On Sun, Aug 29, 2021 at 07:19:18PM +1000, Alistair Francis wrote:
> When we query the device let's also read the descriptor from the device.
> This tells us useful information, including the version, which we use to
> determine a generation.
>
> This is based on the driver from Wacom.
>
> Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx>
> ---
> drivers/input/touchscreen/wacom_i2c.c | 64 +++++++++++++++++++++++++++
> 1 file changed, 64 insertions(+)
>
> diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
> index 28255c77d426..72ba4a36459b 100644
> --- a/drivers/input/touchscreen/wacom_i2c.c
> +++ b/drivers/input/touchscreen/wacom_i2c.c
> @@ -16,6 +16,7 @@
> #include <linux/of.h>
> #include <asm/unaligned.h>
>
> +#define WACOM_DESC_REG 0x01
> #define WACOM_CMD_QUERY0 0x04
> #define WACOM_CMD_QUERY1 0x00
> #define WACOM_CMD_QUERY2 0x33
> @@ -24,11 +25,46 @@
> #define WACOM_CMD_THROW1 0x00
> #define WACOM_QUERY_SIZE 19
>
> +#define WACOM_MAX_DATA_SIZE_BG9 10
> +#define WACOM_MAX_DATA_SIZE_G12 15
> +#define WACOM_MAX_DATA_SIZE_AG14 17
> +#define WACOM_MAX_DATA_SIZE 22
> +
> +/* Generation selction */
> +/* Before and at G9 generation */
> +#define WACOM_BG9 0
> +/* G12 generation the IC supports "height"*/
> +#define WACOM_G12 1
> +/* After and at G14 generation the IC supports "height" and
> + * it is defined as "Z" axis
> + */
> +#define WACOM_AG14 2
> +
> +struct wacom_desc {
> + u16 descLen;
> + u16 version;
> + u16 reportLen;
> + u16 reportReg;
> + u16 inputReg;
> + u16 maxInputLen;
> + u16 outputReg;
> + u16 maxOutputLen;
> + u16 commReg;
> + u16 dataReg;
> + u16 vendorID;
> + u16 productID;
> + u16 fwVersion;
> + u16 misc_high;
> + u16 misc_low;
> +};
This looks like I2C HID descriptor. Is the device actually I2C HID
compatible? If so we should use that and abandon this driver.
Ping, Tatsunosuke, please advise.
Thanks.
--
Dmitry
