drivers/platform/x86/gpd-pocket-fan.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * GPD Pocket fan controller driver
   4  *
   5  * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
   6  */
   7
   8 #include <linux/acpi.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/module.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/power_supply.h>
  14 #include <linux/thermal.h>
  15 #include <linux/workqueue.h>
  16
  17 #define MAX_SPEED 3
  18
  19 static int temp_limits[3] = { 55000, 60000, 65000 };
  20 module_param_array(temp_limits, int, NULL, 0444);
  21 MODULE_PARM_DESC(temp_limits,
  22                  "Milli-celcius values above which the fan speed increases");
  23
  24 static int hysteresis = 3000;
  25 module_param(hysteresis, int, 0444);
  26 MODULE_PARM_DESC(hysteresis,
  27                  "Hysteresis in milli-celcius before lowering the fan speed");
  28
  29 static int speed_on_ac = 2;
  30 module_param(speed_on_ac, int, 0444);
  31 MODULE_PARM_DESC(speed_on_ac,
  32                  "minimum fan speed to allow when system is powered by AC");
  33
  34 struct gpd_pocket_fan_data {
  35         struct device *dev;
  36         struct thermal_zone_device *dts0;
  37         struct thermal_zone_device *dts1;
  38         struct gpio_desc *gpio0;
  39         struct gpio_desc *gpio1;
  40         struct delayed_work work;
  41         int last_speed;
  42 };
  43
  44 static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
  45 {
  46         if (speed == fan->last_speed)
  47                 return;
  48
  49         gpiod_direction_output(fan->gpio0, !!(speed & 1));
  50         gpiod_direction_output(fan->gpio1, !!(speed & 2));
  51
  52         fan->last_speed = speed;
  53 }
  54
  55 static int gpd_pocket_fan_min_speed(void)
  56 {
  57         if (power_supply_is_system_supplied())
  58                 return speed_on_ac;
  59         else
  60                 return 0;
  61 }
  62
  63 static void gpd_pocket_fan_worker(struct work_struct *work)
  64 {
  65         struct gpd_pocket_fan_data *fan =
  66                 container_of(work, struct gpd_pocket_fan_data, work.work);
  67         int t0, t1, temp, speed, min_speed, i;
  68
  69         if (thermal_zone_get_temp(fan->dts0, &t0) ||
  70             thermal_zone_get_temp(fan->dts1, &t1)) {
  71                 dev_warn(fan->dev, "Error getting temperature\n");
  72                 speed = MAX_SPEED;
  73                 goto set_speed;
  74         }
  75
  76         temp = max(t0, t1);
  77
  78         speed = fan->last_speed;
  79         min_speed = gpd_pocket_fan_min_speed();
  80
  81         /* Determine minimum speed */
  82         for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
  83                 if (temp < temp_limits[i])
  84                         break;
  85         }
  86         if (speed < i)
  87                 speed = i;
  88
  89         /* Use hysteresis before lowering speed again */
  90         for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
  91                 if (temp <= (temp_limits[i] - hysteresis))
  92                         break;
  93         }
  94         if (speed > i)
  95                 speed = i;
  96
  97         if (fan->last_speed <= 0 && speed)
  98                 speed = MAX_SPEED; /* kick start motor */
  99
 100 set_speed:
 101         gpd_pocket_fan_set_speed(fan, speed);
 102
 103         /* When mostly idle (low temp/speed), slow down the poll interval. */
 104         queue_delayed_work(system_wq, &fan->work,
 105                            msecs_to_jiffies(4000 / (speed + 1)));
 106 }
 107
 108 static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan)
 109 {
 110         fan->last_speed = -1;
 111         mod_delayed_work(system_wq, &fan->work, 0);
 112 }
 113
 114 static int gpd_pocket_fan_probe(struct platform_device *pdev)
 115 {
 116         struct gpd_pocket_fan_data *fan;
 117         int i;
 118
 119         for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
 120                 if (temp_limits[i] < 40000 || temp_limits[i] > 70000) {
 121                         dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 40000 and 70000)\n",
 122                                 temp_limits[i]);
 123                         return -EINVAL;
 124                 }
 125         }
 126         if (hysteresis < 1000 || hysteresis > 10000) {
 127                 dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n",
 128                         hysteresis);
 129                 return -EINVAL;
 130         }
 131         if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) {
 132                 dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n",
 133                         speed_on_ac);
 134                 return -EINVAL;
 135         }
 136
 137         fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
 138         if (!fan)
 139                 return -ENOMEM;
 140
 141         fan->dev = &pdev->dev;
 142         INIT_DELAYED_WORK(&fan->work, gpd_pocket_fan_worker);
 143
 144         /* Note this returns a "weak" reference which we don't need to free */
 145         fan->dts0 = thermal_zone_get_zone_by_name("soc_dts0");
 146         if (IS_ERR(fan->dts0))
 147                 return -EPROBE_DEFER;
 148
 149         fan->dts1 = thermal_zone_get_zone_by_name("soc_dts1");
 150         if (IS_ERR(fan->dts1))
 151                 return -EPROBE_DEFER;
 152
 153         fan->gpio0 = devm_gpiod_get_index(fan->dev, NULL, 0, GPIOD_ASIS);
 154         if (IS_ERR(fan->gpio0))
 155                 return PTR_ERR(fan->gpio0);
 156
 157         fan->gpio1 = devm_gpiod_get_index(fan->dev, NULL, 1, GPIOD_ASIS);
 158         if (IS_ERR(fan->gpio1))
 159                 return PTR_ERR(fan->gpio1);
 160
 161         gpd_pocket_fan_force_update(fan);
 162
 163         platform_set_drvdata(pdev, fan);
 164         return 0;
 165 }
 166
 167 static int gpd_pocket_fan_remove(struct platform_device *pdev)
 168 {
 169         struct gpd_pocket_fan_data *fan = platform_get_drvdata(pdev);
 170
 171         cancel_delayed_work_sync(&fan->work);
 172         return 0;
 173 }
 174
 175 #ifdef CONFIG_PM_SLEEP
 176 static int gpd_pocket_fan_suspend(struct device *dev)
 177 {
 178         struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
 179
 180         cancel_delayed_work_sync(&fan->work);
 181         gpd_pocket_fan_set_speed(fan, gpd_pocket_fan_min_speed());
 182         return 0;
 183 }
 184
 185 static int gpd_pocket_fan_resume(struct device *dev)
 186 {
 187         struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
 188
 189         gpd_pocket_fan_force_update(fan);
 190         return 0;
 191 }
 192 #endif
 193 static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,
 194                          gpd_pocket_fan_suspend,
 195                          gpd_pocket_fan_resume);
 196
 197 static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {
 198         { "FAN02501" },
 199         {},
 200 };
 201 MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);
 202
 203 static struct platform_driver gpd_pocket_fan_driver = {
 204         .probe  = gpd_pocket_fan_probe,
 205         .remove = gpd_pocket_fan_remove,
 206         .driver = {
 207                 .name                   = "gpd_pocket_fan",
 208                 .acpi_match_table       = gpd_pocket_fan_acpi_match,
 209                 .pm                     = &gpd_pocket_fan_pm_ops,
 210          },
 211 };
 212
 213 module_platform_driver(gpd_pocket_fan_driver);
 214 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
 215 MODULE_DESCRIPTION("GPD pocket fan driver");
 216 MODULE_LICENSE("GPL");