leds: add BCM6328 LED driver
authorÁlvaro Fernández Rojas <noltari@gmail.com>
Tue, 28 Apr 2015 16:50:50 +0000 (09:50 -0700)
committerBryan Wu <cooloney@gmail.com>
Mon, 4 May 2015 18:22:28 +0000 (11:22 -0700)
This adds support for the LED controller on Broadcom's BCM6328.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-bcm6328.c [new file with mode: 0644]

index dd7834c32608093a107cfcb258714c604ea9cb9c..e2c0343878711b2c3142a9559ae0bba29e58085e 100644 (file)
@@ -50,6 +50,14 @@ config LEDS_AAT1290
        help
         This option enables support for the LEDs on the AAT1290.
 
+config LEDS_BCM6328
+       tristate "LED Support for Broadcom BCM6328"
+       depends on LEDS_CLASS
+       depends on OF
+       help
+         This option enables support for LEDs connected to the BCM6328
+         LED HW controller accessed via MMIO registers.
+
 config LEDS_LM3530
        tristate "LCD Backlight driver for LM3530"
        depends on LEDS_CLASS
index 71f7c9accb9424a23dd3e7b118dbf06fbe600106..edd4749e99efa1b0d3fadc75b7f1b32fb683ea6f 100644 (file)
@@ -8,6 +8,7 @@ obj-$(CONFIG_LEDS_TRIGGERS)             += led-triggers.o
 # LED Platform Drivers
 obj-$(CONFIG_LEDS_88PM860X)            += leds-88pm860x.o
 obj-$(CONFIG_LEDS_AAT1290)             += leds-aat1290.o
+obj-$(CONFIG_LEDS_BCM6328)             += leds-bcm6328.o
 obj-$(CONFIG_LEDS_BD2802)              += leds-bd2802.o
 obj-$(CONFIG_LEDS_LOCOMO)              += leds-locomo.o
 obj-$(CONFIG_LEDS_LM3530)              += leds-lm3530.o
diff --git a/drivers/leds/leds-bcm6328.c b/drivers/leds/leds-bcm6328.c
new file mode 100644 (file)
index 0000000..986fe1e
--- /dev/null
@@ -0,0 +1,413 @@
+/*
+ * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
+ *
+ * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
+ * Copyright 2015 Jonas Gorski <jogo@openwrt.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.
+ */
+#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 BCM6328_REG_INIT               0x00
+#define BCM6328_REG_MODE_HI            0x04
+#define BCM6328_REG_MODE_LO            0x08
+#define BCM6328_REG_HWDIS              0x0c
+#define BCM6328_REG_STROBE             0x10
+#define BCM6328_REG_LNKACTSEL_HI       0x14
+#define BCM6328_REG_LNKACTSEL_LO       0x18
+#define BCM6328_REG_RBACK              0x1c
+#define BCM6328_REG_SERMUX             0x20
+
+#define BCM6328_LED_MAX_COUNT          24
+#define BCM6328_LED_DEF_DELAY          500
+#define BCM6328_LED_INTERVAL_MS                20
+
+#define BCM6328_LED_INTV_MASK          0x3f
+#define BCM6328_LED_FAST_INTV_SHIFT    6
+#define BCM6328_LED_FAST_INTV_MASK     (BCM6328_LED_INTV_MASK << \
+                                        BCM6328_LED_FAST_INTV_SHIFT)
+#define BCM6328_SERIAL_LED_EN          BIT(12)
+#define BCM6328_SERIAL_LED_MUX         BIT(13)
+#define BCM6328_SERIAL_LED_CLK_NPOL    BIT(14)
+#define BCM6328_SERIAL_LED_DATA_PPOL   BIT(15)
+#define BCM6328_SERIAL_LED_SHIFT_DIR   BIT(16)
+#define BCM6328_LED_SHIFT_TEST         BIT(30)
+#define BCM6328_LED_TEST               BIT(31)
+
+#define BCM6328_LED_MODE_MASK          3
+#define BCM6328_LED_MODE_OFF           0
+#define BCM6328_LED_MODE_FAST          1
+#define BCM6328_LED_MODE_BLINK         2
+#define BCM6328_LED_MODE_ON            3
+#define BCM6328_LED_SHIFT(X)           ((X) << 1)
+
+/**
+ * struct bcm6328_led - state container for bcm6328 based LEDs
+ * @cdev: LED class device for this LED
+ * @mem: memory resource
+ * @lock: memory lock
+ * @pin: LED pin number
+ * @blink_leds: blinking LEDs
+ * @blink_delay: blinking delay
+ * @active_low: LED is active low
+ */
+struct bcm6328_led {
+       struct led_classdev cdev;
+       void __iomem *mem;
+       spinlock_t *lock;
+       unsigned long pin;
+       unsigned long *blink_leds;
+       unsigned long *blink_delay;
+       bool active_low;
+};
+
+static void bcm6328_led_write(void __iomem *reg, unsigned long data)
+{
+       iowrite32be(data, reg);
+}
+
+static unsigned long bcm6328_led_read(void __iomem *reg)
+{
+       return ioread32be(reg);
+}
+
+/**
+ * LEDMode 64 bits / 24 LEDs
+ * bits [31:0] -> LEDs 8-23
+ * bits [47:32] -> LEDs 0-7
+ * bits [63:48] -> unused
+ */
+static unsigned long bcm6328_pin2shift(unsigned long pin)
+{
+       if (pin < 8)
+               return pin + 16; /* LEDs 0-7 (bits 47:32) */
+       else
+               return pin - 8; /* LEDs 8-23 (bits 31:0) */
+}
+
+static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
+{
+       void __iomem *mode;
+       unsigned long val, shift;
+
+       shift = bcm6328_pin2shift(led->pin);
+       if (shift / 16)
+               mode = led->mem + BCM6328_REG_MODE_HI;
+       else
+               mode = led->mem + BCM6328_REG_MODE_LO;
+
+       val = bcm6328_led_read(mode);
+       val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
+       val |= (value << BCM6328_LED_SHIFT(shift % 16));
+       bcm6328_led_write(mode, val);
+}
+
+static void bcm6328_led_set(struct led_classdev *led_cdev,
+                           enum led_brightness value)
+{
+       struct bcm6328_led *led =
+               container_of(led_cdev, struct bcm6328_led, cdev);
+       unsigned long flags;
+
+       spin_lock_irqsave(led->lock, flags);
+       *(led->blink_leds) &= ~BIT(led->pin);
+       if ((led->active_low && value == LED_OFF) ||
+           (!led->active_low && value != LED_OFF))
+               bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
+       else
+               bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
+       spin_unlock_irqrestore(led->lock, flags);
+}
+
+static int bcm6328_blink_set(struct led_classdev *led_cdev,
+                            unsigned long *delay_on, unsigned long *delay_off)
+{
+       struct bcm6328_led *led =
+               container_of(led_cdev, struct bcm6328_led, cdev);
+       unsigned long delay, flags;
+
+       if (!*delay_on)
+               *delay_on = BCM6328_LED_DEF_DELAY;
+       if (!*delay_off)
+               *delay_off = BCM6328_LED_DEF_DELAY;
+
+       if (*delay_on != *delay_off) {
+               dev_dbg(led_cdev->dev,
+                       "fallback to soft blinking (delay_on != delay_off)\n");
+               return -EINVAL;
+       }
+
+       delay = *delay_on / BCM6328_LED_INTERVAL_MS;
+       if (delay == 0)
+               delay = 1;
+       else if (delay > BCM6328_LED_INTV_MASK) {
+               dev_dbg(led_cdev->dev,
+                       "fallback to soft blinking (delay > %ums)\n",
+                       BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
+               return -EINVAL;
+       }
+
+       spin_lock_irqsave(led->lock, flags);
+       if (*(led->blink_leds) == 0 ||
+           *(led->blink_leds) == BIT(led->pin) ||
+           *(led->blink_delay) == delay) {
+               unsigned long val;
+
+               *(led->blink_leds) |= BIT(led->pin);
+               *(led->blink_delay) = delay;
+
+               val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
+               val &= ~BCM6328_LED_FAST_INTV_MASK;
+               val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
+               bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
+
+               bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
+
+               spin_unlock_irqrestore(led->lock, flags);
+       } else {
+               spin_unlock_irqrestore(led->lock, flags);
+               dev_dbg(led_cdev->dev,
+                       "fallback to soft blinking (delay already set)\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
+                        void __iomem *mem, spinlock_t *lock)
+{
+       int i, cnt;
+       unsigned long flags, val;
+
+       spin_lock_irqsave(lock, flags);
+       val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
+       val &= ~BIT(reg);
+       bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
+       spin_unlock_irqrestore(lock, flags);
+
+       /* Only LEDs 0-7 can be activity/link controlled */
+       if (reg >= 8)
+               return 0;
+
+       cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
+                                             sizeof(u32));
+       for (i = 0; i < cnt; i++) {
+               u32 sel;
+               void __iomem *addr;
+
+               if (reg < 4)
+                       addr = mem + BCM6328_REG_LNKACTSEL_LO;
+               else
+                       addr = mem + BCM6328_REG_LNKACTSEL_HI;
+
+               of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
+                                          &sel);
+
+               if (reg / 4 != sel / 4) {
+                       dev_warn(dev, "invalid link signal source\n");
+                       continue;
+               }
+
+               spin_lock_irqsave(lock, flags);
+               val = bcm6328_led_read(addr);
+               val |= (BIT(reg) << (((sel % 4) * 4) + 16));
+               bcm6328_led_write(addr, val);
+               spin_unlock_irqrestore(lock, flags);
+       }
+
+       cnt = of_property_count_elems_of_size(nc,
+                                             "brcm,activity-signal-sources",
+                                             sizeof(u32));
+       for (i = 0; i < cnt; i++) {
+               u32 sel;
+               void __iomem *addr;
+
+               if (reg < 4)
+                       addr = mem + BCM6328_REG_LNKACTSEL_LO;
+               else
+                       addr = mem + BCM6328_REG_LNKACTSEL_HI;
+
+               of_property_read_u32_index(nc, "brcm,activity-signal-sources",
+                                          i, &sel);
+
+               if (reg / 4 != sel / 4) {
+                       dev_warn(dev, "invalid activity signal source\n");
+                       continue;
+               }
+
+               spin_lock_irqsave(lock, flags);
+               val = bcm6328_led_read(addr);
+               val |= (BIT(reg) << ((sel % 4) * 4));
+               bcm6328_led_write(addr, val);
+               spin_unlock_irqrestore(lock, flags);
+       }
+
+       return 0;
+}
+
+static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
+                      void __iomem *mem, spinlock_t *lock,
+                      unsigned long *blink_leds, unsigned long *blink_delay)
+{
+       struct bcm6328_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;
+       led->blink_leds = blink_leds;
+       led->blink_delay = blink_delay;
+
+       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);
+
+       if (!of_property_read_string(nc, "default-state", &state)) {
+               spin_lock_irqsave(lock, flags);
+               if (!strcmp(state, "on")) {
+                       led->cdev.brightness = LED_FULL;
+                       bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
+               } else if (!strcmp(state, "keep")) {
+                       void __iomem *mode;
+                       unsigned long val, shift;
+
+                       shift = bcm6328_pin2shift(led->pin);
+                       if (shift / 16)
+                               mode = mem + BCM6328_REG_MODE_HI;
+                       else
+                               mode = mem + BCM6328_REG_MODE_LO;
+
+                       val = bcm6328_led_read(mode) >> (shift % 16);
+                       val &= BCM6328_LED_MODE_MASK;
+                       if (val == BCM6328_LED_MODE_ON)
+                               led->cdev.brightness = LED_FULL;
+                       else {
+                               led->cdev.brightness = LED_OFF;
+                               bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
+                       }
+               } else {
+                       led->cdev.brightness = LED_OFF;
+                       bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
+               }
+               spin_unlock_irqrestore(lock, flags);
+       }
+
+       led->cdev.brightness_set = bcm6328_led_set;
+       led->cdev.blink_set = bcm6328_blink_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 bcm6328_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;
+       unsigned long val, *blink_leds, *blink_delay;
+
+       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;
+
+       blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
+       if (!blink_leds)
+               return -ENOMEM;
+
+       blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
+       if (!blink_delay)
+               return -ENOMEM;
+
+       spin_lock_init(lock);
+
+       bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
+       bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
+       bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
+
+       val = bcm6328_led_read(mem + BCM6328_REG_INIT);
+       val &= ~BCM6328_SERIAL_LED_EN;
+       if (of_property_read_bool(np, "brcm,serial-leds"))
+               val |= BCM6328_SERIAL_LED_EN;
+       bcm6328_led_write(mem + BCM6328_REG_INIT, val);
+
+       for_each_available_child_of_node(np, child) {
+               int rc;
+               u32 reg;
+
+               if (of_property_read_u32(child, "reg", &reg))
+                       continue;
+
+               if (reg >= BCM6328_LED_MAX_COUNT) {
+                       dev_err(dev, "invalid LED (>= %d)\n",
+                               BCM6328_LED_MAX_COUNT);
+                       continue;
+               }
+
+               if (of_property_read_bool(child, "brcm,hardware-controlled"))
+                       rc = bcm6328_hwled(dev, child, reg, mem, lock);
+               else
+                       rc = bcm6328_led(dev, child, reg, mem, lock,
+                                        blink_leds, blink_delay);
+
+               if (rc < 0)
+                       return rc;
+       }
+
+       return 0;
+}
+
+static const struct of_device_id bcm6328_leds_of_match[] = {
+       { .compatible = "brcm,bcm6328-leds", },
+       { },
+};
+
+static struct platform_driver bcm6328_leds_driver = {
+       .probe = bcm6328_leds_probe,
+       .driver = {
+               .name = "leds-bcm6328",
+               .of_match_table = bcm6328_leds_of_match,
+       },
+};
+
+module_platform_driver(bcm6328_leds_driver);
+
+MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
+MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
+MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds-bcm6328");
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