[PATCH v3 2/2] input: touchscreen: elants_i2c: Add eth3915n touchscreen chip

[Yunlong Jia <yunlong.jia@ecs.corp-partner.google.com>]

The eth3915n requires more delay time than the eth3500 when poweron
 & reset.
Define EKTH3915_POWERON_DELAY_MSEC as the poweron delay time of eth3915n,
 about 80ms.
Define EKTH3915_RESET_DELAY_MSEC as the reset delay time of eth3915n,
 about 300ms.

Signed-off-by: Yunlong Jia <yunlong.jia@ecs.com.tw>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

---

Changes in v3:
 1. Add poweron delay time.

Changes in v2:
 1. Adjust the 'Signed-off-by'.

 drivers/input/touchscreen/elants_i2c.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index c9dd703b0c7d8..fb99dd10b0b6d 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -116,6 +116,8 @@
 
 #define ELAN_POWERON_DELAY_USEC	500
 #define ELAN_RESET_DELAY_MSEC	20
+#define EKTH3915_POWERON_DELAY_MSEC    80
+#define EKTH3915_RESET_DELAY_MSEC	300
 
 /* FW boot code version */
 #define BC_VER_H_BYTE_FOR_EKTH3900x1_I2C        0x72
@@ -133,6 +135,7 @@
 enum elants_chip_id {
 	EKTH3500,
 	EKTF3624,
+	EKTH3915,
 };
 
 enum elants_state {
@@ -664,6 +667,7 @@ static int elants_i2c_initialize(struct elants_data *ts)
 
 	switch (ts->chip_id) {
 	case EKTH3500:
+	case EKTH3915:
 		if (!error)
 			error = elants_i2c_query_ts_info_ekth(ts);
 		break;
@@ -1331,6 +1335,9 @@ static int elants_i2c_power_on(struct elants_data *ts)
 	if (IS_ERR_OR_NULL(ts->reset_gpio))
 		return 0;
 
+	if (ts->chip_id == EKTH3915)
+		msleep(EKTH3915_POWERON_DELAY_MSEC);
+
 	gpiod_set_value_cansleep(ts->reset_gpio, 1);
 
 	error = regulator_enable(ts->vcc33);
@@ -1361,7 +1368,17 @@ static int elants_i2c_power_on(struct elants_data *ts)
 	if (error)
 		return error;
 
-	msleep(ELAN_RESET_DELAY_MSEC);
+	if (ts->chip_id == EKTH3915)
+		/*
+		 * There need delay 300ms for power on sequence.
+		 * T1 + T2 + T3 >= 305 ms
+		 * T1: 0<time<500us
+		 * T2: >5ms
+		 * T3: >300ms
+		 */
+		msleep(EKTH3915_RESET_DELAY_MSEC);
+	else
+		msleep(ELAN_RESET_DELAY_MSEC);
 
 	return 0;
 }
@@ -1686,6 +1703,7 @@ static const struct i2c_device_id elants_i2c_id[] = {
 	{ DEVICE_NAME, EKTH3500 },
 	{ "ekth3500", EKTH3500 },
 	{ "ektf3624", EKTF3624 },
+	{ "ekth3915", EKTH3915 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
@@ -1702,6 +1720,7 @@ MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
 static const struct of_device_id elants_of_match[] = {
 	{ .compatible = "elan,ekth3500", .data = (void *)EKTH3500 },
 	{ .compatible = "elan,ektf3624", .data = (void *)EKTF3624 },
+	{ .compatible = "elan,ekth3915", .data = (void *)EKTH3915 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, elants_of_match);
-- 
2.17.1