leds: add BCM6358 LED driver
This adds support for the LED controller on Broadcom's BCM6358.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/leds-bcm6358.c b/drivers/leds/leds-bcm6358.c
new file mode 100644
index 0000000..21f9693
--- /dev/null
+++ b/drivers/leds/leds-bcm6358.c
@@ -0,0 +1,243 @@
+/*
+ * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
+ *
+ * Copyright 2015 Álvaro Fernández Rojas <noltari@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.
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define BCM6358_REG_MODE 0x0
+#define BCM6358_REG_CTRL 0x4
+
+#define BCM6358_SLED_CLKDIV_MASK 3
+#define BCM6358_SLED_CLKDIV_1 0
+#define BCM6358_SLED_CLKDIV_2 1
+#define BCM6358_SLED_CLKDIV_4 2
+#define BCM6358_SLED_CLKDIV_8 3
+
+#define BCM6358_SLED_POLARITY BIT(2)
+#define BCM6358_SLED_BUSY BIT(3)
+
+#define BCM6358_SLED_MAX_COUNT 32
+#define BCM6358_SLED_WAIT 100
+
+/**
+ * struct bcm6358_led - state container for bcm6358 based LEDs
+ * @cdev: LED class device for this LED
+ * @mem: memory resource
+ * @lock: memory lock
+ * @pin: LED pin number
+ * @active_low: LED is active low
+ */
+struct bcm6358_led {
+ struct led_classdev cdev;
+ void __iomem *mem;
+ spinlock_t *lock;
+ unsigned long pin;
+ bool active_low;
+};
+
+static void bcm6358_led_write(void __iomem *reg, unsigned long data)
+{
+ iowrite32be(data, reg);
+}
+
+static unsigned long bcm6358_led_read(void __iomem *reg)
+{
+ return ioread32be(reg);
+}
+
+static unsigned long bcm6358_led_busy(void __iomem *mem)
+{
+ unsigned long val;
+
+ while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
+ BCM6358_SLED_BUSY)
+ udelay(BCM6358_SLED_WAIT);
+
+ return val;
+}
+
+static void bcm6358_led_mode(struct bcm6358_led *led, unsigned long value)
+{
+ unsigned long val;
+
+ bcm6358_led_busy(led->mem);
+
+ val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
+ if ((led->active_low && value == LED_OFF) ||
+ (!led->active_low && value != LED_OFF))
+ val |= BIT(led->pin);
+ else
+ val &= ~(BIT(led->pin));
+ bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
+}
+
+static void bcm6358_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct bcm6358_led *led =
+ container_of(led_cdev, struct bcm6358_led, cdev);
+ unsigned long flags;
+
+ spin_lock_irqsave(led->lock, flags);
+ bcm6358_led_mode(led, value);
+ spin_unlock_irqrestore(led->lock, flags);
+}
+
+static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg,
+ void __iomem *mem, spinlock_t *lock)
+{
+ struct bcm6358_led *led;
+ unsigned long flags;
+ const char *state;
+ int rc;
+
+ led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ led->pin = reg;
+ led->mem = mem;
+ led->lock = lock;
+
+ if (of_property_read_bool(nc, "active-low"))
+ led->active_low = true;
+
+ led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
+ led->cdev.default_trigger = of_get_property(nc,
+ "linux,default-trigger",
+ NULL);
+
+ spin_lock_irqsave(lock, flags);
+ if (!of_property_read_string(nc, "default-state", &state)) {
+ if (!strcmp(state, "on")) {
+ led->cdev.brightness = LED_FULL;
+ } else if (!strcmp(state, "keep")) {
+ unsigned long val;
+
+ bcm6358_led_busy(led->mem);
+
+ val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
+ val &= BIT(led->pin);
+ if ((led->active_low && !val) ||
+ (!led->active_low && val))
+ led->cdev.brightness = LED_FULL;
+ else
+ led->cdev.brightness = LED_OFF;
+ } else {
+ led->cdev.brightness = LED_OFF;
+ }
+ } else {
+ led->cdev.brightness = LED_OFF;
+ }
+ bcm6358_led_mode(led, led->cdev.brightness);
+ spin_unlock_irqrestore(lock, flags);
+
+ led->cdev.brightness_set = bcm6358_led_set;
+
+ rc = led_classdev_register(dev, &led->cdev);
+ if (rc < 0)
+ return rc;
+
+ dev_dbg(dev, "registered LED %s\n", led->cdev.name);
+
+ return 0;
+}
+
+static int bcm6358_leds_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *child;
+ struct resource *mem_r;
+ void __iomem *mem;
+ spinlock_t *lock; /* memory lock */
+ unsigned long val;
+ u32 clk_div;
+
+ mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem_r)
+ return -EINVAL;
+
+ mem = devm_ioremap_resource(dev, mem_r);
+ if (IS_ERR(mem))
+ return PTR_ERR(mem);
+
+ lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
+ if (!lock)
+ return -ENOMEM;
+
+ spin_lock_init(lock);
+
+ val = bcm6358_led_busy(mem);
+ val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
+ if (of_property_read_bool(np, "brcm,clk-dat-low"))
+ val |= BCM6358_SLED_POLARITY;
+ of_property_read_u32(np, "brcm,clk-div", &clk_div);
+ switch (clk_div) {
+ case 8:
+ val |= BCM6358_SLED_CLKDIV_8;
+ break;
+ case 4:
+ val |= BCM6358_SLED_CLKDIV_4;
+ break;
+ case 2:
+ val |= BCM6358_SLED_CLKDIV_2;
+ break;
+ default:
+ val |= BCM6358_SLED_CLKDIV_1;
+ break;
+ }
+ bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
+
+ for_each_available_child_of_node(np, child) {
+ int rc;
+ u32 reg;
+
+ if (of_property_read_u32(child, "reg", ®))
+ continue;
+
+ if (reg >= BCM6358_SLED_MAX_COUNT) {
+ dev_err(dev, "invalid LED (%u >= %d)\n", reg,
+ BCM6358_SLED_MAX_COUNT);
+ continue;
+ }
+
+ rc = bcm6358_led(dev, child, reg, mem, lock);
+ if (rc < 0)
+ return rc;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id bcm6358_leds_of_match[] = {
+ { .compatible = "brcm,bcm6358-leds", },
+ { },
+};
+
+static struct platform_driver bcm6358_leds_driver = {
+ .probe = bcm6358_leds_probe,
+ .driver = {
+ .name = "leds-bcm6358",
+ .of_match_table = bcm6358_leds_of_match,
+ },
+};
+
+module_platform_driver(bcm6358_leds_driver);
+
+MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
+MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds-bcm6358");