thermal: bcm2835: add thermal driver for bcm2835 SoC
Add basic thermal driver for bcm2835 SoC. This driver currently make sure that tsense HW block is set up correctly. Tested-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Eric Anholt <eric@anholt.net> Acked-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
This commit is contained in:
Stefan Wahren
Eduardo Valentin
Родитель
1e2ac9821d
Коммит
bcb7dd9ef2
|
|
@ -453,4 +453,12 @@ config ZX2967_THERMAL
|
|||
the primitive temperature sensor embedded in zx2967 SoCs.
|
||||
This sensor generates the real time die temperature.
|
||||
|
||||
config BCM2835_THERMAL
|
||||
tristate "Thermal sensors on bcm2835 SoC"
|
||||
depends on ARCH_BCM2835 || COMPILE_TEST
|
||||
depends on HAS_IOMEM
|
||||
depends on THERMAL_OF
|
||||
help
|
||||
Support for thermal sensors on Broadcom bcm2835 SoCs.
|
||||
|
||||
endif
|
||||
|
|
|
|||
|
|
@ -58,3 +58,4 @@ obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
|
|||
obj-$(CONFIG_MTK_THERMAL) += mtk_thermal.o
|
||||
obj-$(CONFIG_GENERIC_ADC_THERMAL) += thermal-generic-adc.o
|
||||
obj-$(CONFIG_ZX2967_THERMAL) += zx2967_thermal.o
|
||||
obj-$(CONFIG_BCM2835_THERMAL) += bcm2835_thermal.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,314 @@
|
|||
/*
|
||||
* Driver for Broadcom BCM2835 SoC temperature sensor
|
||||
*
|
||||
* Copyright (C) 2016 Martin Sperl
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*/
|
||||
|
||||
#include <linux/clk.h>
|
||||
#include <linux/debugfs.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/io.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/of.h>
|
||||
#include <linux/of_address.h>
|
||||
#include <linux/of_device.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/thermal.h>
|
||||
|
||||
#define BCM2835_TS_TSENSCTL 0x00
|
||||
#define BCM2835_TS_TSENSSTAT 0x04
|
||||
|
||||
#define BCM2835_TS_TSENSCTL_PRWDW BIT(0)
|
||||
#define BCM2835_TS_TSENSCTL_RSTB BIT(1)
|
||||
|
||||
/*
|
||||
* bandgap reference voltage in 6 mV increments
|
||||
* 000b = 1178 mV, 001b = 1184 mV, ... 111b = 1220 mV
|
||||
*/
|
||||
#define BCM2835_TS_TSENSCTL_CTRL_BITS 3
|
||||
#define BCM2835_TS_TSENSCTL_CTRL_SHIFT 2
|
||||
#define BCM2835_TS_TSENSCTL_CTRL_MASK \
|
||||
GENMASK(BCM2835_TS_TSENSCTL_CTRL_BITS + \
|
||||
BCM2835_TS_TSENSCTL_CTRL_SHIFT - 1, \
|
||||
BCM2835_TS_TSENSCTL_CTRL_SHIFT)
|
||||
#define BCM2835_TS_TSENSCTL_CTRL_DEFAULT 1
|
||||
#define BCM2835_TS_TSENSCTL_EN_INT BIT(5)
|
||||
#define BCM2835_TS_TSENSCTL_DIRECT BIT(6)
|
||||
#define BCM2835_TS_TSENSCTL_CLR_INT BIT(7)
|
||||
#define BCM2835_TS_TSENSCTL_THOLD_SHIFT 8
|
||||
#define BCM2835_TS_TSENSCTL_THOLD_BITS 10
|
||||
#define BCM2835_TS_TSENSCTL_THOLD_MASK \
|
||||
GENMASK(BCM2835_TS_TSENSCTL_THOLD_BITS + \
|
||||
BCM2835_TS_TSENSCTL_THOLD_SHIFT - 1, \
|
||||
BCM2835_TS_TSENSCTL_THOLD_SHIFT)
|
||||
/*
|
||||
* time how long the block to be asserted in reset
|
||||
* which based on a clock counter (TSENS clock assumed)
|
||||
*/
|
||||
#define BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT 18
|
||||
#define BCM2835_TS_TSENSCTL_RSTDELAY_BITS 8
|
||||
#define BCM2835_TS_TSENSCTL_REGULEN BIT(26)
|
||||
|
||||
#define BCM2835_TS_TSENSSTAT_DATA_BITS 10
|
||||
#define BCM2835_TS_TSENSSTAT_DATA_SHIFT 0
|
||||
#define BCM2835_TS_TSENSSTAT_DATA_MASK \
|
||||
GENMASK(BCM2835_TS_TSENSSTAT_DATA_BITS + \
|
||||
BCM2835_TS_TSENSSTAT_DATA_SHIFT - 1, \
|
||||
BCM2835_TS_TSENSSTAT_DATA_SHIFT)
|
||||
#define BCM2835_TS_TSENSSTAT_VALID BIT(10)
|
||||
#define BCM2835_TS_TSENSSTAT_INTERRUPT BIT(11)
|
||||
|
||||
struct bcm2835_thermal_data {
|
||||
struct thermal_zone_device *tz;
|
||||
void __iomem *regs;
|
||||
struct clk *clk;
|
||||
struct dentry *debugfsdir;
|
||||
};
|
||||
|
||||
static int bcm2835_thermal_adc2temp(u32 adc, int offset, int slope)
|
||||
{
|
||||
return offset + slope * adc;
|
||||
}
|
||||
|
||||
static int bcm2835_thermal_temp2adc(int temp, int offset, int slope)
|
||||
{
|
||||
temp -= offset;
|
||||
temp /= slope;
|
||||
|
||||
if (temp < 0)
|
||||
temp = 0;
|
||||
if (temp >= BIT(BCM2835_TS_TSENSSTAT_DATA_BITS))
|
||||
temp = BIT(BCM2835_TS_TSENSSTAT_DATA_BITS) - 1;
|
||||
|
||||
return temp;
|
||||
}
|
||||
|
||||
static int bcm2835_thermal_get_temp(void *d, int *temp)
|
||||
{
|
||||
struct bcm2835_thermal_data *data = d;
|
||||
u32 val = readl(data->regs + BCM2835_TS_TSENSSTAT);
|
||||
|
||||
if (!(val & BCM2835_TS_TSENSSTAT_VALID))
|
||||
return -EIO;
|
||||
|
||||
val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
|
||||
|
||||
*temp = bcm2835_thermal_adc2temp(
|
||||
val,
|
||||
thermal_zone_get_offset(data->tz),
|
||||
thermal_zone_get_slope(data->tz));
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct debugfs_reg32 bcm2835_thermal_regs[] = {
|
||||
{
|
||||
.name = "ctl",
|
||||
.offset = 0
|
||||
},
|
||||
{
|
||||
.name = "stat",
|
||||
.offset = 4
|
||||
}
|
||||
};
|
||||
|
||||
static void bcm2835_thermal_debugfs(struct platform_device *pdev)
|
||||
{
|
||||
struct thermal_zone_device *tz = platform_get_drvdata(pdev);
|
||||
struct bcm2835_thermal_data *data = tz->devdata;
|
||||
struct debugfs_regset32 *regset;
|
||||
|
||||
data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL);
|
||||
if (!data->debugfsdir)
|
||||
return;
|
||||
|
||||
regset = devm_kzalloc(&pdev->dev, sizeof(*regset), GFP_KERNEL);
|
||||
if (!regset)
|
||||
return;
|
||||
|
||||
regset->regs = bcm2835_thermal_regs;
|
||||
regset->nregs = ARRAY_SIZE(bcm2835_thermal_regs);
|
||||
regset->base = data->regs;
|
||||
|
||||
debugfs_create_regset32("regset", 0444, data->debugfsdir, regset);
|
||||
}
|
||||
|
||||
static struct thermal_zone_of_device_ops bcm2835_thermal_ops = {
|
||||
.get_temp = bcm2835_thermal_get_temp,
|
||||
};
|
||||
|
||||
/*
|
||||
* Note: as per Raspberry Foundation FAQ
|
||||
* (https://www.raspberrypi.org/help/faqs/#performanceOperatingTemperature)
|
||||
* the recommended temperature range for the SoC -40C to +85C
|
||||
* so the trip limit is set to 80C.
|
||||
* this applies to all the BCM283X SoC
|
||||
*/
|
||||
|
||||
static const struct of_device_id bcm2835_thermal_of_match_table[] = {
|
||||
{
|
||||
.compatible = "brcm,bcm2835-thermal",
|
||||
},
|
||||
{
|
||||
.compatible = "brcm,bcm2836-thermal",
|
||||
},
|
||||
{
|
||||
.compatible = "brcm,bcm2837-thermal",
|
||||
},
|
||||
{},
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
|
||||
|
||||
static int bcm2835_thermal_probe(struct platform_device *pdev)
|
||||
{
|
||||
const struct of_device_id *match;
|
||||
struct thermal_zone_device *tz;
|
||||
struct bcm2835_thermal_data *data;
|
||||
struct resource *res;
|
||||
int err = 0;
|
||||
u32 val;
|
||||
unsigned long rate;
|
||||
|
||||
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
|
||||
if (!data)
|
||||
return -ENOMEM;
|
||||
|
||||
match = of_match_device(bcm2835_thermal_of_match_table,
|
||||
&pdev->dev);
|
||||
if (!match)
|
||||
return -EINVAL;
|
||||
|
||||
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||||
data->regs = devm_ioremap_resource(&pdev->dev, res);
|
||||
if (IS_ERR(data->regs)) {
|
||||
err = PTR_ERR(data->regs);
|
||||
dev_err(&pdev->dev, "Could not get registers: %d\n", err);
|
||||
return err;
|
||||
}
|
||||
|
||||
data->clk = devm_clk_get(&pdev->dev, NULL);
|
||||
if (IS_ERR(data->clk)) {
|
||||
err = PTR_ERR(data->clk);
|
||||
if (err != -EPROBE_DEFER)
|
||||
dev_err(&pdev->dev, "Could not get clk: %d\n", err);
|
||||
return err;
|
||||
}
|
||||
|
||||
err = clk_prepare_enable(data->clk);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
rate = clk_get_rate(data->clk);
|
||||
if ((rate < 1920000) || (rate > 5000000))
|
||||
dev_warn(&pdev->dev,
|
||||
"Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92 to 5MHz\n",
|
||||
data->clk, data->clk);
|
||||
|
||||
/* register of thermal sensor and get info from DT */
|
||||
tz = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
|
||||
&bcm2835_thermal_ops);
|
||||
if (IS_ERR(tz)) {
|
||||
err = PTR_ERR(tz);
|
||||
dev_err(&pdev->dev,
|
||||
"Failed to register the thermal device: %d\n",
|
||||
err);
|
||||
goto err_clk;
|
||||
}
|
||||
|
||||
/*
|
||||
* right now the FW does set up the HW-block, so we are not
|
||||
* touching the configuration registers.
|
||||
* But if the HW is not enabled, then set it up
|
||||
* using "sane" values used by the firmware right now.
|
||||
*/
|
||||
val = readl(data->regs + BCM2835_TS_TSENSCTL);
|
||||
if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
|
||||
int trip_temp, offset, slope;
|
||||
|
||||
slope = thermal_zone_get_slope(tz);
|
||||
offset = thermal_zone_get_offset(tz);
|
||||
/*
|
||||
* For now we deal only with critical, otherwise
|
||||
* would need to iterate
|
||||
*/
|
||||
err = tz->ops->get_trip_temp(tz, 0, &trip_temp);
|
||||
if (err < 0) {
|
||||
err = PTR_ERR(tz);
|
||||
dev_err(&pdev->dev,
|
||||
"Not able to read trip_temp: %d\n",
|
||||
err);
|
||||
goto err_tz;
|
||||
}
|
||||
|
||||
/* set bandgap reference voltage and enable voltage regulator */
|
||||
val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
|
||||
BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
|
||||
BCM2835_TS_TSENSCTL_REGULEN;
|
||||
|
||||
/* use the recommended reset duration */
|
||||
val |= (0xFE << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
|
||||
|
||||
/* trip_adc value from info */
|
||||
val |= bcm2835_thermal_temp2adc(trip_temp,
|
||||
offset,
|
||||
slope)
|
||||
<< BCM2835_TS_TSENSCTL_THOLD_SHIFT;
|
||||
|
||||
/* write the value back to the register as 2 steps */
|
||||
writel(val, data->regs + BCM2835_TS_TSENSCTL);
|
||||
val |= BCM2835_TS_TSENSCTL_RSTB;
|
||||
writel(val, data->regs + BCM2835_TS_TSENSCTL);
|
||||
}
|
||||
|
||||
data->tz = tz;
|
||||
|
||||
platform_set_drvdata(pdev, tz);
|
||||
|
||||
bcm2835_thermal_debugfs(pdev);
|
||||
|
||||
return 0;
|
||||
err_tz:
|
||||
thermal_zone_of_sensor_unregister(&pdev->dev, tz);
|
||||
err_clk:
|
||||
clk_disable_unprepare(data->clk);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int bcm2835_thermal_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct thermal_zone_device *tz = platform_get_drvdata(pdev);
|
||||
struct bcm2835_thermal_data *data = tz->devdata;
|
||||
|
||||
debugfs_remove_recursive(data->debugfsdir);
|
||||
thermal_zone_of_sensor_unregister(&pdev->dev, tz);
|
||||
clk_disable_unprepare(data->clk);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct platform_driver bcm2835_thermal_driver = {
|
||||
.probe = bcm2835_thermal_probe,
|
||||
.remove = bcm2835_thermal_remove,
|
||||
.driver = {
|
||||
.name = "bcm2835_thermal",
|
||||
.of_match_table = bcm2835_thermal_of_match_table,
|
||||
},
|
||||
};
|
||||
module_platform_driver(bcm2835_thermal_driver);
|
||||
|
||||
MODULE_AUTHOR("Martin Sperl");
|
||||
MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
|
||||
MODULE_LICENSE("GPL");
|
||||
Загрузка…
Ссылка в новой задаче