[PATCH 2/4] HID: hid-oxp: Add Second Generation RGB Control

["Derek J. Clark" <derekjohn.clark@gmail.com>]

Adds support for the second generation of RGB Control for OneXPlayer
devices. The interface mirrors the first generation, with some
differences to how messages are formatted.

Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
 drivers/hid/hid-ids.h |  3 ++
 drivers/hid/hid-oxp.c | 96 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 8b272d1ab9ba..b33782ba6556 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -1105,6 +1105,9 @@
 #define USB_VENDOR_ID_CRSC			0x1a2c
 #define USB_DEVICE_ID_ONEXPLAYER_GEN1		0xb001
 
+#define USB_VENDOR_ID_WCH			0x1a86
+#define USB_DEVICE_ID_ONEXPLAYER_GEN2		0xfe00
+
 #define USB_VENDOR_ID_ONTRAK		0x0a07
 #define USB_DEVICE_ID_ONTRAK_ADU100	0x0064
 
diff --git a/drivers/hid/hid-oxp.c b/drivers/hid/hid-oxp.c
index 391de2798320..587e0d57c85f 100644
--- a/drivers/hid/hid-oxp.c
+++ b/drivers/hid/hid-oxp.c
@@ -24,12 +24,15 @@
 #define OXP_PACKET_SIZE 64
 
 #define GEN1_MESSAGE_ID	0xff
+#define GEN2_MESSAGE_ID	0x3f
 
 #define GEN1_USAGE_PAGE	0xff01
+#define GEN2_USAGE_PAGE	0xff00
 
 enum oxp_function_index {
 	OXP_FID_GEN1_RGB_SET =		0x07,
 	OXP_FID_GEN1_RGB_REPLY =	0x0f,
+	OXP_FID_GEN2_RGB_EVENT =	0xb8,
 };
 
 static struct oxp_hid_cfg {
@@ -121,6 +124,22 @@ struct oxp_gen_1_rgb_report {
 	u8 blue;
 } __packed;
 
+struct oxp_gen_2_rgb_report {
+	u8 report_id;
+	u8 header_id;
+	u8 padding_2;
+	u8 message_id;
+	u8 padding_4[2];
+	u8 enabled;
+	u8 speed;
+	u8 brightness;
+	u8 red;
+	u8 green;
+	u8 blue;
+	u8 padding_12[3];
+	u8 effect;
+} __packed;
+
 static u16 get_usage_page(struct hid_device *hdev)
 {
 	return hdev->collection[0].usage >> 16;
@@ -162,6 +181,45 @@ static int oxp_hid_raw_event_gen_1(struct hid_device *hdev,
 	return 0;
 }
 
+static int oxp_hid_raw_event_gen_2(struct hid_device *hdev,
+				   struct hid_report *report, u8 *data,
+				   int size)
+{
+	struct led_classdev_mc *led_mc = drvdata.led_mc;
+	struct oxp_gen_2_rgb_report *rgb_rep;
+
+	if (data[0] != OXP_FID_GEN2_RGB_EVENT)
+		return 0;
+
+	if (data[3] != OXP_GET_PROPERTY)
+		return 0;
+
+	rgb_rep = (struct oxp_gen_2_rgb_report *)data;
+	/* Ensure we save monocolor as the list value */
+	drvdata.rgb_effect =
+		rgb_rep->effect == OXP_EFFECT_MONO_TRUE ?
+				   OXP_EFFECT_MONO_LIST :
+				   rgb_rep->effect;
+	drvdata.rgb_speed = rgb_rep->speed;
+	drvdata.rgb_en = rgb_rep->enabled == 0 ? OXP_FEAT_DISABLED :
+						 OXP_FEAT_ENABLED;
+	drvdata.rgb_brightness = rgb_rep->brightness;
+	led_mc->led_cdev.brightness = rgb_rep->brightness / 4 *
+				      led_mc->led_cdev.max_brightness;
+	/* If monocolor had less than 100% brightness on the previous boot,
+	 * there will be no reliable way to determine the real intensity.
+	 * Since intensity scaling is used with a hardware brightness set at max,
+	 * our brightness will always look like 100%. Use the last set value to
+	 * prevent successive boots from lowering the brightness further.
+	 * Brightness will be "wrong" but the effect will remain the same visually.
+	 */
+	led_mc->subled_info[0].intensity = rgb_rep->red;
+	led_mc->subled_info[1].intensity = rgb_rep->green;
+	led_mc->subled_info[2].intensity = rgb_rep->blue;
+
+	return 0;
+}
+
 static int oxp_hid_raw_event(struct hid_device *hdev, struct hid_report *report,
 			     u8 *data, int size)
 {
@@ -172,6 +230,8 @@ static int oxp_hid_raw_event(struct hid_device *hdev, struct hid_report *report,
 	switch (up) {
 	case GEN1_USAGE_PAGE:
 		return oxp_hid_raw_event_gen_1(hdev, report, data, size);
+	case GEN2_USAGE_PAGE:
+		return oxp_hid_raw_event_gen_2(hdev, report, data, size);
 	default:
 		break;
 	}
@@ -217,6 +277,18 @@ static int oxp_gen_1_property_out(enum oxp_function_index fid, u8 *data,
 	return mcu_property_out(header, header_size, data, data_size, NULL, 0);
 }
 
+static int oxp_gen_2_property_out(enum oxp_function_index fid, u8 *data,
+				  u8 data_size)
+{
+	u8 header[] = { fid, GEN2_MESSAGE_ID, 0x01 };
+	u8 footer[] = { GEN2_MESSAGE_ID, fid };
+	size_t header_size = ARRAY_SIZE(header);
+	size_t footer_size = ARRAY_SIZE(footer);
+
+	return mcu_property_out(header, header_size, data, data_size, footer,
+				footer_size);
+}
+
 static int oxp_rgb_status_store(u8 enabled, u8 speed, u8 brightness)
 {
 	u16 up = get_usage_page(drvdata.hdev);
@@ -231,6 +303,11 @@ static int oxp_rgb_status_store(u8 enabled, u8 speed, u8 brightness)
 		if (drvdata.rgb_effect == OXP_EFFECT_MONO_LIST)
 			data[3] = 0x04;
 		return oxp_gen_1_property_out(OXP_FID_GEN1_RGB_SET, data, 4);
+	case GEN2_USAGE_PAGE:
+		data = (u8[6]) { OXP_SET_PROPERTY, 0x00, 0x02, enabled, speed, brightness };
+		if (drvdata.rgb_effect == OXP_EFFECT_MONO_LIST)
+			data[5] = 0x04;
+		return oxp_gen_2_property_out(OXP_FID_GEN2_RGB_EVENT, data, 6);
 	default:
 		return -ENODEV;
 	}
@@ -245,6 +322,9 @@ static ssize_t oxp_rgb_status_show(void)
 	case GEN1_USAGE_PAGE:
 		data = (u8[1]) { OXP_GET_PROPERTY };
 		return oxp_gen_1_property_out(OXP_FID_GEN1_RGB_SET, data, 1);
+	case GEN2_USAGE_PAGE:
+		data = (u8[3]) { OXP_GET_PROPERTY, 0x00, 0x02 };
+		return oxp_gen_2_property_out(OXP_FID_GEN2_RGB_EVENT, data, 3);
 	default:
 		return -ENODEV;
 	}
@@ -275,6 +355,16 @@ static int oxp_rgb_color_set(void)
 			data[3 * i + 3] = blue;
 		}
 		return oxp_gen_1_property_out(OXP_FID_GEN1_RGB_SET, data, size);
+	case GEN2_USAGE_PAGE:
+		size = 57;
+		data = (u8[57]) { OXP_EFFECT_MONO_TRUE, 0x00, 0x02 };
+
+		for (i = 1; i < size / 3; i++) {
+			data[3 * i] = red;
+			data[3 * i + 1] = green;
+			data[3 * i + 2] = blue;
+		}
+		return oxp_gen_2_property_out(OXP_FID_GEN2_RGB_EVENT, data, size);
 	default:
 		return -ENODEV;
 	}
@@ -311,6 +401,10 @@ static int oxp_rgb_effect_set(u8 effect)
 			data = (u8[1]) { effect };
 			ret = oxp_gen_1_property_out(OXP_FID_GEN1_RGB_SET, data, 1);
 			break;
+		case GEN2_USAGE_PAGE:
+			data = (u8[3]) { effect, 0x00, 0x02 };
+			ret = oxp_gen_2_property_out(OXP_FID_GEN2_RGB_EVENT, data, 3);
+			break;
 		default:
 			ret = -ENODEV;
 		}
@@ -614,6 +708,7 @@ static int oxp_hid_probe(struct hid_device *hdev,
 
 	switch (up) {
 	case GEN1_USAGE_PAGE:
+	case GEN2_USAGE_PAGE:
 		ret = oxp_cfg_probe(hdev, up);
 		if (ret) {
 			hid_hw_close(hdev);
@@ -634,6 +729,7 @@ static void oxp_hid_remove(struct hid_device *hdev)
 
 static const struct hid_device_id oxp_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CRSC, USB_DEVICE_ID_ONEXPLAYER_GEN1) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WCH, USB_DEVICE_ID_ONEXPLAYER_GEN2) },
 	{}
 };
 
-- 
2.53.0