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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.c147
1 files changed, 91 insertions, 56 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index b45a45ca7cc..8c12a974b41 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -48,10 +48,13 @@
#define TS_POLL_PERIOD msecs_to_jiffies(10)
+/* this driver doesn't aim at the peak continuous sample rate */
+#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
+
struct ts_event {
/* For portability, we can't read 12 bit values using SPI (which
* would make the controller deliver them as native byteorder u16
- * with msbs zeroed). Instead, we read them as two 8-byte values,
+ * with msbs zeroed). Instead, we read them as two 8-bit values,
* which need byteswapping then range adjustment.
*/
__be16 x;
@@ -60,7 +63,7 @@ struct ts_event {
};
struct ads7846 {
- struct input_dev input;
+ struct input_dev *input;
char phys[32];
struct spi_device *spi;
@@ -68,6 +71,7 @@ struct ads7846 {
u16 vref_delay_usecs;
u16 x_plate_ohms;
+ u8 read_x, read_y, read_z1, read_z2;
struct ts_event tc;
struct spi_transfer xfer[8];
@@ -117,10 +121,10 @@ struct ads7846 {
#define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
| ADS_12_BIT | ADS_DFR)
-static const u8 read_y = READ_12BIT_DFR(y) | ADS_PD10_ADC_ON;
-static const u8 read_z1 = READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON;
-static const u8 read_z2 = READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON;
-static const u8 read_x = READ_12BIT_DFR(x) | ADS_PD10_PDOWN; /* LAST */
+#define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON)
+#define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON)
+#define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON)
+#define READ_X (READ_12BIT_DFR(x) | ADS_PD10_PDOWN) /* LAST */
/* single-ended samples need to first power up reference voltage;
* we leave both ADC and VREF powered
@@ -128,8 +132,8 @@ static const u8 read_x = READ_12BIT_DFR(x) | ADS_PD10_PDOWN; /* LAST */
#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
| ADS_12_BIT | ADS_SER)
-static const u8 ref_on = READ_12BIT_DFR(x) | ADS_PD10_ALL_ON;
-static const u8 ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN;
+#define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
+#define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
/*--------------------------------------------------------------------------*/
@@ -138,7 +142,9 @@ static const u8 ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN;
*/
struct ser_req {
+ u8 ref_on;
u8 command;
+ u8 ref_off;
u16 scratch;
__be16 sample;
struct spi_message msg;
@@ -152,7 +158,7 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
struct ser_req *req = kzalloc(sizeof *req, SLAB_KERNEL);
int status;
int sample;
- int i;
+ int i;
if (!req)
return -ENOMEM;
@@ -160,7 +166,8 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
INIT_LIST_HEAD(&req->msg.transfers);
/* activate reference, so it has time to settle; */
- req->xfer[0].tx_buf = &ref_on;
+ req->ref_on = REF_ON;
+ req->xfer[0].tx_buf = &req->ref_on;
req->xfer[0].len = 1;
req->xfer[1].rx_buf = &req->scratch;
req->xfer[1].len = 2;
@@ -182,7 +189,8 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
/* REVISIT: take a few more samples, and compare ... */
/* turn off reference */
- req->xfer[4].tx_buf = &ref_off;
+ req->ref_off = REF_OFF;
+ req->xfer[4].tx_buf = &req->ref_off;
req->xfer[4].len = 1;
req->xfer[5].rx_buf = &req->scratch;
req->xfer[5].len = 2;
@@ -236,11 +244,12 @@ SHOW(vbatt)
static void ads7846_rx(void *ads)
{
- struct ads7846 *ts = ads;
- unsigned Rt;
- unsigned sync = 0;
- u16 x, y, z1, z2;
- unsigned long flags;
+ struct ads7846 *ts = ads;
+ struct input_dev *input_dev = ts->input;
+ unsigned Rt;
+ unsigned sync = 0;
+ u16 x, y, z1, z2;
+ unsigned long flags;
/* adjust: 12 bit samples (left aligned), built from
* two 8 bit values writen msb-first.
@@ -276,21 +285,21 @@ static void ads7846_rx(void *ads)
* won't notice that, even if nPENIRQ never fires ...
*/
if (!ts->pendown && Rt != 0) {
- input_report_key(&ts->input, BTN_TOUCH, 1);
+ input_report_key(input_dev, BTN_TOUCH, 1);
sync = 1;
} else if (ts->pendown && Rt == 0) {
- input_report_key(&ts->input, BTN_TOUCH, 0);
+ input_report_key(input_dev, BTN_TOUCH, 0);
sync = 1;
}
if (Rt) {
- input_report_abs(&ts->input, ABS_X, x);
- input_report_abs(&ts->input, ABS_Y, y);
- input_report_abs(&ts->input, ABS_PRESSURE, Rt);
+ input_report_abs(input_dev, ABS_X, x);
+ input_report_abs(input_dev, ABS_Y, y);
+ input_report_abs(input_dev, ABS_PRESSURE, Rt);
sync = 1;
}
if (sync)
- input_sync(&ts->input);
+ input_sync(input_dev);
#ifdef VERBOSE
if (Rt || ts->pendown)
@@ -396,9 +405,10 @@ static int ads7846_resume(struct spi_device *spi)
static int __devinit ads7846_probe(struct spi_device *spi)
{
struct ads7846 *ts;
+ struct input_dev *input_dev;
struct ads7846_platform_data *pdata = spi->dev.platform_data;
struct spi_transfer *x;
- int i;
+ int err;
if (!spi->irq) {
dev_dbg(&spi->dev, "no IRQ?\n");
@@ -411,9 +421,9 @@ static int __devinit ads7846_probe(struct spi_device *spi)
}
/* don't exceed max specified sample rate */
- if (spi->max_speed_hz > (125000 * 16)) {
+ if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
- (spi->max_speed_hz/16)/1000);
+ (spi->max_speed_hz/SAMPLE_BITS)/1000);
return -EINVAL;
}
@@ -423,13 +433,18 @@ static int __devinit ads7846_probe(struct spi_device *spi)
* to discard the four garbage LSBs.
*/
- if (!(ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL)))
- return -ENOMEM;
+ ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!ts || !input_dev) {
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
dev_set_drvdata(&spi->dev, ts);
+ spi->dev.power.power_state = PMSG_ON;
ts->spi = spi;
- spi->dev.power.power_state = PMSG_ON;
+ ts->input = input_dev;
init_timer(&ts->timer);
ts->timer.data = (unsigned long) ts;
@@ -439,70 +454,80 @@ static int __devinit ads7846_probe(struct spi_device *spi)
ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
- init_input_dev(&ts->input);
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
- ts->input.dev = &spi->dev;
- ts->input.name = "ADS784x Touchscreen";
- snprintf(ts->phys, sizeof ts->phys, "%s/input0", spi->dev.bus_id);
- ts->input.phys = ts->phys;
+ input_dev->name = "ADS784x Touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->cdev.dev = &spi->dev;
- ts->input.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
- ts->input.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
- input_set_abs_params(&ts->input, ABS_X,
+ input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
+ input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+ input_set_abs_params(input_dev, ABS_X,
pdata->x_min ? : 0,
pdata->x_max ? : MAX_12BIT,
0, 0);
- input_set_abs_params(&ts->input, ABS_Y,
+ input_set_abs_params(input_dev, ABS_Y,
pdata->y_min ? : 0,
pdata->y_max ? : MAX_12BIT,
0, 0);
- input_set_abs_params(&ts->input, ABS_PRESSURE,
+ input_set_abs_params(input_dev, ABS_PRESSURE,
pdata->pressure_min, pdata->pressure_max, 0, 0);
- input_register_device(&ts->input);
-
/* set up the transfers to read touchscreen state; this assumes we
* use formula #2 for pressure, not #3.
*/
+ INIT_LIST_HEAD(&ts->msg.transfers);
x = ts->xfer;
/* y- still on; turn on only y+ (and ADC) */
- x->tx_buf = &read_y;
+ ts->read_y = READ_Y;
+ x->tx_buf = &ts->read_y;
x->len = 1;
+ spi_message_add_tail(x, &ts->msg);
+
x++;
x->rx_buf = &ts->tc.y;
x->len = 2;
- x++;
+ spi_message_add_tail(x, &ts->msg);
/* turn y+ off, x- on; we'll use formula #2 */
if (ts->model == 7846) {
- x->tx_buf = &read_z1;
+ x++;
+ ts->read_z1 = READ_Z1;
+ x->tx_buf = &ts->read_z1;
x->len = 1;
+ spi_message_add_tail(x, &ts->msg);
+
x++;
x->rx_buf = &ts->tc.z1;
x->len = 2;
- x++;
+ spi_message_add_tail(x, &ts->msg);
- x->tx_buf = &read_z2;
+ x++;
+ ts->read_z2 = READ_Z2;
+ x->tx_buf = &ts->read_z2;
x->len = 1;
+ spi_message_add_tail(x, &ts->msg);
+
x++;
x->rx_buf = &ts->tc.z2;
x->len = 2;
- x++;
+ spi_message_add_tail(x, &ts->msg);
}
/* turn y- off, x+ on, then leave in lowpower */
- x->tx_buf = &read_x;
+ x++;
+ ts->read_x = READ_X;
+ x->tx_buf = &ts->read_x;
x->len = 1;
+ spi_message_add_tail(x, &ts->msg);
+
x++;
x->rx_buf = &ts->tc.x;
x->len = 2;
- x++;
-
- CS_CHANGE(x[-1]);
+ CS_CHANGE(*x);
+ spi_message_add_tail(x, &ts->msg);
- for (i = 0; i < x - ts->xfer; i++)
- spi_message_add_tail(&ts->xfer[i], &ts->msg);
ts->msg.complete = ads7846_rx;
ts->msg.context = ts;
@@ -510,9 +535,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
SA_SAMPLE_RANDOM | SA_TRIGGER_FALLING,
spi->dev.bus_id, ts)) {
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
- input_unregister_device(&ts->input);
- kfree(ts);
- return -EBUSY;
+ err = -EBUSY;
+ goto err_free_mem;
}
dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
@@ -534,7 +558,18 @@ static int __devinit ads7846_probe(struct spi_device *spi)
device_create_file(&spi->dev, &dev_attr_vbatt);
device_create_file(&spi->dev, &dev_attr_vaux);
+ err = input_register_device(input_dev);
+ if (err)
+ goto err_free_irq;
+
return 0;
+
+ err_free_irq:
+ free_irq(spi->irq, ts);
+ err_free_mem:
+ input_free_device(input_dev);
+ kfree(ts);
+ return err;
}
static int __devexit ads7846_remove(struct spi_device *spi)
@@ -554,7 +589,7 @@ static int __devexit ads7846_remove(struct spi_device *spi)
device_remove_file(&spi->dev, &dev_attr_vbatt);
device_remove_file(&spi->dev, &dev_attr_vaux);
- input_unregister_device(&ts->input);
+ input_unregister_device(ts->input);
kfree(ts);
dev_dbg(&spi->dev, "unregistered touchscreen\n");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 08:21:38 +0000