Hi Haibo,
On Tue, Feb 11, 2020 at 04:41:11PM +0800, haibo.chen@xxxxxxx wrote:
> From: Haibo Chen <haibo.chen@xxxxxxx>
>
> For HannStar (HSD100PXN1 Rev: 1-A00C11 F/W:0634) LVDS touch screen,
> it has a special request for the EETI touch controller. The host
> needs to trigger I2C event to device FW at booting first, and then
> the FW can switch to I2C interface. Otherwise, the FW can’t work
> with I2C interface, and can't generate any interrupt when touch
> the screen.
>
> This patch send an I2C command before the device wake up, make sure
> the device switch to I2C interface first.
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
> ---
> drivers/input/touchscreen/egalax_ts.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
> index 83ac8c128192..5e35ca5edc7b 100644
> --- a/drivers/input/touchscreen/egalax_ts.c
> +++ b/drivers/input/touchscreen/egalax_ts.c
> @@ -183,6 +183,20 @@ static int egalax_ts_probe(struct i2c_client *client,
> ts->client = client;
> ts->input_dev = input_dev;
>
> + /* HannStar (HSD100PXN1 Rev: 1-A00C11 F/W:0634) LVDS touch
> + * screen needs to trigger I2C event to device FW at booting
> + * first, and then the FW can switch to I2C interface.
> + * Otherwise, the FW can’t work with I2C interface. So here
> + * just use the exist function egalax_firmware_version() to
> + * send a I2C command to the device, make sure the device FW
> + * switch to I2C interface.
> + */
> + error = egalax_firmware_version(client);
> + if (error) {
> + dev_err(&client->dev, "Failed to switch to I2C interface\n");
> + return error;
> + }
> +
> /* controller may be in sleep, wake it up. */
> error = egalax_wake_up_device(client);
> if (error) {
I think this should be part of egalax_wake_up_device(), in case where we
do not have dedicated reset gpio. Also, instead of abusing firmware
read, would a dummy byte read be enough (i2c_probe_func_quick_read)?
Thanks.
--
Dmitry
