forked from mirrors/linux
71aa369349
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>
129 lines
3 KiB
C
129 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*/
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#include <linux/module.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/thermal.h>
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struct thermal_mmio {
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void __iomem *mmio_base;
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u32 (*read_mmio)(void __iomem *mmio_base);
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u32 mask;
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int factor;
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};
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static u32 thermal_mmio_readb(void __iomem *mmio_base)
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{
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return readb(mmio_base);
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}
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static int thermal_mmio_get_temperature(void *private, int *temp)
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{
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int t;
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struct thermal_mmio *sensor =
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(struct thermal_mmio *)private;
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t = sensor->read_mmio(sensor->mmio_base) & sensor->mask;
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t *= sensor->factor;
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*temp = t;
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return 0;
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}
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static struct thermal_zone_of_device_ops thermal_mmio_ops = {
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.get_temp = thermal_mmio_get_temperature,
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};
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static int thermal_mmio_probe(struct platform_device *pdev)
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{
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struct resource *resource;
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struct thermal_mmio *sensor;
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int (*sensor_init_func)(struct platform_device *pdev,
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struct thermal_mmio *sensor);
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struct thermal_zone_device *thermal_zone;
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int ret;
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int temperature;
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sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);
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if (!sensor)
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return -ENOMEM;
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resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (IS_ERR(resource)) {
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dev_err(&pdev->dev,
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"fail to get platform memory resource (%ld)\n",
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PTR_ERR(resource));
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return PTR_ERR(resource);
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}
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sensor->mmio_base = devm_ioremap_resource(&pdev->dev, resource);
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if (IS_ERR(sensor->mmio_base)) {
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dev_err(&pdev->dev, "failed to ioremap memory (%ld)\n",
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PTR_ERR(sensor->mmio_base));
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return PTR_ERR(sensor->mmio_base);
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}
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sensor_init_func = device_get_match_data(&pdev->dev);
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if (sensor_init_func) {
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ret = sensor_init_func(pdev, sensor);
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if (ret) {
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dev_err(&pdev->dev,
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"failed to initialize sensor (%d)\n",
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ret);
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return ret;
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}
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}
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thermal_zone = devm_thermal_zone_of_sensor_register(&pdev->dev,
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0,
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sensor,
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&thermal_mmio_ops);
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if (IS_ERR(thermal_zone)) {
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dev_err(&pdev->dev,
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"failed to register sensor (%ld)\n",
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PTR_ERR(thermal_zone));
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return PTR_ERR(thermal_zone);
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}
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thermal_mmio_get_temperature(sensor, &temperature);
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dev_info(&pdev->dev,
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"thermal mmio sensor %s registered, current temperature: %d\n",
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pdev->name, temperature);
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return 0;
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}
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static int al_thermal_init(struct platform_device *pdev,
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struct thermal_mmio *sensor)
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{
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sensor->read_mmio = thermal_mmio_readb;
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sensor->mask = 0xff;
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sensor->factor = 1000;
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return 0;
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}
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static const struct of_device_id thermal_mmio_id_table[] = {
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{ .compatible = "amazon,al-thermal", .data = al_thermal_init},
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{}
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};
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MODULE_DEVICE_TABLE(of, thermal_mmio_id_table);
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static struct platform_driver thermal_mmio_driver = {
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.probe = thermal_mmio_probe,
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.driver = {
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.name = "thermal-mmio",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(thermal_mmio_id_table),
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},
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};
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module_platform_driver(thermal_mmio_driver);
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MODULE_AUTHOR("Talel Shenhar <talel@amazon.com>");
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MODULE_DESCRIPTION("Thermal MMIO Driver");
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MODULE_LICENSE("GPL v2");
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