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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Khadas MCU Controlled FAN driver4 *5 * Copyright (C) 2020 BayLibre SAS6 * Author(s): Neil Armstrong <narmstrong@baylibre.com>7 */8 9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/mfd/khadas-mcu.h>13#include <linux/regmap.h>14#include <linux/sysfs.h>15#include <linux/thermal.h>16 17#define MAX_LEVEL 318 19struct khadas_mcu_fan_ctx {20 struct khadas_mcu *mcu;21 unsigned int level;22 struct thermal_cooling_device *cdev;23};24 25static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,26 unsigned int level)27{28 int ret;29 30 ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,31 level);32 if (ret)33 return ret;34 35 ctx->level = level;36 37 return 0;38}39 40static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,41 unsigned long *state)42{43 *state = MAX_LEVEL;44 45 return 0;46}47 48static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,49 unsigned long *state)50{51 struct khadas_mcu_fan_ctx *ctx = cdev->devdata;52 53 *state = ctx->level;54 55 return 0;56}57 58static int59khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,60 unsigned long state)61{62 struct khadas_mcu_fan_ctx *ctx = cdev->devdata;63 64 if (state > MAX_LEVEL)65 return -EINVAL;66 67 if (state == ctx->level)68 return 0;69 70 return khadas_mcu_fan_set_level(ctx, state);71}72 73static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {74 .get_max_state = khadas_mcu_fan_get_max_state,75 .get_cur_state = khadas_mcu_fan_get_cur_state,76 .set_cur_state = khadas_mcu_fan_set_cur_state,77};78 79static int khadas_mcu_fan_probe(struct platform_device *pdev)80{81 struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);82 struct thermal_cooling_device *cdev;83 struct device *dev = &pdev->dev;84 struct khadas_mcu_fan_ctx *ctx;85 int ret;86 87 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);88 if (!ctx)89 return -ENOMEM;90 ctx->mcu = mcu;91 platform_set_drvdata(pdev, ctx);92 93 cdev = devm_thermal_of_cooling_device_register(dev->parent,94 dev->parent->of_node, "khadas-mcu-fan", ctx,95 &khadas_mcu_fan_cooling_ops);96 if (IS_ERR(cdev)) {97 ret = PTR_ERR(cdev);98 dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",99 ret);100 return ret;101 }102 ctx->cdev = cdev;103 104 return 0;105}106 107static void khadas_mcu_fan_shutdown(struct platform_device *pdev)108{109 struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);110 111 khadas_mcu_fan_set_level(ctx, 0);112}113 114#ifdef CONFIG_PM_SLEEP115static int khadas_mcu_fan_suspend(struct device *dev)116{117 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);118 unsigned int level_save = ctx->level;119 int ret;120 121 ret = khadas_mcu_fan_set_level(ctx, 0);122 if (ret)123 return ret;124 125 ctx->level = level_save;126 127 return 0;128}129 130static int khadas_mcu_fan_resume(struct device *dev)131{132 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);133 134 return khadas_mcu_fan_set_level(ctx, ctx->level);135}136#endif137 138static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,139 khadas_mcu_fan_resume);140 141static const struct platform_device_id khadas_mcu_fan_id_table[] = {142 { .name = "khadas-mcu-fan-ctrl", },143 {},144};145MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);146 147static struct platform_driver khadas_mcu_fan_driver = {148 .probe = khadas_mcu_fan_probe,149 .shutdown = khadas_mcu_fan_shutdown,150 .driver = {151 .name = "khadas-mcu-fan-ctrl",152 .pm = &khadas_mcu_fan_pm,153 },154 .id_table = khadas_mcu_fan_id_table,155};156 157module_platform_driver(khadas_mcu_fan_driver);158 159MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");160MODULE_DESCRIPTION("Khadas MCU FAN driver");161MODULE_LICENSE("GPL");162