thermal: Add support for the MCU controlled FAN on Khadas boards

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>
This commit is contained in:
Neil Armstrong 2020-06-24 18:15:27 +02:00 committed by Lee Jones
parent 6c27219e34
commit 5772717e59
3 changed files with 174 additions and 0 deletions

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@ -500,4 +500,15 @@ config SPRD_THERMAL
help
Support for the Spreadtrum thermal sensor driver in the Linux thermal
framework.
config KHADAS_MCU_FAN_THERMAL
tristate "Khadas MCU controller FAN cooling support"
depends on OF || COMPILE_TEST
depends on MFD_KHADAS_MCU
select MFD_CORE
select REGMAP
help
If you say yes here you get support for the FAN controlled
by the Microcontroller found on the Khadas VIM boards.
endif

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@ -61,3 +61,4 @@ obj-$(CONFIG_ZX2967_THERMAL) += zx2967_thermal.o
obj-$(CONFIG_UNIPHIER_THERMAL) += uniphier_thermal.o
obj-$(CONFIG_AMLOGIC_THERMAL) += amlogic_thermal.o
obj-$(CONFIG_SPRD_THERMAL) += sprd_thermal.o
obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL) += khadas_mcu_fan.o

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@ -0,0 +1,162 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Khadas MCU Controlled FAN driver
*
* Copyright (C) 2020 BayLibre SAS
* Author(s): Neil Armstrong <narmstrong@baylibre.com>
*/
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/khadas-mcu.h>
#include <linux/regmap.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
#define MAX_LEVEL 3
struct khadas_mcu_fan_ctx {
struct khadas_mcu *mcu;
unsigned int level;
struct thermal_cooling_device *cdev;
};
static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
unsigned int level)
{
int ret;
ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
level);
if (ret)
return ret;
ctx->level = level;
return 0;
}
static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
*state = MAX_LEVEL;
return 0;
}
static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
*state = ctx->level;
return 0;
}
static int
khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
if (state > MAX_LEVEL)
return -EINVAL;
if (state == ctx->level)
return 0;
return khadas_mcu_fan_set_level(ctx, state);
}
static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
.get_max_state = khadas_mcu_fan_get_max_state,
.get_cur_state = khadas_mcu_fan_get_cur_state,
.set_cur_state = khadas_mcu_fan_set_cur_state,
};
static int khadas_mcu_fan_probe(struct platform_device *pdev)
{
struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
struct thermal_cooling_device *cdev;
struct device *dev = &pdev->dev;
struct khadas_mcu_fan_ctx *ctx;
int ret;
ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->mcu = mcu;
platform_set_drvdata(pdev, ctx);
cdev = devm_thermal_of_cooling_device_register(dev->parent,
dev->parent->of_node, "khadas-mcu-fan", ctx,
&khadas_mcu_fan_cooling_ops);
if (IS_ERR(cdev)) {
ret = PTR_ERR(cdev);
dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",
ret);
return ret;
}
ctx->cdev = cdev;
thermal_cdev_update(cdev);
return 0;
}
static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
{
struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
khadas_mcu_fan_set_level(ctx, 0);
}
#ifdef CONFIG_PM_SLEEP
static int khadas_mcu_fan_suspend(struct device *dev)
{
struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
unsigned int level_save = ctx->level;
int ret;
ret = khadas_mcu_fan_set_level(ctx, 0);
if (ret)
return ret;
ctx->level = level_save;
return 0;
}
static int khadas_mcu_fan_resume(struct device *dev)
{
struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
return khadas_mcu_fan_set_level(ctx, ctx->level);
}
#endif
static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
khadas_mcu_fan_resume);
static const struct platform_device_id khadas_mcu_fan_id_table[] = {
{ .name = "khadas-mcu-fan-ctrl", },
{},
};
MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
static struct platform_driver khadas_mcu_fan_driver = {
.probe = khadas_mcu_fan_probe,
.shutdown = khadas_mcu_fan_shutdown,
.driver = {
.name = "khadas-mcu-fan-ctrl",
.pm = &khadas_mcu_fan_pm,
},
.id_table = khadas_mcu_fan_id_table,
};
module_platform_driver(khadas_mcu_fan_driver);
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Khadas MCU FAN driver");
MODULE_LICENSE("GPL");