summaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-bcm6358.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/leds/leds-bcm6358.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/leds/leds-bcm6358.c b/drivers/leds/leds-bcm6358.c
new file mode 100644
index 000000000..9d2e487fa
--- /dev/null
+++ b/drivers/leds/leds-bcm6358.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
+ *
+ * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
+ */
+#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)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ iowrite32be(data, reg);
+#else
+ writel(data, reg);
+#endif
+}
+
+static unsigned long bcm6358_led_read(void __iomem *reg)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ return ioread32be(reg);
+#else
+ return readl(reg);
+#endif
+}
+
+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_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, val;
+
+ spin_lock_irqsave(led->lock, flags);
+ 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);
+ 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 led_init_data init_data = {};
+ struct bcm6358_led *led;
+ 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;
+
+ 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;
+ 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_set(&led->cdev, led->cdev.brightness);
+
+ led->cdev.brightness_set = bcm6358_led_set;
+ init_data.fwnode = of_fwnode_handle(nc);
+
+ rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
+ 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 = dev_of_node(&pdev->dev);
+ struct device_node *child;
+ void __iomem *mem;
+ spinlock_t *lock; /* memory lock */
+ unsigned long val;
+ u32 clk_div;
+
+ mem = devm_platform_ioremap_resource(pdev, 0);
+ 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", &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) {
+ of_node_put(child);
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static const struct of_device_id bcm6358_leds_of_match[] = {
+ { .compatible = "brcm,bcm6358-leds", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
+
+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");