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 #define TEMP_LIMIT0_DEFAULT     55000
  20 #define TEMP_LIMIT1_DEFAULT     60000
  21 #define TEMP_LIMIT2_DEFAULT     65000
  22
  23 #define HYSTERESIS_DEFAULT      3000
  24
  25 #define SPEED_ON_AC_DEFAULT     2
  26
  27 static int temp_limits[3] = {
  28         TEMP_LIMIT0_DEFAULT, TEMP_LIMIT1_DEFAULT, TEMP_LIMIT2_DEFAULT,
  29 };
  30 module_param_array(temp_limits, int, NULL, 0444);
  31 MODULE_PARM_DESC(temp_limits,
  32                  "Millicelsius values above which the fan speed increases");
  33
  34 static int hysteresis = HYSTERESIS_DEFAULT;
  35 module_param(hysteresis, int, 0444);
  36 MODULE_PARM_DESC(hysteresis,
  37                  "Hysteresis in millicelsius before lowering the fan speed");
  38
  39 static int speed_on_ac = SPEED_ON_AC_DEFAULT;
  40 module_param(speed_on_ac, int, 0444);
  41 MODULE_PARM_DESC(speed_on_ac,
  42                  "minimum fan speed to allow when system is powered by AC");
  43
  44 struct gpd_pocket_fan_data {
  45         struct device *dev;
  46         struct thermal_zone_device *dts0;
  47         struct thermal_zone_device *dts1;
  48         struct gpio_desc *gpio0;
  49         struct gpio_desc *gpio1;
  50         struct delayed_work work;
  51         int last_speed;
  52 };
  53
  54 static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
  55 {
  56         if (speed == fan->last_speed)
  57                 return;
  58
  59         gpiod_direction_output(fan->gpio0, !!(speed & 1));
  60         gpiod_direction_output(fan->gpio1, !!(speed & 2));
  61
  62         fan->last_speed = speed;
  63 }
  64
  65 static int gpd_pocket_fan_min_speed(void)
  66 {
  67         if (power_supply_is_system_supplied())
  68                 return speed_on_ac;
  69         else
  70                 return 0;
  71 }
  72
  73 static void gpd_pocket_fan_worker(struct work_struct *work)
  74 {
  75         struct gpd_pocket_fan_data *fan =
  76                 container_of(work, struct gpd_pocket_fan_data, work.work);
  77         int t0, t1, temp, speed, min_speed, i;
  78
  79         if (thermal_zone_get_temp(fan->dts0, &t0) ||
  80             thermal_zone_get_temp(fan->dts1, &t1)) {
  81                 dev_warn(fan->dev, "Error getting temperature\n");
  82                 speed = MAX_SPEED;
  83                 goto set_speed;
  84         }
  85
  86         temp = max(t0, t1);
  87
  88         speed = fan->last_speed;
  89         min_speed = gpd_pocket_fan_min_speed();
  90
  91         /* Determine minimum speed */
  92         for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
  93                 if (temp < temp_limits[i])
  94                         break;
  95         }
  96         if (speed < i)
  97                 speed = i;
  98
  99         /* Use hysteresis before lowering speed again */
 100         for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
 101                 if (temp <= (temp_limits[i] - hysteresis))
 102                         break;
 103         }
 104         if (speed > i)
 105                 speed = i;
 106
 107         if (fan->last_speed <= 0 && speed)
 108                 speed = MAX_SPEED; /* kick start motor */
 109
 110 set_speed:
 111         gpd_pocket_fan_set_speed(fan, speed);
 112
 113         /* When mostly idle (low temp/speed), slow down the poll interval. */
 114         queue_delayed_work(system_wq, &fan->work,
 115                            msecs_to_jiffies(4000 / (speed + 1)));
 116 }
 117
 118 static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan)
 119 {
 120         fan->last_speed = -1;
 121         mod_delayed_work(system_wq, &fan->work, 0);
 122 }
 123
 124 static int gpd_pocket_fan_probe(struct platform_device *pdev)
 125 {
 126         struct gpd_pocket_fan_data *fan;
 127         int i;
 128
 129         for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
 130                 if (temp_limits[i] < 20000 || temp_limits[i] > 90000) {
 131                         dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 20000 and 90000)\n",
 132                                 temp_limits[i]);
 133                         temp_limits[0] = TEMP_LIMIT0_DEFAULT;
 134                         temp_limits[1] = TEMP_LIMIT1_DEFAULT;
 135                         temp_limits[2] = TEMP_LIMIT2_DEFAULT;
 136                         break;
 137                 }
 138         }
 139         if (hysteresis < 1000 || hysteresis > 10000) {
 140                 dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n",
 141                         hysteresis);
 142                 hysteresis = HYSTERESIS_DEFAULT;
 143         }
 144         if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) {
 145                 dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n",
 146                         speed_on_ac);
 147                 speed_on_ac = SPEED_ON_AC_DEFAULT;
 148         }
 149
 150         fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
 151         if (!fan)
 152                 return -ENOMEM;
 153
 154         fan->dev = &pdev->dev;
 155         INIT_DELAYED_WORK(&fan->work, gpd_pocket_fan_worker);
 156
 157         /* Note this returns a "weak" reference which we don't need to free */
 158         fan->dts0 = thermal_zone_get_zone_by_name("soc_dts0");
 159         if (IS_ERR(fan->dts0))
 160                 return -EPROBE_DEFER;
 161
 162         fan->dts1 = thermal_zone_get_zone_by_name("soc_dts1");
 163         if (IS_ERR(fan->dts1))
 164                 return -EPROBE_DEFER;
 165
 166         fan->gpio0 = devm_gpiod_get_index(fan->dev, NULL, 0, GPIOD_ASIS);
 167         if (IS_ERR(fan->gpio0))
 168                 return PTR_ERR(fan->gpio0);
 169
 170         fan->gpio1 = devm_gpiod_get_index(fan->dev, NULL, 1, GPIOD_ASIS);
 171         if (IS_ERR(fan->gpio1))
 172                 return PTR_ERR(fan->gpio1);
 173
 174         gpd_pocket_fan_force_update(fan);
 175
 176         platform_set_drvdata(pdev, fan);
 177         return 0;
 178 }
 179
 180 static int gpd_pocket_fan_remove(struct platform_device *pdev)
 181 {
 182         struct gpd_pocket_fan_data *fan = platform_get_drvdata(pdev);
 183
 184         cancel_delayed_work_sync(&fan->work);
 185         return 0;
 186 }
 187
 188 #ifdef CONFIG_PM_SLEEP
 189 static int gpd_pocket_fan_suspend(struct device *dev)
 190 {
 191         struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
 192
 193         cancel_delayed_work_sync(&fan->work);
 194         gpd_pocket_fan_set_speed(fan, gpd_pocket_fan_min_speed());
 195         return 0;
 196 }
 197
 198 static int gpd_pocket_fan_resume(struct device *dev)
 199 {
 200         struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
 201
 202         gpd_pocket_fan_force_update(fan);
 203         return 0;
 204 }
 205 #endif
 206 static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,
 207                          gpd_pocket_fan_suspend,
 208                          gpd_pocket_fan_resume);
 209
 210 static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {
 211         { "FAN02501" },
 212         {},
 213 };
 214 MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);
 215
 216 static struct platform_driver gpd_pocket_fan_driver = {
 217         .probe  = gpd_pocket_fan_probe,
 218         .remove = gpd_pocket_fan_remove,
 219         .driver = {
 220                 .name                   = "gpd_pocket_fan",
 221                 .acpi_match_table       = gpd_pocket_fan_acpi_match,
 222                 .pm                     = &gpd_pocket_fan_pm_ops,
 223          },
 224 };
 225
 226 module_platform_driver(gpd_pocket_fan_driver);
 227 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
 228 MODULE_DESCRIPTION("GPD pocket fan driver");
 229 MODULE_LICENSE("GPL");