leds-turris-omnia.c
// SPDX-License-Identifier: GPL-2.0
/*
* CZ.NIC's Turris Omnia LEDs driver
*
* 2020 by Marek BehĂșn <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_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 = i2c_smbus_write_byte_data(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 = i2c_smbus_write_byte_data(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 = i2c_smbus_write_byte_data(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);
struct omnia_leds *leds = i2c_get_clientdata(client);
int ret;
mutex_lock(&leds->lock);
ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);
mutex_unlock(&leds->lock);
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);
struct omnia_leds *leds = i2c_get_clientdata(client);
unsigned long brightness;
int ret;
if (kstrtoul(buf, 10, &brightness))
return -EINVAL;
if (brightness > 100)
return -EINVAL;
mutex_lock(&leds->lock);
ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS,
(u8)brightness);
mutex_unlock(&leds->lock);
if (ret < 0)
return ret;
return 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 */
i2c_smbus_write_byte_data(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");