[PATCH RESEND v6 2/2] thermal: imx91: Add support for i.MX91 thermal monitoring unit
Frank Li
Frank.li at nxp.com
Fri Apr 18 08:20:35 PDT 2025
On Fri, Apr 18, 2025 at 12:05:52PM +0200, Daniel Lezcano wrote:
> On Mon, Apr 07, 2025 at 04:05:40PM -0400, 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.
> >
> > This sensor provides a resolution of 1/64°C (6-bit fraction). For actual
> > accuracy, refer to the datasheet, as it varies depending on the chip grade.
> > Provide an interrupt for end of measurement and threshold violation and
> > Contain temperature threshold comparators, in normal and secure address
> > space, with direction and threshold programmability.
> >
> > Datasheet Link: https://www.nxp.com/docs/en/data-sheet/IMX91CEC.pdf
> >
> > 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 v5 to v6
> > - remove Macro's review tag
> > - remove mutex lock
> > - use set_trips callback
> >
> > Change from v4 to v5
> > - add irq support
> > - use period mode
> > - Marco, if need drop review tag, let me know
> >
> > Change from v3 to v4
> > - Add Macro's review tag
> > - Use devm_add_action()
> > - Move pm_runtim_put before thermal_of_zone_register()
> >
> > change from v2 to v3
> > - add IMX91_TMU_ prefix for register define
> > - remove unused register define
> > - fix missed pm_runtime_put() at error path in imx91_tmu_get_temp()
> > - use dev variable in probe function
> > - use pm_runtime_set_active() in probe
> > - move START to imx91_tmu_get_temp()
> > - use DEFINE_RUNTIME_DEV_PM_OPS()
> > - keep set reset value because there are not sw "reset" bit in controller,
> > uboot may change and enable tmu.
> >
> > 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 | 398 ++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 409 insertions(+)
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> > index d3f9686e26e71..78a05d1030882 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
> > + Include one sensor and six comparators. Each of them compares the
> > + temperature value (from the sensor) against the programmable
> > + threshold values. The direction of the comparison is configurable
> > + (greater / lesser than).
> > +
> > 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..e8deb0b07dc98
> > --- /dev/null
> > +++ b/drivers/thermal/imx91_thermal.c
> > @@ -0,0 +1,398 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2025 NXP.
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <linux/interrupt.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>
> > +#include <linux/units.h>
> > +
> > +#define REG_SET 0x4
> > +#define REG_CLR 0x8
> > +#define REG_TOG 0xc
> > +
> > +#define IMX91_TMU_CTRL0 0x0
> > +#define IMX91_TMU_CTRL0_THR1_IE BIT(9)
> > +#define IMX91_TMU_CTRL0_THR1_MASK GENMASK(3, 2)
> > +#define IMX91_TMU_CTRL0_CLR_FLT1 BIT(21)
> > +
> > +#define IMX91_TMU_THR_MODE_LE 0
> > +#define IMX91_TMU_THR_MODE_GE 1
> > +
> > +#define IMX91_TMU_STAT0 0x10
> > +#define IMX91_TMU_STAT0_THR1_IF BIT(9)
> > +#define IMX91_TMU_STAT0_THR1_STAT BIT(13)
> > +#define IMX91_TMU_STAT0_DRDY0_IF_MASK BIT(16)
> > +
> > +#define IMX91_TMU_DATA0 0x20
> > +
> > +#define IMX91_TMU_CTRL1 0x200
> > +#define IMX91_TMU_CTRL1_EN BIT(31)
> > +#define IMX91_TMU_CTRL1_START BIT(30)
> > +#define IMX91_TMU_CTRL1_STOP BIT(29)
> > +#define IMX91_TMU_CTRL1_RES_MASK GENMASK(19, 18)
> > +#define IMX91_TMU_CTRL1_MEAS_MODE_MASK GENMASK(25, 24)
> > +#define IMX91_TMU_CTRL1_MEAS_MODE_SINGLE 0
> > +#define IMX91_TMU_CTRL1_MEAS_MODE_CONTINUES 1
> > +#define IMX91_TMU_CTRL1_MEAS_MODE_PERIODIC 2
> > +
> > +#define IMX91_TMU_THR_CTRL01 0x30
> > +#define IMX91_TMU_THR_CTRL01_THR1_MASK GENMASK(31, 16)
> > +
> > +#define IMX91_TMU_REF_DIV 0x280
> > +#define IMX91_TMU_DIV_EN BIT(31)
> > +#define IMX91_TMU_DIV_MASK GENMASK(23, 16)
> > +#define IMX91_TMU_DIV_MAX 255
> > +
> > +#define IMX91_TMU_PUD_ST_CTRL 0x2b0
> > +#define IMX91_TMU_PUDL_MASK GENMASK(23, 16)
> > +
> > +#define IMX91_TMU_TRIM1 0x2e0
> > +#define IMX91_TMU_TRIM2 0x2f0
> > +
> > +#define IMX91_TMU_TEMP_LOW_LIMIT -40000
> > +#define IMX91_TMU_TEMP_HIGH_LIMIT 125000
> > +
> > +#define IMX91_TMU_DEFAULT_TRIM1_CONFIG 0xb561bc2d
> > +#define IMX91_TMU_DEFAULT_TRIM2_CONFIG 0x65d4
> > +
> > +#define IMX91_TMU_PERIOD_CTRL 0x270
> > +#define IMX91_TMU_PERIOD_CTRL_MEAS_MASK GENMASK(23, 0)
> > +
> > +#define IMX91_TMP_FRAC 64
> > +
> > +struct imx91_tmu {
> > + void __iomem *base;
> > + struct clk *clk;
> > + struct device *dev;
> > + struct thermal_zone_device *tzd;
> > + int high;
> > + bool enable;
> > +};
> > +
> > +static void imx91_tmu_start(struct imx91_tmu *tmu, bool start)
> > +{
> > + u32 val = start ? IMX91_TMU_CTRL1_START : IMX91_TMU_CTRL1_STOP;
> > +
> > + writel_relaxed(val, tmu->base + IMX91_TMU_CTRL1 + REG_SET);
> > +}
> > +
> > +static void imx91_tmu_enable(struct imx91_tmu *tmu, bool enable)
> > +{
> > + u32 reg = IMX91_TMU_CTRL1;
> > +
> > + reg += enable ? REG_SET : REG_CLR;
> > +
> > + writel_relaxed(IMX91_TMU_CTRL1_EN, tmu->base + reg);
> > +}
> > +
> > +static int imx91_tmu_to_mcelsius(int x)
> > +{
> > + return x * MILLIDEGREE_PER_DEGREE / IMX91_TMP_FRAC;
> > +}
> > +
> > +static int imx91_tmu_from_mcelsius(int x)
> > +{
> > + return x * IMX91_TMP_FRAC / MILLIDEGREE_PER_DEGREE;
> > +}
> > +
> > +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;
> > +
> > + ret = pm_runtime_resume_and_get(tmu->dev);
> > + if (ret < 0)
> > + return ret;
>
> Why using pm_runtime* all over the place ?
>
> It would make sense to have in the probe/remove functions (or in the set_mode -
> enabled / disabled), suspend / resume but the other place it does not make
> sense IMO. If the sensor is enabled by the set_mode function and then
> pm_runtime_get() is called, then the ref is taken during all the time the
> sensor is in use, so others pm_runtime_get / pm_runtime_put will be helpless,
> no ?
>
>
> > + /* DATA0 is 16bit signed number */
> > + data = readw_relaxed(tmu->base + IMX91_TMU_DATA0);
> > + *temp = imx91_tmu_to_mcelsius(data);
> > + if (*temp < IMX91_TMU_TEMP_LOW_LIMIT || *temp > IMX91_TMU_TEMP_HIGH_LIMIT)
> > + ret = -EAGAIN;
>
> When the measured temperature can be out of limits ?
It is safety check. It may be caused by incorrect calibration data or some
glitch at ref voltage.
>
> > + if (*temp <= tmu->high && tmu->enable) {
>
> I suggest to provide a change in the thermal core to return -EAGAIN if the
> thermal zone is not enabled when calling thermal_zone_get_temp() and get rid of the tmu->enable
>
> > + writel_relaxed(IMX91_TMU_STAT0_THR1_IF, tmu->base + IMX91_TMU_STAT0 + REG_CLR);
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_SET);
> > + }
>
> For my understanding what are for these REG_CLR and REG_SET in this function?
REG_CLR\REG_SET is offset 8\4 for each register, which used clear\set only
some bits without touch other value
SET register work as
val = readl(reg);
val |= mask;
writel (val, reg);
the benenfit of use CLR/SET register make code simple and it is atomic change
one bit.
>
> > + pm_runtime_put(tmu->dev);
> > +
> > + return ret;
> > +}
> > +
> > +static int imx91_tmu_set_trips(struct thermal_zone_device *tz, int low, int high)
> > +{
> > + struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
> > + int val;
> > + int ret;
> > +
> > + ret = pm_runtime_resume_and_get(tmu->dev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (high >= IMX91_TMU_TEMP_HIGH_LIMIT)
> > + return -EINVAL;
> > +
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
> > +
> > + /* Comparator1 for temperature threshold */
> > + writel_relaxed(IMX91_TMU_THR_CTRL01_THR1_MASK, tmu->base + IMX91_TMU_THR_CTRL01 + REG_CLR);
> > + val = FIELD_PREP(IMX91_TMU_THR_CTRL01_THR1_MASK, imx91_tmu_from_mcelsius(high));
> > + writel_relaxed(val, tmu->base + IMX91_TMU_THR_CTRL01 + REG_SET);
> > +
> > + writel_relaxed(IMX91_TMU_STAT0_THR1_IF, tmu->base + IMX91_TMU_STAT0 + REG_CLR);
> > +
> > + tmu->high = high;
>
> Why is 'high' needed?
Need re-enable irq when tempture below high.
Frank
>
> > +
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_SET);
> > + pm_runtime_put(tmu->dev);
> > +
> > + return 0;
> > +}
> > +
> > +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 + IMX91_TMU_TRIM1);
> > + writel_relaxed(trim2, tmu->base + IMX91_TMU_TRIM2);
> > +
> > + return 0;
> > +}
> > +
> > +static void imx91_tmu_action_remove(void *data)
> > +{
> > + struct imx91_tmu *tmu = data;
> > +
> > + /* disable tmu */
> > + imx91_tmu_enable(tmu, false);
> > +}
> > +
> > +static irqreturn_t imx91_tmu_alarm_irq_thread(int irq, void *dev)
> > +{
> > + struct imx91_tmu *tmu = dev;
> > + int val;
> > + int ret;
> > +
> > + ret = pm_runtime_resume_and_get(tmu->dev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + thermal_zone_device_update(tmu->tzd, THERMAL_EVENT_UNSPECIFIED);
>
> Ack the IRQ before calling thermal_zone_device_update()
>
> > + val = readl_relaxed(tmu->base + IMX91_TMU_STAT0);
>
> One blank line to let the code breath
>
> > + /* Have to use CLR register to clean up w1c bits */
> > + writel_relaxed(val, tmu->base + IMX91_TMU_STAT0 + REG_CLR);
> > +
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
> > +
> > + pm_runtime_put(tmu->dev);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int imx91_tmu_change_mode(struct thermal_zone_device *tz, enum thermal_device_mode mode)
> > +{
> > + struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
> > + int ret;
> > +
> > + if (mode == THERMAL_DEVICE_ENABLED) {
> > + ret = pm_runtime_get(tmu->dev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + imx91_tmu_start(tmu, true);
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_SET);
> > + tmu->enable = true;
> > + } else {
> > + writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
> > + imx91_tmu_start(tmu, false);
> > + pm_runtime_put(tmu->dev);
> > + tmu->enable = false;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static struct thermal_zone_device_ops tmu_tz_ops = {
> > + .get_temp = imx91_tmu_get_temp,
> > + .change_mode = imx91_tmu_change_mode,
> > + .set_trips = imx91_tmu_set_trips,
> > +};
> > +
>
> [ ... ]
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