--- /dev/null
+/*
+ * LED driver for NU801
+ *
+ * Kevin Paul Herbert
+ * Copyright (c) 2012, Meraki, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/leds-nu801.h>
+
+#include <asm/gpio.h>
+#include <linux/of_gpio.h>
+
+#define MAX_NAME_LENGTH 24
+#define NUM_COLORS 3
+
+static const char * const led_nu801_colors[] = { "blue", "green", "red" };
+
+struct led_nu801_led_data {
+ struct led_classdev cdev;
+ struct led_nu801_data *controller;
+ enum led_brightness level;
+ char name[MAX_NAME_LENGTH];
+};
+
+struct led_nu801_data {
+ unsigned cki;
+ unsigned sdi;
+ int lei;
+ struct delayed_work work;
+ struct led_nu801_led_data *led_chain;
+ int num_leds;
+ const char *device_name;
+ const char *name;
+ u32 ndelay;
+ atomic_t pending;
+};
+
+static void led_nu801_work(struct work_struct *work)
+{
+ struct led_nu801_data *controller =
+ container_of(work, struct led_nu801_data, work.work);
+ struct led_nu801_led_data *led;
+ u16 bit;
+ u16 brightness;
+ int index;
+
+ for (index = 0; index < controller->num_leds; index++) {
+ led = &controller->led_chain[index];
+ brightness = led->level << 8; /* To do: gamma correction */
+ for (bit = 0x8000; bit; bit = bit >> 1) {
+ gpio_set_value(controller->sdi,
+ (brightness & bit) != 0);
+ gpio_set_value(controller->cki, 1);
+ if (unlikely(((index == (controller->num_leds - 1)) &&
+ (bit == 1) &&
+ (controller->lei < 0)))) {
+ udelay(600);
+ } else {
+ ndelay(controller->ndelay);
+ }
+ gpio_set_value(controller->cki, 0);
+ ndelay(controller->ndelay);
+ }
+ }
+ if (controller->lei >= 0) {
+ gpio_set_value(controller->lei, 1);
+ ndelay(controller->ndelay);
+ gpio_set_value(controller->lei, 0);
+ }
+ atomic_set(&controller->pending, 1);
+}
+
+static void led_nu801_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct led_nu801_led_data *led_dat =
+ container_of(led_cdev, struct led_nu801_led_data, cdev);
+ struct led_nu801_data *controller = led_dat->controller;
+
+ if (led_dat->level != value) {
+ led_dat->level = value;
+ if (atomic_dec_and_test(&controller->pending))
+ schedule_delayed_work(&led_dat->controller->work,
+ (HZ/1000) + 1);
+ }
+}
+
+static int __init led_nu801_create(struct led_nu801_data *controller,
+ struct device *parent,
+ int index,
+ enum led_brightness brightness,
+#ifdef CONFIG_LEDS_TRIGGERS
+ const char *default_trigger,
+#endif
+ const char *color)
+{
+ struct led_nu801_led_data *led = &controller->led_chain[index];
+ int ret;
+
+ scnprintf(led->name, sizeof(led->name), "%s:%s:%s%d",
+ controller->device_name, color, controller->name,
+ (controller->num_leds - (index + 1)) / NUM_COLORS);
+ led->cdev.name = led->name;
+ led->cdev.brightness_set = led_nu801_set;
+#ifdef CONFIG_LEDS_TRIGGERS
+ led->cdev.default_trigger = default_trigger;
+#endif
+ led->level = brightness;
+ led->controller = controller;
+ ret = led_classdev_register(parent, &led->cdev);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+
+err:
+ kfree(led);
+ return ret;
+}
+
+static int __init
+led_nu801_create_chain(const struct led_nu801_template *template,
+ struct led_nu801_data *controller,
+ struct device *parent)
+{
+ int ret;
+ int index;
+
+ controller->cki = template->cki;
+ controller->sdi = template->sdi;
+ controller->lei = template->lei;
+ controller->num_leds = template->num_leds * 3;
+ controller->device_name = template->device_name;
+ controller->name = template->name;
+ controller->ndelay = template->ndelay;
+ atomic_set(&controller->pending, 1);
+
+ controller->led_chain = kzalloc(sizeof(struct led_nu801_led_data) *
+ controller->num_leds, GFP_KERNEL);
+
+ if (!controller->led_chain)
+ return -ENOMEM;
+
+ ret = gpio_request(controller->cki, template->name);
+ if (ret < 0)
+ goto err_free_chain;
+
+ ret = gpio_request(controller->sdi, template->name);
+ if (ret < 0)
+ goto err_ret_cki;
+
+ if (controller->lei >= 0) {
+ ret = gpio_request(controller->lei, template->name);
+ if (ret < 0)
+ goto err_ret_sdi;
+ ret = gpio_direction_output(controller->lei, 0);
+ if (ret < 0)
+ goto err_ret_lei;
+ }
+
+ ret = gpio_direction_output(controller->cki, 0);
+ if (ret < 0)
+ goto err_ret_lei;
+
+ ret = gpio_direction_output(controller->sdi, 0);
+ if (ret < 0)
+ goto err_ret_lei;
+
+ for (index = 0; index < controller->num_leds; index++) {
+ ret = led_nu801_create(controller, parent, index,
+ template->init_brightness
+ [index % NUM_COLORS],
+#ifdef CONFIG_LEDS_TRIGGERS
+ template->default_trigger,
+#endif
+ template->led_colors[index % NUM_COLORS] ?
+ template->led_colors[index % NUM_COLORS] :
+ led_nu801_colors[index % NUM_COLORS]);
+ if (ret < 0)
+ goto err_ret_sdi;
+ }
+
+ INIT_DELAYED_WORK(&controller->work, led_nu801_work);
+ schedule_delayed_work(&controller->work, 0);
+
+ return 0;
+
+err_ret_lei:
+ if (controller->lei >= 0)
+ gpio_free(controller->lei);
+err_ret_sdi:
+ gpio_free(controller->sdi);
+err_ret_cki:
+ gpio_free(controller->cki);
+err_free_chain:
+ kfree(controller->led_chain);
+
+ return ret;
+}
+
+static void led_nu801_delete_chain(struct led_nu801_data *controller)
+{
+ struct led_nu801_led_data *led_chain;
+ struct led_nu801_led_data *led;
+ int index;
+ int num_leds;
+
+ led_chain = controller->led_chain;
+ controller->led_chain = 0;
+ num_leds = controller->num_leds;
+ controller->num_leds = 0;
+ cancel_delayed_work_sync(&controller->work);
+
+ for (index = 0; index < num_leds; index++) {
+ led = &led_chain[index];
+ led_classdev_unregister(&led->cdev);
+ }
+
+ gpio_free(controller->cki);
+ gpio_free(controller->sdi);
+ if (controller->lei >= 0)
+ gpio_free(controller->lei);
+
+ kfree(led_chain);
+}
+
+static struct led_nu801_data * __init
+leds_nu801_create_of(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node, *child;
+ struct led_nu801_data *controllers;
+ int count = 0, ret;
+ int i = 0;
+
+ for_each_child_of_node(np, child)
+ count++;
+ if (!count)
+ return NULL;
+
+ controllers = kzalloc(sizeof(struct led_nu801_data) * count,
+ GFP_KERNEL);
+ if (!controllers)
+ return NULL;
+
+ for_each_child_of_node(np, child) {
+ const char *state;
+ struct led_nu801_template template = {};
+ struct device_node *colors;
+ int jj;
+
+ template.cki = of_get_named_gpio_flags(child, "cki", 0, NULL);
+ template.sdi = of_get_named_gpio_flags(child, "sdi", 0, NULL);
+ if (of_find_property(child, "lei", NULL)) {
+ template.lei = of_get_named_gpio_flags(child, "lei",
+ 0, NULL);
+ } else {
+ template.lei = -1;
+ }
+ of_property_read_u32(child, "ndelay", &template.ndelay);
+ of_property_read_u32(child, "num_leds", &template.num_leds);
+ template.name = of_get_property(child, "label", NULL) ? :
+ child->name;
+ template.default_trigger = of_get_property(child,
+ "default-trigger", NULL);
+
+ jj = 0;
+ for_each_child_of_node(child, colors) {
+ template.led_colors[jj] = of_get_property(colors,
+ "label", NULL);
+ state = of_get_property(colors, "state", NULL);
+ if (!strncmp(state, "off", 3))
+ template.init_brightness[jj] = LED_OFF;
+ else if (!strncmp(state, "half", 4))
+ template.init_brightness[jj] = LED_HALF;
+ else if (!strncmp(state, "full", 4))
+ template.init_brightness[jj] = LED_FULL;
+ jj++;
+ }
+
+ ret = led_nu801_create_chain(&template,
+ &controllers[i],
+ &pdev->dev);
+ if (ret < 0)
+ goto err;
+ i++;
+ }
+
+ return controllers;
+
+err:
+ for (i = i - 1; i >= 0; i--)
+ led_nu801_delete_chain(&controllers[i]);
+ kfree(controllers);
+ return NULL;
+}
+
+static int __init led_nu801_probe(struct platform_device *pdev)
+{
+ struct led_nu801_platform_data *pdata = pdev->dev.platform_data;
+ struct led_nu801_data *controllers;
+ int i, ret = 0;
+
+ if (!(pdata && pdata->num_controllers)) {
+ controllers = leds_nu801_create_of(pdev);
+ if (!controllers)
+ return -ENODEV;
+ }
+
+ controllers = kzalloc(sizeof(struct led_nu801_data) *
+ pdata->num_controllers, GFP_KERNEL);
+ if (!controllers)
+ return -ENOMEM;
+
+ for (i = 0; i < pdata->num_controllers; i++) {
+ ret = led_nu801_create_chain(&pdata->template[i],
+ &controllers[i],
+ &pdev->dev);
+ if (ret < 0)
+ goto err;
+ }
+
+ platform_set_drvdata(pdev, controllers);
+
+ return 0;
+
+err:
+ for (i = i - 1; i >= 0; i--)
+ led_nu801_delete_chain(&controllers[i]);
+
+ kfree(controllers);
+
+ return ret;
+}
+
+static int led_nu801_remove(struct platform_device *pdev)
+{
+ int i;
+ struct led_nu801_platform_data *pdata = pdev->dev.platform_data;
+ struct led_nu801_data *controllers;
+
+ controllers = platform_get_drvdata(pdev);
+
+ for (i = 0; i < pdata->num_controllers; i++)
+ led_nu801_delete_chain(&controllers[i]);
+
+ kfree(controllers);
+
+ return 0;
+}
+
+static const struct of_device_id of_numen_leds_match[] = {
+ { .compatible = "numen,leds-nu801", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
+
+static struct platform_driver led_nu801_driver = {
+ .probe = led_nu801_probe,
+ .remove = led_nu801_remove,
+ .driver = {
+ .name = "leds-nu801",
+ .owner = THIS_MODULE,
+ .of_match_table = of_numen_leds_match,
+ },
+};
+
+static int __init led_nu801_init(void)
+{
+ return platform_driver_register(&led_nu801_driver);
+}
+
+static void __exit led_nu801_exit(void)
+{
+ platform_driver_unregister(&led_nu801_driver);
+}
+
+module_init(led_nu801_init);
+module_exit(led_nu801_exit);
+
+MODULE_AUTHOR("Kevin Paul Herbert <kph@meraki.net>");
+MODULE_DESCRIPTION("NU801 LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds-nu801");
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