Re: [PATCH 6/6] input: elants: read touchscreen size for EKTF3624

[Dmitry Osipenko]

10.12.2019 03:19, MichaÅ MirosÅaw ÐÐÑÐÑ:
> EKTF3624 as present in Asus TF300T tablet has touchscreen size encoded
> in different registers.
> 
> Signed-off-by: MichaÅ MirosÅaw <mirq-linux@xxxxxxxxxxxx>
> ---
>  drivers/input/touchscreen/elants_i2c.c | 77 ++++++++++++++++++++++++--
>  1 file changed, 72 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
> index 27aca3971da5..e60a5eb9fb37 100644
> --- a/drivers/input/touchscreen/elants_i2c.c
> +++ b/drivers/input/touchscreen/elants_i2c.c
> @@ -34,7 +34,7 @@
>  #include <linux/input/touchscreen.h>
>  #include <linux/input/mt.h>
>  #include <linux/acpi.h>
> -#include <linux/of.h>
> +#include <linux/of_device.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/regulator/consumer.h>
>  #include <asm/unaligned.h>
> @@ -42,6 +42,10 @@
>  /* Device, Driver information */
>  #define DEVICE_NAME	"elants_i2c"
>  
> +/* Device IDs */
> +#define EKTH3500	0
> +#define EKTF3624	1
> +
>  /* Convert from rows or columns into resolution */
>  #define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
>  
> @@ -160,6 +164,7 @@ struct elants_data {
>  
>  	bool wake_irq_enabled;
>  	bool keep_power_in_suspend;
> +	u8 chip_id;
>  
>  	/* Must be last to be used for DMA operations */
>  	u8 buf[MAX_PACKET_SIZE] ____cacheline_aligned;
> @@ -434,7 +439,53 @@ static int elants_i2c_query_bc_version(struct elants_data *ts)
>  	return 0;
>  }
>  
> -static int elants_i2c_query_ts_info(struct elants_data *ts)
> +static int elants_i2c_query_ts_info_ektf(struct elants_data *ts)
> +{
> +	struct i2c_client *client = ts->client;
> +	int error;
> +	u8 resp[4];
> +	u16 phy_x, phy_y;
> +	const u8 get_xres_cmd[] = {
> +		CMD_HEADER_READ, E_INFO_X_RES, 0x00, 0x00
> +	};
> +	const u8 get_yres_cmd[] = {
> +		CMD_HEADER_READ, E_INFO_Y_RES, 0x00, 0x00
> +	};
> +
> +	/* Get X/Y size in mm */
> +	error = elants_i2c_execute_command(client, get_xres_cmd,
> +					   sizeof(get_xres_cmd),
> +					   resp, sizeof(resp), 1,
> +					   "get X size");
> +	if (error)
> +		return error;
> +
> +	phy_x = resp[2] | ((resp[3] & 0xF0) << 4);
> +
> +	error = elants_i2c_execute_command(client, get_yres_cmd,
> +					   sizeof(get_yres_cmd),
> +					   resp, sizeof(resp), 1,
> +					   "get Y size");
> +	if (error)
> +		return error;
> +
> +	phy_y = resp[2] | ((resp[3] & 0xF0) << 4);
> +
> +	/* calculate resolution from size */
> +	if (!ts->prop.max_x)
> +		ts->prop.max_x = 2240;
> +	ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, phy_x);
> +
> +	if (!ts->prop.max_y)
> +		ts->prop.max_y = 1408;
> +	ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, phy_y);
> +
> +	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
> +
> +	return 0;
> +}
> +
> +static int elants_i2c_query_ts_info_ekth(struct elants_data *ts)
>  {
>  	struct i2c_client *client = ts->client;
>  	int error;
> @@ -587,8 +638,20 @@ static int elants_i2c_initialize(struct elants_data *ts)
>  		error = elants_i2c_query_test_version(ts);
>  	if (!error)
>  		error = elants_i2c_query_bc_version(ts);
> -	if (!error)
> -		error = elants_i2c_query_ts_info(ts);
> +
> +	switch (ts->chip_id) {
> +	case EKTH3500:
> +		if (!error)
> +			error = elants_i2c_query_ts_info_ekth(ts);
> +		break;
> +	case EKTF3624:
> +		if (!error)
> +			error = elants_i2c_query_ts_info_ektf(ts);
> +		break;
> +	default:
> +		unreachable();
> +		break;
> +	}
>  
>  	if (error)
>  		ts->iap_mode = ELAN_IAP_RECOVERY;
> @@ -1185,6 +1248,9 @@ static int elants_i2c_probe(struct i2c_client *client,
>  	ts->client = client;
>  	i2c_set_clientdata(client, ts);
>  
> +	if (client->dev.of_node)
> +		ts->chip_id = (uintptr_t)of_device_get_match_data(&client->dev);
> +
>  	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
>  	if (IS_ERR(ts->vcc33)) {
>  		error = PTR_ERR(ts->vcc33);
> @@ -1422,7 +1488,8 @@ MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
>  
>  #ifdef CONFIG_OF
>  static const struct of_device_id elants_of_match[] = {
> -	{ .compatible = "elan,ekth3500" },
> +	{ .compatible = "elan,ekth3500", .data = (void *)EKTH3500 },
> +	{ .compatible = "elan,ektf3624", .data = (void *)EKTF3624 },
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, elants_of_match);

It also should be possible to remove elants_of_match entirely and do the
following in the I2C ID table:

static const struct i2c_device_id elants_i2c_id[] = {
	{ "ekth3500", EKTH3500 },
	{ "ektf3624", EKTF3624 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, elants_i2c_id);

Then OF core will take care of device ID matching by removing the
"elan," part from the compatible value of the device-tree and comparing
it with the values in elants_i2c_id[].

And then in elants_i2c_probe() you could :

	chip->chip_id = (uintptr_t)id->driver_data;

See "drivers/mfd/max77620.c" for the example.