// SPDX-License-Identifier: GPL-2.0 /* * CZ.NIC's Turris Omnia LEDs driver * * 2020, 2023, 2024 by Marek Behún */ #include #include #include #include #include #include #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 "); MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs"); MODULE_LICENSE("GPL v2");