Re: [PATCH RESEND v4 2/2] input: zinitix: Add touchkey support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Nikita,

On Sat, Jul 13, 2024 at 08:28:09PM +0500, Nikita Travkin wrote:
> Zinitix touch controllers can use some of the sense lines for virtual
> keys (like those found on many phones). Add support for those keys.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>

A few comments:

> ---
>  drivers/input/touchscreen/zinitix.c | 61 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 58 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/zinitix.c b/drivers/input/touchscreen/zinitix.c
> index 1b4807ba4624..75390d67689e 100644
> --- a/drivers/input/touchscreen/zinitix.c
> +++ b/drivers/input/touchscreen/zinitix.c
> @@ -119,6 +119,7 @@
>  
>  #define DEFAULT_TOUCH_POINT_MODE		2
>  #define MAX_SUPPORTED_FINGER_NUM		5
> +#define MAX_SUPPORTED_BUTTON_NUM		8
>  
>  #define CHIP_ON_DELAY				15 // ms
>  #define FIRMWARE_ON_DELAY			40 // ms
> @@ -146,6 +147,8 @@ struct bt541_ts_data {
>  	struct touchscreen_properties prop;
>  	struct regulator_bulk_data supplies[2];
>  	u32 zinitix_mode;
> +	u32 keycodes[MAX_SUPPORTED_BUTTON_NUM];
> +	int num_keycodes;
>  };
>  
>  static int zinitix_read_data(struct i2c_client *client,
> @@ -195,6 +198,7 @@ static int zinitix_init_touch(struct bt541_ts_data *bt541)
>  	struct i2c_client *client = bt541->client;
>  	int i;
>  	int error;
> +	u16 int_flags = 0;

It is initialized unconditionally below, no need to initialize here.

>  
>  	error = zinitix_write_cmd(client, ZINITIX_SWRESET_CMD);
>  	if (error) {
> @@ -225,6 +229,11 @@ static int zinitix_init_touch(struct bt541_ts_data *bt541)
>  	if (error)
>  		return error;
>  
> +	error = zinitix_write_u16(client, ZINITIX_BUTTON_SUPPORTED_NUM,
> +				  bt541->num_keycodes);
> +	if (error)
> +		return error;
> +
>  	error = zinitix_write_u16(client, ZINITIX_INITIAL_TOUCH_MODE,
>  				  bt541->zinitix_mode);
>  	if (error)
> @@ -235,9 +244,12 @@ static int zinitix_init_touch(struct bt541_ts_data *bt541)
>  	if (error)
>  		return error;
>  
> -	error = zinitix_write_u16(client, ZINITIX_INT_ENABLE_FLAG,
> -				  BIT_PT_CNT_CHANGE | BIT_DOWN | BIT_MOVE |
> -					BIT_UP);
> +	int_flags = BIT_PT_CNT_CHANGE | BIT_DOWN | BIT_MOVE | BIT_UP;
> +

Drop empty line.

> +	if (bt541->num_keycodes)
> +		int_flags |= BIT_ICON_EVENT;
> +
> +	error = zinitix_write_u16(client, ZINITIX_INT_ENABLE_FLAG, int_flags);
>  	if (error)
>  		return error;
>  
> @@ -350,6 +362,15 @@ static void zinitix_report_finger(struct bt541_ts_data *bt541, int slot,
>  	}
>  }
>  
> +static void zinitix_report_keys(struct bt541_ts_data *bt541, u16 icon_events)
> +{
> +	int i;
> +
> +	for (i = 0; i < bt541->num_keycodes; i++)
> +		input_report_key(bt541->input_dev,
> +				 bt541->keycodes[i], !!(icon_events & BIT(i)));
> +}
> +
>  static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler)
>  {
>  	struct bt541_ts_data *bt541 = bt541_handler;
> @@ -358,6 +379,7 @@ static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler)
>  	unsigned long finger_mask;
>  	int error;
>  	int i;
> +	__le16 icon_events = 0;

I do not believe this needs to be initialized.

>  
>  	memset(&touch_event, 0, sizeof(struct touch_event));
>  
> @@ -368,6 +390,17 @@ static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler)
>  		goto out;
>  	}
>  
> +	if (le16_to_cpu(touch_event.status) & BIT_ICON_EVENT) {
> +		error = zinitix_read_data(bt541->client, ZINITIX_ICON_STATUS_REG,
> +					  &icon_events, sizeof(icon_events));
> +		if (error) {
> +			dev_err(&client->dev, "Failed to read icon events\n");
> +			goto out;
> +		}
> +
> +		zinitix_report_keys(bt541, le16_to_cpu(icon_events));
> +	}
> +
>  	finger_mask = touch_event.finger_mask;
>  	for_each_set_bit(i, &finger_mask, MAX_SUPPORTED_FINGER_NUM) {
>  		const struct point_coord *p = &touch_event.point_coord[i];
> @@ -453,6 +486,7 @@ static int zinitix_init_input_dev(struct bt541_ts_data *bt541)
>  {
>  	struct input_dev *input_dev;
>  	int error;
> +	int i;
>  
>  	input_dev = devm_input_allocate_device(&bt541->client->dev);
>  	if (!input_dev) {
> @@ -470,6 +504,14 @@ static int zinitix_init_input_dev(struct bt541_ts_data *bt541)
>  	input_dev->open = zinitix_input_open;
>  	input_dev->close = zinitix_input_close;
>  
> +	if (bt541->num_keycodes) {
> +		input_dev->keycode = bt541->keycodes;
> +		input_dev->keycodemax = bt541->num_keycodes;
> +		input_dev->keycodesize = sizeof(bt541->keycodes[0]);
> +		for (i = 0; i < bt541->num_keycodes; i++)
> +			input_set_capability(input_dev, EV_KEY, bt541->keycodes[i]);
> +	}
> +
>  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
>  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
>  	input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
> @@ -534,6 +576,19 @@ static int zinitix_ts_probe(struct i2c_client *client)
>  		return error;
>  	}
>  
> +	bt541->num_keycodes = of_property_read_variable_u32_array(
> +					client->dev.of_node, "linux,keycodes",
> +					bt541->keycodes, 0,
> +					ARRAY_SIZE(bt541->keycodes));

Please use generic device properties (device_property_*). There is no
equivalent for "read variable" so you'll need 2 calls, one to figure out
the array size and another one to read it.

See drivers/input/keyboard/mpr121_touchkey.c for an example.

> +	if (bt541->num_keycodes == -EINVAL) {
> +		bt541->num_keycodes = 0;
> +	} else if (bt541->num_keycodes < 0) {
> +		dev_err(&client->dev,
> +			"Unable to parse \"linux,keycodes\" property: %d\n",
> +			bt541->num_keycodes);
> +		return bt541->num_keycodes;
> +	}
> +
>  	error = zinitix_init_input_dev(bt541);
>  	if (error) {
>  		dev_err(&client->dev,
> 
> -- 
> 2.45.2
> 

Thanks.

-- 
Dmitry