linux/drivers/thermal/imx8mm_thermal.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2020 NXP.
*
* Author: Anson Huang <Anson.Huang@nxp.com>
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>
#include "thermal_core.h"
#define TER 0x0 /* TMU enable */
#define TPS 0x4
#define TRITSR 0x20 /* TMU immediate temp */
#define TER_EN BIT(31)
#define TRITSR_TEMP0_VAL_MASK 0xff
#define TRITSR_TEMP1_VAL_MASK 0xff0000
#define PROBE_SEL_ALL GENMASK(31, 30)
#define probe_status_offset(x) (30 + x)
#define SIGN_BIT BIT(7)
#define TEMP_VAL_MASK GENMASK(6, 0)
#define VER1_TEMP_LOW_LIMIT 10000
#define VER2_TEMP_LOW_LIMIT -40000
#define VER2_TEMP_HIGH_LIMIT 125000
#define TMU_VER1 0x1
#define TMU_VER2 0x2
struct thermal_soc_data {
u32 num_sensors;
u32 version;
int (*get_temp)(void *, int *);
};
struct tmu_sensor {
struct imx8mm_tmu *priv;
u32 hw_id;
struct thermal_zone_device *tzd;
};
struct imx8mm_tmu {
void __iomem *base;
struct clk *clk;
const struct thermal_soc_data *socdata;
thermal: imx8mm: Replace zero-length array with flexible-array The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200507192517.GA16557@embeddedor
2020-05-07 19:25:17 +00:00
struct tmu_sensor sensors[];
};
static int imx8mm_tmu_get_temp(void *data, int *temp)
{
struct tmu_sensor *sensor = data;
struct imx8mm_tmu *tmu = sensor->priv;
u32 val;
val = readl_relaxed(tmu->base + TRITSR) & TRITSR_TEMP0_VAL_MASK;
*temp = val * 1000;
if (*temp < VER1_TEMP_LOW_LIMIT)
return -EAGAIN;
return 0;
}
static int imx8mp_tmu_get_temp(void *data, int *temp)
{
struct tmu_sensor *sensor = data;
struct imx8mm_tmu *tmu = sensor->priv;
unsigned long val;
bool ready;
val = readl_relaxed(tmu->base + TRITSR);
ready = test_bit(probe_status_offset(sensor->hw_id), &val);
if (!ready)
return -EAGAIN;
val = sensor->hw_id ? FIELD_GET(TRITSR_TEMP1_VAL_MASK, val) :
FIELD_GET(TRITSR_TEMP0_VAL_MASK, val);
if (val & SIGN_BIT) /* negative */
val = (~(val & TEMP_VAL_MASK) + 1);
*temp = val * 1000;
if (*temp < VER2_TEMP_LOW_LIMIT || *temp > VER2_TEMP_HIGH_LIMIT)
return -EAGAIN;
return 0;
}
static int tmu_get_temp(void *data, int *temp)
{
struct tmu_sensor *sensor = data;
struct imx8mm_tmu *tmu = sensor->priv;
return tmu->socdata->get_temp(data, temp);
}
static struct thermal_zone_of_device_ops tmu_tz_ops = {
.get_temp = tmu_get_temp,
};
static void imx8mm_tmu_enable(struct imx8mm_tmu *tmu, bool enable)
{
u32 val;
val = readl_relaxed(tmu->base + TER);
val = enable ? (val | TER_EN) : (val & ~TER_EN);
writel_relaxed(val, tmu->base + TER);
}
static void imx8mm_tmu_probe_sel_all(struct imx8mm_tmu *tmu)
{
u32 val;
val = readl_relaxed(tmu->base + TPS);
val |= PROBE_SEL_ALL;
writel_relaxed(val, tmu->base + TPS);
}
static int imx8mm_tmu_probe(struct platform_device *pdev)
{
const struct thermal_soc_data *data;
struct imx8mm_tmu *tmu;
int ret;
int i;
data = of_device_get_match_data(&pdev->dev);
tmu = devm_kzalloc(&pdev->dev, struct_size(tmu, sensors,
data->num_sensors), GFP_KERNEL);
if (!tmu)
return -ENOMEM;
tmu->socdata = data;
tmu->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(tmu->base))
return PTR_ERR(tmu->base);
tmu->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(tmu->clk)) {
ret = PTR_ERR(tmu->clk);
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev,
"failed to get tmu clock: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(tmu->clk);
if (ret) {
dev_err(&pdev->dev, "failed to enable tmu clock: %d\n", ret);
return ret;
}
/* disable the monitor during initialization */
imx8mm_tmu_enable(tmu, false);
for (i = 0; i < data->num_sensors; i++) {
tmu->sensors[i].priv = tmu;
tmu->sensors[i].tzd =
devm_thermal_zone_of_sensor_register(&pdev->dev, i,
&tmu->sensors[i],
&tmu_tz_ops);
if (IS_ERR(tmu->sensors[i].tzd)) {
dev_err(&pdev->dev,
"failed to register thermal zone sensor[%d]: %d\n",
i, ret);
return PTR_ERR(tmu->sensors[i].tzd);
}
tmu->sensors[i].hw_id = i;
}
platform_set_drvdata(pdev, tmu);
/* enable all the probes for V2 TMU */
if (tmu->socdata->version == TMU_VER2)
imx8mm_tmu_probe_sel_all(tmu);
/* enable the monitor */
imx8mm_tmu_enable(tmu, true);
return 0;
}
static int imx8mm_tmu_remove(struct platform_device *pdev)
{
struct imx8mm_tmu *tmu = platform_get_drvdata(pdev);
/* disable TMU */
imx8mm_tmu_enable(tmu, false);
clk_disable_unprepare(tmu->clk);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct thermal_soc_data imx8mm_tmu_data = {
.num_sensors = 1,
.version = TMU_VER1,
.get_temp = imx8mm_tmu_get_temp,
};
static struct thermal_soc_data imx8mp_tmu_data = {
.num_sensors = 2,
.version = TMU_VER2,
.get_temp = imx8mp_tmu_get_temp,
};
static const struct of_device_id imx8mm_tmu_table[] = {
{ .compatible = "fsl,imx8mm-tmu", .data = &imx8mm_tmu_data, },
{ .compatible = "fsl,imx8mp-tmu", .data = &imx8mp_tmu_data, },
{ },
};
static struct platform_driver imx8mm_tmu = {
.driver = {
.name = "i.mx8mm_thermal",
.of_match_table = imx8mm_tmu_table,
},
.probe = imx8mm_tmu_probe,
.remove = imx8mm_tmu_remove,
};
module_platform_driver(imx8mm_tmu);
MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
MODULE_DESCRIPTION("i.MX8MM Thermal Monitor Unit driver");
MODULE_LICENSE("GPL v2");