Re: [PATCH v2 1/2] Input: goodix - Add support for more then one touch-key

[Bastien Nocera <hadess@hadess.net>]

On Fri, 2020-03-13 at 17:18 +0300, Dmitry Mastykin wrote:
> Hi,
> 
>  > Can't say that I like the magic "2" used here and in a number of
> other
>  > places in this patch. Is it always the same 2? If so, could we use
> a
>  > constant instead? (GOODIX_TOUCH_KEYS_HEADER_FOOTER_SIZE?)
>  >
> I may suggest following refactoring to get rid of magic "2":

That looks much clearer to me, thanks!

> @@ -280,6 +280,13 @@ static int goodix_ts_read_input_report(struct 
> goodix_ts_data *ts, u8 *data)
>          unsigned long max_timeout;
>          int touch_num;
>          int error;
> +       u16 addr = GOODIX_READ_COOR_ADDR;
> +       /*
> +        * We are going to read 1-byte header,
> +        * ts->contact_size * max(1, touch_num) bytes of coordinates
> +        * and 1-byte footer which contains the touch-key code.
> +        */
> +       const int header_contact_keycode_size = 1 + ts->contact_size
> + 1;
> 
>          /*
>           * The 'buffer status' bit, which indicates that the data
> is 
> valid, is
> @@ -288,14 +295,8 @@ static int goodix_ts_read_input_report(struct 
> goodix_ts_data *ts, u8 *data)
>           */
>          max_timeout = jiffies + 
> msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
>          do {
> -               /*
> -                * We are going to read ts->contact_size * max(1, 
> touch_num) + 2
> -                * bytes, where + 2 consists of reading 1 extra byte
> for the
> -                * header + 1 extra byte for the footer which
> contains the
> -                * touch-key code.
> -                */
> -               error = goodix_i2c_read(ts->client,
> GOODIX_READ_COOR_ADDR,
> -                                       data, ts->contact_size + 2);
> +               error = goodix_i2c_read(ts->client, addr, data,
> +                                       header_contact_keycode_size);
>                  if (error) {
>                          dev_err(&ts->client->dev, "I2C transfer
> error: 
> %d\n",
>                                          error);
> @@ -308,11 +309,10 @@ static int goodix_ts_read_input_report(struct 
> goodix_ts_data *ts, u8 *data)
>                                  return -EPROTO;
> 
>                          if (touch_num > 1) {
> -                               data += 2 + ts->contact_size;
> +                               addr += header_contact_keycode_size;
> +                               data += header_contact_keycode_size;
>                                  error = goodix_i2c_read(ts->client,
> -                                               GOODIX_READ_COOR_ADDR
> +
> -                                                       2 + 
> ts->contact_size,
> -                                               data,
> +                                               addr, data,
>                                                  ts->contact_size *
>                                                          (touch_num -
> 1));
>                                  if (error)
> 
> 
> Kind regards
> Dmitry Mastykin
> 
> 
> On 3/13/20 4:19 PM, Bastien Nocera wrote:
> > On Thu, 2020-03-12 at 17:50 +0300, Dmitry Mastykin wrote:
> > > Some devices with a goodix touchscreen have more then 1
> > > capacitive
> > > touch-key. This commit replaces the current support for a single
> > > touch-key, which ignored the reported key-code. With support for
> > > up to 7 touch-keys, based upon checking the key-code which is
> > > post-fixed to any reported touch-data.
> > > 
> > > KEY_LEFTMETA is assigned to the first touch-key (it will still be
> > > the default keycode for devices with a single touch-key).
> > > KEY_F1, KEY_F2... are assigned as default keycode for the other
> > > touch-keys.
> > > 
> > > This commit also add supports for keycode remapping, so that
> > > systemd-udev's hwdb can be used to remap the codes to send
> > > keycodes to match the icons on the buttons for devices with more
> > > then 1 touch-key.
> > > 
> > > Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
> > > ---
> > > Changes in v2:
> > > - Improve commit message
> > > ---
> > >   drivers/input/touchscreen/goodix.c | 54
> > > ++++++++++++++++++++++++--
> > > ----
> > >   1 file changed, 44 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/drivers/input/touchscreen/goodix.c
> > > b/drivers/input/touchscreen/goodix.c
> > > index adb9b92..daf1781 100644
> > > --- a/drivers/input/touchscreen/goodix.c
> > > +++ b/drivers/input/touchscreen/goodix.c
> > > @@ -38,6 +38,7 @@
> > >   #define GOODIX_CONTACT_SIZE		8
> > >   #define GOODIX_MAX_CONTACT_SIZE		9
> > >   #define GOODIX_MAX_CONTACTS		10
> > > +#define GOODIX_MAX_KEYS			7
> > >   
> > >   #define GOODIX_CONFIG_MIN_LENGTH	186
> > >   #define GOODIX_CONFIG_911_LENGTH	186
> > > @@ -55,6 +56,7 @@
> > >   #define GOODIX_REG_ID			0x8140
> > >   
> > >   #define GOODIX_BUFFER_STATUS_READY	BIT(7)
> > > +#define GOODIX_HAVE_KEY			BIT(4)
> > >   #define GOODIX_BUFFER_STATUS_TIMEOUT	20
> > >   
> > >   #define RESOLUTION_LOC		1
> > > @@ -100,6 +102,7 @@ struct goodix_ts_data {
> > >   	enum goodix_irq_pin_access_method
> > > irq_pin_access_method;
> > >   	unsigned int contact_size;
> > >   	u8 config[GOODIX_CONFIG_MAX_LENGTH];
> > > +	unsigned short keymap[GOODIX_MAX_KEYS];
> > >   };
> > >   
> > >   static int goodix_check_cfg_8(struct goodix_ts_data *ts,
> > > @@ -285,8 +288,14 @@ static int
> > > goodix_ts_read_input_report(struct
> > > goodix_ts_data *ts, u8 *data)
> > >   	 */
> > >   	max_timeout = jiffies +
> > > msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
> > >   	do {
> > > +		/*
> > > +		 * We are going to read ts->contact_size * max(1,
> > > touch_num) + 2
> > > +		 * bytes, where + 2 consists of reading 1 extra byte
> > > for the
> > > +		 * header + 1 extra byte for the footer which contains
> > > the
> > > +		 * touch-key code.
> > 
> > Can't say that I like the magic "2" used here and in a number of
> > other
> > places in this patch. Is it always the same 2? If so, could we use
> > a
> > constant instead? (GOODIX_TOUCH_KEYS_HEADER_FOOTER_SIZE?)
> > 
> > Looks good otherwise.
> > 
> > > +		 */
> > >   		error = goodix_i2c_read(ts->client,
> > > GOODIX_READ_COOR_ADDR,
> > > -					data, ts->contact_size + 1);
> > > +					data, ts->contact_size + 2);
> > >   		if (error) {
> > >   			dev_err(&ts->client->dev, "I2C transfer
> > > error:
> > > %d\n",
> > >   					error);
> > > @@ -299,10 +308,10 @@ static int
> > > goodix_ts_read_input_report(struct
> > > goodix_ts_data *ts, u8 *data)
> > >   				return -EPROTO;
> > >   
> > >   			if (touch_num > 1) {
> > > -				data += 1 + ts->contact_size;
> > > +				data += 2 + ts->contact_size;
> > >   				error = goodix_i2c_read(ts-
> > > >client,
> > >   						GOODIX_READ_COO
> > > R_ADDR +
> > > -							1 + ts-
> > > > contact_size,
> > > +							2 + ts-
> > > > contact_size,
> > >   						data,
> > >   						ts-
> > > >contact_size *
> > >   							(touch_
> > > num -
> > > 1));
> > > @@ -353,6 +362,23 @@ static void goodix_ts_report_touch_9b(struct
> > > goodix_ts_data *ts, u8 *coor_data)
> > >   	input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR,
> > > input_w);
> > >   }
> > >   
> > > +static void goodix_ts_report_key(struct goodix_ts_data *ts, u8
> > > *data)
> > > +{
> > > +	int touch_num;
> > > +	u8 key_value;
> > > +	int i;
> > > +
> > > +	if (data[0] & GOODIX_HAVE_KEY) {
> > > +		touch_num = data[0] & 0x0f;
> > > +		key_value = data[1 + ts->contact_size * touch_num];
> > > +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> > > +			if (key_value & (1 << i))
> > > +				input_report_key(ts->input_dev, ts-
> > > > keymap[i], 1);
> > > +	} else
> > > +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> > > +			input_report_key(ts->input_dev, ts->keymap[i],
> > > 0);
> > > +}
> > > +
> > >   /**
> > >    * goodix_process_events - Process incoming events
> > >    *
> > > @@ -363,7 +389,7 @@ static void goodix_ts_report_touch_9b(struct
> > > goodix_ts_data *ts, u8 *coor_data)
> > >    */
> > >   static void goodix_process_events(struct goodix_ts_data *ts)
> > >   {
> > > -	u8  point_data[1 + GOODIX_MAX_CONTACT_SIZE *
> > > GOODIX_MAX_CONTACTS];
> > > +	u8  point_data[2 + GOODIX_MAX_CONTACT_SIZE *
> > > GOODIX_MAX_CONTACTS];
> > >   	int touch_num;
> > >   	int i;
> > >   
> > > @@ -371,11 +397,7 @@ static void goodix_process_events(struct
> > > goodix_ts_data *ts)
> > >   	if (touch_num < 0)
> > >   		return;
> > >   
> > > -	/*
> > > -	 * Bit 4 of the first byte reports the status of the capacitive
> > > -	 * Windows/Home button.
> > > -	 */
> > > -	input_report_key(ts->input_dev, KEY_LEFTMETA, point_data[0] &
> > > BIT(4));
> > > +	goodix_ts_report_key(ts, point_data);
> > >   
> > >   	for (i = 0; i < touch_num; i++)
> > >   		if (ts->contact_size == 9)
> > > @@ -961,6 +983,7 @@ static int goodix_i2c_test(struct i2c_client
> > > *client)
> > >   static int goodix_configure_dev(struct goodix_ts_data *ts)
> > >   {
> > >   	int error;
> > > +	int i;
> > >   
> > >   	ts->int_trigger_type = GOODIX_INT_TRIGGER;
> > >   	ts->max_touch_num = GOODIX_MAX_CONTACTS;
> > > @@ -978,8 +1001,19 @@ static int goodix_configure_dev(struct
> > > goodix_ts_data *ts)
> > >   	ts->input_dev->id.product = ts->id;
> > >   	ts->input_dev->id.version = ts->version;
> > >   
> > > +	ts->input_dev->keycode = ts->keymap;
> > > +	ts->input_dev->keycodesize = sizeof(ts->keymap[0]);
> > > +	ts->input_dev->keycodemax = GOODIX_MAX_KEYS;
> > > +
> > >   	/* Capacitive Windows/Home button on some devices */
> > > -	input_set_capability(ts->input_dev, EV_KEY, KEY_LEFTMETA);
> > > +	for (i = 0; i < GOODIX_MAX_KEYS; ++i) {
> > > +		if (i == 0)
> > > +			ts->keymap[i] = KEY_LEFTMETA;
> > > +		else
> > > +			ts->keymap[i] = KEY_F1 + (i - 1);
> > > +
> > > +		input_set_capability(ts->input_dev, EV_KEY, ts-
> > > > keymap[i]);
> > > +	}
> > >   
> > >   	input_set_capability(ts->input_dev, EV_ABS,
> > > ABS_MT_POSITION_X);
> > >   	input_set_capability(ts->input_dev, EV_ABS,
> > > ABS_MT_POSITION_Y);