target/linux/generic/backport-6.6/804-v6.5-08-leds-trigger-netdev-add-support-for-LED-hw-control.patch

   1 From 7c145a34ba6e380616af93262fcab9fc7261d851 Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Mon, 29 May 2023 18:32:38 +0200
   4 Subject: [PATCH 08/13] leds: trigger: netdev: add support for LED hw control
   5
   6 Add support for LED hw control for the netdev trigger.
   7
   8 The trigger on calling set_baseline_state to configure a new mode, will
   9 do various check to verify if hw control can be used for the requested
  10 mode in can_hw_control() function.
  11
  12 It will first check if the LED driver supports hw control for the netdev
  13 trigger, then will use hw_control_is_supported() and finally will call
  14 hw_control_set() to apply the requested mode.
  15
  16 To use such mode, interval MUST be set to the default value and net_dev
  17 MUST be set. If one of these 2 value are not valid, hw control will
  18 never be used and normal software fallback is used.
  19
  20 The default interval value is moved to a define to make sure they are
  21 always synced.
  22
  23 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  24 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
  25 Signed-off-by: David S. Miller <davem@davemloft.net>
  26 ---
  27  drivers/leds/trigger/ledtrig-netdev.c | 43 +++++++++++++++++++++++++--
  28  1 file changed, 41 insertions(+), 2 deletions(-)
  29
  30 --- a/drivers/leds/trigger/ledtrig-netdev.c
  31 +++ b/drivers/leds/trigger/ledtrig-netdev.c
  32 @@ -24,6 +24,8 @@
  33  #include <linux/timer.h>
  34  #include "../leds.h"
  35
  36 +#define NETDEV_LED_DEFAULT_INTERVAL    50
  37 +
  38  /*
  39   * Configurable sysfs attributes:
  40   *
  41 @@ -68,6 +70,13 @@ static void set_baseline_state(struct le
  42         int current_brightness;
  43         struct led_classdev *led_cdev = trigger_data->led_cdev;
  44
  45 +       /* Already validated, hw control is possible with the requested mode */
  46 +       if (trigger_data->hw_control) {
  47 +               led_cdev->hw_control_set(led_cdev, trigger_data->mode);
  48 +
  49 +               return;
  50 +       }
  51 +
  52         current_brightness = led_cdev->brightness;
  53         if (current_brightness)
  54                 led_cdev->blink_brightness = current_brightness;
  55 @@ -103,12 +112,42 @@ static bool supports_hw_control(struct l
  56
  57  static bool can_hw_control(struct led_netdev_data *trigger_data)
  58  {
  59 +       unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
  60 +       unsigned int interval = atomic_read(&trigger_data->interval);
  61         struct led_classdev *led_cdev = trigger_data->led_cdev;
  62 +       int ret;
  63
  64         if (!supports_hw_control(led_cdev))
  65                 return false;
  66
  67 -       return false;
  68 +       /*
  69 +        * Interval must be set to the default
  70 +        * value. Any different value is rejected if in hw
  71 +        * control.
  72 +        */
  73 +       if (interval != default_interval)
  74 +               return false;
  75 +
  76 +       /*
  77 +        * net_dev must be set with hw control, otherwise no
  78 +        * blinking can be happening and there is nothing to
  79 +        * offloaded.
  80 +        */
  81 +       if (!trigger_data->net_dev)
  82 +               return false;
  83 +
  84 +       /* Check if the requested mode is supported */
  85 +       ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
  86 +       /* Fall back to software blinking if not supported */
  87 +       if (ret == -EOPNOTSUPP)
  88 +               return false;
  89 +       if (ret) {
  90 +               dev_warn(led_cdev->dev,
  91 +                        "Current mode check failed with error %d\n", ret);
  92 +               return false;
  93 +       }
  94 +
  95 +       return true;
  96  }
  97
  98  static ssize_t device_name_show(struct device *dev,
  99 @@ -413,7 +452,7 @@ static int netdev_trig_activate(struct l
 100         trigger_data->device_name[0] = 0;
 101
 102         trigger_data->mode = 0;
 103 -       atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
 104 +       atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
 105         trigger_data->last_activity = 0;
 106
 107         led_set_trigger_data(led_cdev, trigger_data);