On Tue, Dec 18, 2018 at 09:36:00AM +0100, Richard Leitner wrote:
> The sx8654 features a NRST input which may be connected to a GPIO.
> Therefore add support for hard-resetting the sx8654 via this NRST.
>
> If the reset-gpio property is provided the sx8654 is resetted via NRST
> instead of the soft-reset via I2C.
>
> Signed-off-by: Richard Leitner <[email protected]>
> ---
> drivers/input/touchscreen/sx8654.c | 40
> +++++++++++++++++++++++++++++++++++---
> 1 file changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/touchscreen/sx8654.c
> b/drivers/input/touchscreen/sx8654.c
> index ed29db3ec731..238f56b1581b 100644
> --- a/drivers/input/touchscreen/sx8654.c
> +++ b/drivers/input/touchscreen/sx8654.c
> @@ -33,6 +33,8 @@
> #include <linux/i2c.h>
> #include <linux/interrupt.h>
> #include <linux/irq.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/delay.h>
>
> /* register addresses */
> #define I2C_REG_TOUCH0 0x00
> @@ -74,6 +76,7 @@
> struct sx8654 {
> struct input_dev *input;
> struct i2c_client *client;
> + struct gpio_desc *gpio_reset;
> };
>
> static irqreturn_t sx8654_irq(int irq, void *handle)
> @@ -124,6 +127,27 @@ static irqreturn_t sx8654_irq(int irq, void *handle)
> return IRQ_HANDLED;
> }
>
> +static int sx8654_reset(struct sx8654 *ts)
> +{
> + int err;
> +
> + if (ts->gpio_reset) {
> + gpiod_set_value_cansleep(ts->gpio_reset, 1);
> + udelay(2); /* Tpulse > 1µs */
> + gpiod_set_value_cansleep(ts->gpio_reset, 0);
> +
> + return 0;
I rearranged code a bit to avoid this early return and applied. Thank
you.
> + }
> +
> + dev_dbg(&ts->client->dev, "NRST unavailable, try softreset\n");
> + err = i2c_smbus_write_byte_data(ts->client, I2C_REG_SOFTRESET,
> + SOFTRESET_VALUE);
> + if (err)
> + return err;
> + else
> + return 0;
> +}
> +
> static int sx8654_open(struct input_dev *dev)
> {
> struct sx8654 *sx8654 = input_get_drvdata(dev);
> @@ -186,6 +210,17 @@ static int sx8654_probe(struct i2c_client *client,
> if (!sx8654)
> return -ENOMEM;
>
> + sx8654->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(sx8654->gpio_reset)) {
> + error = PTR_ERR(sx8654->gpio_reset);
> + if (error != -EPROBE_DEFER)
> + dev_err(&client->dev, "unable to get reset-gpio: %d\n",
> + error);
> + return error;
> + }
> + dev_dbg(&client->dev, "got GPIO reset pin\n");
> +
> input = devm_input_allocate_device(&client->dev);
> if (!input)
> return -ENOMEM;
> @@ -206,10 +241,9 @@ static int sx8654_probe(struct i2c_client *client,
>
> input_set_drvdata(sx8654->input, sx8654);
>
> - error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET,
> - SOFTRESET_VALUE);
> + error = sx8654_reset(sx8654);
> if (error) {
> - dev_err(&client->dev, "writing softreset value failed");
> + dev_err(&client->dev, "reset failed");
> return error;
> }
>
> --
> 2.11.0
>
--
Dmitry
