIO_ACTIVE_LOW,
GPIO_ACTIVE_HIGH flags in such dts expression:
pendown-gpio = <&gpio5 5 GPIO_ACTIVE_HIGH>;

In times of usage arch/arm/.. you can handle this
by get_pendown_state callback passed via platform_data,
but at now with Device Tree it is impossible to handle
1 as interrupt trigger, this patch fixes this.

Test on beagleboard-xm<-SPI->ads7845

It made on top of "ads7846: fix ads7846 driver for work with ads7845",
but can applied with "hunks" on top of Linus's master,
and it independent of "ads7846: fix ads7846 driver for work with
ads7845".

Signed-off-by: Evgeniy A. Dushistov <dushistov@...l.ru>
---
 drivers/input/touchscreen/ads7846.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 76728d4..0a02364 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -140,6 +140,7 @@ struct ads7846 {
 	void			(*filter_cleanup)(void *data);
 	int			(*get_pendown_state)(void);
 	int			gpio_pendown;
+	bool		        active_low;
 
 	void			(*wait_for_sync)(void);
 };
@@ -574,7 +575,7 @@ static int get_pendown_state(struct ads7846 *ts)
 	if (ts->get_pendown_state)
 		return ts->get_pendown_state();
 
-	return !gpio_get_value(ts->gpio_pendown);
+	return ts->active_low != (!!gpio_get_value(ts->gpio_pendown));
 }
 
 static void null_wait_for_sync(void)
@@ -1108,11 +1109,13 @@ static const struct of_device_id ads7846_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
 
-static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
+static const struct ads7846_platform_data *
+ads7846_probe_dt(struct device *dev, bool *pen_active_low)
 {
 	struct ads7846_platform_data *pdata;
 	struct device_node *node = dev->of_node;
 	const struct of_device_id *match;
+	enum of_gpio_flags gpio_flags;
 
 	if (!node) {
 		dev_err(dev, "Device does not have associated DT data\n");
@@ -1163,12 +1166,16 @@ static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
 
 	pdata->wakeup = of_property_read_bool(node, "linux,wakeup");
 
-	pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
+	pdata->gpio_pendown = of_get_named_gpio_flags(dev->of_node,
+						      "pendown-gpio",
+						      0, &gpio_flags);
+	*pen_active_low = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
 
 	return pdata;
 }
 #else
-static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
+static const struct ads7846_platform_data *ads7846_probe_dt(
+	struct device *dev, bool *pen_active_low)
 {
 	dev_err(dev, "no platform data defined\n");
 	return ERR_PTR(-EINVAL);
@@ -1183,6 +1190,7 @@ static int ads7846_probe(struct spi_device *spi)
 	struct input_dev *input_dev;
 	unsigned long irq_flags;
 	int err;
+	bool pen_active_low = true;
 
 	if (!spi->irq) {
 		dev_dbg(&spi->dev, "no IRQ?\n");
@@ -1226,7 +1234,7 @@ static int ads7846_probe(struct spi_device *spi)
 
 	pdata = dev_get_platdata(&spi->dev);
 	if (!pdata) {
-		pdata = ads7846_probe_dt(&spi->dev);
+		pdata = ads7846_probe_dt(&spi->dev, &pen_active_low);
 		if (IS_ERR(pdata)) {
 			err = PTR_ERR(pdata);
 			goto err_free_mem;
@@ -1240,6 +1248,7 @@ static int ads7846_probe(struct spi_device *spi)
 
 	ts->vref_mv = pdata->vref_mv;
 	ts->swap_xy = pdata->swap_xy;
+	ts->active_low = pen_active_low;
 
 	if (pdata->filter != NULL) {
 		if (pdata->filter_init != NULL) {
-- 
2.3.6

-- 
/Evgeniy
--
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