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Date:   Fri, 21 Feb 2020 13:53:00 +0100
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
To:     Anson Huang <Anson.Huang@nxp.com>
Cc:     robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org,
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Subject: Re: [PATCH V15 RESEND 3/5] thermal: imx_sc: add i.MX system
 controller thermal support
Message-ID: <20200221125300.GB10516@linaro.org>
References: <1582161028-2844-1-git-send-email-Anson.Huang@nxp.com>
 <1582161028-2844-3-git-send-email-Anson.Huang@nxp.com>
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Hi Anson,

sorry for the delay with this review, hopefully the upstreaming will be now a
bit more smooth.

Apart the comments below, the driver looks good to me.

On Thu, Feb 20, 2020 at 09:10:26AM +0800, 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>
> ---
> No change.
> ---
>  drivers/thermal/Kconfig          |  11 +++
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/imx_sc_thermal.c | 142 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 154 insertions(+)
>  create mode 100644 drivers/thermal/imx_sc_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 5a05db5..d1cb8dc 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -251,6 +251,17 @@ 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

IMX_SCU depends on IMX_MBOX which depends on ARCH_MXC. This dependency could be
simplified.

Also add the COMPILE_TEST option to improve compilation test coverage.

> +	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 9fb88e2..a11a6d8 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -43,6 +43,7 @@ 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..d406ecb
> --- /dev/null
> +++ b/drivers/thermal/imx_sc_thermal.c
> @@ -0,0 +1,142 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2018-2019 NXP.

*sigh* 2020 now ...

[ ... ]

> +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;

Can you explain this 'size' value?

[ ... ]

> +MODULE_DEVICE_TABLE(of, imx_sc_thermal_table);
> +
> +static struct platform_driver imx_sc_thermal_driver = {
> +		.probe = imx_sc_thermal_probe,

The driver can be compiled as module but there is no 'remove' callback

> +		.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");


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