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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.c162
1 files changed, 109 insertions, 53 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index ce6f48c695f5..b9b7fc6ff1eb 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>
@@ -68,6 +69,17 @@ struct ts_event {
int ignore;
};
+/*
+ * We allocate this separately to avoid cache line sharing issues when
+ * driver is used with DMA-based SPI controllers (like atmel_spi) on
+ * systems where main memory is not DMA-coherent (most non-x86 boards).
+ */
+struct ads7846_packet {
+ u8 read_x, read_y, read_z1, read_z2, pwrdown;
+ u16 dummy; /* for the pwrdown read */
+ struct ts_event tc;
+};
+
struct ads7846 {
struct input_dev *input;
char phys[32];
@@ -85,9 +97,7 @@ struct ads7846 {
u16 x_plate_ohms;
u16 pressure_max;
- u8 read_x, read_y, read_z1, read_z2, pwrdown;
- u16 dummy; /* for the pwrdown read */
- struct ts_event tc;
+ struct ads7846_packet *packet;
struct spi_transfer xfer[18];
struct spi_message msg[5];
@@ -116,6 +126,7 @@ 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? */
@@ -461,10 +472,11 @@ static ssize_t ads7846_disable_store(struct device *dev,
const char *buf, size_t count)
{
struct ads7846 *ts = dev_get_drvdata(dev);
- char *endp;
- int i;
+ long i;
+
+ if (strict_strtoul(buf, 10, &i))
+ return -EINVAL;
- i = simple_strtoul(buf, &endp, 10);
spin_lock_irq(&ts->lock);
if (i)
@@ -491,6 +503,14 @@ 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.
@@ -502,16 +522,17 @@ static struct attribute_group ads784x_attr_group = {
static void ads7846_rx(void *ads)
{
struct ads7846 *ts = ads;
+ struct ads7846_packet *packet = ts->packet;
unsigned Rt;
u16 x, y, z1, z2;
/* ads7846_rx_val() did in-place conversion (including byteswap) from
* on-the-wire format as part of debouncing to get stable readings.
*/
- x = ts->tc.x;
- y = ts->tc.y;
- z1 = ts->tc.z1;
- z2 = ts->tc.z2;
+ x = packet->tc.x;
+ y = packet->tc.y;
+ z1 = packet->tc.z1;
+ z2 = packet->tc.z2;
/* range filtering */
if (x == MAX_12BIT)
@@ -535,10 +556,10 @@ static void ads7846_rx(void *ads)
* the maximum. Don't report it to user space, repeat at least
* once more the measurement
*/
- if (ts->tc.ignore || Rt > ts->pressure_max) {
+ if (packet->tc.ignore || Rt > ts->pressure_max) {
#ifdef VERBOSE
pr_debug("%s: ignored %d pressure %d\n",
- ts->spi->dev.bus_id, ts->tc.ignore, Rt);
+ ts->spi->dev.bus_id, packet->tc.ignore, Rt);
#endif
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
HRTIMER_MODE_REL);
@@ -550,7 +571,7 @@ 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;
}
@@ -631,6 +652,7 @@ static int ads7846_no_filter(void *ads, int data_idx, int *val)
static void ads7846_rx_val(void *ads)
{
struct ads7846 *ts = ads;
+ struct ads7846_packet *packet = ts->packet;
struct spi_message *m;
struct spi_transfer *t;
int val;
@@ -650,7 +672,7 @@ static void ads7846_rx_val(void *ads)
case ADS7846_FILTER_REPEAT:
break;
case ADS7846_FILTER_IGNORE:
- ts->tc.ignore = 1;
+ packet->tc.ignore = 1;
/* Last message will contain ads7846_rx() as the
* completion function.
*/
@@ -658,7 +680,7 @@ static void ads7846_rx_val(void *ads)
break;
case ADS7846_FILTER_OK:
*(u16 *)t->rx_buf = val;
- ts->tc.ignore = 0;
+ packet->tc.ignore = 0;
m = &ts->msg[++ts->msg_idx];
break;
default:
@@ -677,7 +699,7 @@ 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 +738,7 @@ 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
@@ -763,7 +785,6 @@ static void ads7846_disable(struct ads7846 *ts)
/* we know the chip's in lowpower mode since we always
* leave it that way after every request
*/
-
}
/* Must be called with ts->lock held */
@@ -806,9 +827,40 @@ 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;
+ struct ads7846_packet *packet;
struct input_dev *input_dev;
struct ads7846_platform_data *pdata = spi->dev.platform_data;
struct spi_message *m;
@@ -833,15 +885,6 @@ 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.
@@ -853,14 +896,16 @@ static int __devinit ads7846_probe(struct spi_device *spi)
return err;
ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
+ packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
input_dev = input_allocate_device();
- if (!ts || !input_dev) {
+ if (!ts || !packet || !input_dev) {
err = -ENOMEM;
goto err_free_mem;
}
dev_set_drvdata(&spi->dev, ts);
+ ts->packet = packet;
ts->spi = spi;
ts->input = input_dev;
ts->vref_mv = pdata->vref_mv;
@@ -893,7 +938,10 @@ 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 =
@@ -929,13 +977,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
spi_message_init(m);
/* y- still on; turn on only y+ (and ADC) */
- ts->read_y = READ_Y(vref);
- x->tx_buf = &ts->read_y;
+ packet->read_y = READ_Y(vref);
+ x->tx_buf = &packet->read_y;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.y;
+ x->rx_buf = &packet->tc.y;
x->len = 2;
spi_message_add_tail(x, m);
@@ -947,12 +995,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
x->delay_usecs = pdata->settle_delay_usecs;
x++;
- x->tx_buf = &ts->read_y;
+ x->tx_buf = &packet->read_y;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.y;
+ x->rx_buf = &packet->tc.y;
x->len = 2;
spi_message_add_tail(x, m);
}
@@ -965,13 +1013,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
/* turn y- off, x+ on, then leave in lowpower */
x++;
- ts->read_x = READ_X(vref);
- x->tx_buf = &ts->read_x;
+ packet->read_x = READ_X(vref);
+ x->tx_buf = &packet->read_x;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.x;
+ x->rx_buf = &packet->tc.x;
x->len = 2;
spi_message_add_tail(x, m);
@@ -980,12 +1028,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
x->delay_usecs = pdata->settle_delay_usecs;
x++;
- x->tx_buf = &ts->read_x;
+ x->tx_buf = &packet->read_x;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.x;
+ x->rx_buf = &packet->tc.x;
x->len = 2;
spi_message_add_tail(x, m);
}
@@ -999,13 +1047,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
spi_message_init(m);
x++;
- ts->read_z1 = READ_Z1(vref);
- x->tx_buf = &ts->read_z1;
+ packet->read_z1 = READ_Z1(vref);
+ x->tx_buf = &packet->read_z1;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z1;
+ x->rx_buf = &packet->tc.z1;
x->len = 2;
spi_message_add_tail(x, m);
@@ -1014,12 +1062,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
x->delay_usecs = pdata->settle_delay_usecs;
x++;
- x->tx_buf = &ts->read_z1;
+ x->tx_buf = &packet->read_z1;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z1;
+ x->rx_buf = &packet->tc.z1;
x->len = 2;
spi_message_add_tail(x, m);
}
@@ -1031,13 +1079,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
spi_message_init(m);
x++;
- ts->read_z2 = READ_Z2(vref);
- x->tx_buf = &ts->read_z2;
+ packet->read_z2 = READ_Z2(vref);
+ x->tx_buf = &packet->read_z2;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z2;
+ x->rx_buf = &packet->tc.z2;
x->len = 2;
spi_message_add_tail(x, m);
@@ -1046,12 +1094,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
x->delay_usecs = pdata->settle_delay_usecs;
x++;
- x->tx_buf = &ts->read_z2;
+ x->tx_buf = &packet->read_z2;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z2;
+ x->rx_buf = &packet->tc.z2;
x->len = 2;
spi_message_add_tail(x, m);
}
@@ -1065,13 +1113,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
spi_message_init(m);
x++;
- ts->pwrdown = PWRDOWN;
- x->tx_buf = &ts->pwrdown;
+ packet->pwrdown = PWRDOWN;
+ x->tx_buf = &packet->pwrdown;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->dummy;
+ x->rx_buf = &packet->dummy;
x->len = 2;
CS_CHANGE(*x);
spi_message_add_tail(x, m);
@@ -1085,7 +1133,7 @@ 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);
@@ -1116,11 +1164,15 @@ 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);
err_free_mem:
input_free_device(input_dev);
+ kfree(packet);
kfree(ts);
return err;
}
@@ -1140,9 +1192,13 @@ 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);
+ kfree(ts->packet);
kfree(ts);
dev_dbg(&spi->dev, "unregistered touchscreen\n");
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-20 21:53:02 +0300