1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Khadas MCU Controlled FAN driver 4 * 5 * Copyright (C) 2020 BayLibre SAS 6 * 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 3 18 19 struct khadas_mcu_fan_ctx { 20 struct khadas_mcu *mcu; 21 unsigned int level; 22 struct thermal_cooling_device *cdev; 23 }; 24 25 static 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 40 static 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 48 static 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 58 static int 59 khadas_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 73 static 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 79 static 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 } 106 107 static 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_SLEEP 115 static 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 } 129 130 static 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 #endif 137 138 static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend, 139 khadas_mcu_fan_resume); 140 141 static const struct platform_device_id khadas_mcu_fan_id_table[] = { 142 { .name = "khadas-mcu-fan-ctrl", }, 143 {}, 144 }; 145 MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table); 146 147 static 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 }; 156 157 module_platform_driver(khadas_mcu_fan_driver); 158 159 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); 160 MODULE_DESCRIPTION("Khadas MCU FAN driver"); 161 MODULE_LICENSE("GPL"); 162