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/devm-helpers.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/module.h> 12 #include <linux/moduleparam.h> 13 #include <linux/platform_device.h> 14 #include <linux/power_supply.h> 15 #include <linux/thermal.h> 16 #include <linux/workqueue.h> 17 18 #define MAX_SPEED 3 19 20 #define TEMP_LIMIT0_DEFAULT 55000 21 #define TEMP_LIMIT1_DEFAULT 60000 22 #define TEMP_LIMIT2_DEFAULT 65000 23 24 #define HYSTERESIS_DEFAULT 3000 25 26 #define SPEED_ON_AC_DEFAULT 2 27 28 static int temp_limits[3] = { 29 TEMP_LIMIT0_DEFAULT, TEMP_LIMIT1_DEFAULT, TEMP_LIMIT2_DEFAULT, 30 }; 31 module_param_array(temp_limits, int, NULL, 0444); 32 MODULE_PARM_DESC(temp_limits, 33 "Millicelsius values above which the fan speed increases"); 34 35 static int hysteresis = HYSTERESIS_DEFAULT; 36 module_param(hysteresis, int, 0444); 37 MODULE_PARM_DESC(hysteresis, 38 "Hysteresis in millicelsius before lowering the fan speed"); 39 40 static int speed_on_ac = SPEED_ON_AC_DEFAULT; 41 module_param(speed_on_ac, int, 0444); 42 MODULE_PARM_DESC(speed_on_ac, 43 "minimum fan speed to allow when system is powered by AC"); 44 45 struct gpd_pocket_fan_data { 46 struct device *dev; 47 struct thermal_zone_device *dts0; 48 struct thermal_zone_device *dts1; 49 struct gpio_desc *gpio0; 50 struct gpio_desc *gpio1; 51 struct delayed_work work; 52 int last_speed; 53 }; 54 55 static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed) 56 { 57 if (speed == fan->last_speed) 58 return; 59 60 gpiod_direction_output(fan->gpio0, !!(speed & 1)); 61 gpiod_direction_output(fan->gpio1, !!(speed & 2)); 62 63 fan->last_speed = speed; 64 } 65 66 static int gpd_pocket_fan_min_speed(void) 67 { 68 if (power_supply_is_system_supplied()) 69 return speed_on_ac; 70 else 71 return 0; 72 } 73 74 static void gpd_pocket_fan_worker(struct work_struct *work) 75 { 76 struct gpd_pocket_fan_data *fan = 77 container_of(work, struct gpd_pocket_fan_data, work.work); 78 int t0, t1, temp, speed, min_speed, i; 79 80 if (thermal_zone_get_temp(fan->dts0, &t0) || 81 thermal_zone_get_temp(fan->dts1, &t1)) { 82 dev_warn(fan->dev, "Error getting temperature\n"); 83 speed = MAX_SPEED; 84 goto set_speed; 85 } 86 87 temp = max(t0, t1); 88 89 speed = fan->last_speed; 90 min_speed = gpd_pocket_fan_min_speed(); 91 92 /* Determine minimum speed */ 93 for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) { 94 if (temp < temp_limits[i]) 95 break; 96 } 97 if (speed < i) 98 speed = i; 99 100 /* Use hysteresis before lowering speed again */ 101 for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) { 102 if (temp <= (temp_limits[i] - hysteresis)) 103 break; 104 } 105 if (speed > i) 106 speed = i; 107 108 if (fan->last_speed <= 0 && speed) 109 speed = MAX_SPEED; /* kick start motor */ 110 111 set_speed: 112 gpd_pocket_fan_set_speed(fan, speed); 113 114 /* When mostly idle (low temp/speed), slow down the poll interval. */ 115 queue_delayed_work(system_wq, &fan->work, 116 msecs_to_jiffies(4000 / (speed + 1))); 117 } 118 119 static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan) 120 { 121 fan->last_speed = -1; 122 mod_delayed_work(system_wq, &fan->work, 0); 123 } 124 125 static int gpd_pocket_fan_probe(struct platform_device *pdev) 126 { 127 struct gpd_pocket_fan_data *fan; 128 int i, ret; 129 130 for (i = 0; i < ARRAY_SIZE(temp_limits); i++) { 131 if (temp_limits[i] < 20000 || temp_limits[i] > 90000) { 132 dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 20000 and 90000)\n", 133 temp_limits[i]); 134 temp_limits[0] = TEMP_LIMIT0_DEFAULT; 135 temp_limits[1] = TEMP_LIMIT1_DEFAULT; 136 temp_limits[2] = TEMP_LIMIT2_DEFAULT; 137 break; 138 } 139 } 140 if (hysteresis < 1000 || hysteresis > 10000) { 141 dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n", 142 hysteresis); 143 hysteresis = HYSTERESIS_DEFAULT; 144 } 145 if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) { 146 dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n", 147 speed_on_ac); 148 speed_on_ac = SPEED_ON_AC_DEFAULT; 149 } 150 151 fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL); 152 if (!fan) 153 return -ENOMEM; 154 155 fan->dev = &pdev->dev; 156 ret = devm_delayed_work_autocancel(&pdev->dev, &fan->work, 157 gpd_pocket_fan_worker); 158 if (ret) 159 return ret; 160 161 /* Note this returns a "weak" reference which we don't need to free */ 162 fan->dts0 = thermal_zone_get_zone_by_name("soc_dts0"); 163 if (IS_ERR(fan->dts0)) 164 return -EPROBE_DEFER; 165 166 fan->dts1 = thermal_zone_get_zone_by_name("soc_dts1"); 167 if (IS_ERR(fan->dts1)) 168 return -EPROBE_DEFER; 169 170 fan->gpio0 = devm_gpiod_get_index(fan->dev, NULL, 0, GPIOD_ASIS); 171 if (IS_ERR(fan->gpio0)) 172 return PTR_ERR(fan->gpio0); 173 174 fan->gpio1 = devm_gpiod_get_index(fan->dev, NULL, 1, GPIOD_ASIS); 175 if (IS_ERR(fan->gpio1)) 176 return PTR_ERR(fan->gpio1); 177 178 gpd_pocket_fan_force_update(fan); 179 180 platform_set_drvdata(pdev, fan); 181 return 0; 182 } 183 184 #ifdef CONFIG_PM_SLEEP 185 static int gpd_pocket_fan_suspend(struct device *dev) 186 { 187 struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev); 188 189 cancel_delayed_work_sync(&fan->work); 190 gpd_pocket_fan_set_speed(fan, gpd_pocket_fan_min_speed()); 191 return 0; 192 } 193 194 static int gpd_pocket_fan_resume(struct device *dev) 195 { 196 struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev); 197 198 gpd_pocket_fan_force_update(fan); 199 return 0; 200 } 201 #endif 202 static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops, 203 gpd_pocket_fan_suspend, 204 gpd_pocket_fan_resume); 205 206 static struct acpi_device_id gpd_pocket_fan_acpi_match[] = { 207 { "FAN02501" }, 208 {}, 209 }; 210 MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match); 211 212 static struct platform_driver gpd_pocket_fan_driver = { 213 .probe = gpd_pocket_fan_probe, 214 .driver = { 215 .name = "gpd_pocket_fan", 216 .acpi_match_table = gpd_pocket_fan_acpi_match, 217 .pm = &gpd_pocket_fan_pm_ops, 218 }, 219 }; 220 221 module_platform_driver(gpd_pocket_fan_driver); 222 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com"); 223 MODULE_DESCRIPTION("GPD pocket fan driver"); 224 MODULE_LICENSE("GPL"); 225