RE: [PATCH V12 3/5] thermal: imx_sc: add i.MX system controller thermal support

[Aisheng Dong]

> From: Anson Huang
> Sent: Tuesday, April 16, 2019 11:22 AM
> 
> 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@xxxxxxx>
> ---
> Changes since V11:
> 	- move the API of getting thermal zone sensor ID to of-thermal.c as
> generic API;
> 	- remove unnecessary __packed.
> ---
>  drivers/thermal/Kconfig          |  11 ++++
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/imx_sc_thermal.c | 137
> +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 149 insertions(+)
>  create mode 100644 drivers/thermal/imx_sc_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index
> 653aa27..4e4fa7e 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

COMPILE_TEST seems won't work and may cause build issue due to
the dependency of IMX_SCU.

> +	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.
> +

[...]

> +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;

IMX_SC_C_TEMP duplicates with enum imx_sc_ctrl we already have.
include/linux/firmware/imx/types.h

But I guess you're not want to use a CTRL here.
So please fix the name convention.

> +
> +	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);

The error message is meaningless.
Can't convert to dev_err?

> +		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, *child;
> +	int ret;
> +
> +	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;
> +
> +	for_each_available_child_of_node(np, child) {
> +		struct of_phandle_args sensor_specs;
> +		struct imx_sc_sensor *sensor =
> +			devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);

Usually we do not mix the complicated code in the declare line.
You can move the declarations into the top level to make code more clean.

> +		if (!sensor)
> +			return -ENOMEM;
> +
> +		ret = thermal_zone_of_get_sensor_id(child,
> +						    &sensor_specs,

It looks a bit strange why need sensor_specs as you even did not use it.

Regards
Dong Aisheng

> +						    &sensor->resource_id);
> +		if (ret < 0) {
> +			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,
> +								   sensor->resource_id,
> +								   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;
> +		}
> +	}
> +
> +	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@xxxxxxx>");
> +MODULE_DESCRIPTION("Thermal driver for NXP i.MX SoCs with system
> +controller"); MODULE_LICENSE("GPL v2");
> --
> 2.7.4