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 "Millicelsius 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 millicelsius 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"); 217