4 files changed, 136 insertions, 47 deletions

diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
index ef7c595c9403..e8d51f410cc1 100644
--- a/drivers/hid/i2c-hid/Kconfig
+++ b/drivers/hid/i2c-hid/Kconfig
@@ -2,7 +2,7 @@
 menuconfig I2C_HID
 	tristate "I2C HID support"
 	default y
-	depends on I2C && INPUT && HID
+	depends on I2C
 
 if I2C_HID
 
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index d965382196c6..d3912e3f2f13 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -36,7 +36,7 @@
 #include <linux/kernel.h>
 #include <linux/hid.h>
 #include <linux/mutex.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
 
 #include <drm/drm_panel.h>
 
@@ -50,6 +50,8 @@
 #define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(3)
 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET	BIT(4)
 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND	BIT(5)
+#define I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME BIT(6)
+#define I2C_HID_QUIRK_RE_POWER_ON		BIT(7)
 
 /* Command opcodes */
 #define I2C_HID_OPCODE_RESET			0x01
@@ -105,6 +107,7 @@ struct i2c_hid {
 
 	wait_queue_head_t	wait;		/* For waiting the interrupt */
 
+	struct mutex		cmd_lock;	/* protects cmdbuf and rawbuf */
 	struct mutex		reset_lock;
 
 	struct i2chid_ops	*ops;
@@ -134,11 +137,18 @@ static const struct i2c_hid_quirks {
 	{ I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
 		I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
 	/*
+	 * Without additional power on command, at least some QTEC devices send garbage
+	 */
+	{ I2C_VENDOR_ID_QTEC, HID_ANY_ID,
+		I2C_HID_QUIRK_RE_POWER_ON },
+	/*
 	 * Sending the wakeup after reset actually break ELAN touchscreen controller
 	 */
 	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
 		 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 		 I2C_HID_QUIRK_BOGUS_IRQ },
+	{ I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42,
+		 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME },
 	{ 0, 0 }
 };
 
@@ -163,6 +173,24 @@ static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
 	return quirks;
 }
 
+static int i2c_hid_probe_address(struct i2c_hid *ihid)
+{
+	int ret;
+
+	/*
+	 * Some STM-based devices need 400µs after a rising clock edge to wake
+	 * from deep sleep, in which case the first read will fail. Try after a
+	 * short sleep to see if the device came alive on the bus. Certain
+	 * Weida Tech devices also need this.
+	 */
+	ret = i2c_smbus_read_byte(ihid->client);
+	if (ret < 0) {
+		usleep_range(400, 500);
+		ret = i2c_smbus_read_byte(ihid->client);
+	}
+	return ret < 0 ? ret : 0;
+}
+
 static int i2c_hid_xfer(struct i2c_hid *ihid,
 			u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
 {
@@ -202,6 +230,8 @@ static int i2c_hid_xfer(struct i2c_hid *ihid,
 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
 				 void *buf, size_t len)
 {
+	guard(mutex)(&ihid->cmd_lock);
+
 	*(__le16 *)ihid->cmdbuf = reg;
 
 	return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
@@ -234,6 +264,8 @@ static int i2c_hid_get_report(struct i2c_hid *ihid,
 
 	i2c_hid_dbg(ihid, "%s\n", __func__);
 
+	guard(mutex)(&ihid->cmd_lock);
+
 	/* Command register goes first */
 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 	length += sizeof(__le16);
@@ -258,7 +290,7 @@ static int i2c_hid_get_report(struct i2c_hid *ihid,
 			     ihid->rawbuf, recv_len + sizeof(__le16));
 	if (error) {
 		dev_err(&ihid->client->dev,
-			"failed to set a report to device: %d\n", error);
+			"failed to get a report from device: %d\n", error);
 		return error;
 	}
 
@@ -324,6 +356,8 @@ static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
 	if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
 		return -ENOSYS;
 
+	guard(mutex)(&ihid->cmd_lock);
+
 	if (do_set) {
 		/* Command register goes first */
 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
@@ -366,6 +400,8 @@ static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
 {
 	size_t length;
 
+	guard(mutex)(&ihid->cmd_lock);
+
 	/* SET_POWER uses command register */
 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
 	length = sizeof(__le16);
@@ -385,25 +421,22 @@ static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
 	i2c_hid_dbg(ihid, "%s\n", __func__);
 
 	/*
-	 * Some devices require to send a command to wakeup before power on.
-	 * The call will get a return value (EREMOTEIO) but device will be
-	 * triggered and activated. After that, it goes like a normal device.
+	 * Some STM-based devices need 400µs after a rising clock edge to wake
+	 * from deep sleep, in which case the first request will fail due to
+	 * the address not being acknowledged. Try after a short sleep to see
+	 * if the device came alive on the bus. Certain Weida Tech devices also
+	 * need this.
 	 */
-	if (power_state == I2C_HID_PWR_ON) {
+	ret = i2c_hid_set_power_command(ihid, power_state);
+	if (ret && power_state == I2C_HID_PWR_ON) {
+		usleep_range(400, 500);
 		ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
-
-		/* Device was already activated */
-		if (!ret)
-			goto set_pwr_exit;
 	}
 
-	ret = i2c_hid_set_power_command(ihid, power_state);
 	if (ret)
 		dev_err(&ihid->client->dev,
 			"failed to change power setting.\n");
 
-set_pwr_exit:
-
 	/*
 	 * The HID over I2C specification states that if a DEVICE needs time
 	 * after the PWR_ON request, it should utilise CLOCK stretching.
@@ -437,25 +470,27 @@ static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
 	if (ret)
 		return ret;
 
-	/* Prepare reset command. Command register goes first. */
-	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
-	length += sizeof(__le16);
-	/* Next is RESET command itself */
-	length += i2c_hid_encode_command(ihid->cmdbuf + length,
-					 I2C_HID_OPCODE_RESET, 0, 0);
+	scoped_guard(mutex, &ihid->cmd_lock) {
+		/* Prepare reset command. Command register goes first. */
+		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
+		length += sizeof(__le16);
+		/* Next is RESET command itself */
+		length += i2c_hid_encode_command(ihid->cmdbuf + length,
+						 I2C_HID_OPCODE_RESET, 0, 0);
 
-	set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
+		set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 
-	ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
-	if (ret) {
-		dev_err(&ihid->client->dev,
-			"failed to reset device: %d\n", ret);
-		goto err_clear_reset;
-	}
+		ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
+		if (ret) {
+			dev_err(&ihid->client->dev,
+				"failed to reset device: %d\n", ret);
+			break;
+		}
 
-	return 0;
+		return 0;
+	}
 
-err_clear_reset:
+	/* Clean up if sending reset command failed */
 	clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
 	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 	return ret;
@@ -959,6 +994,13 @@ static int i2c_hid_core_resume(struct i2c_hid *ihid)
 
 	enable_irq(client->irq);
 
+	/* On Goodix 27c6:0d42 wait extra time before device wakeup.
+	 * It's not clear why but if we send wakeup too early, the device will
+	 * never trigger input interrupts.
+	 */
+	if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
+		msleep(1500);
+
 	/* Instead of resetting device, simply powers the device on. This
 	 * solves "incomplete reports" on Raydium devices 2386:3118 and
 	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
@@ -992,8 +1034,7 @@ static int __i2c_hid_core_probe(struct i2c_hid *ihid)
 	struct hid_device *hid = ihid->hid;
 	int ret;
 
-	/* Make sure there is something at this address */
-	ret = i2c_smbus_read_byte(client);
+	ret = i2c_hid_probe_address(ihid);
 	if (ret < 0) {
 		i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
 		return -ENXIO;
@@ -1038,7 +1079,11 @@ static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
 		return ret;
 	}
 
-	return 0;
+	/* At least some QTEC devices need this after initialization */
+	if (ihid->quirks & I2C_HID_QUIRK_RE_POWER_ON)
+		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
+
+	return ret;
 }
 
 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
@@ -1190,6 +1235,7 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 	ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
 
 	init_waitqueue_head(&ihid->wait);
+	mutex_init(&ihid->cmd_lock);
 	mutex_init(&ihid->reset_lock);
 	INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
 
diff --git a/drivers/hid/i2c-hid/i2c-hid-of-elan.c b/drivers/hid/i2c-hid/i2c-hid-of-elan.c
index 5b91fb106cfc..3fcff6daa0d3 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of-elan.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of-elan.c
@@ -31,6 +31,7 @@ struct i2c_hid_of_elan {
 	struct regulator *vcc33;
 	struct regulator *vccio;
 	struct gpio_desc *reset_gpio;
+	bool no_reset_on_power_off;
 	const struct elan_i2c_hid_chip_data *chip_data;
 };
 
@@ -40,17 +41,17 @@ static int elan_i2c_hid_power_up(struct i2chid_ops *ops)
 		container_of(ops, struct i2c_hid_of_elan, ops);
 	int ret;
 
+	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
+
 	if (ihid_elan->vcc33) {
 		ret = regulator_enable(ihid_elan->vcc33);
 		if (ret)
-			return ret;
+			goto err_deassert_reset;
 	}
 
 	ret = regulator_enable(ihid_elan->vccio);
-	if (ret) {
-		regulator_disable(ihid_elan->vcc33);
-		return ret;
-	}
+	if (ret)
+		goto err_disable_vcc33;
 
 	if (ihid_elan->chip_data->post_power_delay_ms)
 		msleep(ihid_elan->chip_data->post_power_delay_ms);
@@ -60,6 +61,15 @@ static int elan_i2c_hid_power_up(struct i2chid_ops *ops)
 		msleep(ihid_elan->chip_data->post_gpio_reset_on_delay_ms);
 
 	return 0;
+
+err_disable_vcc33:
+	if (ihid_elan->vcc33)
+		regulator_disable(ihid_elan->vcc33);
+err_deassert_reset:
+	if (ihid_elan->no_reset_on_power_off)
+		gpiod_set_value_cansleep(ihid_elan->reset_gpio, 0);
+
+	return ret;
 }
 
 static void elan_i2c_hid_power_down(struct i2chid_ops *ops)
@@ -67,7 +77,14 @@ static void elan_i2c_hid_power_down(struct i2chid_ops *ops)
 	struct i2c_hid_of_elan *ihid_elan =
 		container_of(ops, struct i2c_hid_of_elan, ops);
 
-	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
+	/*
+	 * Do not assert reset when the hardware allows for it to remain
+	 * deasserted regardless of the state of the (shared) power supply to
+	 * avoid wasting power when the supply is left on.
+	 */
+	if (!ihid_elan->no_reset_on_power_off)
+		gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
+
 	if (ihid_elan->chip_data->post_gpio_reset_off_delay_ms)
 		msleep(ihid_elan->chip_data->post_gpio_reset_off_delay_ms);
 
@@ -79,6 +96,7 @@ static void elan_i2c_hid_power_down(struct i2chid_ops *ops)
 static int i2c_hid_of_elan_probe(struct i2c_client *client)
 {
 	struct i2c_hid_of_elan *ihid_elan;
+	int ret;
 
 	ihid_elan = devm_kzalloc(&client->dev, sizeof(*ihid_elan), GFP_KERNEL);
 	if (!ihid_elan)
@@ -93,21 +111,38 @@ static int i2c_hid_of_elan_probe(struct i2c_client *client)
 	if (IS_ERR(ihid_elan->reset_gpio))
 		return PTR_ERR(ihid_elan->reset_gpio);
 
+	ihid_elan->no_reset_on_power_off = of_property_read_bool(client->dev.of_node,
+						"no-reset-on-power-off");
+
 	ihid_elan->vccio = devm_regulator_get(&client->dev, "vccio");
-	if (IS_ERR(ihid_elan->vccio))
-		return PTR_ERR(ihid_elan->vccio);
+	if (IS_ERR(ihid_elan->vccio)) {
+		ret = PTR_ERR(ihid_elan->vccio);
+		goto err_deassert_reset;
+	}
 
 	ihid_elan->chip_data = device_get_match_data(&client->dev);
 
 	if (ihid_elan->chip_data->main_supply_name) {
 		ihid_elan->vcc33 = devm_regulator_get(&client->dev,
 						      ihid_elan->chip_data->main_supply_name);
-		if (IS_ERR(ihid_elan->vcc33))
-			return PTR_ERR(ihid_elan->vcc33);
+		if (IS_ERR(ihid_elan->vcc33)) {
+			ret = PTR_ERR(ihid_elan->vcc33);
+			goto err_deassert_reset;
+		}
 	}
 
-	return i2c_hid_core_probe(client, &ihid_elan->ops,
-				  ihid_elan->chip_data->hid_descriptor_address, 0);
+	ret = i2c_hid_core_probe(client, &ihid_elan->ops,
+				 ihid_elan->chip_data->hid_descriptor_address, 0);
+	if (ret)
+		goto err_deassert_reset;
+
+	return 0;
+
+err_deassert_reset:
+	if (ihid_elan->no_reset_on_power_off)
+		gpiod_set_value_cansleep(ihid_elan->reset_gpio, 0);
+
+	return ret;
 }
 
 static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
@@ -117,6 +152,13 @@ static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
 	.main_supply_name = "vcc33",
 };
 
+static const struct elan_i2c_hid_chip_data elan_ekth6a12nay_chip_data = {
+	.post_power_delay_ms = 10,
+	.post_gpio_reset_on_delay_ms = 300,
+	.hid_descriptor_address = 0x0001,
+	.main_supply_name = "vcc33",
+};
+
 static const struct elan_i2c_hid_chip_data ilitek_ili9882t_chip_data = {
 	.post_power_delay_ms = 1,
 	.post_gpio_reset_on_delay_ms = 200,
@@ -139,6 +181,7 @@ static const struct elan_i2c_hid_chip_data ilitek_ili2901_chip_data = {
 
 static const struct of_device_id elan_i2c_hid_of_match[] = {
 	{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },
+	{ .compatible = "elan,ekth6a12nay", .data = &elan_ekth6a12nay_chip_data },
 	{ .compatible = "ilitek,ili9882t", .data = &ilitek_ili9882t_chip_data },
 	{ .compatible = "ilitek,ili2901", .data = &ilitek_ili2901_chip_data },
 	{ }
diff --git a/drivers/hid/i2c-hid/i2c-hid-of.c b/drivers/hid/i2c-hid/i2c-hid-of.c
index 8be4d576da77..57379b77e977 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of.c
@@ -144,9 +144,9 @@ MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
 #endif
 
 static const struct i2c_device_id i2c_hid_of_id_table[] = {
-	{ "hid", 0 },
-	{ "hid-over-i2c", 0 },
-	{ },
+	{ "hid" },
+	{ "hid-over-i2c" },
+	{ }
 };
 MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table);