![Neil Armstrong](/assets/img/avatar_default.png)
The new Khadas VIM2 and VIM3 boards controls the cooling fan via the on-board microcontroller. This implements the FAN control as thermal devices and as cell of the Khadas MCU MFD driver. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
163 lines
3.6 KiB
C
163 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Khadas MCU Controlled FAN driver
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*
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* Copyright (C) 2020 BayLibre SAS
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* Author(s): Neil Armstrong <narmstrong@baylibre.com>
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*/
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/mfd/khadas-mcu.h>
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#include <linux/regmap.h>
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#include <linux/sysfs.h>
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#include <linux/thermal.h>
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#define MAX_LEVEL 3
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struct khadas_mcu_fan_ctx {
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struct khadas_mcu *mcu;
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unsigned int level;
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struct thermal_cooling_device *cdev;
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};
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static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
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unsigned int level)
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{
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int ret;
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ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
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level);
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if (ret)
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return ret;
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ctx->level = level;
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return 0;
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}
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static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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*state = MAX_LEVEL;
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return 0;
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}
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static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
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*state = ctx->level;
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return 0;
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}
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static int
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khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
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unsigned long state)
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{
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struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
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if (state > MAX_LEVEL)
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return -EINVAL;
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if (state == ctx->level)
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return 0;
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return khadas_mcu_fan_set_level(ctx, state);
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}
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static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
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.get_max_state = khadas_mcu_fan_get_max_state,
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.get_cur_state = khadas_mcu_fan_get_cur_state,
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.set_cur_state = khadas_mcu_fan_set_cur_state,
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};
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static int khadas_mcu_fan_probe(struct platform_device *pdev)
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{
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struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
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struct thermal_cooling_device *cdev;
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struct device *dev = &pdev->dev;
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struct khadas_mcu_fan_ctx *ctx;
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int ret;
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ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return -ENOMEM;
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ctx->mcu = mcu;
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platform_set_drvdata(pdev, ctx);
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cdev = devm_thermal_of_cooling_device_register(dev->parent,
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dev->parent->of_node, "khadas-mcu-fan", ctx,
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&khadas_mcu_fan_cooling_ops);
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if (IS_ERR(cdev)) {
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ret = PTR_ERR(cdev);
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dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",
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ret);
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return ret;
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}
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ctx->cdev = cdev;
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thermal_cdev_update(cdev);
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return 0;
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}
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static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
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{
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struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
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khadas_mcu_fan_set_level(ctx, 0);
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}
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#ifdef CONFIG_PM_SLEEP
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static int khadas_mcu_fan_suspend(struct device *dev)
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{
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struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
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unsigned int level_save = ctx->level;
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int ret;
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ret = khadas_mcu_fan_set_level(ctx, 0);
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if (ret)
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return ret;
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ctx->level = level_save;
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return 0;
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}
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static int khadas_mcu_fan_resume(struct device *dev)
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{
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struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
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return khadas_mcu_fan_set_level(ctx, ctx->level);
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}
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#endif
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static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
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khadas_mcu_fan_resume);
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static const struct platform_device_id khadas_mcu_fan_id_table[] = {
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{ .name = "khadas-mcu-fan-ctrl", },
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{},
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};
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MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
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static struct platform_driver khadas_mcu_fan_driver = {
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.probe = khadas_mcu_fan_probe,
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.shutdown = khadas_mcu_fan_shutdown,
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.driver = {
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.name = "khadas-mcu-fan-ctrl",
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.pm = &khadas_mcu_fan_pm,
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},
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.id_table = khadas_mcu_fan_id_table,
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};
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module_platform_driver(khadas_mcu_fan_driver);
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MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
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MODULE_DESCRIPTION("Khadas MCU FAN driver");
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MODULE_LICENSE("GPL");
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