RE: [PATCH V5 2/4] thermal: imx_sc: add i.MX system controller thermal support

[Anson Huang <anson.huang@nxp.com>]

Hi, Eduardo

Best Regards!
Anson Huang

> -----Original Message-----
> From: Anson Huang
> Sent: 2019年1月10日 17:28
> To: 'Eduardo Valentin' <edubezval@gmail.com>
> Cc: 'robh+dt@kernel.org' <robh+dt@kernel.org>; 'mark.rutland@arm.com'
> <mark.rutland@arm.com>; 'catalin.marinas@arm.com'
> <catalin.marinas@arm.com>; 'will.deacon@arm.com'
> <will.deacon@arm.com>; 'rui.zhang@intel.com' <rui.zhang@intel.com>;
> 'daniel.lezcano@linaro.org' <daniel.lezcano@linaro.org>; Aisheng Dong
> <aisheng.dong@nxp.com>; 's.hauer@pengutronix.de'
> <s.hauer@pengutronix.de>; 'shawnguo@kernel.org' <shawnguo@kernel.org>;
> Andy Gross <andy.gross@linaro.org>; 'arnd@arndb.de' <arnd@arndb.de>;
> 'horms+renesas@verge.net.au' <horms+renesas@verge.net.au>;
> 'heiko@sntech.de' <heiko@sntech.de>; 'bjorn.andersson@linaro.org'
> <bjorn.andersson@linaro.org>; 'enric.balletbo@collabora.com'
> <enric.balletbo@collabora.com>; 'amit.kucheria@linaro.org'
> <amit.kucheria@linaro.org>; 'ezequiel@collabora.com'
> <ezequiel@collabora.com>; 'olof@lixom.net' <olof@lixom.net>;
> 'devicetree@vger.kernel.org' <devicetree@vger.kernel.org>;
> 'linux-kernel@vger.kernel.org' <linux-kernel@vger.kernel.org>;
> 'linux-arm-kernel@lists.infradead.org' <linux-arm-kernel@lists.infradead.org>;
> 'linux-pm@vger.kernel.org' <linux-pm@vger.kernel.org>; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: RE: [PATCH V5 2/4] thermal: imx_sc: add i.MX system controller
> thermal support
> 
> Hi, Eduardo
> 
> Best Regards!
> Anson Huang
> 
> > -----Original Message-----
> > From: Anson Huang
> > Sent: 2018年12月26日 11:36
> > To: 'Eduardo Valentin' <edubezval@gmail.com>
> > Cc: robh+dt@kernel.org; mark.rutland@arm.com;
> catalin.marinas@arm.com;
> > will.deacon@arm.com; rui.zhang@intel.com; daniel.lezcano@linaro.org;
> > Aisheng Dong <aisheng.dong@nxp.com>; s.hauer@pengutronix.de;
> > shawnguo@kernel.org; Andy Gross <andy.gross@linaro.org>;
> > arnd@arndb.de;
> > horms+renesas@verge.net.au; heiko@sntech.de;
> > horms+bjorn.andersson@linaro.org;
> > enric.balletbo@collabora.com; amit.kucheria@linaro.org;
> > ezequiel@collabora.com; olof@lixom.net; devicetree@vger.kernel.org;
> > linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> > linux-pm@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>
> > Subject: RE: [PATCH V5 2/4] thermal: imx_sc: add i.MX system
> > controller thermal support
> >
> > Hi, Eduardo
> >
> > Best Regards!
> > Anson Huang
> >
> > > -----Original Message-----
> > > From: Eduardo Valentin [mailto:edubezval@gmail.com]
> > > Sent: 2018年12月26日 6:44
> > > To: Anson Huang <anson.huang@nxp.com>
> > > Cc: robh+dt@kernel.org; mark.rutland@arm.com;
> > catalin.marinas@arm.com;
> > > will.deacon@arm.com; rui.zhang@intel.com; daniel.lezcano@linaro.org;
> > > Aisheng Dong <aisheng.dong@nxp.com>; s.hauer@pengutronix.de;
> > > shawnguo@kernel.org; Andy Gross <andy.gross@linaro.org>;
> > > arnd@arndb.de;
> > > horms+renesas@verge.net.au; heiko@sntech.de;
> > > horms+bjorn.andersson@linaro.org;
> > > enric.balletbo@collabora.com; amit.kucheria@linaro.org;
> > > ezequiel@collabora.com; olof@lixom.net; devicetree@vger.kernel.org;
> > > linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> > > linux-pm@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>
> > > Subject: Re: [PATCH V5 2/4] thermal: imx_sc: add i.MX system
> > > controller thermal support
> > >
> > > On Thu, Dec 20, 2018 at 09:08:32AM +0000, Anson Huang wrote:
> > > > i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller
> > > > inside, the system controller is in charge of controlling power,
> > > > clock and thermal sensors etc..
> > > >
> > > > This patch adds i.MX system controller thermal driver support,
> > > > Linux kernel has to communicate with system controller via MU
> > > > (message
> > > > unit) IPC to get each thermal sensor's temperature, it supports
> > > > multiple sensors which are passed from device tree, please see the
> > > > binding doc for details.
> > > >
> > > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > > > ---
> > > > ChangeLog since V4:
> > > >     - Add driver dependency on IMX_SCU to avoid compile error when
> > > IMX_SCU is NOT selected;
> > > >     - Remove unnecessary of different errors handle for
> > > imx_scu_get_handle, already included in API.
> > > > ---
> > > >  drivers/thermal/Kconfig          |  11 +++
> > > >  drivers/thermal/Makefile         |   1 +
> > > >  drivers/thermal/imx_sc_thermal.c | 200
> > > > +++++++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 212 insertions(+)  create mode 100644
> > > > drivers/thermal/imx_sc_thermal.c
> > > >
> > > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> > > > index 0e69edc..8d4601d 100644
> > > > --- a/drivers/thermal/Kconfig
> > > > +++ b/drivers/thermal/Kconfig
> > > > @@ -222,6 +222,17 @@ config IMX_THERMAL
> > > >  	  cpufreq is used as the cooling device to throttle CPUs when the
> > > >  	  passive trip is crossed.
> > > >
> > > > +config IMX_SC_THERMAL
> > > > +	tristate "Temperature sensor driver for NXP i.MX SoCs with
> > > > +System
> > > Controller"
> > > > +	depends on (ARCH_MXC && IMX_SCU) || COMPILE_TEST
> > > > +	depends on OF
> > > > +	help
> > > > +	  Support for Temperature Monitor (TEMPMON) found on NXP i.MX
> > > > +SoCs
> > > with
> > > > +	  system controller inside, Linux kernel has to communicate with
> system
> > > > +	  controller via MU (message unit) IPC to get temperature from
> thermal
> > > > +	  sensor. It supports one critical trip point and one
> > > > +	  passive trip point for each thermal sensor.
> > > > +
> > > >  config MAX77620_THERMAL
> > > >  	tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
> > > >  	depends on MFD_MAX77620
> > > > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> > > > index 610344e..1b13f6a 100644
> > > > --- a/drivers/thermal/Makefile
> > > > +++ b/drivers/thermal/Makefile
> > > > @@ -41,6 +41,7 @@ obj-$(CONFIG_DB8500_THERMAL)	+=
> > > db8500_thermal.o
> > > >  obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
> > > >  obj-$(CONFIG_TANGO_THERMAL)	+= tango_thermal.o
> > > >  obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
> > > > +obj-$(CONFIG_IMX_SC_THERMAL)	+= imx_sc_thermal.o
> > > >  obj-$(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/imx_sc_thermal.c
> > > > b/drivers/thermal/imx_sc_thermal.c
> > > > new file mode 100644
> > > > index 0000000..1030a31
> > > > --- /dev/null
> > > > +++ b/drivers/thermal/imx_sc_thermal.c
> > > > @@ -0,0 +1,200 @@
> > > > +// SPDX-License-Identifier: GPL-2.0+
> > > > +/*
> > > > + * Copyright 2018 NXP.
> > > > + */
> > > > +
> > > > +#include <linux/err.h>
> > > > +#include <linux/firmware/imx/sci.h> #include <linux/module.h>
> > > > +#include <linux/of.h> #include <linux/of_device.h> #include
> > > > +<linux/platform_device.h> #include <linux/slab.h> #include
> > > > +<linux/thermal.h>
> > > > +
> > > > +#include "thermal_core.h"
> > > > +
> > > > +#define IMX_SC_MISC_FUNC_GET_TEMP	13
> > > > +#define IMX_SC_C_TEMP			0
> > > > +
> > > > +static struct imx_sc_ipc *thermal_ipc_handle;
> > > > +
> > > > +struct imx_sc_sensor {
> > > > +	struct thermal_zone_device *tzd;
> > > > +	u32 resource_id;
> > > > +};
> > > > +
> > > > +struct imx_sc_thermal_data {
> > > > +	struct imx_sc_sensor *sensor;
> > > > +};
> > > > +
> > > > +struct req_get_temp {
> > > > +	u16 resource_id;
> > > > +	u8 type;
> > > > +} __packed;
> > > > +
> > > > +struct resp_get_temp {
> > > > +	u16 celsius;
> > > > +	u8 tenths;
> > > > +} __packed;
> > > > +
> > > > +struct imx_sc_msg_misc_get_temp {
> > > > +	struct imx_sc_rpc_msg hdr;
> > > > +	union {
> > > > +		struct req_get_temp req;
> > > > +		struct resp_get_temp resp;
> > > > +	} data;
> > > > +} __packed;
> > > > +
> > > > +static int imx_sc_thermal_get_temp(void *data, int *temp) {
> > > > +	struct imx_sc_msg_misc_get_temp msg;
> > > > +	struct imx_sc_rpc_msg *hdr = &msg.hdr;
> > > > +	struct imx_sc_sensor *sensor = data;
> > > > +	int ret;
> > > > +
> > > > +	msg.data.req.resource_id = sensor->resource_id;
> > > > +	msg.data.req.type = IMX_SC_C_TEMP;
> > > > +
> > > > +	hdr->ver = IMX_SC_RPC_VERSION;
> > > > +	hdr->svc = IMX_SC_RPC_SVC_MISC;
> > > > +	hdr->func = IMX_SC_MISC_FUNC_GET_TEMP;
> > > > +	hdr->size = 2;
> > > > +
> > > > +	ret = imx_scu_call_rpc(thermal_ipc_handle, &msg, true);
> > > > +	if (ret) {
> > > > +		pr_err("read temp sensor %d failed, ret %d\n",
> > > > +			sensor->resource_id, ret);
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	*temp = msg.data.resp.celsius * 1000 + msg.data.resp.tenths *
> > > > +100;
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static const struct thermal_zone_of_device_ops imx_sc_thermal_ops = {
> > > > +	.get_temp = imx_sc_thermal_get_temp, };
> > > > +
> > > > +static int imx_sc_thermal_register_sensor(struct platform_device *pdev,
> > > > +					  struct imx_sc_sensor *sensor) {
> > > > +	struct thermal_zone_device *tzd;
> > > > +
> > > > +	tzd = devm_thermal_zone_of_sensor_register(&pdev->dev,
> > > > +						   sensor->resource_id,
> > > > +						   sensor,
> > > > +						   &imx_sc_thermal_ops);
> > > > +	if (IS_ERR(tzd)) {
> > > > +		dev_err(&pdev->dev, "failed to register sensor: %d\n",
> > > > +			sensor->resource_id);
> > > > +		return PTR_ERR(tzd);
> > > > +	}
> > > > +
> > > > +	sensor->tzd = tzd;
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static int imx_sc_thermal_get_sensor_id(struct device_node
> > > > +*sensor_np, u32 *id) {
> > > > +	struct of_phandle_args sensor_specs;
> > > > +	int ret;
> > > > +
> > > > +	ret = of_parse_phandle_with_args(sensor_np, "thermal-sensors",
> > > > +			"#thermal-sensor-cells",
> > > > +			0, &sensor_specs);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > > +	if (sensor_specs.args_count >= 1) {
> > > > +		*id = sensor_specs.args[0];
> > > > +		WARN(sensor_specs.args_count > 1,
> > > > +				"%pOFn: too many cells in sensor specifier %d\n",
> > > > +				sensor_specs.np, sensor_specs.args_count);
> > > > +	} else {
> > > > +		return -EINVAL;
> > > > +	}
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > >
> > > So, there should be no need for doing a search of sensor ids. In
> > > fact, if the amount of sensors or the type of sensors supported changes, i.e.
> > > the sensor ids are do not match, you should have a different
> > > compatible,
> > IMO.
> >
> > So do you mean I can just read the sensor id (actually it is our SoC's
> > resource id) from the DTB file's each child node of thermal_zones?
> > Then I can skip the search of sensor ids, just add a sensor id
> > property and read it out during thermal driver probe? Yes, this looks like
> easier, is my understanding correct?
> > If yes, I can do it in next version. Thanks.
> >
> > Anson
> 
> Can you be more detail about the search of sensor ids? For this SoC, there will
> be more
> sensors(thermal-zone) added later, like DDR controller thermal sensor and
> pmic sensor etc., they will use same compatible, and in the
> imx_sc_thermal_get_sensor_id(), it just read out the sensor id from the dtb's
> each thermal zone's " thermal-sensors " property, I did NOT see any search
> here, thanks!
> 
> Anson.

I can remove the imx_sc_thermal_get_sensor_id() in the patch, and add below property in dts, then
just read out the resource id using of_property_read_u32(), then we can save the sensor id search function
in the driver, but need to add a property in dts, is this what you mean?

.probe:
-               ret = imx_sc_thermal_get_sensor_id(sensor_np, &sensor->resource_id);
-               if (ret < 0) {
+               if (of_property_read_u32(sensor_np, "sensor-resource-id",
+                       &sensor->resource_id)) {

dts:
454         thermal_zones: thermal-zones {
455                 cpu-thermal0 {
456                         polling-delay-passive = <250>;
457                         polling-delay = <2000>;
458 +                         sensor-resource-id = <355>;
459                         thermal-sensors = <&tsens 355>;

Anson.

> 
> >
> > >
> > > > +static int imx_sc_thermal_probe(struct platform_device *pdev) {
> > > > +	struct device_node *np = pdev->dev.of_node;
> > > > +	struct device_node *sensor_np = NULL;
> > > > +	struct imx_sc_thermal_data *data;
> > > > +	struct imx_sc_sensor *sensors;
> > > > +	u32 sensor_num;
> > > > +	int ret, i;
> > > > +
> > > > +	ret = imx_scu_get_handle(&thermal_ipc_handle);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > > +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > > > +	if (!data)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	ret = of_property_read_u32(np, "tsens-num", &sensor_num);
> > > > +	if (ret || !sensor_num) {
> > > > +		dev_err(&pdev->dev, "failed to get valid temp sensor
> number!\n");
> > > > +		return -EINVAL;
> > > > +	}
> > > > +
> > > > +	sensors = devm_kzalloc(&pdev->dev, sizeof(*data->sensor) *
> sensor_num,
> > > > +			       GFP_KERNEL);
> > > > +	if (!sensors)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	data->sensor = sensors;
> > > > +
> > > > +	np = of_find_node_by_name(NULL, "thermal-zones");
> > > > +	if (!np)
> > > > +		return -ENODEV;
> > > > +
> > > > +	for (i = 0; i < sensor_num; i++) {
> > > > +		struct imx_sc_sensor *sensor = &data->sensor[i];
> > > > +
> > > > +		sensor_np = of_get_next_child(np, sensor_np);
> > > > +		ret = imx_sc_thermal_get_sensor_id(sensor_np,
> > > &sensor->resource_id);
> > > > +		if (ret < 0) {
> > > > +			dev_err(&pdev->dev,
> > > > +				"failed to get valid sensor resource id: %d\n",
> > > > +				ret);
> > > > +			break;
> > > > +		}
> > > > +
> > > > +		ret = imx_sc_thermal_register_sensor(pdev, sensor);
> > > > +		if (ret) {
> > > > +			dev_err(&pdev->dev, "failed to register thermal
> sensor: %d\n",
> > > > +				ret);
> > > > +			break;
> > > > +		}
> > > > +	}
> > > > +
> > > > +	of_node_put(np);
> > > > +	of_node_put(sensor_np);
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +static const struct of_device_id imx_sc_thermal_table[] = {
> > > > +	{ .compatible = "fsl,imx8qxp-sc-thermal", },
> > > > +	{}
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, imx_sc_thermal_table);
> > > > +
> > > > +static struct platform_driver imx_sc_thermal_driver = {
> > > > +		.probe = imx_sc_thermal_probe,
> > > > +		.driver = {
> > > > +			.name = "imx-sc-thermal",
> > > > +			.of_match_table = imx_sc_thermal_table,
> > > > +		},
> > > > +};
> > > > +module_platform_driver(imx_sc_thermal_driver);
> > > > +
> > > > +MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
> > > > +MODULE_DESCRIPTION("Thermal driver for NXP i.MX SoCs with system
> > > > +controller"); MODULE_LICENSE("GPL v2");
> > > > --
> > > > 2.7.4
> > > >