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

From: Dmitry Torokhov
Date: Mon May 19 2014 - 01:55:22 EST


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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