Fixed MTP to work with TWRP

drivers/leds/leds-syscon.c

@@ -0,0 +1,166 @@
+/*
+ * Generic Syscon LEDs Driver
+ *
+ * Copyright (c) 2014, Linaro Limited
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * This driver provides system reboot functionality for APM X-Gene SoC.
+ * For system shutdown, this is board specify. If a board designer
+ * implements GPIO shutdown, use the gpio-poweroff.c driver.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/leds.h>
+
+/**
+ * struct syscon_led - state container for syscon based LEDs
+ * @cdev: LED class device for this LED
+ * @map: regmap to access the syscon device backing this LED
+ * @offset: the offset into the syscon regmap for the LED register
+ * @mask: the bit in the register corresponding to the LED
+ * @state: current state of the LED
+ */
+struct syscon_led {
+	struct led_classdev cdev;
+	struct regmap *map;
+	u32 offset;
+	u32 mask;
+	bool state;
+};
+
+static void syscon_led_set(struct led_classdev *led_cdev,
+	enum led_brightness value)
+{
+	struct syscon_led *sled =
+		container_of(led_cdev, struct syscon_led, cdev);
+	u32 val;
+	int ret;
+
+	if (value == LED_OFF) {
+		val = 0;
+		sled->state = false;
+	} else {
+		val = sled->mask;
+		sled->state = true;
+	}
+
+	ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
+	if (ret < 0)
+		dev_err(sled->cdev.dev, "error updating LED status\n");
+}
+
+static const struct of_device_id syscon_match[] = {
+	{ .compatible = "syscon", },
+	{},
+};
+
+static int __init syscon_leds_init(void)
+{
+	const struct of_device_id *devid;
+	struct device_node *np;
+	struct device_node *child;
+	struct regmap *map;
+	struct platform_device *pdev;
+	struct device *dev;
+	int ret;
+
+	np = of_find_matching_node_and_match(NULL, syscon_match,
+					     &devid);
+	if (!np)
+		return -ENODEV;
+
+	map = syscon_node_to_regmap(np);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	/*
+	 * If the map is there, the device should be there, we allocate
+	 * memory on the syscon device's behalf here.
+	 */
+	pdev = of_find_device_by_node(np);
+	if (!pdev)
+		return -ENODEV;
+	dev = &pdev->dev;
+
+	for_each_available_child_of_node(np, child) {
+		struct syscon_led *sled;
+		const char *state;
+
+		/* Only check for register-bit-leds */
+		if (of_property_match_string(child, "compatible",
+					     "register-bit-led") < 0)
+			continue;
+
+		sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
+		if (!sled)
+			return -ENOMEM;
+
+		sled->map = map;
+
+		if (of_property_read_u32(child, "offset", &sled->offset))
+			return -EINVAL;
+		if (of_property_read_u32(child, "mask", &sled->mask))
+			return -EINVAL;
+		sled->cdev.name =
+			of_get_property(child, "label", NULL) ? : child->name;
+		sled->cdev.default_trigger =
+			of_get_property(child, "linux,default-trigger", NULL);
+
+		state = of_get_property(child, "default-state", NULL);
+		if (state) {
+			if (!strcmp(state, "keep")) {
+				u32 val;
+
+				ret = regmap_read(map, sled->offset, &val);
+				if (ret < 0)
+					return ret;
+				sled->state = !!(val & sled->mask);
+			} else if (!strcmp(state, "on")) {
+				sled->state = true;
+				ret = regmap_update_bits(map, sled->offset,
+							 sled->mask,
+							 sled->mask);
+				if (ret < 0)
+					return ret;
+			} else {
+				sled->state = false;
+				ret = regmap_update_bits(map, sled->offset,
+							 sled->mask, 0);
+				if (ret < 0)
+					return ret;
+			}
+
+		}
+		sled->cdev.brightness_set = syscon_led_set;
+
+		ret = led_classdev_register(dev, &sled->cdev);
+		if (ret < 0)
+			return ret;
+
+		dev_info(dev, "registered LED %s\n", sled->cdev.name);
+	}
+
+       return 0;
+}
+device_initcall(syscon_leds_init);