Re: [PATCH v5 2/7] Input: pixcir_i2c_ts - initialize interrupt mode and power mode

[Dmitry Torokhov]

On Tue, May 06, 2014 at 02:06:07PM +0300, Roger Quadros wrote:
> Introduce helper functions to configure power and interrupt registers.
> Default to IDLE mode on probe as device supports auto wakeup to ACVIE mode
> on detecting finger touch.
> 
> Configure interrupt mode and polarity on start up.  Power down on device
> closure or module removal.
> 
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> Acked-by: Mugunthan V N <mugunthanvnm@xxxxxx>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>

Applied, thank you.

> ---
>  drivers/input/touchscreen/pixcir_i2c_ts.c | 182 ++++++++++++++++++++++++++++--
>  include/linux/input/pixcir_ts.h           |  42 +++++++
>  2 files changed, 216 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
> index 8a083bd..96a1b1e 100644
> --- a/drivers/input/touchscreen/pixcir_i2c_ts.c
> +++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
> @@ -29,7 +29,7 @@ struct pixcir_i2c_ts_data {
>  	struct i2c_client *client;
>  	struct input_dev *input;
>  	const struct pixcir_ts_platform_data *chip;
> -	bool exiting;
> +	bool running;
>  };
>  
>  static void pixcir_ts_poscheck(struct pixcir_i2c_ts_data *data)
> @@ -88,7 +88,7 @@ static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
>  {
>  	struct pixcir_i2c_ts_data *tsdata = dev_id;
>  
> -	while (!tsdata->exiting) {
> +	while (tsdata->running) {
>  		pixcir_ts_poscheck(tsdata);
>  
>  		if (tsdata->chip->attb_read_val())
> @@ -100,6 +100,164 @@ static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> +static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
> +				 enum pixcir_power_mode mode)
> +{
> +	struct device *dev = &ts->client->dev;
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't read reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_POWER_MODE, ret);
> +		return ret;
> +	}
> +
> +	ret &= ~PIXCIR_POWER_MODE_MASK;
> +	ret |= mode;
> +
> +	/* Always AUTO_IDLE */
> +	ret |= PIXCIR_POWER_ALLOW_IDLE;
> +
> +	ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't write reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_POWER_MODE, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * Set the interrupt mode for the device i.e. ATTB line behaviour
> + *
> + * @polarity : 1 for active high, 0 for active low.
> + */
> +static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
> +			       enum pixcir_int_mode mode, bool polarity)
> +{
> +	struct device *dev = &ts->client->dev;
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't read reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_INT_MODE, ret);
> +		return ret;
> +	}
> +
> +	ret &= ~PIXCIR_INT_MODE_MASK;
> +	ret |= mode;
> +
> +	if (polarity)
> +		ret |= PIXCIR_INT_POL_HIGH;
> +	else
> +		ret &= ~PIXCIR_INT_POL_HIGH;
> +
> +	ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't write reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_INT_MODE, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * Enable/disable interrupt generation
> + */
> +static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
> +{
> +	struct device *dev = &ts->client->dev;
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't read reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_INT_MODE, ret);
> +		return ret;
> +	}
> +
> +	if (enable)
> +		ret |= PIXCIR_INT_ENABLE;
> +	else
> +		ret &= ~PIXCIR_INT_ENABLE;
> +
> +	ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
> +	if (ret < 0) {
> +		dev_err(dev, "%s: can't write reg 0x%x : %d\n",
> +			__func__, PIXCIR_REG_INT_MODE, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int pixcir_start(struct pixcir_i2c_ts_data *ts)
> +{
> +	struct device *dev = &ts->client->dev;
> +	int error;
> +
> +	/* LEVEL_TOUCH interrupt with active low polarity */
> +	error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
> +	if (error) {
> +		dev_err(dev, "Failed to set interrupt mode: %d\n", error);
> +		return error;
> +	}
> +
> +	ts->running = true;
> +	mb();	/* Update status before IRQ can fire */
> +
> +	/* enable interrupt generation */
> +	error = pixcir_int_enable(ts, true);
> +	if (error) {
> +		dev_err(dev, "Failed to enable interrupt generation: %d\n",
> +			error);
> +		return error;
> +	}
> +
> +	return 0;
> +}
> +
> +static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
> +{
> +	int error;
> +
> +	/* Disable interrupt generation */
> +	error = pixcir_int_enable(ts, false);
> +	if (error) {
> +		dev_err(&ts->client->dev,
> +			"Failed to disable interrupt generation: %d\n",
> +			error);
> +		return error;
> +	}
> +
> +	/* Exit ISR if running, no more report parsing */
> +	ts->running = false;
> +	mb();	/* update status before we synchronize irq */
> +
> +	/* Wait till running ISR is complete */
> +	synchronize_irq(ts->client->irq);
> +
> +	return 0;
> +}
> +
> +static int pixcir_input_open(struct input_dev *dev)
> +{
> +	struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
> +
> +	return pixcir_start(ts);
> +}
> +
> +static void pixcir_input_close(struct input_dev *dev)
> +{
> +	struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
> +
> +	pixcir_stop(ts);
> +}
> +
>  #ifdef CONFIG_PM_SLEEP
>  static int pixcir_i2c_ts_suspend(struct device *dev)
>  {
> @@ -156,6 +314,8 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
>  
>  	input->name = client->name;
>  	input->id.bustype = BUS_I2C;
> +	input->open = pixcir_input_open;
> +	input->close = pixcir_input_close;
>  	input->dev.parent = &client->dev;
>  
>  	__set_bit(EV_KEY, input->evbit);
> @@ -176,11 +336,22 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
>  		return error;
>  	}
>  
> +	/* Always be in IDLE mode to save power, device supports auto wake */
> +	error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
> +	if (error) {
> +		dev_err(dev, "Failed to set IDLE mode\n");
> +		return error;
> +	}
> +
> +	/* Stop device till opened */
> +	error = pixcir_stop(tsdata);
> +	if (error)
> +		return error;
> +
>  	error = input_register_device(input);
>  	if (error)
>  		return error;
>  
> -	i2c_set_clientdata(client, tsdata);
>  	device_init_wakeup(&client->dev, 1);
>  
>  	return 0;
> @@ -188,13 +359,8 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
>  
>  static int pixcir_i2c_ts_remove(struct i2c_client *client)
>  {
> -	struct pixcir_i2c_ts_data *tsdata = i2c_get_clientdata(client);
> -
>  	device_init_wakeup(&client->dev, 0);
>  
> -	tsdata->exiting = true;
> -	mb();
> -
>  	return 0;
>  }
>  
> diff --git a/include/linux/input/pixcir_ts.h b/include/linux/input/pixcir_ts.h
> index 7163d91..7942804 100644
> --- a/include/linux/input/pixcir_ts.h
> +++ b/include/linux/input/pixcir_ts.h
> @@ -1,6 +1,48 @@
>  #ifndef	_PIXCIR_I2C_TS_H
>  #define	_PIXCIR_I2C_TS_H
>  
> +/*
> + * Register map
> + */
> +#define PIXCIR_REG_POWER_MODE	51
> +#define PIXCIR_REG_INT_MODE	52
> +
> +/*
> + * Power modes:
> + * active: max scan speed
> + * idle: lower scan speed with automatic transition to active on touch
> + * halt: datasheet says sleep but this is more like halt as the chip
> + *       clocks are cut and it can only be brought out of this mode
> + *	 using the RESET pin.
> + */
> +enum pixcir_power_mode {
> +	PIXCIR_POWER_ACTIVE,
> +	PIXCIR_POWER_IDLE,
> +	PIXCIR_POWER_HALT,
> +};
> +
> +#define PIXCIR_POWER_MODE_MASK	0x03
> +#define PIXCIR_POWER_ALLOW_IDLE (1UL << 2)
> +
> +/*
> + * Interrupt modes:
> + * periodical: interrupt is asserted periodicaly
> + * diff coordinates: interrupt is asserted when coordinates change
> + * level on touch: interrupt level asserted during touch
> + * pulse on touch: interrupt pulse asserted druing touch
> + *
> + */
> +enum pixcir_int_mode {
> +	PIXCIR_INT_PERIODICAL,
> +	PIXCIR_INT_DIFF_COORD,
> +	PIXCIR_INT_LEVEL_TOUCH,
> +	PIXCIR_INT_PULSE_TOUCH,
> +};
> +
> +#define PIXCIR_INT_MODE_MASK	0x03
> +#define PIXCIR_INT_ENABLE	(1UL << 3)
> +#define PIXCIR_INT_POL_HIGH	(1UL << 2)
> +
>  struct pixcir_ts_platform_data {
>  	int (*attb_read_val)(void);
>  	int x_max;
> -- 
> 1.8.3.2
> 

-- 
Dmitry
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