diff options
Diffstat (limited to 'drivers/leds/leds-turris-omnia.c')
| -rw-r--r-- | drivers/leds/leds-turris-omnia.c | 555 |
1 files changed, 555 insertions, 0 deletions
diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c new file mode 100644 index 000000000000..25ee5c1eb820 --- /dev/null +++ b/drivers/leds/leds-turris-omnia.c @@ -0,0 +1,555 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CZ.NIC's Turris Omnia LEDs driver + * + * 2020, 2023, 2024 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 <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"); |