| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * CZ.NIC's Turris Omnia LEDs driver |
| * |
| * 2020, 2023, 2024 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 <linux/turris-omnia-mcu-interface.h> |
| |
| #define OMNIA_BOARD_LEDS 12 |
| #define OMNIA_LED_NUM_CHANNELS 3 |
| |
| /* MCU controller I2C address 0x2a, needed for detecting MCU features */ |
| #define OMNIA_MCU_I2C_ADDR 0x2a |
| |
| /** |
| * struct omnia_led - per-LED part of driver private data structure |
| * @mc_cdev: multi-color LED class device |
| * @subled_info: per-channel information |
| * @cached_channels: cached values of per-channel brightness that was sent to the MCU |
| * @on: whether the LED was set on |
| * @hwtrig: whether the LED blinking was offloaded to the MCU |
| * @reg: LED identifier to the MCU |
| */ |
| struct omnia_led { |
| struct led_classdev_mc mc_cdev; |
| struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS]; |
| u8 cached_channels[OMNIA_LED_NUM_CHANNELS]; |
| bool on, hwtrig; |
| int reg; |
| }; |
| |
| #define to_omnia_led(l) container_of(l, struct omnia_led, mc_cdev) |
| |
| /** |
| * struct omnia_leds - driver private data structure |
| * @client: I2C client device |
| * @lock: mutex to protect cached state |
| * @has_gamma_correction: whether the MCU firmware supports gamma correction |
| * @brightness_knode: kernel node of the "brightness" device sysfs attribute (this is the |
| * driver specific global brightness, not the LED classdev brightness) |
| * @leds: flexible array of per-LED data |
| */ |
| struct omnia_leds { |
| struct i2c_client *client; |
| struct mutex lock; |
| bool has_gamma_correction; |
| struct kernfs_node *brightness_knode; |
| struct omnia_led leds[]; |
| }; |
| |
| static int omnia_cmd_set_color(const struct i2c_client *client, u8 led, u8 r, u8 g, u8 b) |
| { |
| u8 buf[5] = { OMNIA_CMD_LED_COLOR, led, r, g, b }; |
| |
| return omnia_cmd_write(client, buf, sizeof(buf)); |
| } |
| |
| static int omnia_led_send_color_cmd(const struct i2c_client *client, |
| struct omnia_led *led) |
| { |
| int ret; |
| |
| /* Send the color change command */ |
| ret = omnia_cmd_set_color(client, led->reg, led->subled_info[0].brightness, |
| led->subled_info[1].brightness, led->subled_info[2].brightness); |
| if (ret < 0) |
| return ret; |
| |
| /* Cache the RGB channel brightnesses */ |
| for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) |
| led->cached_channels[i] = led->subled_info[i].brightness; |
| |
| return 0; |
| } |
| |
| /* Determine if the computed RGB channels are different from the cached ones */ |
| static bool omnia_led_channels_changed(struct omnia_led *led) |
| { |
| for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) |
| if (led->subled_info[i].brightness != led->cached_channels[i]) |
| return true; |
| |
| return false; |
| } |
| |
| 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); |
| int err = 0; |
| |
| mutex_lock(&leds->lock); |
| |
| /* |
| * Only recalculate RGB brightnesses from intensities if brightness is |
| * non-zero (if it is zero and the LED is in HW blinking mode, we use |
| * max_brightness as brightness). Otherwise we won't be using them and |
| * we can save ourselves some software divisions (Omnia's CPU does not |
| * implement the division instruction). |
| */ |
| if (brightness || led->hwtrig) { |
| led_mc_calc_color_components(mc_cdev, brightness ?: |
| cdev->max_brightness); |
| |
| /* |
| * Send color command only if brightness is non-zero and the RGB |
| * channel brightnesses changed. |
| */ |
| if (omnia_led_channels_changed(led)) |
| err = omnia_led_send_color_cmd(leds->client, led); |
| } |
| |
| /* |
| * Send on/off state change only if (bool)brightness changed and the LED |
| * is not being blinked by HW. |
| */ |
| if (!err && !led->hwtrig && !brightness != !led->on) { |
| u8 state = OMNIA_CMD_LED_STATE_LED(led->reg); |
| |
| if (brightness) |
| state |= OMNIA_CMD_LED_STATE_ON; |
| |
| err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_STATE, state); |
| if (!err) |
| led->on = !!brightness; |
| } |
| |
| mutex_unlock(&leds->lock); |
| |
| return err; |
| } |
| |
| static struct led_hw_trigger_type omnia_hw_trigger_type; |
| |
| static int omnia_hwtrig_activate(struct led_classdev *cdev) |
| { |
| 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); |
| int err = 0; |
| |
| mutex_lock(&leds->lock); |
| |
| if (!led->on) { |
| /* |
| * If the LED is off (brightness was set to 0), the last |
| * configured color was not necessarily sent to the MCU. |
| * Recompute with max_brightness and send if needed. |
| */ |
| led_mc_calc_color_components(mc_cdev, cdev->max_brightness); |
| |
| if (omnia_led_channels_changed(led)) |
| err = omnia_led_send_color_cmd(leds->client, led); |
| } |
| |
| if (!err) { |
| /* Put the LED into MCU controlled mode */ |
| err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_MODE, |
| OMNIA_CMD_LED_MODE_LED(led->reg)); |
| if (!err) |
| led->hwtrig = true; |
| } |
| |
| mutex_unlock(&leds->lock); |
| |
| return err; |
| } |
| |
| static void omnia_hwtrig_deactivate(struct led_classdev *cdev) |
| { |
| struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent); |
| struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev)); |
| int err; |
| |
| mutex_lock(&leds->lock); |
| |
| led->hwtrig = false; |
| |
| /* Put the LED into software mode */ |
| err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_MODE, |
| OMNIA_CMD_LED_MODE_LED(led->reg) | OMNIA_CMD_LED_MODE_USER); |
| |
| mutex_unlock(&leds->lock); |
| |
| if (err) |
| dev_err(cdev->dev, "Cannot put LED to software mode: %i\n", |
| err); |
| } |
| |
| static struct led_trigger omnia_hw_trigger = { |
| .name = "omnia-mcu", |
| .activate = omnia_hwtrig_activate, |
| .deactivate = omnia_hwtrig_deactivate, |
| .trigger_type = &omnia_hw_trigger_type, |
| }; |
| |
| 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[1].color_index = LED_COLOR_ID_GREEN; |
| led->subled_info[2].color_index = LED_COLOR_ID_BLUE; |
| |
| /* Initial color is white */ |
| for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) { |
| led->subled_info[i].intensity = 255; |
| led->subled_info[i].brightness = 255; |
| led->subled_info[i].channel = i; |
| } |
| |
| 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; |
| cdev->trigger_type = &omnia_hw_trigger_type; |
| /* |
| * Use the omnia-mcu trigger as the default trigger. It may be rewritten |
| * by LED class from the linux,default-trigger property. |
| */ |
| cdev->default_trigger = omnia_hw_trigger.name; |
| |
| /* Put the LED into software mode */ |
| ret = omnia_cmd_write_u8(client, OMNIA_CMD_LED_MODE, OMNIA_CMD_LED_MODE_LED(led->reg) | |
| OMNIA_CMD_LED_MODE_USER); |
| if (ret) |
| return dev_err_probe(dev, ret, "Cannot set LED %pOF to software mode\n", np); |
| |
| /* Disable the LED */ |
| ret = omnia_cmd_write_u8(client, OMNIA_CMD_LED_STATE, OMNIA_CMD_LED_STATE_LED(led->reg)); |
| if (ret) |
| return dev_err_probe(dev, ret, "Cannot set LED %pOF brightness\n", np); |
| |
| /* Set initial color and cache it */ |
| ret = omnia_led_send_color_cmd(client, led); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Cannot set LED %pOF initial color\n", np); |
| |
| ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev, |
| &init_data); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Cannot register LED %pOF\n", np); |
| |
| 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); |
| u8 reply; |
| int err; |
| |
| err = omnia_cmd_read_u8(client, OMNIA_CMD_GET_BRIGHTNESS, &reply); |
| if (err < 0) |
| return err; |
| |
| return sysfs_emit(buf, "%d\n", reply); |
| } |
| |
| 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 err; |
| |
| if (kstrtoul(buf, 10, &brightness)) |
| return -EINVAL; |
| |
| if (brightness > 100) |
| return -EINVAL; |
| |
| err = omnia_cmd_write_u8(client, OMNIA_CMD_SET_BRIGHTNESS, brightness); |
| |
| return err ?: count; |
| } |
| static DEVICE_ATTR_RW(brightness); |
| |
| static ssize_t gamma_correction_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); |
| u8 reply = 0; |
| int err; |
| |
| if (leds->has_gamma_correction) { |
| err = omnia_cmd_read_u8(client, OMNIA_CMD_GET_GAMMA_CORRECTION, &reply); |
| if (err < 0) |
| return err; |
| } |
| |
| return sysfs_emit(buf, "%d\n", !!reply); |
| } |
| |
| static ssize_t gamma_correction_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); |
| bool val; |
| int err; |
| |
| if (!leds->has_gamma_correction) |
| return -EOPNOTSUPP; |
| |
| if (kstrtobool(buf, &val) < 0) |
| return -EINVAL; |
| |
| err = omnia_cmd_write_u8(client, OMNIA_CMD_SET_GAMMA_CORRECTION, val); |
| |
| return err ?: count; |
| } |
| static DEVICE_ATTR_RW(gamma_correction); |
| |
| static struct attribute *omnia_led_controller_attrs[] = { |
| &dev_attr_brightness.attr, |
| &dev_attr_gamma_correction.attr, |
| NULL |
| }; |
| ATTRIBUTE_GROUPS(omnia_led_controller); |
| |
| static irqreturn_t omnia_brightness_changed_threaded_fn(int irq, void *data) |
| { |
| struct omnia_leds *leds = data; |
| |
| if (unlikely(!leds->brightness_knode)) { |
| /* |
| * Note that sysfs_get_dirent() may sleep. This is okay, because we are in threaded |
| * context. |
| */ |
| leds->brightness_knode = sysfs_get_dirent(leds->client->dev.kobj.sd, "brightness"); |
| if (!leds->brightness_knode) |
| return IRQ_NONE; |
| } |
| |
| sysfs_notify_dirent(leds->brightness_knode); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void omnia_brightness_knode_put(void *data) |
| { |
| struct omnia_leds *leds = data; |
| |
| if (leds->brightness_knode) |
| sysfs_put(leds->brightness_knode); |
| } |
| |
| static int omnia_request_brightness_irq(struct omnia_leds *leds) |
| { |
| struct device *dev = &leds->client->dev; |
| int ret; |
| |
| if (!leds->client->irq) { |
| dev_info(dev, |
| "Brightness change interrupt supported by MCU firmware but not described in device-tree\n"); |
| |
| return 0; |
| } |
| |
| /* |
| * Registering the brightness_knode destructor before requesting the IRQ ensures that on |
| * removal the brightness_knode sysfs node is put only after the IRQ is freed. |
| * This is needed because the interrupt handler uses the knode. |
| */ |
| ret = devm_add_action(dev, omnia_brightness_knode_put, leds); |
| if (ret < 0) |
| return ret; |
| |
| return devm_request_threaded_irq(dev, leds->client->irq, NULL, |
| omnia_brightness_changed_threaded_fn, IRQF_ONESHOT, |
| "leds-turris-omnia", leds); |
| } |
| |
| static int omnia_mcu_get_features(const struct i2c_client *mcu_client) |
| { |
| u16 reply; |
| int err; |
| |
| err = omnia_cmd_read_u16(mcu_client, OMNIA_CMD_GET_STATUS_WORD, &reply); |
| if (err) |
| return err; |
| |
| /* Check whether MCU firmware supports the OMNIA_CMD_GET_FEAUTRES command */ |
| if (!(reply & OMNIA_STS_FEATURES_SUPPORTED)) |
| return 0; |
| |
| err = omnia_cmd_read_u16(mcu_client, OMNIA_CMD_GET_FEATURES, &reply); |
| if (err) |
| return err; |
| |
| return reply; |
| } |
| |
| static int omnia_match_mcu_client(struct device *dev, const void *data) |
| { |
| struct i2c_client *client; |
| |
| client = i2c_verify_client(dev); |
| if (!client) |
| return 0; |
| |
| return client->addr == OMNIA_MCU_I2C_ADDR; |
| } |
| |
| static int omnia_find_mcu_and_get_features(struct device *dev) |
| { |
| struct device *mcu_dev; |
| int ret; |
| |
| mcu_dev = device_find_child(dev->parent, NULL, omnia_match_mcu_client); |
| if (!mcu_dev) |
| return -ENODEV; |
| |
| ret = omnia_mcu_get_features(i2c_verify_client(mcu_dev)); |
| |
| put_device(mcu_dev); |
| |
| return ret; |
| } |
| |
| static int omnia_leds_probe(struct i2c_client *client) |
| { |
| struct device *dev = &client->dev; |
| struct device_node *np = dev_of_node(dev); |
| struct omnia_leds *leds; |
| struct omnia_led *led; |
| int ret, count; |
| |
| count = of_get_available_child_count(np); |
| if (count == 0) |
| return dev_err_probe(dev, -ENODEV, "LEDs are not defined in device tree!\n"); |
| if (count > OMNIA_BOARD_LEDS) |
| return dev_err_probe(dev, -EINVAL, "Too many LEDs defined in device tree!\n"); |
| |
| leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL); |
| if (!leds) |
| return -ENOMEM; |
| |
| leds->client = client; |
| i2c_set_clientdata(client, leds); |
| |
| ret = omnia_find_mcu_and_get_features(dev); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Cannot determine MCU supported features\n"); |
| |
| leds->has_gamma_correction = ret & OMNIA_FEAT_LED_GAMMA_CORRECTION; |
| |
| if (ret & OMNIA_FEAT_BRIGHTNESS_INT) { |
| ret = omnia_request_brightness_irq(leds); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Cannot request brightness IRQ\n"); |
| } |
| |
| mutex_init(&leds->lock); |
| |
| ret = devm_led_trigger_register(dev, &omnia_hw_trigger); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Cannot register private LED trigger\n"); |
| |
| led = &leds->leds[0]; |
| for_each_available_child_of_node_scoped(np, child) { |
| ret = omnia_led_register(client, led, child); |
| if (ret < 0) |
| return ret; |
| |
| led += ret; |
| } |
| |
| return 0; |
| } |
| |
| static void omnia_leds_remove(struct i2c_client *client) |
| { |
| /* Put all LEDs into default (HW triggered) mode */ |
| omnia_cmd_write_u8(client, OMNIA_CMD_LED_MODE, OMNIA_CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); |
| |
| /* Set all LEDs color to [255, 255, 255] */ |
| omnia_cmd_set_color(client, OMNIA_BOARD_LEDS, 255, 255, 255); |
| } |
| |
| static const struct of_device_id of_omnia_leds_match[] = { |
| { .compatible = "cznic,turris-omnia-leds", }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, of_omnia_leds_match); |
| |
| static const struct i2c_device_id omnia_id[] = { |
| { "omnia" }, |
| { } |
| }; |
| 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"); |