From aaf38273cf766d88296f4aa3f2e4e3c0d399a4a2 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 18 Sep 2023 18:11:03 +0200 Subject: leds: turris-omnia: Support HW controlled mode via private trigger MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add support for enabling MCU controlled mode of the Turris Omnia LEDs via a LED private trigger called "omnia-mcu". Recall that private LED triggers will only be listed in the sysfs trigger file for LEDs that support them (currently there is no user of this mechanism). When in MCU controlled mode, the user can still set LED color, but the blinking is done by MCU, which does different things for different LEDs: - WAN LED is blinked according to the LED[0] pin of the WAN PHY - LAN LEDs are blinked according to the LED[0] output of the corresponding port of the LAN switch - PCIe LEDs are blinked according to the logical OR of the MiniPCIe port LED pins In the future I want to make the netdev trigger to transparently offload the blinking to the HW if user sets compatible settings for the netdev trigger (for LEDs associated with network devices). There was some work on this already, and hopefully we will be able to complete it sometime, but for now there are still multiple blockers for this, and even if there weren't, we still would not be able to configure HW controlled mode for the LEDs associated with MiniPCIe ports. In the meantime let's support HW controlled mode via the private LED trigger mechanism. If, in the future, we manage to complete the netdev trigger offloading, we can still keep this private trigger for backwards compatibility, if needed. We also set "omnia-mcu" to cdev->default_trigger, so that the MCU keeps control until the user first wants to take over it. If a different default trigger is specified in device-tree via the 'linux,default-trigger' property, LED class will overwrite cdev->default_trigger, and so the DT property will be respected. Signed-off-by: Marek Behún Link: https://lore.kernel.org/r/20230918161104.20860-4-kabel@kernel.org Signed-off-by: Lee Jones --- drivers/leds/Kconfig | 1 + drivers/leds/leds-turris-omnia.c | 98 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 91 insertions(+), 8 deletions(-) --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -163,6 +163,7 @@ config LEDS_TURRIS_OMNIA depends on I2C depends on MACH_ARMADA_38X || COMPILE_TEST depends on OF + select LEDS_TRIGGERS help This option enables basic support for the LEDs found on the front side of CZ.NIC's Turris Omnia router. There are 12 RGB LEDs on the --- a/drivers/leds/leds-turris-omnia.c +++ b/drivers/leds/leds-turris-omnia.c @@ -31,7 +31,7 @@ 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; + bool on, hwtrig; int reg; }; @@ -120,12 +120,14 @@ static int omnia_led_brightness_set_bloc /* * Only recalculate RGB brightnesses from intensities if brightness is - * non-zero. Otherwise we won't be using them and we can save ourselves - * some software divisions (Omnia's CPU does not implement the division - * instruction). + * 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_mc_calc_color_components(mc_cdev, brightness); + 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 @@ -135,8 +137,11 @@ static int omnia_led_brightness_set_bloc err = omnia_led_send_color_cmd(leds->client, led); } - /* Send on/off state change only if (bool)brightness changed */ - if (!err && !brightness != !led->on) { + /* + * 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 = CMD_LED_STATE_LED(led->reg); if (brightness) @@ -152,6 +157,71 @@ static int omnia_led_brightness_set_bloc 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, CMD_LED_MODE, + 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, CMD_LED_MODE, + CMD_LED_MODE_LED(led->reg) | + CMD_LED_MODE_USER); + + mutex_unlock(&leds->lock); + + if (err < 0) + 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) { @@ -195,6 +265,12 @@ static int omnia_led_register(struct i2c 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, CMD_LED_MODE, @@ -309,6 +385,12 @@ static int omnia_leds_probe(struct i2c_c mutex_init(&leds->lock); + ret = devm_led_trigger_register(dev, &omnia_hw_trigger); + if (ret < 0) { + dev_err(dev, "Cannot register private LED trigger: %d\n", ret); + return ret; + } + led = &leds->leds[0]; for_each_available_child_of_node(np, child) { ret = omnia_led_register(client, led, child);