On Wed, Oct 13, 2021 at 1:10 PM Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
>
> Hi Alistair,
>
> On Sat, Oct 09, 2021 at 09:37:06PM +1000, Alistair Francis wrote:
> > Improve the query device fields to be more verbose.
> >
> > Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx>
> > ---
> > drivers/input/touchscreen/wacom_i2c.c | 49 ++++++++++++++++-----------
> > 1 file changed, 30 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
> > index 22826c387da5..8d7267ccc661 100644
> > --- a/drivers/input/touchscreen/wacom_i2c.c
> > +++ b/drivers/input/touchscreen/wacom_i2c.c
> > @@ -14,13 +14,21 @@
> > #include <linux/interrupt.h>
> > #include <asm/unaligned.h>
> >
> > -#define WACOM_CMD_QUERY0 0x04
> > -#define WACOM_CMD_QUERY1 0x00
> > -#define WACOM_CMD_QUERY2 0x33
> > -#define WACOM_CMD_QUERY3 0x02
> > -#define WACOM_CMD_THROW0 0x05
> > -#define WACOM_CMD_THROW1 0x00
> > -#define WACOM_QUERY_SIZE 19
> > +// Registers
> > +#define WACOM_COMMAND_LSB 0x04
> > +#define WACOM_COMMAND_MSB 0x00
> > +
> > +#define WACOM_DATA_LSB 0x05
> > +#define WACOM_DATA_MSB 0x00
> > +
> > +// Report types
> > +#define REPORT_FEATURE 0x30
> > +
> > +// Requests / operations
> > +#define OPCODE_GET_REPORT 0x02
> > +
> > +#define WACOM_QUERY_REPORT 3
> > +#define WACOM_QUERY_SIZE 22
> >
> > struct wacom_features {
> > int x_max;
> > @@ -41,27 +49,30 @@ static int wacom_query_device(struct i2c_client *client,
> > struct wacom_features *features)
> > {
> > int ret;
> > - u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
> > - WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
> > - u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
> > u8 data[WACOM_QUERY_SIZE];
> > +
> > + u8 get_query_data_cmd[] = {
> > + WACOM_COMMAND_LSB,
> > + WACOM_COMMAND_MSB,
> > + REPORT_FEATURE | WACOM_QUERY_REPORT,
> > + OPCODE_GET_REPORT,
> > + WACOM_DATA_LSB,
> > + WACOM_DATA_MSB,
> > + };
> > +
> > struct i2c_msg msgs[] = {
> > + // Request reading of feature ReportID: 3 (Pen Query Data)
> > {
> > .addr = client->addr,
> > .flags = 0,
> > - .len = sizeof(cmd1),
> > - .buf = cmd1,
> > - },
> > - {
> > - .addr = client->addr,
> > - .flags = 0,
> > - .len = sizeof(cmd2),
> > - .buf = cmd2,
> > + .len = sizeof(get_query_data_cmd),
> > + .buf = get_query_data_cmd,
> > },
> > + // Read 21 bytes
> > {
> > .addr = client->addr,
> > .flags = I2C_M_RD,
> > - .len = sizeof(data),
> > + .len = WACOM_QUERY_SIZE - 1,
>
> Why is this change? If we are indeed supposed to read 1 byte less this
> should be a separate patch.
It shouldn't be a change, we are still reading 21 bytes of data. We
are just using a macro instead of sizeof().
Alistair
