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 40000 and 70000)\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"); 230