[PATCH v2] HID: i2c-hid: Add a small delay after sleep command for Raydium touchpanel

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

Raydium touchpanel (2386:4B33) sometimes does not work in desktop session
although it works in display manager.

During user logging, the display manager exits, close the HID device,
then the device gets runtime suspended and powered off. The desktop
session begins shortly after, opens the HID device, then the device gets
runtime resumed and powered on.

If the trasition from display manager to desktop sesesion is fast, the
touchpanel cannot switch from powered off to powered on in short
timeframe. So add a small delay to workaround the issue.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v2:
- Use quirk to only match affected touchpanel
- Only delay the next power on if the time hasn't elapsed

 drivers/hid/hid-ids.h              |  3 +++
 drivers/hid/i2c-hid/i2c-hid-core.c | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 16342188df19..c1b5f03eb630 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -926,6 +926,9 @@
 #define USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3003		0x3003
 #define USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3008		0x3008
 
+#define I2C_VENDOR_ID_RAYDIUM		0x2386
+#define I2C_PRODUCT_ID_RAYDIUM_4B33	0x4b33
+
 #define USB_VENDOR_ID_RAZER            0x1532
 #define USB_DEVICE_ID_RAZER_BLADE_14   0x011D
 
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 4aab96cf0818..3cde7c1b9c33 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -49,6 +49,7 @@
 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV	BIT(0)
 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET	BIT(1)
 #define I2C_HID_QUIRK_NO_RUNTIME_PM		BIT(2)
+#define I2C_HID_QUIRK_DELAY_AFTER_SLEEP		BIT(3)
 
 /* flags */
 #define I2C_HID_STARTED		0
@@ -158,6 +159,8 @@ struct i2c_hid {
 
 	bool			irq_wake_enabled;
 	struct mutex		reset_lock;
+
+	unsigned long		sleep_delay;
 };
 
 static const struct i2c_hid_quirks {
@@ -172,6 +175,8 @@ static const struct i2c_hid_quirks {
 	{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
 		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET |
 		I2C_HID_QUIRK_NO_RUNTIME_PM },
+	{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_4B33,
+		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
 	{ 0, 0 }
 };
 
@@ -387,6 +392,7 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 {
 	struct i2c_hid *ihid = i2c_get_clientdata(client);
 	int ret;
+	unsigned long now, delay;
 
 	i2c_hid_dbg(ihid, "%s\n", __func__);
 
@@ -404,9 +410,22 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 			goto set_pwr_exit;
 	}
 
+	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
+	    power_state == I2C_HID_PWR_ON) {
+		now = jiffies;
+		if (time_after(ihid->sleep_delay, now)) {
+			delay = jiffies_to_usecs(ihid->sleep_delay - now);
+			usleep_range(delay, delay + 1);
+		}
+	}
+
 	ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 		0, NULL, 0, NULL, 0);
 
+	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
+	    power_state == I2C_HID_PWR_SLEEP)
+		ihid->sleep_delay = jiffies + msecs_to_jiffies(20);
+
 	if (ret)
 		dev_err(&client->dev, "failed to change power setting.\n");
 
-- 
2.17.1