[PATCH v2 2/2] thermal: imx91: Add support for i.MX91 thermal monitoring unit
Marco Felsch
m.felsch at pengutronix.de
Wed Dec 11 10:57:05 PST 2024
On 24-12-11, Frank Li wrote:
> On Wed, Dec 11, 2024 at 04:46:22PM +0100, Marco Felsch wrote:
> > On 24-12-10, Frank Li wrote:
> > > From: Pengfei Li <pengfei.li_1 at nxp.com>
> > >
> > > Introduce support for the i.MX91 thermal monitoring unit, which features a
> > > single sensor for the CPU. The register layout differs from other chips,
> > > necessitating the creation of a dedicated file for this.
> > >
> > > Signed-off-by: Pengfei Li <pengfei.li_1 at nxp.com>
> > > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> > > Signed-off-by: Frank Li <Frank.Li at nxp.com>
> > > ---
> > > change from v1 to v2
> > > - use low case for hexvalue
> > > - combine struct imx91_tmu and tmu_sensor
> > > - simplify imx91_tmu_start() and imx91_tmu_enable()
> > > - use s16 for imx91_tmu_get_temp(), which may negative value
> > > - use reverse christmas tree style
> > > - use run time pm
> > > - use oneshot to sample temp
> > > - register thermal zone after hardware init
> > > ---
> > > drivers/thermal/Kconfig | 10 ++
> > > drivers/thermal/Makefile | 1 +
> > > drivers/thermal/imx91_thermal.c | 265 ++++++++++++++++++++++++++++++++++++++++
> > > 3 files changed, 276 insertions(+)
> > >
> > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> > > index d3f9686e26e71..da403ed86aeb1 100644
> > > --- a/drivers/thermal/Kconfig
> > > +++ b/drivers/thermal/Kconfig
> > > @@ -296,6 +296,16 @@ config IMX8MM_THERMAL
> > > cpufreq is used as the cooling device to throttle CPUs when the passive
> > > trip is crossed.
> > >
> > > +config IMX91_THERMAL
> > > + tristate "Temperature sensor driver for NXP i.MX91 SoC"
> > > + depends on ARCH_MXC || COMPILE_TEST
> > > + depends on OF
> > > + help
> > > + Support for Temperature sensor found on NXP i.MX91 SoC.
> > > + It supports one critical trip point and one passive trip point. The
> > > + cpufreq is used as the cooling device to throttle CPUs when the passive
> > > + trip is crossed.
> > > +
> > > config K3_THERMAL
> > > tristate "Texas Instruments K3 thermal support"
> > > depends on ARCH_K3 || COMPILE_TEST
> > > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> > > index 9abf43a74f2bb..08da241e6a598 100644
> > > --- a/drivers/thermal/Makefile
> > > +++ b/drivers/thermal/Makefile
> > > @@ -50,6 +50,7 @@ obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
> > > obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
> > > obj-$(CONFIG_IMX_SC_THERMAL) += imx_sc_thermal.o
> > > obj-$(CONFIG_IMX8MM_THERMAL) += imx8mm_thermal.o
> > > +obj-$(CONFIG_IMX91_THERMAL) += imx91_thermal.o
> > > obj-$(CONFIG_MAX77620_THERMAL) += max77620_thermal.o
> > > obj-$(CONFIG_QORIQ_THERMAL) += qoriq_thermal.o
> > > obj-$(CONFIG_DA9062_THERMAL) += da9062-thermal.o
> > > diff --git a/drivers/thermal/imx91_thermal.c b/drivers/thermal/imx91_thermal.c
> > > new file mode 100644
> > > index 0000000000000..ebb59eda92951
> > > --- /dev/null
> > > +++ b/drivers/thermal/imx91_thermal.c
> > > @@ -0,0 +1,265 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Copyright 2024 NXP.
> > > + */
> > > +
> > > +#include <linux/bitfield.h>
> > > +#include <linux/clk.h>
> > > +#include <linux/err.h>
> > > +#include <linux/iopoll.h>
> > > +#include <linux/nvmem-consumer.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_device.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/thermal.h>
> > > +
> > > +#define CTRL0 0x0
> >
> > Unused
> >
> > > +
> > > +#define STAT0 0x10
> > > +#define STAT0_DRDY0_IF_MASK BIT(16)
> > > +
> > > +#define DATA0 0x20
> > > +
> > > +#define THR_CTRL01 0x30
> > > +#define THR_CTRL23 0x40
> >
> > Both are unused too
> >
> > > +#define CTRL1 0x200
> >
> > Unused
> >
> > > +#define CTRL1_SET 0x204
> > > +#define CTRL1_CLR 0x208
> > > +#define CTRL1_EN BIT(31)
> > > +#define CTRL1_START BIT(30)
> > > +#define CTRL1_STOP BIT(29)
> > > +#define CTRL1_RES_MASK GENMASK(19, 18)
> > > +#define CTRL1_MEAS_MODE_MASK GENMASK(25, 24)
> > > +#define CTRL1_MEAS_MODE_SINGLE 0
> > > +#define CTRL1_MEAS_MODE_CONTINUES 1
> > > +#define CTRL1_MEAS_MODE_PERIODIC 2
> > > +
> > > +#define REF_DIV 0x280
> > > +#define DIV_EN BIT(31)
> > > +#define DIV_MASK GENMASK(23, 16)
> > > +
> > > +#define PUD_ST_CTRL 0x2B0
> > > +#define PUDL_MASK GENMASK(23, 16)
> > > +
> > > +#define TRIM1 0x2E0
> > > +#define TRIM2 0x2F0
> > ^
> > still upper-case
> >
> > > +#define TMU_TEMP_LOW_LIMIT -40000
> > > +#define TMU_TEMP_HIGH_LIMIT 125000
> > > +
> > > +#define DEFAULT_TRIM1_CONFIG 0xb561bc2d
> > > +#define DEFAULT_TRIM2_CONFIG 0x65d4
> > > +
> > > +struct imx91_tmu {
> > > + void __iomem *base;
> > > + struct clk *clk;
> > > + struct device *dev;
> > > + struct thermal_zone_device *tzd;
> > > +};
> > > +
> > > +static void imx91_tmu_start(struct imx91_tmu *tmu, bool start)
> > > +{
> > > + u32 val = start ? CTRL1_START : CTRL1_STOP;
> > > +
> > > + writel_relaxed(val, tmu->base + CTRL1_SET);
> > > +}
> > > +
> > > +static void imx91_tmu_enable(struct imx91_tmu *tmu, bool enable)
> > > +{
> > > + u32 reg = enable ? CTRL1_SET : CTRL1_CLR;
> > > +
> > > + writel_relaxed(CTRL1_EN, tmu->base + reg);
> > > +}
> > > +
> > > +static int imx91_tmu_get_temp(struct thermal_zone_device *tz, int *temp)
> > > +{
> > > + struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
> > > + s16 data;
> > > + int ret;
> > > + u32 val;
> > > +
> > > + ret = pm_runtime_resume_and_get(tmu->dev);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + ret = readl_relaxed_poll_timeout(tmu->base + STAT0, val,
> > > + val & STAT0_DRDY0_IF_MASK, 1000,
> > > + 40000);
> > > + if (ret)
> > > + return -EAGAIN;
> > ^
> > Missing pm_runtime_put(). Instead goto out;
> >
> > > +
> > > + /* DATA0 is 16bit signed number */
> > > + data = readw_relaxed(tmu->base + DATA0);
> > > + *temp = data * 1000 / 64;
> > > + if (*temp < TMU_TEMP_LOW_LIMIT || *temp > TMU_TEMP_HIGH_LIMIT)
> > > + return -EAGAIN;
> > ^
> > ret = -EAGAIN;
> > goto out;
> >
> > out:
> > > +
> > > + pm_runtime_put(tmu->dev);
> > > +
> > > + return 0;
> >
> > return ret;
> > > +}
> > > +
> > > +static struct thermal_zone_device_ops tmu_tz_ops = {
> > > + .get_temp = imx91_tmu_get_temp,
> > > +};
> > > +
> > > +static int imx91_init_from_nvmem_cells(struct imx91_tmu *tmu)
> > > +{
> > > + struct device *dev = tmu->dev;
> > > + u32 trim1, trim2;
> > > + int ret;
> > > +
> > > + ret = nvmem_cell_read_u32(dev, "trim1", &trim1);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + ret = nvmem_cell_read_u32(dev, "trim2", &trim2);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + if (trim1 == 0 || trim2 == 0)
> > > + return -EINVAL;
> > > +
> > > + writel_relaxed(trim1, tmu->base + TRIM1);
> > > + writel_relaxed(trim2, tmu->base + TRIM2);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int imx91_tmu_probe(struct platform_device *pdev)
> > > +{
> > > + struct device *dev = &pdev->dev;
> >
> > Since you already have the dev pointer, you can make use of it...
> >
> > > + struct imx91_tmu *tmu;
> > > + unsigned long rate;
> > > + u32 div;
> > > + int ret;
> > > +
> > > + tmu = devm_kzalloc(&pdev->dev, sizeof(struct imx91_tmu), GFP_KERNEL);
> > ^
> > here
> > > + if (!tmu)
> > > + return -ENOMEM;
> > > +
> > > + tmu->dev = &pdev->dev;
> >
> > and here
> >
> > > +
> > > + tmu->base = devm_platform_ioremap_resource(pdev, 0);
> > > + if (IS_ERR(tmu->base))
> > > + return PTR_ERR(tmu->base);
> > ^
> > dev_err_probe();
> >
> > > +
> > > + tmu->clk = devm_clk_get_enabled(dev, NULL);
> > > + if (IS_ERR(tmu->clk))
> > > + return dev_err_probe(dev, PTR_ERR(tmu->clk), "failed to get tmu clock\n");
> > > +
> > > + platform_set_drvdata(pdev, tmu);
> > > +
> > > + /* disable the monitor during initialization */
> > > + imx91_tmu_enable(tmu, false);
> > > + imx91_tmu_start(tmu, false);
> >
> > No need to disable it here since both bits (ENABLE and START) are 0
> > after a reset.
>
> Maybe uboot enable it. We can't depend on reset value without really set
> hardware reset bit.
So the module can't be rested e.g. by disabling module power? Having a
dedicated reset mechanism would be much simpler instead of writing each
reg-field to the default value.
> > > + ret = imx91_init_from_nvmem_cells(tmu);
> > > + if (ret) {
> > > + writel_relaxed(DEFAULT_TRIM1_CONFIG, tmu->base + TRIM1);
> > > + writel_relaxed(DEFAULT_TRIM2_CONFIG, tmu->base + TRIM2);
> > ^
> > Can you please anwer if _relaxed API is sufficient? I don't know why you
> > making use of the _relaxed API here anyway. We have only a few MMIO
> > accesses here, so why can't we use the writel() instead? This applies to
> > the whole driver.
>
> There are not big difference writel_relaxed() or writel() for this driver.
> Just original owner pick one.
NACK, the difference is that _relaxed() APIs don't guarantee the order
the register access is done.
> > > + }
> > > +
> > > + /* The typical conv clk is 4MHz, the output freq is 'rate / (div + 1)' */
> > > + rate = clk_get_rate(tmu->clk);
> > > + div = (rate / 4000000) - 1;
> > > + if (div > FIELD_GET(DIV_MASK, DIV_MASK))
> > ^
> > This misuse the FIELD_GET() API. Instead please add a define e.g. DIV_MAX.
>
> I don't think so, It avoid define another macro DIV_MAX, which may miss
> defined, the related marco should come from one source.
>
> For example:
>
> DIV_MASK is GENMASK(23, 16), DIV_MAX is 256. But if hardware upgrade,
> DIV_MASK to GENMASK(24, 16), DIV_MAX is quite easy to forget update it and
> hard to find such mis-match when div value < 256.
We not talking about "possible" other HW. For now it's just this one and
using FIELD_GET() this way is seems odd, at least to me.
> > > + return -EINVAL;
> > ^
> > dev_err_probe()
> > > +
> > > + /* Set divider value and enable divider */
> > > + writel_relaxed(DIV_EN | FIELD_PREP(DIV_MASK, div), tmu->base + REF_DIV);
> > > +
> > > + /* Set max power up delay: 'Tpud(ms) = 0xFF * 1000 / 4000000' */
> > > + writel_relaxed(FIELD_PREP(PUDL_MASK, 100U), tmu->base + PUD_ST_CTRL);
> > ^
> > You dont need to repeat the default value, so this line can be dropped.
> >
> > > +
> > > + /*
> > > + * Set resolution mode
> > > + * 00b - Conversion time = 0.59325 ms
> > > + * 01b - Conversion time = 1.10525 ms
> > > + * 10b - Conversion time = 2.12925 ms
> > > + * 11b - Conversion time = 4.17725 ms
> > > + */
> > > + writel_relaxed(FIELD_PREP(CTRL1_RES_MASK, 0x3), tmu->base + CTRL1_CLR);
> > > + writel_relaxed(FIELD_PREP(CTRL1_RES_MASK, 0x1), tmu->base + CTRL1_SET);
> >
> > Same here, you repeat the module default after reset, so please drop it.
> >
> > > + writel_relaxed(CTRL1_MEAS_MODE_MASK, tmu->base + CTRL1_CLR);
> > > + writel_relaxed(FIELD_PREP(CTRL1_MEAS_MODE_MASK, CTRL1_MEAS_MODE_SINGLE),
> > > + tmu->base + CTRL1_SET);
> > > +
> > > + clk_disable_unprepare(tmu->clk);
> >
> > Drop this, and
> >
> > > + pm_runtime_set_suspended(dev);
> >
> > replace this with: pm_runtime_set_active();
>
> No big difference, if set_active, we need add Enable TMU here. I can
> change to set_active.
You don't need to manually disable the clock, it would be done by the
runtime-pm.
Regards,
Marco
> Frank
>
> >
> > > + pm_runtime_enable(dev);
> > ^
> > devm_pm_runtime_enable()
> >
> > > + tmu->tzd = devm_thermal_of_zone_register(dev, 0, tmu, &tmu_tz_ops);
> > > + if (IS_ERR(tmu->tzd))
> > > + return dev_err_probe(dev, PTR_ERR(tmu->tzd),
> > > + "failed to register thermal zone sensor\n");
> >
> >
> > pm_runtime_put()
> >
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void imx91_tmu_remove(struct platform_device *pdev)
> > > +{
> > > + struct imx91_tmu *tmu = platform_get_drvdata(pdev);
> > > +
> > > + /* disable tmu */
> > > + imx91_tmu_start(tmu, false);
> >
> > No need to clear the START bit since we are running in
> > single-shot-measurements now.
> >
> > > + imx91_tmu_enable(tmu, false);
> > > +}
> > > +
> > > +static int imx91_tmu_runtime_suspend(struct device *dev)
> > > +{
> > > + struct imx91_tmu *tmu = dev_get_drvdata(dev);
> > > +
> > > + /* disable tmu */
> > > + imx91_tmu_start(tmu, false);
> >
> > Can be dropped.
> >
> > > + imx91_tmu_enable(tmu, false);
> > > +
> > > + clk_disable_unprepare(tmu->clk);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int imx91_tmu_runtime_resume(struct device *dev)
> > > +{
> > > + struct imx91_tmu *tmu = dev_get_drvdata(dev);
> > > + int ret;
> > > +
> > > + ret = clk_prepare_enable(tmu->clk);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + imx91_tmu_enable(tmu, true);
> > > + imx91_tmu_start(tmu, true);
> >
> > Drop imx91_tmu_start() from the resume since this isn't related to the
> > runtime-pm. Instead the function needs to be called within
> > imx91_tmu_get_temp().
> >
> > > + return 0;
> > > +}
> > > +
> > > +static const struct dev_pm_ops imx91_tmu_pm_ops = {
> > > + SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
> > > + RUNTIME_PM_OPS(imx91_tmu_runtime_suspend, imx91_tmu_runtime_resume, NULL)
> > > +};
> >
> > DEFINE_RUNTIME_DEV_PM_OPS()
> >
> > > +
> > > +static const struct of_device_id imx91_tmu_table[] = {
> > > + { .compatible = "fsl,imx91-tmu", },
> > > + { },
> > > +};
> > > +MODULE_DEVICE_TABLE(of, imx91_tmu_table);
> > > +
> > > +static struct platform_driver imx91_tmu = {
> > > + .driver = {
> > > + .name = "i.MX91_thermal",
> > ^
> > Please don't use such names, instead use imx91_thermal.
> >
> > Regards,
> > Marco
> >
> > > + .pm = pm_ptr(&imx91_tmu_pm_ops),
> > > + .of_match_table = imx91_tmu_table,
> > > + },
> > > + .probe = imx91_tmu_probe,
> > > + .remove = imx91_tmu_remove,
> > > +};
> > > +module_platform_driver(imx91_tmu);
> > > +
> > > +MODULE_AUTHOR("Peng Fan <peng.fan at nxp.com>");
> > > +MODULE_DESCRIPTION("i.MX91 Thermal Monitor Unit driver");
> > > +MODULE_LICENSE("GPL");
> > >
> > > --
> > > 2.34.1
> > >
> > >
>
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