[PATCH 1/3] Input: migor-ts - convert to a threaded IRQ

[PATCH 1/3] Input: migor-ts - convert to a threaded IRQ

[Dmitry Torokhov]

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
 drivers/input/touchscreen/migor_ts.c |   65 ++++++++++++---------------------
 1 files changed, 24 insertions(+), 41 deletions(-)

diff --git a/drivers/input/touchscreen/migor_ts.c b/drivers/input/touchscreen/migor_ts.c
index 5803bd0..af746b7 100644
--- a/drivers/input/touchscreen/migor_ts.c
+++ b/drivers/input/touchscreen/migor_ts.c
@@ -36,7 +36,6 @@
 struct migor_ts_priv {
 	struct i2c_client *client;
 	struct input_dev *input;
-	struct delayed_work work;
 	int irq;
 };
 
@@ -44,15 +43,24 @@ static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
 					       0x01, 0x06, 0x07, };
 static const u_int8_t migor_ts_dis_seq[17] = { };
 
-static void migor_ts_poscheck(struct work_struct *work)
+static irqreturn_t migor_ts_isr(int irq, void *dev_id)
 {
-	struct migor_ts_priv *priv = container_of(work,
-						  struct migor_ts_priv,
-						  work.work);
+	struct migor_ts_priv *priv = dev_id;
 	unsigned short xpos, ypos;
 	unsigned char event;
 	u_int8_t buf[16];
 
+	/*
+	 * The touch screen controller chip is hooked up to the CPU
+	 * using I2C and a single interrupt line. The interrupt line
+	 * is pulled low whenever someone taps the screen. To deassert
+	 * the interrupt line we need to acknowledge the interrupt by
+	 * communicating with the controller over the slow i2c bus.
+	 *
+	 * Since I2C bus controller may sleep we are using threaded
+	 * IRQ here.
+	 */
+
 	memset(buf, 0, sizeof(buf));
 
 	/* Set Index 0 */
@@ -72,41 +80,25 @@ static void migor_ts_poscheck(struct work_struct *work)
 	xpos = ((buf[11] & 0x03) << 8 | buf[10]);
 	event = buf[12];
 
-	if (event == EVENT_PENDOWN || event == EVENT_REPEAT) {
+	switch (event) {
+	case EVENT_PENDOWN:
+	case EVENT_REPEAT:
 		input_report_key(priv->input, BTN_TOUCH, 1);
 		input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
 		input_report_abs(priv->input, ABS_Y, xpos);
 		input_sync(priv->input);
-	} else if (event == EVENT_PENUP) {
+		break;
+
+	case EVENT_PENUP:
 		input_report_key(priv->input, BTN_TOUCH, 0);
 		input_sync(priv->input);
+		break;
 	}
- out:
-	enable_irq(priv->irq);
-}
-
-static irqreturn_t migor_ts_isr(int irq, void *dev_id)
-{
-	struct migor_ts_priv *priv = dev_id;
-
-	/* the touch screen controller chip is hooked up to the cpu
-	 * using i2c and a single interrupt line. the interrupt line
-	 * is pulled low whenever someone taps the screen. to deassert
-	 * the interrupt line we need to acknowledge the interrupt by
-	 * communicating with the controller over the slow i2c bus.
-	 *
-	 * we can't acknowledge from interrupt context since the i2c
-	 * bus controller may sleep, so we just disable the interrupt
-	 * here and handle the acknowledge using delayed work.
-	 */
-
-	disable_irq_nosync(irq);
-	schedule_delayed_work(&priv->work, HZ / 20);
 
+ out:
 	return IRQ_HANDLED;
 }
 
-
 static int migor_ts_open(struct input_dev *dev)
 {
 	struct migor_ts_priv *priv = input_get_drvdata(dev);
@@ -131,15 +123,6 @@ static void migor_ts_close(struct input_dev *dev)
 
 	disable_irq(priv->irq);
 
-	/* cancel pending work and wait for migor_ts_poscheck() to finish */
-	if (cancel_delayed_work_sync(&priv->work)) {
-		/*
-		 * if migor_ts_poscheck was canceled we need to enable IRQ
-		 * here to balance disable done in migor_ts_isr.
-		 */
-		enable_irq(priv->irq);
-	}
-
 	/* disable controller */
 	i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));
 
@@ -186,15 +169,15 @@ static int migor_ts_probe(struct i2c_client *client,
 
 	priv->client = client;
 	priv->input = input;
-	INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck);
 	priv->irq = client->irq;
 
 	error = input_register_device(input);
 	if (error)
 		goto err1;
 
-	error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW,
-			    client->name, priv);
+	error = request_threaded_irq(priv->irq, NULL, migor_ts_isr,
+                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                     client->name, priv);
 	if (error) {
 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 		goto err2;
-- 
1.7.6.4

[PATCH 2/3] Input: migor-ts - use proper client data accessor functions

[Dmitry Torokhov]

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
 drivers/input/touchscreen/migor_ts.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/migor_ts.c b/drivers/input/touchscreen/migor_ts.c
index af746b7..704169f 100644
--- a/drivers/input/touchscreen/migor_ts.c
+++ b/drivers/input/touchscreen/migor_ts.c
@@ -143,8 +143,6 @@ static int migor_ts_probe(struct i2c_client *client,
 		goto err0;
 	}
 
-	dev_set_drvdata(&client->dev, priv);
-
 	input = input_allocate_device();
 	if (!input) {
 		dev_err(&client->dev, "Failed to allocate input device.\n");
@@ -183,6 +181,7 @@ static int migor_ts_probe(struct i2c_client *client,
 		goto err2;
 	}
 
+	i2c_set_clientdata(client, priv);
 	device_init_wakeup(&client->dev, 1);
 	return 0;
 
@@ -199,7 +198,7 @@ static int migor_ts_probe(struct i2c_client *client,
 
 static int migor_ts_remove(struct i2c_client *client)
 {
-	struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
+	struct migor_ts_priv *priv = i2c_get_clientdata(client);
 
 	free_irq(priv->irq, priv);
 	input_unregister_device(priv->input);
@@ -213,7 +212,7 @@ static int migor_ts_remove(struct i2c_client *client)
 static int migor_ts_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
+	struct migor_ts_priv *priv = i2c_get_clientdata(client);
 
 	if (device_may_wakeup(&client->dev))
 		enable_irq_wake(priv->irq);
@@ -224,7 +223,7 @@ static int migor_ts_suspend(struct device *dev)
 static int migor_ts_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
+	struct migor_ts_priv *priv = i2c_get_clientdata(client);
 
 	if (device_may_wakeup(&client->dev))
 		disable_irq_wake(priv->irq);
-- 
1.7.6.4

[PATCH 3/3] Input: migor-ts - rework probe() to simplify error path

[Dmitry Torokhov]

Register input device last so that we do not have to reset
input device pointer after calling input_unregister_device().

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
 drivers/input/touchscreen/migor_ts.c |   43 ++++++++++++++-------------------
 1 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/drivers/input/touchscreen/migor_ts.c b/drivers/input/touchscreen/migor_ts.c
index 704169f..5226194 100644
--- a/drivers/input/touchscreen/migor_ts.c
+++ b/drivers/input/touchscreen/migor_ts.c
@@ -137,21 +137,20 @@ static int migor_ts_probe(struct i2c_client *client,
 	int error;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv) {
-		dev_err(&client->dev, "failed to allocate driver data\n");
-		error = -ENOMEM;
-		goto err0;
-	}
-
 	input = input_allocate_device();
-	if (!input) {
-		dev_err(&client->dev, "Failed to allocate input device.\n");
+	if (!priv || !input) {
+		dev_err(&client->dev, "failed to allocate memory\n");
 		error = -ENOMEM;
-		goto err1;
+		goto err_free_mem;
 	}
 
+	priv->client = client;
+	priv->input = input;
+	priv->irq = client->irq;
+
 	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
-	input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	__set_bit(BTN_TOUCH, input->keybit);
 
 	input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
 	input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
@@ -165,34 +164,28 @@ static int migor_ts_probe(struct i2c_client *client,
 
 	input_set_drvdata(input, priv);
 
-	priv->client = client;
-	priv->input = input;
-	priv->irq = client->irq;
-
-	error = input_register_device(input);
-	if (error)
-		goto err1;
-
 	error = request_threaded_irq(priv->irq, NULL, migor_ts_isr,
                                      IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                                      client->name, priv);
 	if (error) {
 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
-		goto err2;
+		goto err_free_mem;
 	}
 
+	error = input_register_device(input);
+	if (error)
+		goto err_free_irq;
+
 	i2c_set_clientdata(client, priv);
 	device_init_wakeup(&client->dev, 1);
+
 	return 0;
 
- err2:
-	input_unregister_device(input);
-	input = NULL; /* so we dont try to free it below */
- err1:
+ err_free_irq:
+	free_irq(priv->irq, priv);
+ err_free_mem:
 	input_free_device(input);
 	kfree(priv);
- err0:
-	dev_set_drvdata(&client->dev, NULL);
 	return error;
 }
 
-- 
1.7.6.4