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1// SPDX-License-Identifier: GPL-2.0+2/*3 * GPD Pocket fan controller driver4 *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 319 20#define TEMP_LIMIT0_DEFAULT 5500021#define TEMP_LIMIT1_DEFAULT 6000022#define TEMP_LIMIT2_DEFAULT 6500023 24#define HYSTERESIS_DEFAULT 300025 26#define SPEED_ON_AC_DEFAULT 227 28static int temp_limits[3] = {29 TEMP_LIMIT0_DEFAULT, TEMP_LIMIT1_DEFAULT, TEMP_LIMIT2_DEFAULT,30};31module_param_array(temp_limits, int, NULL, 0444);32MODULE_PARM_DESC(temp_limits,33 "Millicelsius values above which the fan speed increases");34 35static int hysteresis = HYSTERESIS_DEFAULT;36module_param(hysteresis, int, 0444);37MODULE_PARM_DESC(hysteresis,38 "Hysteresis in millicelsius before lowering the fan speed");39 40static int speed_on_ac = SPEED_ON_AC_DEFAULT;41module_param(speed_on_ac, int, 0444);42MODULE_PARM_DESC(speed_on_ac,43 "minimum fan speed to allow when system is powered by AC");44 45struct 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 55static 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 66static int gpd_pocket_fan_min_speed(void)67{68 if (power_supply_is_system_supplied())69 return speed_on_ac;70 else71 return 0;72}73 74static 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 111set_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 119static 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 125static 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_SLEEP185static 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 194static 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#endif202static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,203 gpd_pocket_fan_suspend,204 gpd_pocket_fan_resume);205 206static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {207 { "FAN02501" },208 {},209};210MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);211 212static 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 221module_platform_driver(gpd_pocket_fan_driver);222MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");223MODULE_DESCRIPTION("GPD pocket fan driver");224MODULE_LICENSE("GPL");225