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