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Commit 6ae19b04 authored by Eric Miao's avatar Eric Miao Committed by Russell King
Browse files

Input: ads7846 - introduce .gpio_pendown to get pendown state 



The GPIO connected to ADS7846 nPENIRQ signal is usually used to get
the pendown state as well. Introduce a .gpio_pendown, and use this
to decide the pendown state if .get_pendown_state is NULL.

Signed-off-by: default avatarEric Miao <eric.miao@marvell.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent adee14b2

drivers/input/touchscreen/ads7846.c

+54 −14
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/input.h>

#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/gpio.h>

#include <linux/spi/spi.h>

#include <linux/spi/ads7846.h>

#include <asm/irq.h>
@@ -116,6 +117,7 @@ struct ads7846 { 
	void			*filter_data;

	void			(*filter_cleanup)(void *data);

	int			(*get_pendown_state)(void);

	int			gpio_pendown;

};



/* leave chip selected when we're done, for quicker re-select? */
@@ -491,6 +493,14 @@ static struct attribute_group ads784x_attr_group = { 


/*--------------------------------------------------------------------------*/



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);

}



/*

 * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,

 * to retrieve touchscreen status.
@@ -550,7 +560,7 @@ static void ads7846_rx(void *ads) 
	 */

	if (ts->penirq_recheck_delay_usecs) {

		udelay(ts->penirq_recheck_delay_usecs);

		if (!ts->get_pendown_state())

		if (!get_pendown_state(ts))

			Rt = 0;

	}
@@ -677,7 +687,7 @@ static enum hrtimer_restart ads7846_timer(struct hrtimer *handle) 


	spin_lock_irq(&ts->lock);



	if (unlikely(!ts->get_pendown_state() ||

	if (unlikely(!get_pendown_state(ts) ||

		     device_suspended(&ts->spi->dev))) {

		if (ts->pendown) {

			struct input_dev *input = ts->input;
@@ -716,7 +726,7 @@ static irqreturn_t ads7846_irq(int irq, void *handle) 
	unsigned long flags;



	spin_lock_irqsave(&ts->lock, flags);

	if (likely(ts->get_pendown_state())) {

	if (likely(get_pendown_state(ts))) {

		if (!ts->irq_disabled) {

			/* The ARM do_simple_IRQ() dispatcher doesn't act

			 * like the other dispatchers:  it will report IRQs
@@ -806,6 +816,36 @@ static int ads7846_resume(struct spi_device *spi) 
	return 0;

}



static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)

{

	struct ads7846_platform_data *pdata = spi->dev.platform_data;

	int err;



	/* REVISIT when the irq can be triggered active-low, or if for some

	 * reason the touchscreen isn't hooked up, we don't need to access

	 * the pendown state.

	 */

	if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {

		dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");

		return -EINVAL;

	}



	if (pdata->get_pendown_state) {

		ts->get_pendown_state = pdata->get_pendown_state;

		return 0;

	}



	err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");

	if (err) {

		dev_err(&spi->dev, "failed to request pendown GPIO%d\n",

				pdata->gpio_pendown);

		return err;

	}



	ts->gpio_pendown = pdata->gpio_pendown;

	return 0;

}



static int __devinit ads7846_probe(struct spi_device *spi)

{

	struct ads7846			*ts;
@@ -833,15 +873,6 @@ static int __devinit ads7846_probe(struct spi_device *spi) 
		return -EINVAL;

	}



	/* REVISIT when the irq can be triggered active-low, or if for some

	 * reason the touchscreen isn't hooked up, we don't need to access

	 * the pendown state.

	 */

	if (pdata->get_pendown_state == NULL) {

		dev_dbg(&spi->dev, "no get_pendown_state function?\n");

		return -EINVAL;

	}



	/* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except

	 * that even if the hardware can do that, the SPI controller driver

	 * may not.  So we stick to very-portable 8 bit words, both RX and TX.
@@ -893,7 +924,10 @@ static int __devinit ads7846_probe(struct spi_device *spi) 
		ts->filter_data = ts;

	} else

		ts->filter = ads7846_no_filter;

	ts->get_pendown_state = pdata->get_pendown_state;



	err = setup_pendown(spi, ts);

	if (err)

		goto err_cleanup_filter;



	if (pdata->penirq_recheck_delay_usecs)

		ts->penirq_recheck_delay_usecs =
@@ -1085,7 +1119,7 @@ static int __devinit ads7846_probe(struct spi_device *spi) 
			spi->dev.driver->name, ts)) {

		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);

		err = -EBUSY;

		goto err_cleanup_filter;

		goto err_free_gpio;

	}



	err = ads784x_hwmon_register(spi, ts);
@@ -1116,6 +1150,9 @@ static int __devinit ads7846_probe(struct spi_device *spi) 
	ads784x_hwmon_unregister(spi, ts);

 err_free_irq:

	free_irq(spi->irq, ts);

 err_free_gpio:

	if (ts->gpio_pendown != -1)

		gpio_free(ts->gpio_pendown);

 err_cleanup_filter:

	if (ts->filter_cleanup)

		ts->filter_cleanup(ts->filter_data);
@@ -1140,6 +1177,9 @@ static int __devexit ads7846_remove(struct spi_device *spi) 
	/* suspend left the IRQ disabled */

	enable_irq(ts->spi->irq);



	if (ts->gpio_pendown != -1)

		gpio_free(ts->gpio_pendown);



	if (ts->filter_cleanup)

		ts->filter_cleanup(ts->filter_data);

include/linux/spi/ads7846.h

+3 −0
Original line number Diff line number Diff line
@@ -43,6 +43,9 @@ struct ads7846_platform_data { 
	u16	debounce_tol;		/* tolerance used for filtering */

	u16	debounce_rep;		/* additional consecutive good readings

					 * required after the first two */

	int	gpio_pendown;		/* the GPIO used to decide the pendown

					 * state if get_pendown_state == NULL

					 */

	int	(*get_pendown_state)(void);

	int	(*filter_init)	(struct ads7846_platform_data *pdata,

				 void **filter_data);