HID: i2c-hid: add a simple quirk to fix device defects

Certain devices produced by Weida Tech need to have a wakeup command sent to
them before powering on. The call itself will come back with error, but the
device can be powered on afterwards.

[jkosina@suse.cz: rewrite changelog]
[jkosina@suse.cz: remove unused device ID addition]
Signed-off-by: HungNien Chen <hn.chen@weidahitech.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-ids.h

@@ -1030,6 +1030,10 @@
 #define USB_DEVICE_ID_WALTOP_MEDIA_TABLET_14_1_INCH	0x0500
 #define USB_DEVICE_ID_WALTOP_SIRIUS_BATTERY_FREE_TABLET	0x0502
 
+#define	USB_VENDOR_ID_WEIDA		0x2575
+#define	USB_DEVICE_ID_WEIDA_8752	0xC300
+#define	USB_DEVICE_ID_WEIDA_8755	0xC301
+
 #define USB_VENDOR_ID_WISEGROUP		0x0925
 #define USB_DEVICE_ID_SMARTJOY_PLUS	0x0005
 #define USB_DEVICE_ID_SUPER_JOY_BOX_3	0x8888

drivers/hid/i2c-hid/i2c-hid.c

@@ -40,6 +40,11 @@
 
 #include <linux/i2c/i2c-hid.h>
 
+#include "../hid-ids.h"
+
+/* quirks to control the device */
+#define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV	BIT(0)
+
 /* flags */
 #define I2C_HID_STARTED		0
 #define I2C_HID_RESET_PENDING	1
@@ -142,6 +147,7 @@ struct i2c_hid {
 	char			*argsbuf;	/* Command arguments buffer */
 
 	unsigned long		flags;		/* device flags */
+	unsigned long		quirks;		/* Various quirks */
 
 	wait_queue_head_t	wait;		/* For waiting the interrupt */
 
@@ -151,6 +157,39 @@ struct i2c_hid {
 	struct mutex		reset_lock;
 };
 
+static const struct i2c_hid_quirks {
+	__u16 idVendor;
+	__u16 idProduct;
+	__u32 quirks;
+} i2c_hid_quirks[] = {
+	{ USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
+		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
+	{ USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
+		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
+	{ 0, 0 }
+};
+
+/*
+ * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
+ * @idVendor: the 16-bit vendor ID
+ * @idProduct: the 16-bit product ID
+ *
+ * Returns: a u32 quirks value.
+ */
+static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
+{
+	u32 quirks = 0;
+	int n;
+
+	for (n = 0; i2c_hid_quirks[n].idVendor; n++)
+		if (i2c_hid_quirks[n].idVendor == idVendor &&
+		    (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
+		     i2c_hid_quirks[n].idProduct == idProduct))
+			quirks = i2c_hid_quirks[n].quirks;
+
+	return quirks;
+}
+
 static int __i2c_hid_command(struct i2c_client *client,
 		const struct i2c_hid_cmd *command, u8 reportID,
 		u8 reportType, u8 *args, int args_len,
@@ -343,11 +382,27 @@ static int i2c_hid_set_power(struct i2c_client *client, 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.
+	 */
+	if (power_state == I2C_HID_PWR_ON &&
+	    ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
+		ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
+
+		/* Device was already activated */
+		if (!ret)
+			goto set_pwr_exit;
+	}
+
 	ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
 		0, NULL, 0, NULL, 0);
+
 	if (ret)
 		dev_err(&client->dev, "failed to change power setting.\n");
 
+set_pwr_exit:
 	return ret;
 }
 
@@ -1032,6 +1087,8 @@ static int i2c_hid_probe(struct i2c_client *client,
 		 client->name, hid->vendor, hid->product);
 	strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
 
+	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
+
 	ret = hid_add_device(hid);
 	if (ret) {
 		if (ret != -ENODEV)