2015-05-20 07:26:27

by Evgeniy Dushistov

[permalink] [raw]
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 <[email protected]>
---
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


2015-05-20 16:56:55

by Dmitry Torokhov

[permalink] [raw]
Subject: Re: [PATCH] ads7846: do not ignore pendown-gpio flags

Hi Evgeniy,

On Wed, May 20, 2015 at 10:26:20AM +0300, Evgeniy Dushistov wrote:
> 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 <[email protected]>

Can we switch the driver to use gpiod instead? Then the active high/low
condition would be handled automatically.

> ---
> 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

--
Dmitry