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

[Dmitry Osipenko]

10.12.2019 04:23, Dmitry Osipenko ÐÐÑÐÑ:
> 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.
> 

But maybe it's not really worth the effort at all since we need to
override the sizes in device-tree anyway?

What about to just ignore the firmware values of eKTF3624 for simplicity?