Re: [PATCH v3 1/8] Input: atmel_mxt_ts - add support for T37 diagnostic data

Dmitry Torokhov
2016-06-01T18:12:17Z

Hi Nick,

On Wed, Jun 01, 2016 at 05:39:45PM +0100, Nick Dyer wrote:
> Atmel maXTouch devices have a T37 object which can be used to read raw
> touch deltas from the device. This consists of an array of 16-bit
> integers, one for each node on the touchscreen matrix.
>
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 152 +++++++++++++++++++++++++++++++
> 1 file changed, 152 insertions(+)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index 5af7907..21f42ed 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -124,6 +124,17 @@ struct t9_range {
> #define MXT_COMMS_CTRL 0
> #define MXT_COMMS_CMD 1
>
> +/* MXT_DEBUG_DIAGNOSTIC_T37 */
> +#define MXT_DIAGNOSTIC_PAGEUP 0x01
> +#define MXT_DIAGNOSTIC_DELTAS 0x10
> +#define MXT_DIAGNOSTIC_SIZE 128
> +
> +struct t37_debug {
> + u8 mode;
> + u8 page;
> + u8 data[MXT_DIAGNOSTIC_SIZE];
> +};
> +
> /* Define for MXT_GEN_COMMAND_T6 */
> #define MXT_BOOT_VALUE 0xa5
> #define MXT_RESET_VALUE 0x01
> @@ -205,6 +216,14 @@ struct mxt_object {
> u8 num_report_ids;
> } __packed;
>
> +struct mxt_dbg {
> + u16 t37_address;
> + u16 diag_cmd_address;
> + struct t37_debug *t37_buf;
> + unsigned int t37_pages;
> + unsigned int t37_nodes;
> +};
> +
> /* Each client has this additional data */
> struct mxt_data {
> struct i2c_client *client;
> @@ -233,6 +252,7 @@ struct mxt_data {
> u8 num_touchids;
> u8 multitouch;
> struct t7_config t7_cfg;
> + struct mxt_dbg dbg;
>
> /* Cached parameters from object table */
> u16 T5_address;
> @@ -2043,6 +2063,136 @@ recheck:
> return 0;
> }
>
> +static u16 mxt_get_debug_value(struct mxt_data *data, unsigned int x,
> + unsigned int y)
> +{
> + struct mxt_dbg *dbg = &data->dbg;
> + unsigned int ofs, page;
> +
> + ofs = (y + (x * data->info.matrix_ysize)) * sizeof(u16);
> + page = ofs / MXT_DIAGNOSTIC_SIZE;
> + ofs %= MXT_DIAGNOSTIC_SIZE;
> +
> + return get_unaligned_le16(&dbg->t37_buf[page].data[ofs]);
> +}
> +
> +static int mxt_convert_debug_pages(struct mxt_data *data, u16 *outbuf)
> +{
> + struct mxt_dbg *dbg = &data->dbg;
> + unsigned int x = 0;
> + unsigned int y = 0;
> + unsigned int i;
> +
> + for (i = 0; i < dbg->t37_nodes; i++) {
> + outbuf[i] = mxt_get_debug_value(data, x, y);
> +
> + /* Next value */
> + if (++x >= data->info.matrix_xsize) {
> + x = 0;
> + y++;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int mxt_read_diagnostic_debug(struct mxt_data *data, u8 mode,
> + u16 *outbuf)
> +{
> + struct mxt_dbg *dbg = &data->dbg;
> + int retries = 0;
> + int page;
> + int ret;
> + u8 cmd = mode;
> + struct t37_debug *p;
> + u8 cmd_poll;
> +
> + for (page = 0; page < dbg->t37_pages; page++) {
> + p = dbg->t37_buf + page;
> +
> + ret = mxt_write_reg(data->client, dbg->diag_cmd_address,
> + cmd);
> + if (ret)
> + return ret;
> +
> + retries = 0;
> + msleep(20);
> +wait_cmd:
> + /* Read back command byte */
> + ret = __mxt_read_reg(data->client, dbg->diag_cmd_address,
> + sizeof(cmd_poll), &cmd_poll);
> + if (ret)
> + return ret;
> +
> + /* Field is cleared once the command has been processed */
> + if (cmd_poll) {
> + if (retries++ > 100)
> + return -EINVAL;
> +
> + msleep(20);
> + goto wait_cmd;
> + }
> +
> + /* Read T37 page */
> + ret = __mxt_read_reg(data->client, dbg->t37_address,
> + sizeof(struct t37_debug), p);
> + if (ret)
> + return ret;
> +
> + if ((p->mode != mode) || (p->page != page)) {

No need for extra parenthesis.

> + dev_err(&data->client->dev, "T37 page mismatch\n");
> + return -EINVAL;
> + }
> +
> + dev_dbg(&data->client->dev, "%s page:%d retries:%d\n",
> + __func__, page, retries);
> +
> + /* For remaining pages, write PAGEUP rather than mode */
> + cmd = MXT_DIAGNOSTIC_PAGEUP;
> + }
> +
> + return mxt_convert_debug_pages(data, outbuf);
> +}
> +
> +static void mxt_debug_init(struct mxt_data *data)
> +{
> + struct mxt_dbg *dbg = &data->dbg;
> + struct mxt_object *object;
> +
> + object = mxt_get_object(data, MXT_GEN_COMMAND_T6);
> + if (!object)
> + return;
> +
> + dbg->diag_cmd_address = object->start_address + MXT_COMMAND_DIAGNOSTIC;
> +
> + object = mxt_get_object(data, MXT_DEBUG_DIAGNOSTIC_T37);
> + if (!object)
> + return;
> +
> + if (mxt_obj_size(object) != sizeof(struct t37_debug)) {
> + dev_warn(&data->client->dev, "Bad T37 size");
> + return;
> + }
> +
> + dbg->t37_address = object->start_address;
> +
> + /* Calculate size of data and allocate buffer */
> + dbg->t37_nodes = data->info.matrix_xsize * data->info.matrix_ysize;
> + dbg->t37_pages = dbg->t37_nodes * sizeof(u16)
> + / sizeof(dbg->t37_buf->data) + 1;
> +
> + dbg->t37_buf = devm_kzalloc(&data->client->dev,
> + sizeof(struct t37_debug) * dbg->t37_pages,
> + GFP_KERNEL);

devm_kcalloc() or devm_kmalloc_array() if memory does not need to be
zeroed out.

> + if (!dbg->t37_buf)
> + goto error;
> +
> + return;
> +
> +error:
> + dev_err(&data->client->dev, "Error initialising T37 diagnostic data\n");

Why do we only emit this message if memory allocation fails? And if it
is intentional why don't we do it inline?

> +}
> +
> static int mxt_configure_objects(struct mxt_data *data,
> const struct firmware *cfg)
> {
> @@ -2070,6 +2220,8 @@ static int mxt_configure_objects(struct mxt_data *data,
> dev_warn(dev, "No touch object detected\n");
> }
>
> + mxt_debug_init(data);
> +
> dev_info(dev,
> "Family: %u Variant: %u Firmware V%u.%u.%02X Objects: %u\n",
> info->family_id, info->variant_id, info->version >> 4,
> --
> 2.5.0
>

Thanks.

--
Dmitry