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Message-ID: <CAGS+omCHJjHeo7cjhVADxP8c0nThjKOfvkdcbPC7eMHFdWfqjQ@mail.gmail.com>
Date: Mon, 19 Mar 2012 17:06:10 +0800
From: Daniel Kurtz <djkurtz@...omium.org>
To: Henrik Rydberg <rydberg@...omail.se>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Joonyoung Shim <jy0922.shim@...sung.com>,
Iiro Valkonen <iiro.valkonen@...el.com>,
linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
Benson Leung <bleung@...omium.org>,
Yufeng Shen <miletus@...omium.org>
Subject: Re: [PATCH 12/20] Input: atmel_mxt_ts - simplify event reporting
On Mon, Mar 19, 2012 at 4:26 PM, Henrik Rydberg <rydberg@...omail.se> wrote:
> Hi Daniel,
>
>> Instead of carrying around per-finger state in the driver instance, just
>> report each finger as it arrives to the input layer, and let the input
>> layer (evdev) hold the event state (which it does anyway).
>>
>> Also, the atmel pad reports "amplitude", which is reported to userspace
>> using the "PRESSURE" event type. The variables now reflect this.
>>
>> Note: this driver does not really do MT-B properly. Each input report
>> (a goup of input events followed by a SYN_REPORT) only contains data for
>> a single contact. When multiple fingers are present on a device, each is
>> properly reported in its own MT_SLOT. However, there is only ever one
>> MT_SLOT per SYN_REPORT. This is fixed in a subsequent patch.
>>
>> Signed-off-by: Daniel Kurtz <djkurtz@...omium.org>
>> ---
>
> Simplification looking good overall, together with that later
> patch. Please find some comments below.
>
>> drivers/input/touchscreen/atmel_mxt_ts.c | 122 +++++++++---------------------
>> 1 files changed, 36 insertions(+), 86 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
>> index 4363511..fa692e5 100644
>> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
>> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
>> @@ -194,6 +194,7 @@
>> #define MXT_BOOT_STATUS_MASK 0x3f
>>
>> /* Touch status */
>> +#define MXT_UNGRIP (1 << 0)
>> #define MXT_SUPPRESS (1 << 1)
>> #define MXT_AMP (1 << 2)
>> #define MXT_VECTOR (1 << 3)
>> @@ -238,14 +239,6 @@ struct mxt_message {
>> u8 message[7];
>> };
>>
>> -struct mxt_finger {
>> - int status;
>> - int x;
>> - int y;
>> - int area;
>> - int pressure;
>> -};
>> -
>> /* Each client has this additional data */
>> struct mxt_data {
>> struct i2c_client *client;
>> @@ -253,7 +246,6 @@ struct mxt_data {
>> const struct mxt_platform_data *pdata;
>> struct mxt_object *object_table;
>> struct mxt_info info;
>> - struct mxt_finger finger[MXT_MAX_FINGER];
>> unsigned int irq;
>> unsigned int max_x;
>> unsigned int max_y;
>> @@ -526,97 +518,55 @@ static int mxt_write_object(struct mxt_data *data,
>> return mxt_write_reg(data->client, reg + offset, 1, &val);
>> }
>>
>> -static void mxt_input_report(struct mxt_data *data, int single_id)
>> -{
>> - struct mxt_finger *finger = data->finger;
>> - struct input_dev *input_dev = data->input_dev;
>> - int status = finger[single_id].status;
>> - int finger_num = 0;
>> - int id;
>> -
>> - for (id = 0; id < MXT_MAX_FINGER; id++) {
>> - if (!finger[id].status)
>> - continue;
>> -
>> - input_mt_slot(input_dev, id);
>> - input_mt_report_slot_state(input_dev, MT_TOOL_FINGER,
>> - finger[id].status != MXT_RELEASE);
>> -
>> - if (finger[id].status != MXT_RELEASE) {
>> - finger_num++;
>> - input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
>> - finger[id].area);
>> - input_report_abs(input_dev, ABS_MT_POSITION_X,
>> - finger[id].x);
>> - input_report_abs(input_dev, ABS_MT_POSITION_Y,
>> - finger[id].y);
>> - input_report_abs(input_dev, ABS_MT_PRESSURE,
>> - finger[id].pressure);
>> - } else {
>> - finger[id].status = 0;
>> - }
>> - }
>> -
>> - input_report_key(input_dev, BTN_TOUCH, finger_num > 0);
>> -
>> - if (status != MXT_RELEASE) {
>> - input_report_abs(input_dev, ABS_X, finger[single_id].x);
>> - input_report_abs(input_dev, ABS_Y, finger[single_id].y);
>> - input_report_abs(input_dev,
>> - ABS_PRESSURE, finger[single_id].pressure);
>> - }
>> -
>> - input_sync(input_dev);
>> -}
>> -
>> static void mxt_input_touchevent(struct mxt_data *data,
>> - struct mxt_message *message, int id)
>> + struct mxt_message *message, int id)
>> {
>> - struct mxt_finger *finger = data->finger;
>> struct device *dev = &data->client->dev;
>> - u8 status = message->message[0];
>> + struct input_dev *input_dev = data->input_dev;
>> + u8 status;
>> int x;
>> int y;
>> int area;
>> - int pressure;
>> -
>> - /* Check the touch is present on the screen */
>> - if (!(status & MXT_DETECT)) {
>> - if (status & MXT_RELEASE) {
>> - dev_dbg(dev, "[%d] released\n", id);
>> -
>> - finger[id].status = MXT_RELEASE;
>> - mxt_input_report(data, id);
>> - }
>> - return;
>> - }
>> -
>> - /* Check only AMP detection */
>> - if (!(status & (MXT_PRESS | MXT_MOVE)))
>> - return;
>> + int amplitude;
>>
>> + status = message->message[0];
>> x = (message->message[1] << 4) | ((message->message[3] >> 4) & 0xf);
>> y = (message->message[2] << 4) | ((message->message[3] & 0xf));
>> if (data->max_x < 1024)
>> - x = x >> 2;
>> + x >>= 2;
>> if (data->max_y < 1024)
>> - y = y >> 2;
>> + y >>= 2;
>>
>> area = message->message[4];
>> - pressure = message->message[5];
>> -
>> - dev_dbg(dev, "[%d] %s x: %d, y: %d, area: %d\n", id,
>> - status & MXT_MOVE ? "moved" : "pressed",
>> - x, y, area);
>> -
>> - finger[id].status = status & MXT_MOVE ?
>> - MXT_MOVE : MXT_PRESS;
>> - finger[id].x = x;
>> - finger[id].y = y;
>> - finger[id].area = area;
>> - finger[id].pressure = pressure;
>> + amplitude = message->message[5];
>> +
>> + dev_dbg(dev,
>> + "[%d] %c%c%c%c%c%c%c%c x: %d y: %d area: %d amp: %d\n",
>> + id,
>> + (status & MXT_DETECT) ? 'D' : '.',
>> + (status & MXT_PRESS) ? 'P' : '.',
>> + (status & MXT_RELEASE) ? 'R' : '.',
>> + (status & MXT_MOVE) ? 'M' : '.',
>> + (status & MXT_VECTOR) ? 'V' : '.',
>> + (status & MXT_AMP) ? 'A' : '.',
>> + (status & MXT_SUPPRESS) ? 'S' : '.',
>> + (status & MXT_UNGRIP) ? 'U' : '.',
>> + x, y, area, amplitude);
>> +
>> + input_mt_slot(input_dev, id);
>> + input_mt_report_slot_state(input_dev, MT_TOOL_FINGER,
>> + status & MXT_DETECT);
>> +
>> + if (status & MXT_DETECT) {
>> + 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_PRESSURE, amplitude);
>> + /* TODO: This should really be sqrt(area) */
>> + input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, area);
>
> The functional relationship might not be perfect, but at least the
> reported scale should match the position units, as several userspace
> drivers depend on its accuracy. If the line size looks reasonable in
> mtview, for instance, it should be fine.
Please note this patch doesn't actually change how TOUCH_MAJOR is
reported. All I did here was add the TODO, since reporting 'area' as
TOUCH_MAJOR looks suspect to me :). Unfortunately, I don't actually
know the relationship between what the firmware sends as 'area' and
the position units... perhaps someone with more experience with how
the firmware works could help us here.
-Dan
>
>> + }
>>
>> - mxt_input_report(data, id);
>> + input_mt_report_pointer_emulation(input_dev, false);
>> + input_sync(input_dev);
>> }
>>
>> static irqreturn_t mxt_interrupt(int irq, void *dev_id)
>> --
>
> Thanks,
> Henrik
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