Re: [PATCH RESEND 1/1] Add support for touch screens using the General Touch ST6001S controller.

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Gareth,

On Sun, Oct 03, 2021 at 10:54:21PM +0100, Gareth Randall wrote:
> Add support for touch screens using the General Touch ST6001S
> controller, as found in the GPEG model AOD22WZ-ST monitor.
> This controller can output the ELO 10-byte protocol,
> but requires different initialisation.
> 
> Signed-off-by: Gareth Randall <gareth@garethrandall.com>
> ---
>  drivers/input/touchscreen/elo.c | 58 +++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/elo.c
> b/drivers/input/touchscreen/elo.c
> index 96173232e53f..8c15e0eea6b4 100644
> --- a/drivers/input/touchscreen/elo.c
> +++ b/drivers/input/touchscreen/elo.c
> @@ -44,6 +44,8 @@ MODULE_LICENSE("GPL");
>  #define ELO10_ACK_PACKET	'A'
>  #define ELI10_ID_PACKET		'I'
> 
> +#define ELO_GT_INIT_PACKET	"\001XfE\r"
> +
>  /*
>   * Per-touchscreen data.
>   */
> @@ -201,6 +203,7 @@ static irqreturn_t elo_interrupt(struct serio *serio,
> 
>  	switch (elo->id) {
>  	case 0:
> +	case 4:
>  		elo_process_data_10(elo, data);
>  		break;
> 
> @@ -255,6 +258,54 @@ static int elo_command_10(struct elo *elo, unsigned
> char *packet)
>  	return rc;
>  }
> 
> +/*
> + * Initialise the General Touch ST6001S controller.
> + */
> +static int elo_command_10_gt(struct elo *elo)
> +{
> +	int rc = -1;
> +	int i;
> +	unsigned char *packet = ELO_GT_INIT_PACKET;
> +
> +	mutex_lock(&elo->cmd_mutex);
> +
> +	serio_pause_rx(elo->serio);
> +	init_completion(&elo->cmd_done);
> +	serio_continue_rx(elo->serio);
> +
> +	for (i = 0; i < (int)strlen(packet); i++) {
> +		if (serio_write(elo->serio, packet[i]))
> +			goto out;
> +	}
> +
> +	wait_for_completion_timeout(&elo->cmd_done, HZ);
> +	rc = 0;
> +
> + out:
> +	mutex_unlock(&elo->cmd_mutex);
> +	return rc;
> +}
> +
> +static int elo_setup_10_gt(struct elo *elo)
> +{
> +	struct input_dev *dev = elo->dev;
> +
> +	if (elo_command_10_gt(elo))
> +		return -1;

		return -EIO;

> +
> +	__set_bit(INPUT_PROP_DIRECT, dev->propbit);

Please make this a separate patch that would set this property for all
variants of ELO touchscreens (i.e. move it into elo_connect()).

> +
> +	// Values taken from a GPEG model AOD22WZ-ST monitor
> +	input_set_abs_params(dev, ABS_X, 1365, 5828, 0, 0);

I believe the datasheet says that the touch resolution is 4096 x 4096:
http://www.boardcon.com/download/LCD_datasheet/15inch_SAW_LCD/Serial%20Controller%20ST6001S%20SPEC.pdf



> +	// max and min inverted because screen axis is inverted
> +	input_set_abs_params(dev, ABS_Y, 5013, 2260, 0, 0);

I dont think this changes anything for reported coordinates by the
driver.

> +
> +	dev_info(&elo->serio->dev,
> +		 "GeneralTouch ST6001S touchscreen");
> +
> +	return 0;
> +}
> +
>  static int elo_setup_10(struct elo *elo)
>  {
>  	static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
> @@ -361,6 +412,13 @@ static int elo_connect(struct serio *serio, struct
> serio_driver *drv)
>  		input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
>  		input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
>  		break;
> +
> +	case 4: /* 10-byte protocol with General Touch initialisation */
> +		if (elo_setup_10_gt(elo)) {
> +			err = -EIO;
> +			goto fail3;
> +		}
> +		break;
>  	}
> 
>  	err = input_register_device(elo->dev);
> -- 
> 2.27.0

Thanks.

-- 
Dmitry