Re: [PATCH] Input: atmel_mxt_ts - implement T100 touch object support

From: Benson Leung
Date: Thu Dec 18 2014 - 13:50:08 EST

Hi Nick

On Tue, Dec 9, 2014 at 12:16 PM, Nick Dyer <nick.dyer@xxxxxxxxxxx> wrote:
> Add support for the new T100 object which replaces the previous T9 multitouch
> touchscreen object in recent maXTouch devices. T100 provides improved
> reporting with selectable auxiliary information, and a type field for
> hover/stylus/glove reporting.
>
> Signed-off-by: Nick Dyer <nick.dyer@xxxxxxxxxxx>
> Acked-by: Yufeng Shen <miletus@xxxxxxxxxxxx>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 326 ++++++++++++++++++++++++++++++-
> 1 file changed, 323 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index bb07020..569346e 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -79,6 +79,7 @@
> #define MXT_SPT_DIGITIZER_T43 43
> #define MXT_SPT_MESSAGECOUNT_T44 44
> #define MXT_SPT_CTECONFIG_T46 46
> +#define MXT_TOUCH_MULTITOUCHSCREEN_T100 100
>
> /* MXT_GEN_MESSAGE_T5 object */
> #define MXT_RPTID_NOMSG 0xff
> @@ -188,6 +189,33 @@ struct t9_range {
> #define MXT_RESET_VALUE 0x01
> #define MXT_BACKUP_VALUE 0x55
>
> +/* T100 Multiple Touch Touchscreen */
> +#define MXT_T100_CTRL 0
> +#define MXT_T100_CFG1 1
> +#define MXT_T100_TCHAUX 3
> +#define MXT_T100_XRANGE 13
> +#define MXT_T100_YRANGE 24
> +
> +#define MXT_T100_CFG_SWITCHXY (1 << 5)
> +
> +#define MXT_T100_TCHAUX_VECT (1 << 0)
> +#define MXT_T100_TCHAUX_AMPL (1 << 1)
> +#define MXT_T100_TCHAUX_AREA (1 << 2)
> +
> +#define MXT_T100_DETECT (1 << 7)
> +#define MXT_T100_TYPE_MASK 0x70
> +
> +enum t100_type {
> + MXT_T100_TYPE_FINGER = 1,
> + MXT_T100_TYPE_PASSIVE_STYLUS = 2,
> + MXT_T100_TYPE_HOVERING_FINGER = 4,
> + MXT_T100_TYPE_GLOVE = 5,
> + MXT_T100_TYPE_LARGE_TOUCH = 6,
> +};
> +
> +#define MXT_TOUCH_MAJOR_DEFAULT 1
> +#define MXT_PRESSURE_DEFAULT 1
> +
> /* Delay times */
> #define MXT_BACKUP_TIME 50 /* msec */
> #define MXT_RESET_TIME 200 /* msec */
> @@ -247,6 +275,9 @@ struct mxt_data {
> unsigned int max_y;
> bool in_bootloader;
> u16 mem_size;
> + u8 t100_aux_ampl;
> + u8 t100_aux_area;
> + u8 t100_aux_vect;
> u8 max_reportid;
> u32 config_crc;
> u32 info_crc;
> @@ -268,6 +299,8 @@ struct mxt_data {
> u8 T9_reportid_max;
> u8 T19_reportid;
> u16 T44_address;
> + u8 T100_reportid_min;
> + u8 T100_reportid_max;
>
> /* for fw update in bootloader */
> struct completion bl_completion;
> @@ -761,6 +794,113 @@ static void mxt_proc_t9_message(struct mxt_data *data, u8 *message)
> data->update_input = true;
> }
>
> +static void mxt_proc_t100_message(struct mxt_data *data, u8 *message)
> +{
> + struct device *dev = &data->client->dev;
> + struct input_dev *input_dev = data->input_dev;
> + int id;
> + u8 status;
> + u8 type;
> + int x;
> + int y;
> + int tool;
> + u8 major = 0;
> + u8 pressure = 0;
> + u8 orientation = 0;
> + bool active = false;
> + bool hover = false;
> +
> + id = message[0] - data->T100_reportid_min - 2;
> +
> + /* ignore SCRSTATUS events */
> + if (id < 0)
> + return;
> +
> + status = message[1];
> + x = (message[3] << 8) | message[2];
> + y = (message[5] << 8) | message[4];
> +
> + if (status & MXT_T100_DETECT) {
> + type = (status & MXT_T100_TYPE_MASK) >> 4;
> +
> + switch (type) {
> + case MXT_T100_TYPE_HOVERING_FINGER:
> + hover = true;
> + /* fall through */
> + case MXT_T100_TYPE_FINGER:
> + case MXT_T100_TYPE_GLOVE:
> + active = true;
> + tool = MT_TOOL_FINGER;
> +
> + if (data->t100_aux_area)
> + major = message[data->t100_aux_area];
> + if (data->t100_aux_ampl)
> + pressure = message[data->t100_aux_ampl];
> + if (data->t100_aux_vect)
> + orientation = message[data->t100_aux_vect];
> +
> + break;
> +
> + case MXT_T100_TYPE_PASSIVE_STYLUS:
> + active = true;
> + tool = MT_TOOL_PEN;
> +
> + /* Passive stylus is reported with size zero so
> + * hardcode */
> + major = MXT_TOUCH_MAJOR_DEFAULT;
> +
> + if (data->t100_aux_ampl)
> + pressure = message[data->t100_aux_ampl];
> +
> + break;
> +
> + case MXT_T100_TYPE_LARGE_TOUCH:
> + /* Ignore suppressed touch */
> + break;
> +
> + default:
> + dev_dbg(dev, "Unexpected T100 type\n");
> + return;
> + }
> + }
> +
> + if (hover) {
> + pressure = 0;
> + major = 0;
> + } else if (active) {
> + /*
> + * Values reported should be non-zero if tool is touching the
> + * device
> + */
> + if (pressure == 0)
> + pressure = MXT_PRESSURE_DEFAULT;
> +
> + if (major == 0)
> + major = MXT_TOUCH_MAJOR_DEFAULT;
> + }
> +
> + input_mt_slot(input_dev, id);
> +
> + if (active) {
> + dev_dbg(dev, "[%u] type:%u x:%u y:%u a:%02X p:%02X v:%02X\n",
> + id, type, x, y, major, pressure, orientation);
> +
> + input_mt_report_slot_state(input_dev, tool, 1);
> + input_report_abs(input_dev, ABS_MT_POSITION_X, x);
> + input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
> + input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, major);
> + input_report_abs(input_dev, ABS_MT_PRESSURE, pressure);
> + input_report_abs(input_dev, ABS_MT_ORIENTATION, orientation);
> + } else {
> + dev_dbg(dev, "[%u] release\n", id);
> +
> + /* close out slot */
> + input_mt_report_slot_state(input_dev, 0, 0);
> + }
> +
> + data->update_input = true;
> +}
> +

Dmitry and Chung-Yih have had some discussion about how to handle
hovering fingers, and I think the direction they wanted to go was to
use ABS_MT_DISTANCE instead.

http://www.spinics.net/lists/linux-input/msg33950.html

Chung-Yih's also done some work on the forked chromeos-kernel driver
for this as well, if you want to see :
https://chromium-review.googlesource.com/#/c/219280/


--
Benson Leung
Software Engineer, Chrom* OS
bleung@xxxxxxxxxxxx
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