RE: [PATCH V8 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: Eduardo Valentin [mailto:edubezval@gmail.com]
> Sent: 2019年2月24日 5:39
> To: Anson Huang <anson.huang@nxp.com>
> Cc: robh+dt@kernel.org; mark.rutland@arm.com; shawnguo@kernel.org;
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> daniel.lezcano@linaro.org; Aisheng Dong <aisheng.dong@nxp.com>;
> ulf.hansson@linaro.org; sboyd@kernel.org; Daniel Baluta
> <daniel.baluta@nxp.com>; Andy Gross <andy.gross@linaro.org>;
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> Subject: Re: [PATCH V8 2/4] thermal: imx_sc: add i.MX system controller
> thermal support
> 
> Hey Anson,
> 
> On Thu, Feb 21, 2019 at 06:38:39AM +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>
> > ---
> > Changes since V7:
> > 	- remove unused structure imx_sc_thermal_data to simply the driver;
> > 	- move the "imx,sensor-resource-id" property from thermal zone
> node to scu tsens node, and
> > 	  get this property using phandle;
> > 	- remove unused sensor number got from dts, now it is not needed.
> > ---
> >  drivers/thermal/Kconfig          |  11 +++
> >  drivers/thermal/Makefile         |   1 +
> >  drivers/thermal/imx_sc_thermal.c | 144
> > +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 156 insertions(+)
> >  create mode 100644 drivers/thermal/imx_sc_thermal.c
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index
> > 58bb7d7..fec0ef5 100644
> > --- a/drivers/thermal/Kconfig
> > +++ b/drivers/thermal/Kconfig
> > @@ -223,6 +223,17 @@ 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
> > 486d682..4062627 100644
> > --- a/drivers/thermal/Makefile
> > +++ b/drivers/thermal/Makefile
> > @@ -40,6 +40,7 @@ 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..145e73b
> > --- /dev/null
> > +++ b/drivers/thermal/imx_sc_thermal.c
> > @@ -0,0 +1,144 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright 2018-2019 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 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_probe(struct platform_device *pdev) {
> > +	struct device_node *np, *sensor_np;
> > +	int ret, i = 0;
> > +
> > +	ret = imx_scu_get_handle(&thermal_ipc_handle);
> > +	if (ret)
> > +		return ret;
> > +
> > +	np = of_find_node_by_name(NULL, "thermal-zones");
> > +	if (!np)
> > +		return -ENODEV;
> 
> I am still failing to understand why you need to do the search above and ..

I used this to determine how many thermal zones will be supported from dts, and
get each thermal zone's resource ID for communicating with system controller, but
now I just found I can use the  "imx,sensor-resource-id" property's element count
to determine the thermal zone number, so in V9 patch series, I remove this search.

> 
> > +
> > +	for_each_available_child_of_node(np, sensor_np) {
> > +		struct of_phandle_args tsens_args;
> > +		struct imx_sc_sensor *sensor =
> > +			devm_kzalloc(&pdev->dev, sizeof(*sensor),
> GFP_KERNEL);
> > +		if (!sensor)
> > +			return -ENOMEM;
> > +
> > +		ret = of_parse_phandle_with_args(sensor_np, "thermal-
> sensors",
> > +				"#thermal-sensor-cells", i, &tsens_args);
> 
> the above shouldnt be needed too.

Already removed in V9.

> 
> > +		if (ret < 0)
> > +			return ret;
> > +
> > +		ret = of_property_read_u32_index(tsens_args.np,
> > +			"imx,sensor-resource-id", i, &sensor->resource_id);
> 
> If you put "imx,sensor-resource-id" inside tsens node, like described in your
> patch 01, you should be able to get  np from pdev->dev.of_node, right?
> 
> Then you should be able to just read the "imx,sensor-resource-id"
> directly from pdev->dev.of_node, no?

Ah, yes, I just don't remembered why I need to get the device node from phandle,
so stupid in last patch series... Thanks for the comment, please help review V9 patch series.

Anson.

> 
> > +		if (ret) {
> > +			dev_err(&pdev->dev,
> > +				"failed to get valid sensor resource id: %d\n",
> > +				ret);
> > +			break;
> > +		}
> > +
> > +		sensor->tzd =
> devm_thermal_zone_of_sensor_register(&pdev->dev,
> > +								   i++,
> > +								   sensor,
> > +
> &imx_sc_thermal_ops);
> > +		if (IS_ERR(sensor->tzd)) {
> > +			dev_err(&pdev->dev, "failed to register thermal
> zone\n");
> > +			ret = PTR_ERR(sensor->tzd);
> > +			break;
> > +		}
> > +	}
> > +
> > +	of_node_put(np);
> > +	of_node_put(sensor_np);
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct of_device_id imx_sc_thermal_table[] = {
> > +	{ .compatible = "fsl,imx-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
> >