HID: add support for MSI GT683R led panels

This driver adds support for USB controlled led panels that exists in
MSI GT683R laptop

Signed-off-by: Janne Kanniainen <janne.kanniainen@gmail.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 309 insertions, 0 deletions

diff --git a/drivers/hid/hid-gt683r.c b/drivers/hid/hid-gt683r.c
new file mode 100644
index 000000000000..077f7a19c9d5
--- /dev/null
+++ b/drivers/hid/hid-gt683r.c
@@ -0,0 +1,309 @@
+/*
+ * MSI GT683R led driver
+ *
+ * Copyright (c) 2014 Janne Kanniainen <janne.kanniainen@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define GT683R_BUFFER_SIZE			8
+
+/*
+ * GT683R_LED_OFF: all LEDs are off
+ * GT683R_LED_AUDIO: LEDs brightness depends on sound level
+ * GT683R_LED_BREATHING: LEDs brightness varies at human breathing rate
+ * GT683R_LED_NORMAL: LEDs are fully on when enabled
+ */
+enum gt683r_led_mode {
+	GT683R_LED_OFF = 0,
+	GT683R_LED_AUDIO = 2,
+	GT683R_LED_BREATHING = 3,
+	GT683R_LED_NORMAL = 5
+};
+
+enum gt683r_panels {
+	GT683R_LED_BACK = 0,
+	GT683R_LED_SIDE = 1,
+	GT683R_LED_FRONT = 2,
+	GT683R_LED_COUNT,
+};
+
+static const char * const gt683r_panel_names[] = {
+	"back",
+	"side",
+	"front",
+};
+
+struct gt683r_led {
+	struct hid_device *hdev;
+	struct led_classdev led_devs[GT683R_LED_COUNT];
+	struct mutex lock;
+	struct work_struct work;
+	enum led_brightness brightnesses[GT683R_LED_COUNT];
+	enum gt683r_led_mode mode;
+};
+
+static const struct hid_device_id gt683r_led_id[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MSI, USB_DEVICE_ID_MSI_GT683R_LED_PANEL) },
+	{ }
+};
+
+static void gt683r_brightness_set(struct led_classdev *led_cdev,
+				enum led_brightness brightness)
+{
+	int i;
+	struct device *dev = led_cdev->dev->parent;
+	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
+	struct gt683r_led *led = hid_get_drvdata(hdev);
+
+	for (i = 0; i < GT683R_LED_COUNT; i++) {
+		if (led_cdev == &led->led_devs[i])
+			break;
+	}
+
+	if (i < GT683R_LED_COUNT) {
+		led->brightnesses[i] = brightness;
+		schedule_work(&led->work);
+	}
+}
+
+static ssize_t leds_mode_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	u8 sysfs_mode;
+	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
+	struct gt683r_led *led = hid_get_drvdata(hdev);
+
+	if (led->mode == GT683R_LED_NORMAL)
+		sysfs_mode = 0;
+	else if (led->mode == GT683R_LED_AUDIO)
+		sysfs_mode = 1;
+	else
+		sysfs_mode = 2;
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", sysfs_mode);
+}
+
+static ssize_t leds_mode_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	u8 sysfs_mode;
+	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
+	struct gt683r_led *led = hid_get_drvdata(hdev);
+
+
+	if (kstrtou8(buf, 10, &sysfs_mode) || sysfs_mode > 2)
+		return -EINVAL;
+
+	mutex_lock(&led->lock);
+
+	if (sysfs_mode == 0)
+		led->mode = GT683R_LED_NORMAL;
+	else if (sysfs_mode == 1)
+		led->mode = GT683R_LED_AUDIO;
+	else
+		led->mode = GT683R_LED_BREATHING;
+
+	mutex_unlock(&led->lock);
+	schedule_work(&led->work);
+
+	return count;
+}
+
+static int gt683r_led_snd_msg(struct gt683r_led *led, u8 *msg)
+{
+	int ret;
+
+	ret = hid_hw_raw_request(led->hdev, msg[0], msg, GT683R_BUFFER_SIZE,
+				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+	if (ret != GT683R_BUFFER_SIZE) {
+		hid_err(led->hdev,
+			"failed to send set report request: %i\n", ret);
+		if (ret < 0)
+			return ret;
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int gt683r_leds_set(struct gt683r_led *led, u8 leds)
+{
+	int ret;
+	u8 *buffer;
+
+	buffer = kzalloc(GT683R_BUFFER_SIZE, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	buffer[0] = 0x01;
+	buffer[1] = 0x02;
+	buffer[2] = 0x30;
+	buffer[3] = leds;
+	ret = gt683r_led_snd_msg(led, buffer);
+
+	kfree(buffer);
+	return ret;
+}
+
+static int gt683r_mode_set(struct gt683r_led *led, u8 mode)
+{
+	int ret;
+	u8 *buffer;
+
+	buffer = kzalloc(GT683R_BUFFER_SIZE, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	buffer[0] = 0x01;
+	buffer[1] = 0x02;
+	buffer[2] = 0x20;
+	buffer[3] = mode;
+	buffer[4] = 0x01;
+	ret = gt683r_led_snd_msg(led, buffer);
+
+	kfree(buffer);
+	return ret;
+}
+
+static void gt683r_led_work(struct work_struct *work)
+{
+	int i;
+	u8 leds = 0;
+	u8 mode;
+	struct gt683r_led *led = container_of(work, struct gt683r_led, work);
+
+	mutex_lock(&led->lock);
+
+	for (i = 0; i < GT683R_LED_COUNT; i++) {
+		if (led->brightnesses[i])
+			leds |= BIT(i);
+	}
+
+	if (gt683r_leds_set(led, leds))
+		goto fail;
+
+	if (leds)
+		mode = led->mode;
+	else
+		mode = GT683R_LED_OFF;
+
+	gt683r_mode_set(led, mode);
+fail:
+	mutex_unlock(&led->lock);
+}
+
+static DEVICE_ATTR_RW(leds_mode);
+
+static int gt683r_led_probe(struct hid_device *hdev,
+			const struct hid_device_id *id)
+{
+	int i;
+	int ret;
+	int name_sz;
+	char *name;
+	struct gt683r_led *led;
+
+	led = devm_kzalloc(&hdev->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->mode = GT683R_LED_NORMAL;
+	led->hdev = hdev;
+	hid_set_drvdata(hdev, led);
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "hid parsing failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	for (i = 0; i < GT683R_LED_COUNT; i++) {
+		name_sz = strlen(dev_name(&hdev->dev)) +
+				strlen(gt683r_panel_names[i]) + 3;
+
+		name = devm_kzalloc(&hdev->dev, name_sz, GFP_KERNEL);
+		if (!name) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		snprintf(name, name_sz, "%s::%s",
+				dev_name(&hdev->dev), gt683r_panel_names[i]);
+		led->led_devs[i].name = name;
+		led->led_devs[i].max_brightness = 1;
+		led->led_devs[i].brightness_set = gt683r_brightness_set;
+		ret = led_classdev_register(&hdev->dev, &led->led_devs[i]);
+		if (ret) {
+			hid_err(hdev, "could not register led device\n");
+			goto fail;
+		}
+	}
+
+	ret = device_create_file(&led->hdev->dev, &dev_attr_leds_mode);
+	if (ret) {
+		hid_err(hdev, "could not make mode attribute file\n");
+		goto fail;
+	}
+
+	mutex_init(&led->lock);
+	INIT_WORK(&led->work, gt683r_led_work);
+
+	return 0;
+
+fail:
+	for (i = i - 1; i >= 0; i--)
+		led_classdev_unregister(&led->led_devs[i]);
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void gt683r_led_remove(struct hid_device *hdev)
+{
+	int i;
+	struct gt683r_led *led = hid_get_drvdata(hdev);
+
+	device_remove_file(&hdev->dev, &dev_attr_leds_mode);
+	for (i = 0; i < GT683R_LED_COUNT; i++)
+		led_classdev_unregister(&led->led_devs[i]);
+	flush_work(&led->work);
+	hid_hw_stop(hdev);
+}
+
+static struct hid_driver gt683r_led_driver = {
+	.probe = gt683r_led_probe,
+	.remove = gt683r_led_remove,
+	.name = "gt683r_led",
+	.id_table = gt683r_led_id,
+};
+
+module_hid_driver(gt683r_led_driver);
+
+MODULE_AUTHOR("Janne Kanniainen");
+MODULE_DESCRIPTION("MSI GT683R led driver");
+MODULE_LICENSE("GPL");