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

From: Dmitry Osipenko
Date: Mon Dec 09 2019 - 20:48:12 EST


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?