target/linux/apm821xx/patches-5.10/804-hwmon-tc654-add-thermal_cooling-device.patch

   1 From 4d49367c5303e3ebd17502a45b74de280f6be539 Mon Sep 17 00:00:00 2001
   2 From: Christian Lamparter <chunkeey@gmail.com>
   3 Date: Sun, 13 Feb 2022 01:47:33 +0100
   4 Subject: hwmon: (tc654) Add thermal_cooling device support
   5
   6 Adds thermal_cooling device support to the tc654/tc655
   7 driver. This make it possible to integrate it into a
   8 device-tree supported thermal-zone node as a
   9 cooling device.
  10
  11 I have been using this patch as part of the Netgear WNDR4700
  12 Centria NAS Router support within OpenWrt since 2016.
  13
  14 Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
  15 Link: https://lore.kernel.org/r/20220213004733.2421193-1-chunkeey@gmail.com
  16 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  17 ---
  18 --- a/drivers/hwmon/tc654.c
  19 +++ b/drivers/hwmon/tc654.c
  20 @@ -15,6 +15,7 @@
  21  #include <linux/module.h>
  22  #include <linux/mutex.h>
  23  #include <linux/slab.h>
  24 +#include <linux/thermal.h>
  25  #include <linux/util_macros.h>
  26
  27  enum tc654_regs {
  28 @@ -384,28 +385,20 @@ static ssize_t pwm_show(struct device *d
  29         return sprintf(buf, "%d\n", pwm);
  30  }
  31
  32 -static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
  33 -                        const char *buf, size_t count)
  34 +static int _set_pwm(struct tc654_data *data, unsigned long val)
  35  {
  36 -       struct tc654_data *data = dev_get_drvdata(dev);
  37         struct i2c_client *client = data->client;
  38 -       unsigned long val;
  39         int ret;
  40
  41 -       if (kstrtoul(buf, 10, &val))
  42 -               return -EINVAL;
  43 -       if (val > 255)
  44 -               return -EINVAL;
  45 -
  46         mutex_lock(&data->update_lock);
  47
  48 -       if (val == 0)
  49 +       if (val == 0) {
  50                 data->config |= TC654_REG_CONFIG_SDM;
  51 -       else
  52 +               data->duty_cycle = 0;
  53 +       } else {
  54                 data->config &= ~TC654_REG_CONFIG_SDM;
  55 -
  56 -       data->duty_cycle = find_closest(val, tc654_pwm_map,
  57 -                                       ARRAY_SIZE(tc654_pwm_map));
  58 +               data->duty_cycle = val - 1;
  59 +       }
  60
  61         ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
  62         if (ret < 0)
  63 @@ -416,6 +409,24 @@ static ssize_t pwm_store(struct device *
  64
  65  out:
  66         mutex_unlock(&data->update_lock);
  67 +       return ret;
  68 +}
  69 +
  70 +static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
  71 +                        const char *buf, size_t count)
  72 +{
  73 +       struct tc654_data *data = dev_get_drvdata(dev);
  74 +       unsigned long val;
  75 +       int ret;
  76 +
  77 +       if (kstrtoul(buf, 10, &val))
  78 +               return -EINVAL;
  79 +       if (val > 255)
  80 +               return -EINVAL;
  81 +       if (val > 0)
  82 +               val = find_closest(val, tc654_pwm_map, ARRAY_SIZE(tc654_pwm_map)) + 1;
  83 +
  84 +       ret = _set_pwm(data, val);
  85         return ret < 0 ? ret : count;
  86  }
  87
  88 @@ -448,6 +459,58 @@ static struct attribute *tc654_attrs[] =
  89  ATTRIBUTE_GROUPS(tc654);
  90
  91  /*
  92 + * thermal cooling device functions
  93 + *
  94 + * Account for the "ShutDown Mode (SDM)" state by offsetting
  95 + * the 16 PWM duty cycle states by 1.
  96 + *
  97 + * State  0 =   0% PWM | Shutdown - Fan(s) are off
  98 + * State  1 =  30% PWM | duty_cycle =  0
  99 + * State  2 = ~35% PWM | duty_cycle =  1
 100 + * [...]
 101 + * State 15 = ~95% PWM | duty_cycle = 14
 102 + * State 16 = 100% PWM | duty_cycle = 15
 103 + */
 104 +#define TC654_MAX_COOLING_STATE        16
 105 +
 106 +static int tc654_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
 107 +{
 108 +       *state = TC654_MAX_COOLING_STATE;
 109 +       return 0;
 110 +}
 111 +
 112 +static int tc654_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
 113 +{
 114 +       struct tc654_data *data = tc654_update_client(cdev->devdata);
 115 +
 116 +       if (IS_ERR(data))
 117 +               return PTR_ERR(data);
 118 +
 119 +       if (data->config & TC654_REG_CONFIG_SDM)
 120 +               *state = 0;     /* FAN is off */
 121 +       else
 122 +               *state = data->duty_cycle + 1;  /* offset PWM States by 1 */
 123 +
 124 +       return 0;
 125 +}
 126 +
 127 +static int tc654_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
 128 +{
 129 +       struct tc654_data *data = tc654_update_client(cdev->devdata);
 130 +
 131 +       if (IS_ERR(data))
 132 +               return PTR_ERR(data);
 133 +
 134 +       return _set_pwm(data, clamp_val(state, 0, TC654_MAX_COOLING_STATE));
 135 +}
 136 +
 137 +static const struct thermal_cooling_device_ops tc654_fan_cool_ops = {
 138 +       .get_max_state = tc654_get_max_state,
 139 +       .get_cur_state = tc654_get_cur_state,
 140 +       .set_cur_state = tc654_set_cur_state,
 141 +};
 142 +
 143 +/*
 144   * device probe and removal
 145   */
 146
 147 @@ -477,7 +540,18 @@ static int tc654_probe(struct i2c_client
 148         hwmon_dev =
 149             devm_hwmon_device_register_with_groups(dev, client->name, data,
 150                                                    tc654_groups);
 151 -       return PTR_ERR_OR_ZERO(hwmon_dev);
 152 +       if (IS_ERR(hwmon_dev))
 153 +               return PTR_ERR(hwmon_dev);
 154 +
 155 +       if (IS_ENABLED(CONFIG_THERMAL)) {
 156 +               struct thermal_cooling_device *cdev;
 157 +
 158 +               cdev = devm_thermal_of_cooling_device_register(dev, dev->of_node, client->name,
 159 +                                                              hwmon_dev, &tc654_fan_cool_ops);
 160 +               return PTR_ERR_OR_ZERO(cdev);
 161 +       }
 162 +
 163 +       return 0;
 164  }
 165
 166  static const struct i2c_device_id tc654_id[] = {