target/linux/mvebu/patches-6.1/102-leds-turris-omnia-support-HW-controlled-mode-via-pri.patch

   1 From 80e643510cb14f116f687e992210c0008a09d869 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= <kabel@kernel.org>
   3 Date: Mon, 4 Jul 2022 12:59:53 +0200
   4 Subject: [PATCH] leds: turris-omnia: support HW controlled mode via
   5  private trigger
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 Add support for enabling MCU controlled mode of the Turris Omnia LEDs
  11 via a LED private trigger called "omnia-mcu".
  12
  13 When in MCU controlled mode, the user can still set LED color, but the
  14 blinking is done by MCU, which does different things for various LEDs:
  15 - WAN LED is blinked according to the LED[0] pin of the WAN PHY
  16 - LAN LEDs are blinked according to the LED[0] output of corresponding
  17   port of the LAN switch
  18 - PCIe LEDs are blinked according to the logical OR of the MiniPCIe port
  19   LED pins
  20
  21 For a long time I wanted to actually do this differently: I wanted to
  22 make the netdev trigger to transparently offload the blinking to the HW
  23 if user set compatible settings for the netdev trigger.
  24 There was some work on this, and hopefully we will be able to complete
  25 it sometime, but since there are various complications, it will probably
  26 not be soon.
  27
  28 In the meantime let's support HW controlled mode via this private LED
  29 trigger. If, in the future, we manage to complete the netdev trigger
  30 offloading, we can still keep this private trigger for backwards
  31 compatiblity, if needed.
  32
  33 We also set "omnia-mcu" to cdev->default_trigger, so that the MCU keeps
  34 control until the user first wants to take over it. If a different
  35 default trigger is specified in device-tree via the
  36 `linux,default-trigger` property, LED class will overwrite
  37 cdev->default_trigger, and so the DT property will be respected.
  38
  39 Signed-off-by: Marek Behún <kabel@kernel.org>
  40 ---
  41  drivers/leds/Kconfig             |  1 +
  42  drivers/leds/leds-turris-omnia.c | 41 ++++++++++++++++++++++++++++++++
  43  2 files changed, 42 insertions(+)
  44
  45 --- a/drivers/leds/Kconfig
  46 +++ b/drivers/leds/Kconfig
  47 @@ -163,6 +163,7 @@ config LEDS_TURRIS_OMNIA
  48         depends on I2C
  49         depends on MACH_ARMADA_38X || COMPILE_TEST
  50         depends on OF
  51 +       select LEDS_TRIGGERS
  52         help
  53           This option enables basic support for the LEDs found on the front
  54           side of CZ.NIC's Turris Omnia router. There are 12 RGB LEDs on the
  55 --- a/drivers/leds/leds-turris-omnia.c
  56 +++ b/drivers/leds/leds-turris-omnia.c
  57 @@ -41,6 +41,39 @@ struct omnia_leds {
  58         struct omnia_led leds[];
  59  };
  60
  61 +static struct led_hw_trigger_type omnia_hw_trigger_type;
  62 +
  63 +static int omnia_hwtrig_activate(struct led_classdev *cdev)
  64 +{
  65 +       struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
  66 +       struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev));
  67 +
  68 +       /* put the LED into MCU controlled mode */
  69 +       return i2c_smbus_write_byte_data(leds->client, CMD_LED_MODE,
  70 +                                        CMD_LED_MODE_LED(led->reg));
  71 +}
  72 +
  73 +static void omnia_hwtrig_deactivate(struct led_classdev *cdev)
  74 +{
  75 +       struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
  76 +       struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev));
  77 +       int ret;
  78 +
  79 +       /* put the LED into software mode */
  80 +       ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_MODE,
  81 +                                       CMD_LED_MODE_LED(led->reg) |
  82 +                                       CMD_LED_MODE_USER);
  83 +       if (ret < 0)
  84 +               dev_err(cdev->dev, "Cannot put to software mode: %i\n", ret);
  85 +}
  86 +
  87 +static struct led_trigger omnia_hw_trigger = {
  88 +       .name           = "omnia-mcu",
  89 +       .activate       = omnia_hwtrig_activate,
  90 +       .deactivate     = omnia_hwtrig_deactivate,
  91 +       .trigger_type   = &omnia_hw_trigger_type,
  92 +};
  93 +
  94  static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
  95                                              enum led_brightness brightness)
  96  {
  97 @@ -112,6 +145,8 @@ static int omnia_led_register(struct i2c
  98         cdev = &led->mc_cdev.led_cdev;
  99         cdev->max_brightness = 255;
 100         cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
 101 +       cdev->trigger_type = &omnia_hw_trigger_type;
 102 +       cdev->default_trigger = omnia_hw_trigger.name;
 103
 104         /* put the LED into software mode */
 105         ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
 106 @@ -228,6 +263,12 @@ static int omnia_leds_probe(struct i2c_c
 107
 108         mutex_init(&leds->lock);
 109
 110 +       ret = devm_led_trigger_register(dev, &omnia_hw_trigger);
 111 +       if (ret < 0) {
 112 +               dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
 113 +               return ret;
 114 +       }
 115 +
 116         led = &leds->leds[0];
 117         for_each_available_child_of_node(np, child) {
 118                 ret = omnia_led_register(client, led, child);