Subject: [PATCH V2 2/2] thermal: broadcom: add Northstar thermal driver

From: [email-masked] (Jon Mason)
Date: Fri, 24 Mar 2017 10:35:36 -0400

On Thu, Mar 23, 2017 at 11:30:45PM +0100, Rafa? Mi?ecki wrote:
> From: Rafa? Mi?ecki <[email-masked]>
> 
> 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: Rafa? Mi?ecki <[email-masked]>
> Signed-off-by: Jon Mason <[email-masked]>
> ---
> 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!
> ---
>  arch/arm/mach-bcm/Kconfig             |  2 +
>  drivers/thermal/Kconfig               |  5 ++
>  drivers/thermal/Makefile              |  1 +
>  drivers/thermal/broadcom/Kconfig      |  7 +++
>  drivers/thermal/broadcom/Makefile     |  1 +
>  drivers/thermal/broadcom/ns-thermal.c | 98 +++++++++++++++++++++++++++++++++++
>  6 files changed, 114 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/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
> index a0e66d8200c5..da2bfeb8e390 100644
> --- a/arch/arm/mach-bcm/Kconfig
> +++ b/arch/arm/mach-bcm/Kconfig
> @@ -19,6 +19,8 @@ config ARCH_BCM_IPROC
>  	select GPIOLIB
>  	select ARM_AMBA
>  	select PINCTRL
> +	select THERMAL
> +	select THERMAL_OF
>  	help
>  	  This enables support for systems based on Broadcom IPROC architected SoCs.
>  	  The IPROC complex contains one or more ARM CPUs along with common
> 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-$(CONFIG_ROCKCHIP_THERMAL)	+= rockchip_thermal.o
> diff --git a/drivers/thermal/broadcom/Kconfig b/drivers/thermal/broadcom/Kconfig
> new file mode 100644
> index 000000000000..39b92a1f3584
> --- /dev/null
> +++ b/drivers/thermal/broadcom/Kconfig
> @@ -0,0 +1,7 @@
> +config BCM_NS_THERMAL
> +	tristate "Northstar thermal driver"
> +	depends on ARCH_BCM_IPROC || COMPILE_TEST
> +	help
> +	  Northstar's DMU (Device Management Unit) block contains a thermal
> +	  sensor that allows checking CPU temperature. This driver provides
> +	  support for it.
> diff --git a/drivers/thermal/broadcom/Makefile b/drivers/thermal/broadcom/Makefile
> new file mode 100644
> index 000000000000..059df9a0ed69
> --- /dev/null
> +++ b/drivers/thermal/broadcom/Makefile
> @@ -0,0 +1 @@
> +obj-$(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..acf3a4de62a4
> --- /dev/null
> +++ b/drivers/thermal/broadcom/ns-thermal.c
> @@ -0,0 +1,98 @@
> +/*
> + * Copyright (C) 2017 Rafa? Mi?ecki <[email-masked]>
> + *
> + * 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 {
> +	void __iomem *pvtmon;
> +};
> +
> +static int ns_thermal_get_temp(void *data, int *temp)
> +{
> +	struct ns_thermal *ns_thermal = data;
> +	u32 val;
> +
> +	val = readl(ns_thermal->pvtmon + PVTMON_CONTROL0);
> +	if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
> +		val &= ~PVTMON_CONTROL0_SEL_MASK;
> +		val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;

I think this is slightly confusing here.  If this was off, ORing in 0
will not enable it.  I think we need to flip the #define to make it
PVTMON_CONTROL0_SEL_TEMP_MONITOR_DISABLE (or a less crappy name).
then use this line here to toggle it.  Something like

                val &= ~PVTMON_CONTROL0_SEL_TEMP_MONITOR_DISABLE;

Thanks,
Jon

> +		writel(val, ns_thermal->pvtmon + PVTMON_CONTROL0);
> +	}
> +
> +	val = readl(ns_thermal->pvtmon + PVTMON_STATUS);
> +	*temp = (418 - (val * 5556 / 10000)) * 1000;
> +
> +	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;
> +	struct thermal_zone_device *tzd;
> +
> +	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;
> +
> +	tzd = devm_thermal_zone_of_sensor_register(dev, 0, ns_thermal,
> +						   &ns_thermal_ops);
> +	if (IS_ERR(tzd)) {
> +		iounmap(ns_thermal->pvtmon);
> +		return PTR_ERR(tzd);
> +	}
> +
> +	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
>