1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c
new file mode 100644
index 000000000..179eb243d
--- /dev/null
+++ b/drivers/leds/leds-turris-omnia.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CZ.NIC's Turris Omnia LEDs driver
+ *
+ * 2020, 2023 by Marek Behún <kabel@kernel.org>
+ */
+
+#include <linux/i2c.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include "leds.h"
+
+#define OMNIA_BOARD_LEDS	12
+#define OMNIA_LED_NUM_CHANNELS	3
+
+#define CMD_LED_MODE		3
+#define CMD_LED_MODE_LED(l)	((l) & 0x0f)
+#define CMD_LED_MODE_USER	0x10
+
+#define CMD_LED_STATE		4
+#define CMD_LED_STATE_LED(l)	((l) & 0x0f)
+#define CMD_LED_STATE_ON	0x10
+
+#define CMD_LED_COLOR		5
+#define CMD_LED_SET_BRIGHTNESS	7
+#define CMD_LED_GET_BRIGHTNESS	8
+
+struct omnia_led {
+	struct led_classdev_mc mc_cdev;
+	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
+	int reg;
+};
+
+#define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)
+
+struct omnia_leds {
+	struct i2c_client *client;
+	struct mutex lock;
+	struct omnia_led leds[];
+};
+
+static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)
+{
+	u8 buf[2] = { cmd, val };
+
+	return i2c_master_send(client, buf, sizeof(buf));
+}
+
+static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
+{
+	struct i2c_msg msgs[2];
+	u8 reply;
+	int ret;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = 1;
+	msgs[0].buf = &cmd;
+	msgs[1].addr = client->addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = 1;
+	msgs[1].buf = &reply;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (likely(ret == ARRAY_SIZE(msgs)))
+		return reply;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
+					     enum led_brightness brightness)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
+	struct omnia_led *led = to_omnia_led(mc_cdev);
+	u8 buf[5], state;
+	int ret;
+
+	mutex_lock(&leds->lock);
+
+	led_mc_calc_color_components(&led->mc_cdev, brightness);
+
+	buf[0] = CMD_LED_COLOR;
+	buf[1] = led->reg;
+	buf[2] = mc_cdev->subled_info[0].brightness;
+	buf[3] = mc_cdev->subled_info[1].brightness;
+	buf[4] = mc_cdev->subled_info[2].brightness;
+
+	state = CMD_LED_STATE_LED(led->reg);
+	if (buf[2] || buf[3] || buf[4])
+		state |= CMD_LED_STATE_ON;
+
+	ret = omnia_cmd_write_u8(leds->client, CMD_LED_STATE, state);
+	if (ret >= 0 && (state & CMD_LED_STATE_ON))
+		ret = i2c_master_send(leds->client, buf, 5);
+
+	mutex_unlock(&leds->lock);
+
+	return ret;
+}
+
+static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
+			      struct device_node *np)
+{
+	struct led_init_data init_data = {};
+	struct device *dev = &client->dev;
+	struct led_classdev *cdev;
+	int ret, color;
+
+	ret = of_property_read_u32(np, "reg", &led->reg);
+	if (ret || led->reg >= OMNIA_BOARD_LEDS) {
+		dev_warn(dev,
+			 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
+			 np, OMNIA_BOARD_LEDS - 1);
+		return 0;
+	}
+
+	ret = of_property_read_u32(np, "color", &color);
+	if (ret || color != LED_COLOR_ID_RGB) {
+		dev_warn(dev,
+			 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
+			 np);
+		return 0;
+	}
+
+	led->subled_info[0].color_index = LED_COLOR_ID_RED;
+	led->subled_info[0].channel = 0;
+	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+	led->subled_info[1].channel = 1;
+	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+	led->subled_info[2].channel = 2;
+
+	led->mc_cdev.subled_info = led->subled_info;
+	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;
+
+	init_data.fwnode = &np->fwnode;
+
+	cdev = &led->mc_cdev.led_cdev;
+	cdev->max_brightness = 255;
+	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
+
+	/* put the LED into software mode */
+	ret = omnia_cmd_write_u8(client, CMD_LED_MODE,
+				 CMD_LED_MODE_LED(led->reg) |
+				 CMD_LED_MODE_USER);
+	if (ret < 0) {
+		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
+			ret);
+		return ret;
+	}
+
+	/* disable the LED */
+	ret = omnia_cmd_write_u8(client, CMD_LED_STATE,
+				 CMD_LED_STATE_LED(led->reg));
+	if (ret < 0) {
+		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
+		return ret;
+	}
+
+	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
+							&init_data);
+	if (ret < 0) {
+		dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
+		return ret;
+	}
+
+	return 1;
+}
+
+/*
+ * On the front panel of the Turris Omnia router there is also a button which
+ * can be used to control the intensity of all the LEDs at once, so that if they
+ * are too bright, user can dim them.
+ * The microcontroller cycles between 8 levels of this global brightness (from
+ * 100% to 0%), but this setting can have any integer value between 0 and 100.
+ * It is therefore convenient to be able to change this setting from software.
+ * We expose this setting via a sysfs attribute file called "brightness". This
+ * file lives in the device directory of the LED controller, not an individual
+ * LED, so it should not confuse users.
+ */
+static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
+			       char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret;
+
+	ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS);
+
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", ret);
+}
+
+static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
+				const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long brightness;
+	int ret;
+
+	if (kstrtoul(buf, 10, &brightness))
+		return -EINVAL;
+
+	if (brightness > 100)
+		return -EINVAL;
+
+	ret = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);
+
+	return ret < 0 ? ret : count;
+}
+static DEVICE_ATTR_RW(brightness);
+
+static struct attribute *omnia_led_controller_attrs[] = {
+	&dev_attr_brightness.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(omnia_led_controller);
+
+static int omnia_leds_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = dev_of_node(dev), *child;
+	struct omnia_leds *leds;
+	struct omnia_led *led;
+	int ret, count;
+
+	count = of_get_available_child_count(np);
+	if (!count) {
+		dev_err(dev, "LEDs are not defined in device tree!\n");
+		return -ENODEV;
+	} else if (count > OMNIA_BOARD_LEDS) {
+		dev_err(dev, "Too many LEDs defined in device tree!\n");
+		return -EINVAL;
+	}
+
+	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
+	if (!leds)
+		return -ENOMEM;
+
+	leds->client = client;
+	i2c_set_clientdata(client, leds);
+
+	mutex_init(&leds->lock);
+
+	led = &leds->leds[0];
+	for_each_available_child_of_node(np, child) {
+		ret = omnia_led_register(client, led, child);
+		if (ret < 0) {
+			of_node_put(child);
+			return ret;
+		}
+
+		led += ret;
+	}
+
+	return 0;
+}
+
+static void omnia_leds_remove(struct i2c_client *client)
+{
+	u8 buf[5];
+
+	/* put all LEDs into default (HW triggered) mode */
+	omnia_cmd_write_u8(client, CMD_LED_MODE,
+			   CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
+
+	/* set all LEDs color to [255, 255, 255] */
+	buf[0] = CMD_LED_COLOR;
+	buf[1] = OMNIA_BOARD_LEDS;
+	buf[2] = 255;
+	buf[3] = 255;
+	buf[4] = 255;
+
+	i2c_master_send(client, buf, 5);
+}
+
+static const struct of_device_id of_omnia_leds_match[] = {
+	{ .compatible = "cznic,turris-omnia-leds", },
+	{},
+};
+
+static const struct i2c_device_id omnia_id[] = {
+	{ "omnia", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, omnia_id);
+
+static struct i2c_driver omnia_leds_driver = {
+	.probe		= omnia_leds_probe,
+	.remove		= omnia_leds_remove,
+	.id_table	= omnia_id,
+	.driver		= {
+		.name	= "leds-turris-omnia",
+		.of_match_table = of_omnia_leds_match,
+		.dev_groups = omnia_led_controller_groups,
+	},
+};
+
+module_i2c_driver(omnia_leds_driver);
+
+MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
+MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
+MODULE_LICENSE("GPL v2");