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Input: eeti_ts - switch to using threaded interrupt

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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.

Reviewed-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov 2017-02-19 17:23:47 -08:00
parent 173e4d81f7
commit 0378008a99
1 changed files with 36 additions and 43 deletions
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77
drivers/input/touchscreen/eeti_ts.c
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@ -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);
unsigned int res;
u16 x, y;
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;
}
/* 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");
@ -210,17 +202,14 @@ 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,
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",
@ -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;
}