Instead of having standard interrupt handler and manually firing work item
to perform I2C reads, let's switch to threaded interrupts, which were
designed specifically for this purpose.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/touchscreen/eeti_ts.c | 79 +++++++++++++++++--------------------
1 file changed, 36 insertions(+), 43 deletions(-)
diff --git a/drivers/input/touchscreen/eeti_ts.c b/drivers/input/touchscreen/eeti_ts.c
index fc61dbea4736..ee6b87c606ef 100644
--- a/drivers/input/touchscreen/eeti_ts.c
+++ b/drivers/input/touchscreen/eeti_ts.c
@@ -47,9 +47,8 @@ MODULE_PARM_DESC(flip_y, "flip y coordinate");
struct eeti_ts {
struct i2c_client *client;
struct input_dev *input;
- struct work_struct work;
- struct mutex mutex;
int irq_gpio, irq_active_high;
+ bool running;
};
#define EETI_TS_BITDEPTH (11)
@@ -66,29 +65,11 @@ static inline int eeti_ts_irq_active(struct eeti_ts *eeti)
return gpio_get_value_cansleep(eeti->irq_gpio) == eeti->irq_active_high;
}
-static void eeti_ts_read(struct work_struct *work)
+static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
{
- char buf[6];
- unsigned int x, y, res, pressed, to = 100;
- struct eeti_ts *eeti =
- container_of(work, struct eeti_ts, work);
-
- mutex_lock(&eeti->mutex);
-
- while (eeti_ts_irq_active(eeti) && --to)
- i2c_master_recv(eeti->client, buf, sizeof(buf));
-
- if (!to) {
- dev_err(&eeti->client->dev,
- "unable to clear IRQ - line stuck?\n");
- goto out;
- }
+ unsigned int res;
+ u16 x, y;
- /* drop non-report packets */
- if (!(buf[0] & 0x80))
- goto out;
-
- pressed = buf[0] & REPORT_BIT_PRESSED;
res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
x = get_unaligned_be16(&buf[1]);
@@ -109,35 +90,48 @@ static void eeti_ts_read(struct work_struct *work)
input_report_abs(eeti->input, ABS_X, x);
input_report_abs(eeti->input, ABS_Y, y);
- input_report_key(eeti->input, BTN_TOUCH, !!pressed);
+ input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
input_sync(eeti->input);
-
-out:
- mutex_unlock(&eeti->mutex);
}
static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
{
struct eeti_ts *eeti = dev_id;
+ int len;
+ int error;
+ char buf[6];
- /* postpone I2C transactions as we are atomic */
- schedule_work(&eeti->work);
+ do {
+ len = i2c_master_recv(eeti->client, buf, sizeof(buf));
+ if (len != sizeof(buf)) {
+ error = len < 0 ? len : -EIO;
+ dev_err(&eeti->client->dev,
+ "failed to read touchscreen data: %d\n",
+ error);
+ break;
+ }
+
+ if (buf[0] & 0x80) {
+ /* Motion packet */
+ eeti_ts_report_event(eeti, buf);
+ }
+ } while (eeti->running && eeti_ts_irq_active(eeti));
return IRQ_HANDLED;
}
static void eeti_ts_start(struct eeti_ts *eeti)
{
+ eeti->running = true;
+ wmb();
enable_irq(eeti->client->irq);
-
- /* Read the events once to arm the IRQ */
- eeti_ts_read(&eeti->work);
}
static void eeti_ts_stop(struct eeti_ts *eeti)
{
+ eeti->running = false;
+ wmb();
disable_irq(eeti->client->irq);
- cancel_work_sync(&eeti->work);
}
static int eeti_ts_open(struct input_dev *dev)
@@ -179,8 +173,6 @@ static int eeti_ts_probe(struct i2c_client *client,
return -ENOMEM;
}
- mutex_init(&eeti->mutex);
-
input = devm_input_allocate_device(dev);
if (!input) {
dev_err(dev, "Failed to allocate input device.\n");
@@ -210,18 +202,15 @@ static int eeti_ts_probe(struct i2c_client *client,
eeti->irq_active_high = pdata->irq_active_high;
irq_flags = eeti->irq_active_high ?
- IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
+ IRQF_TRIGGER_HIGH : IRQF_TRIGGER_LOW;
- INIT_WORK(&eeti->work, eeti_ts_read);
i2c_set_clientdata(client, eeti);
input_set_drvdata(input, eeti);
- error = input_register_device(input);
- if (error)
- return error;
-
- error = devm_request_irq(dev, client->irq, eeti_ts_isr, irq_flags,
- client->name, eeti);
+ error = devm_request_threaded_irq(dev, client->irq,
+ NULL, eeti_ts_isr,
+ irq_flags | IRQF_ONESHOT,
+ client->name, eeti);
if (error) {
dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
error);
@@ -234,6 +223,10 @@ static int eeti_ts_probe(struct i2c_client *client,
*/
eeti_ts_stop(eeti);
+ error = input_register_device(input);
+ if (error)
+ return error;
+
return 0;
}
--
2.11.0.483.g087da7b7c-goog
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