Input: elants - document some registers and values

Add information found in downstream kernels, to make the code less
magic.

Signed-off-by: Michał Mirosław <[e-mail]>
Reviewed-by: Dmitry Osipenko <[e-mail]>
Tested-by: Dmitry Osipenko <[e-mail]>
Link: https://lore.kernel.org/r/72[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/elants_i2c.c

···
 
 #define HEADER_REPORT_10_FINGER	0x62
 
-/* Header (4 bytes) plus 3 fill 10-finger packets */
+/* Header (4 bytes) plus 3 full 10-finger packets */
 #define MAX_PACKET_SIZE		169
 
 #define BOOT_TIME_DELAY_MS	50
···
 #define E_INFO_OSR		0xD6
 #define E_INFO_PHY_SCAN		0xD7
 #define E_INFO_PHY_DRIVER	0xD8
+
+/* FW write command, 0x54 0x?? 0x0, 0x01 */
+#define E_POWER_STATE_SLEEP	0x50
+#define E_POWER_STATE_RESUME	0x58
 
 #define MAX_RETRIES		3
 #define MAX_FW_UPDATE_RETRIES	30
···
 {
 	struct i2c_client *client = ts->client;
 	int ret, error;
-	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
-	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
+	static const u8 w_flashkey[] = { CMD_HEADER_WRITE, 0xC0, 0xE1, 0x5A };
+	static const u8 rek[] = { CMD_HEADER_WRITE, 0x29, 0x00, 0x01 };
 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
 
 	disable_irq(client->irq);
···
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct elants_data *ts = i2c_get_clientdata(client);
-	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
+	const u8 set_sleep_cmd[] = {
+		CMD_HEADER_WRITE, E_POWER_STATE_SLEEP, 0x00, 0x01
+	};
 	int retry_cnt;
 	int error;
 
···
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct elants_data *ts = i2c_get_clientdata(client);
-	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
+	const u8 set_active_cmd[] = {
+		CMD_HEADER_WRITE, E_POWER_STATE_RESUME, 0x00, 0x01
+	};
 	int retry_cnt;
 	int error;