Re: [PATCH V4 2/2] thermal: broadcom: add Northstar thermal driver

[Eduardo Valentin <edubezval@gmail.com>]

On Fri, Mar 31, 2017 at 10:11:24PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Northstar is a SoC family commonly used in home routers. This commit
> adds a driver for checking CPU temperature. As Northstar Plus seems to
> also have this IP block this new symbol gets ARCH_BCM_IPROC dependency.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> Signed-off-by: Jon Mason <jon.mason@broadcom.com>
> ---

This driver looks fine from what concerns the of thermal usage.
I had only one request on the DT bindings example. I believe better to
get the example fixed so bad DTs does not get copied.


> V2: Make it iProc specific as NSP can also use this driver
>     Select proper symbols in config ARCH_BCM_IPROC
>     Define PVTMON register bits
>     Update code selecting temperature monitor mode
>     Thank you Jon!
> V3: More details in help message for BCM_NS_THERMAL
>     Use slope & offset
>     Drop arch code change (I'll be submitted using a proper tree)
>     Thank you Eduardo!
> V4: Comment operations on PVTMON_CONTROL0 register
> ---
>  drivers/thermal/Kconfig               |   5 ++
>  drivers/thermal/Makefile              |   1 +
>  drivers/thermal/broadcom/Kconfig      |   8 +++
>  drivers/thermal/broadcom/Makefile     |   1 +
>  drivers/thermal/broadcom/ns-thermal.c | 105 ++++++++++++++++++++++++++++++++++

Also, I have just merged a BRCM driver. Does it make sense to move it
here too?

It does not need to be a blocking request for this driver though.

>  5 files changed, 120 insertions(+)
>  create mode 100644 drivers/thermal/broadcom/Kconfig
>  create mode 100644 drivers/thermal/broadcom/Makefile
>  create mode 100644 drivers/thermal/broadcom/ns-thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 776b34396144..008e173ec825 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -392,6 +392,11 @@ config MTK_THERMAL
>  	  Enable this option if you want to have support for thermal management
>  	  controller present in Mediatek SoCs
>  
> +menu "Broadcom thermal drivers"
> +depends on ARCH_BCM || COMPILE_TEST
> +source "drivers/thermal/broadcom/Kconfig"
> +endmenu
> +
>  menu "Texas Instruments thermal drivers"
>  depends on ARCH_HAS_BANDGAP || COMPILE_TEST
>  depends on HAS_IOMEM
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 7adae2029355..549d81b6363c 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -27,6 +27,7 @@ thermal_sys-$(CONFIG_CLOCK_THERMAL)	+= clock_cooling.o
>  thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
>  
>  # platform thermal drivers
> +obj-y				+= broadcom/
>  obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM)	+= qcom-spmi-temp-alarm.o
>  obj-$(CONFIG_SPEAR_THERMAL)	+= spear_thermal.o
>  obj-$(CONFIG_ROCKCHIP_THERMAL)	+= rockchip_thermal.o
> diff --git a/drivers/thermal/broadcom/Kconfig b/drivers/thermal/broadcom/Kconfig
> new file mode 100644
> index 000000000000..f0dea8a8e002
> --- /dev/null
> +++ b/drivers/thermal/broadcom/Kconfig
> @@ -0,0 +1,8 @@
> +config BCM_NS_THERMAL
> +	tristate "Northstar thermal driver"
> +	depends on ARCH_BCM_IPROC || COMPILE_TEST
> +	help
> +	  Northstar is a family of SoCs that includes e.g. BCM4708, BCM47081,
> +	  BCM4709 and BCM47094. It contains DMU (Device Management Unit) block
> +	  with a thermal sensor that allows checking CPU temperature. This
> +	  driver provides support for it.
> diff --git a/drivers/thermal/broadcom/Makefile b/drivers/thermal/broadcom/Makefile
> new file mode 100644
> index 000000000000..059df9a0ed69
> --- /dev/null
> +++ b/drivers/thermal/broadcom/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_BCM_NS_THERMAL)		+= ns-thermal.o
> diff --git a/drivers/thermal/broadcom/ns-thermal.c b/drivers/thermal/broadcom/ns-thermal.c
> new file mode 100644
> index 000000000000..eab96b3572b9
> --- /dev/null
> +++ b/drivers/thermal/broadcom/ns-thermal.c
> @@ -0,0 +1,105 @@
> +/*
> + * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/thermal.h>
> +
> +#define PVTMON_CONTROL0					0x00
> +#define PVTMON_CONTROL0_SEL_MASK			0x0000000e
> +#define PVTMON_CONTROL0_SEL_TEMP_MONITOR		0x00000000
> +#define PVTMON_CONTROL0_SEL_TEST_MODE			0x0000000e
> +#define PVTMON_STATUS					0x08
> +
> +struct ns_thermal {
> +	struct thermal_zone_device *tz;
> +	void __iomem *pvtmon;
> +};
> +
> +static int ns_thermal_get_temp(void *data, int *temp)
> +{
> +	struct ns_thermal *ns_thermal = data;
> +	int offset = thermal_zone_get_offset(ns_thermal->tz);
> +	int slope = thermal_zone_get_slope(ns_thermal->tz);
> +	u32 val;
> +
> +	val = readl(ns_thermal->pvtmon + PVTMON_CONTROL0);
> +	if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
> +		/* Clear current mode selection */
> +		val &= ~PVTMON_CONTROL0_SEL_MASK;
> +
> +		/* Set temp monitor mode (it's the default actually) */
> +		val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
> +
> +		writel(val, ns_thermal->pvtmon + PVTMON_CONTROL0);
> +	}
> +
> +	val = readl(ns_thermal->pvtmon + PVTMON_STATUS);
> +	*temp = slope * val + offset;
> +
> +	return 0;
> +}
> +
> +const struct thermal_zone_of_device_ops ns_thermal_ops = {
> +	.get_temp = ns_thermal_get_temp,
> +};
> +
> +static int ns_thermal_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct ns_thermal *ns_thermal;
> +
> +	ns_thermal = devm_kzalloc(dev, sizeof(*ns_thermal), GFP_KERNEL);
> +	if (!ns_thermal)
> +		return -ENOMEM;
> +
> +	ns_thermal->pvtmon = of_iomap(dev_of_node(dev), 0);
> +	if (WARN_ON(!ns_thermal->pvtmon))
> +		return -ENOENT;
> +
> +	ns_thermal->tz = devm_thermal_zone_of_sensor_register(dev, 0,
> +							      ns_thermal,
> +							      &ns_thermal_ops);
> +	if (IS_ERR(ns_thermal->tz)) {
> +		iounmap(ns_thermal->pvtmon);
> +		return PTR_ERR(ns_thermal->tz);
> +	}
> +
> +	platform_set_drvdata(pdev, ns_thermal);
> +
> +	return 0;
> +}
> +
> +static int ns_thermal_remove(struct platform_device *pdev)
> +{
> +	struct ns_thermal *ns_thermal = platform_get_drvdata(pdev);
> +
> +	iounmap(ns_thermal->pvtmon);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ns_thermal_of_match[] = {
> +	{ .compatible = "brcm,ns-thermal", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
> +
> +static struct platform_driver ns_thermal_driver = {
> +	.probe		= ns_thermal_probe,
> +	.remove		= ns_thermal_remove,
> +	.driver = {
> +		.name = "ns-thermal",
> +		.of_match_table = ns_thermal_of_match,
> +	},
> +};
> +module_platform_driver(ns_thermal_driver);
> +
> +MODULE_DESCRIPTION("Northstar thermal driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.11.0
>