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linux-next/drivers/thermal/thermal_mmio.c
Talel Shenhar 71aa369349 thermal: Introduce Amazon's Annapurna Labs Thermal Driver
This is a generic thermal driver for simple MMIO sensors, of which
amazon,al-thermal is one.

This device uses a single MMIO transaction to read the temperature and
report it to the thermal subsystem.

Signed-off-by: Talel Shenhar <talel@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2019-05-14 07:00:26 -07:00

130 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*/
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>
struct thermal_mmio {
void __iomem *mmio_base;
u32 (*read_mmio)(void __iomem *mmio_base);
u32 mask;
int factor;
};
static u32 thermal_mmio_readb(void __iomem *mmio_base)
{
return readb(mmio_base);
}
static int thermal_mmio_get_temperature(void *private, int *temp)
{
int t;
struct thermal_mmio *sensor =
(struct thermal_mmio *)private;
t = sensor->read_mmio(sensor->mmio_base) & sensor->mask;
t *= sensor->factor;
*temp = t;
return 0;
}
static struct thermal_zone_of_device_ops thermal_mmio_ops = {
.get_temp = thermal_mmio_get_temperature,
};
static int thermal_mmio_probe(struct platform_device *pdev)
{
struct resource *resource;
struct thermal_mmio *sensor;
int (*sensor_init_func)(struct platform_device *pdev,
struct thermal_mmio *sensor);
struct thermal_zone_device *thermal_zone;
int ret;
int temperature;
sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);
if (!sensor)
return -ENOMEM;
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (IS_ERR(resource)) {
dev_err(&pdev->dev,
"fail to get platform memory resource (%ld)\n",
PTR_ERR(resource));
return PTR_ERR(resource);
}
sensor->mmio_base = devm_ioremap_resource(&pdev->dev, resource);
if (IS_ERR(sensor->mmio_base)) {
dev_err(&pdev->dev, "failed to ioremap memory (%ld)\n",
PTR_ERR(sensor->mmio_base));
return PTR_ERR(sensor->mmio_base);
}
sensor_init_func = device_get_match_data(&pdev->dev);
if (sensor_init_func) {
ret = sensor_init_func(pdev, sensor);
if (ret) {
dev_err(&pdev->dev,
"failed to initialize sensor (%d)\n",
ret);
return ret;
}
}
thermal_zone = devm_thermal_zone_of_sensor_register(&pdev->dev,
0,
sensor,
&thermal_mmio_ops);
if (IS_ERR(thermal_zone)) {
dev_err(&pdev->dev,
"failed to register sensor (%ld)\n",
PTR_ERR(thermal_zone));
return PTR_ERR(thermal_zone);
}
thermal_mmio_get_temperature(sensor, &temperature);
dev_info(&pdev->dev,
"thermal mmio sensor %s registered, current temperature: %d\n",
pdev->name, temperature);
return 0;
}
static int al_thermal_init(struct platform_device *pdev,
struct thermal_mmio *sensor)
{
sensor->read_mmio = thermal_mmio_readb;
sensor->mask = 0xff;
sensor->factor = 1000;
return 0;
}
static const struct of_device_id thermal_mmio_id_table[] = {
{ .compatible = "amazon,al-thermal", .data = al_thermal_init},
{}
};
MODULE_DEVICE_TABLE(of, thermal_mmio_id_table);
static struct platform_driver thermal_mmio_driver = {
.probe = thermal_mmio_probe,
.driver = {
.name = "thermal-mmio",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(thermal_mmio_id_table),
},
};
module_platform_driver(thermal_mmio_driver);
MODULE_AUTHOR("Talel Shenhar <talel@amazon.com>");
MODULE_DESCRIPTION("Thermal MMIO Driver");
MODULE_LICENSE("GPL v2");