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path: root/drivers/input/touchscreen/ads7846.c
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Diffstat (limited to 'drivers/input/touchscreen/ads7846.c')
-rw-r--r--drivers/input/touchscreen/ads7846.c84
1 files changed, 61 insertions, 23 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 907a45f..8583c76 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -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.
@@ -517,7 +527,9 @@ static void ads7846_rx(void *ads)
if (x == MAX_12BIT)
x = 0;
- if (likely(x && z1)) {
+ if (ts->model == 7843) {
+ Rt = ts->pressure_max / 2;
+ } else if (likely(x && z1)) {
/* compute touch pressure resistance using equation #2 */
Rt = z2;
Rt -= z1;
@@ -525,11 +537,9 @@ static void ads7846_rx(void *ads)
Rt *= ts->x_plate_ohms;
Rt /= z1;
Rt = (Rt + 2047) >> 12;
- } else
+ } else {
Rt = 0;
-
- if (ts->model == 7843)
- Rt = ts->pressure_max / 2;
+ }
/* Sample found inconsistent by debouncing or pressure is beyond
* the maximum. Don't report it to user space, repeat at least
@@ -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;
}
@@ -633,19 +643,17 @@ static void ads7846_rx_val(void *ads)
struct ads7846 *ts = ads;
struct spi_message *m;
struct spi_transfer *t;
- u16 *rx_val;
int val;
int action;
int status;
m = &ts->msg[ts->msg_idx];
t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
- rx_val = t->rx_buf;
/* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
* built from two 8 bit values written msb-first.
*/
- val = be16_to_cpu(*rx_val) >> 3;
+ val = be16_to_cpup((__be16 *)t->rx_buf) >> 3;
action = ts->filter(ts->filter_data, ts->msg_idx, &val);
switch (action) {
@@ -659,7 +667,7 @@ static void ads7846_rx_val(void *ads)
m = ts->last_msg;
break;
case ADS7846_FILTER_OK:
- *rx_val = val;
+ *(u16 *)t->rx_buf = val;
ts->tc.ignore = 0;
m = &ts->msg[++ts->msg_idx];
break;
@@ -679,7 +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;
@@ -718,7 +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
@@ -808,6 +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;
@@ -835,15 +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.
@@ -895,7 +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 =
@@ -1087,7 +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);
@@ -1118,6 +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);
@@ -1142,6 +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);
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