3 files changed, 177 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 8c96e2ddf43b..dc588b4f5905 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -478,6 +478,16 @@ config LEDS_BLINKM
           This option enables support for the BlinkM RGB LED connected
           through I2C. Say Y to enable support for the BlinkM LED.
 
+config LEDS_SYSCON
+        bool "LED support for LEDs on system controllers"
+        depends on LEDS_CLASS=y
+        depends on MFD_SYSCON
+        depends on OF
+        help
+          This option enabled support for the LEDs on syscon type
+          devices. This will only work with device tree enabled
+          devices.
+
 config LEDS_VERSATILE
         tristate "LED support for the ARM Versatile and RealView"
         depends on ARCH_REALVIEW || ARCH_VERSATILE
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d8cc5f2777de..822dd83ef97a 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_MAX8997)              += leds-max8997.o
 obj-$(CONFIG_LEDS_LM355x)               += leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)               += leds-blinkm.o
+obj-$(CONFIG_LEDS_SYSCON)               += leds-syscon.o
 obj-$(CONFIG_LEDS_VERSATILE)            += leds-versatile.o
 
 # LED SPI Drivers
diff --git a/drivers/leds/leds-syscon.c b/drivers/leds/leds-syscon.c
new file mode 100644
index 000000000000..3afec79c43f4
--- /dev/null
+++ b/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);