Add driver for PWM LED block

2 files changed, 100 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 8e49ff6..dd7ef7c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 obj-m := cds9k-mfd-spi.o
 obj-m += cds9k-gpio.o
+obj-m += cds9k-led.o
 
 SRC := $(shell pwd)
 
diff --git a/cds9k-led.c b/cds9k-led.c
new file mode 100644
index 0000000..e00429e
--- /dev/null
+++ b/cds9k-led.c
@@ -0,0 +1,99 @@
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/leds.h>
+
+#define LED_REG_VALUE 0x0
+#define LED_REG_RATE  0x1
+
+struct cds9k_led {
+	struct led_classdev cdev;
+	struct regmap *regmap;
+	u32 base;
+};
+
+void cds9k_led_brightness_set(struct led_classdev *led_cdev, enum led_brightness brightness)
+{
+	struct cds9k_led *led = container_of(led_cdev, struct cds9k_led, cdev);
+
+	regmap_write(led->regmap, led->base + LED_REG_VALUE, brightness);
+}
+
+enum led_brightness cds9k_led_brightness_get(struct led_classdev *led_cdev)
+{
+	int ret;
+	unsigned int brightness;
+	struct cds9k_led *led = container_of(led_cdev, struct cds9k_led, cdev);
+
+	ret = regmap_read(led->regmap, led->base + LED_REG_VALUE, &brightness);
+	/* FIXME log something */
+	if (!ret)
+		return LED_OFF;
+
+	if (brightness > LED_FULL)
+		brightness = LED_FULL;
+
+	return brightness;
+}
+
+static int cds9k_led_probe(struct platform_device *pdev)
+{
+	int ret;
+	u32 base;
+	struct cds9k_led *led;
+	struct device_node *np = pdev->dev.of_node;
+	struct led_init_data init_data = {};
+	struct fwnode_handle *fwnode;
+
+	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	ret = device_property_read_u32(&pdev->dev, "reg", &led->base);
+	if (ret)
+		return -EINVAL;
+
+	if (!pdev->dev.parent)
+		return -ENODEV;
+
+	led->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!led->regmap)
+		return -ENODEV;
+
+	led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
+	led->cdev.default_trigger = of_get_property(np, "linux,default-trigger", NULL);
+	led->cdev.brightness_set = cds9k_led_brightness_set;
+	led->cdev.brightness_get = cds9k_led_brightness_get;
+	led->cdev.max_brightness = 0xFF;
+	/* FIXME default state keep/on etc */
+
+	init_data.fwnode = of_fwnode_handle(np);
+	init_data.devicename = "cds9k_led";
+
+	ret = devm_led_classdev_register_ext(&pdev->dev, &led->cdev, &init_data);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct of_device_id cds9k_led_of_match[] = {
+	{ .compatible = "david,cds9k-led" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cds9k_led_of_match);
+
+static struct platform_driver cds9k_led = {
+	.driver = {
+		.name = "cds9k-led",
+		.of_match_table = cds9k_led_of_match,
+	},
+	.probe = cds9k_led_probe,
+	//.shutdown = cds9k_led_shutdown,
+};
+module_platform_driver(cds9k_led);
+
+MODULE_AUTHOR("David Phillips <david@yeah.nah.nz>");
+MODULE_DESCRIPTION("LED driver for the CDS9K board controller");
+MODULE_LICENSE("GPL v2");