--- /dev/null
+From aaf38273cf766d88296f4aa3f2e4e3c0d399a4a2 Mon Sep 17 00:00:00 2001
+From: Marek Behún <kabel@kernel.org>
+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 <kabel@kernel.org>
+Link: https://lore.kernel.org/r/20230918161104.20860-4-kabel@kernel.org
+Signed-off-by: Lee Jones <lee@kernel.org>
+---
+ 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);
projects / openwrt / openwrt.git / blobdiff