linux-kernel - Re: [PATCH v5 2/2] Input: msg2638 - Add support for msg2138 key events

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Message-ID: <Y3VJLtY27h/YrBWa@google.com>
Date:   Wed, 16 Nov 2022 12:33:50 -0800
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Vincent Knecht <vincent.knecht@...loo.org>
Cc:     Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        linux-input@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, w.david0@...tonmail.com,
        stephan@...hold.net, phone-devel@...r.kernel.org,
        ~postmarketos/upstreaming@...ts.sr.ht
Subject: Re: [PATCH v5 2/2] Input: msg2638 - Add support for msg2138 key
 events

On Wed, Nov 16, 2022 at 07:17:12PM +0100, Vincent Knecht wrote:
> Some devices with msg2138 have back/menu/home keys.
> Add support for them.
> 
> Signed-off-by: Vincent Knecht <vincent.knecht@...loo.org>
> ---
>  drivers/input/touchscreen/msg2638.c | 57 +++++++++++++++++++++++++++--
>  1 file changed, 53 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/msg2638.c b/drivers/input/touchscreen/msg2638.c
> index 95b18563326a..a0f5e1ecd612 100644
> --- a/drivers/input/touchscreen/msg2638.c
> +++ b/drivers/input/touchscreen/msg2638.c
> @@ -21,6 +21,7 @@
>  #include <linux/kernel.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
> +#include <linux/property.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  
> @@ -29,6 +30,8 @@
>  #define MSG2138_MAX_FINGERS		2
>  #define MSG2638_MAX_FINGERS		5
>  
> +#define MAX_BUTTONS			4
> +
>  #define CHIP_ON_DELAY_MS		15
>  #define FIRMWARE_ON_DELAY_MS		50
>  #define RESET_DELAY_MIN_US		10000
> @@ -72,6 +75,8 @@ struct msg2638_ts_data {
>  	struct regulator_bulk_data supplies[2];
>  	struct gpio_desc *reset_gpiod;
>  	int max_fingers;
> +	u32 keycodes[MAX_BUTTONS];
> +	int num_keycodes;
>  };
>  
>  static u8 msg2638_checksum(u8 *data, u32 length)
> @@ -85,6 +90,18 @@ static u8 msg2638_checksum(u8 *data, u32 length)
>  	return (u8)((-sum) & 0xFF);
>  }
>  
> +static void msg2138_report_keys(struct msg2638_ts_data *msg2638, u8 keys)
> +{
> +	int i;
> +
> +	/* keys can be 0x00 or 0xff when all keys have been released */
> +	if (keys == 0xff)
> +		keys = 0;
> +
> +	for (i = 0; i < msg2638->num_keycodes; ++i)
> +		input_report_key(msg2638->input_dev, msg2638->keycodes[i], keys & BIT(i));
> +}
> +
>  static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
>  {
>  	struct msg2638_ts_data *msg2638 = msg2638_handler;
> @@ -121,9 +138,12 @@ static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
>  	p0 = &touch_event.pkt[0];
>  	p1 = &touch_event.pkt[1];
>  
> -	/* Ignore non-pressed finger data */
> -	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF)
> +	/* Ignore non-pressed finger data, but check for key code */
> +	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF) {
> +		if (p1->xy_hi == 0xFF && p1->y_low == 0xFF)
> +			msg2138_report_keys(msg2638, p1->x_low);
>  		goto report;
> +	}
>  
>  	x = ((p0->xy_hi & 0xF0) << 4) | p0->x_low;
>  	y = ((p0->xy_hi & 0x0F) << 8) | p0->y_low;
> @@ -283,6 +303,7 @@ static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
>  	struct device *dev = &msg2638->client->dev;
>  	struct input_dev *input_dev;
>  	int error;
> +	int i;
>  
>  	input_dev = devm_input_allocate_device(dev);
>  	if (!input_dev) {
> @@ -299,6 +320,14 @@ static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
>  	input_dev->open = msg2638_input_open;
>  	input_dev->close = msg2638_input_close;
>  
> +	if (msg2638->num_keycodes) {
> +		input_dev->keycode = msg2638->keycodes;
> +		input_dev->keycodemax = msg2638->num_keycodes;
> +		input_dev->keycodesize = sizeof(msg2638->keycodes[0]);
> +		for (i = 0; i < msg2638->num_keycodes; i++)
> +			input_set_capability(input_dev, EV_KEY, msg2638->keycodes[i]);
> +	}
> +
>  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
>  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
>  
> @@ -367,9 +396,23 @@ static int msg2638_ts_probe(struct i2c_client *client)
>  		return error;
>  	}
>  
> -	error = msg2638_init_input_dev(msg2638);
> +	msg2638->num_keycodes = fwnode_property_count_u32(dev->fwnode, "linux,keycodes");

Please use device_property_count_u32().

> +	if (msg2638->num_keycodes == -EINVAL) {
> +		msg2638->num_keycodes = 0;
> +	} else if (msg2638->num_keycodes < 0) {
> +		dev_err(dev, "Unable to parse linux,keycodes property: %d\n",
> +			msg2638->num_keycodes);
> +		return msg2638->num_keycodes;
> +	} else if (msg2638->num_keycodes > ARRAY_SIZE(msg2638->keycodes)) {
> +		dev_warn(dev, "Found %d linux,keycodes but max is %ld, ignoring the rest\n",
> +			 msg2638->num_keycodes, ARRAY_SIZE(msg2638->keycodes));

I think you want "%zd" in place of "%ld".

> +		msg2638->num_keycodes = ARRAY_SIZE(msg2638->keycodes);
> +	}
> +
> +	error = fwnode_property_read_u32_array(dev->fwnode, "linux,keycodes",
> +					       msg2638->keycodes, msg2638->num_keycodes);

Please use device_property_read_u32_array().

>  	if (error) {
> -		dev_err(dev, "Failed to initialize input device: %d\n", error);
> +		dev_err(dev, "Unable to read linux,keycodes values: %d\n", error);
>  		return error;
>  	}
>  
> @@ -382,6 +425,12 @@ static int msg2638_ts_probe(struct i2c_client *client)
>  		return error;
>  	}
>  
> +	error = msg2638_init_input_dev(msg2638);
> +	if (error) {
> +		dev_err(dev, "Failed to initialize input device: %d\n", error);
> +		return error;
> +	}
> +
>  	return 0;
>  }
>  
> -- 
> 2.38.1
> 
> 
> 

Thanks.

-- 
Dmitry