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Date:   Fri, 30 Nov 2018 14:10:44 -0800
From:   Guenter Roeck <linux@roeck-us.net>
To:     Eric Anholt <eric@anholt.net>
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        linux-watchdog@vger.kernel.org,
        linux-rpi-kernel@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Stefan Wahren <stefan.wahren@i2se.com>,
        bcm-kernel-feedback-list@broadcom.com
Subject: Re: [PATCH v3 2/5] bcm2835-pm: Move bcm2835-watchdog's DT probe to
 an MFD.
Message-ID: <20181130221044.GA15333@roeck-us.net>
References: <20181130202743.20585-1-eric@anholt.net>
 <20181130202743.20585-3-eric@anholt.net>
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On Fri, Nov 30, 2018 at 12:27:40PM -0800, Eric Anholt wrote:
> The PM block that the wdt driver was binding to actually has multiple
> features we want to expose (power domains, reset, watchdog).  Move the
> DT attachment to a MFD driver and make WDT probe against MFD.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>

For watchdog:

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> v3: don't reset bcm2835_power_off_wdt on remove, drop pm driver's
>     empty remove, sort includes, add a "static".
> 
>  arch/arm/mach-bcm/Kconfig      |  1 +
>  drivers/mfd/Makefile           |  1 +
>  drivers/mfd/bcm2835-pm.c       | 64 ++++++++++++++++++++++++++++++++++
>  drivers/watchdog/bcm2835_wdt.c | 26 +++++---------
>  include/linux/mfd/bcm2835-pm.h | 13 +++++++
>  5 files changed, 88 insertions(+), 17 deletions(-)
>  create mode 100644 drivers/mfd/bcm2835-pm.c
>  create mode 100644 include/linux/mfd/bcm2835-pm.h
> 
> diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
> index 25aac6ee2ab1..95242c2162a2 100644
> --- a/arch/arm/mach-bcm/Kconfig
> +++ b/arch/arm/mach-bcm/Kconfig
> @@ -167,6 +167,7 @@ config ARCH_BCM2835
>  	select BCM2835_TIMER
>  	select PINCTRL
>  	select PINCTRL_BCM2835
> +	select MFD_CORE
>  	help
>  	  This enables support for the Broadcom BCM2835 and BCM2836 SoCs.
>  	  This SoC is used in the Raspberry Pi and Roku 2 devices.
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 12980a4ad460..ee6fb6af655e 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
>  obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
>  obj-$(CONFIG_MFD_SM501)		+= sm501.o
>  obj-$(CONFIG_MFD_ASIC3)		+= asic3.o tmio_core.o
> +obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o
>  obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
>  obj-$(CONFIG_MFD_BD9571MWV)	+= bd9571mwv.o
>  cros_ec_core-objs		:= cros_ec.o
> diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
> new file mode 100644
> index 000000000000..53839e6a81e7
> --- /dev/null
> +++ b/drivers/mfd/bcm2835-pm.c
> @@ -0,0 +1,64 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * PM MFD driver for Broadcom BCM2835
> + *
> + * This driver binds to the PM block and creates the MFD device for
> + * the WDT driver.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/mfd/bcm2835-pm.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +
> +static const struct mfd_cell bcm2835_pm_devs[] = {
> +	{ .name = "bcm2835-wdt" },
> +};
> +
> +static int bcm2835_pm_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	struct bcm2835_pm *pm;
> +
> +	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
> +	if (!pm)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, pm);
> +
> +	pm->dev = dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pm->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(pm->base))
> +		return PTR_ERR(pm->base);
> +
> +	return devm_mfd_add_devices(dev, -1,
> +				    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
> +				    NULL, 0, NULL);
> +}
> +
> +static const struct of_device_id bcm2835_pm_of_match[] = {
> +	{ .compatible = "brcm,bcm2835-pm-wdt", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
> +
> +static struct platform_driver bcm2835_pm_driver = {
> +	.probe		= bcm2835_pm_probe,
> +	.driver = {
> +		.name =	"bcm2835-pm",
> +		.of_match_table = bcm2835_pm_of_match,
> +	},
> +};
> +module_platform_driver(bcm2835_pm_driver);
> +
> +MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
> +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
> index ed05514cc2dc..1834524ae373 100644
> --- a/drivers/watchdog/bcm2835_wdt.c
> +++ b/drivers/watchdog/bcm2835_wdt.c
> @@ -12,6 +12,7 @@
>  
>  #include <linux/delay.h>
>  #include <linux/types.h>
> +#include <linux/mfd/bcm2835-pm.h>
>  #include <linux/module.h>
>  #include <linux/io.h>
>  #include <linux/watchdog.h>
> @@ -47,6 +48,8 @@ struct bcm2835_wdt {
>  	spinlock_t		lock;
>  };
>  
> +static struct bcm2835_wdt *bcm2835_power_off_wdt;
> +
>  static unsigned int heartbeat;
>  static bool nowayout = WATCHDOG_NOWAYOUT;
>  
> @@ -148,10 +151,7 @@ static struct watchdog_device bcm2835_wdt_wdd = {
>   */
>  static void bcm2835_power_off(void)
>  {
> -	struct device_node *np =
> -		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
> -	struct platform_device *pdev = of_find_device_by_node(np);
> -	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
> +	struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;
>  	u32 val;
>  
>  	/*
> @@ -169,7 +169,7 @@ static void bcm2835_power_off(void)
>  
>  static int bcm2835_wdt_probe(struct platform_device *pdev)
>  {
> -	struct resource *res;
> +	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
>  	struct device *dev = &pdev->dev;
>  	struct bcm2835_wdt *wdt;
>  	int err;
> @@ -181,10 +181,7 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
>  
>  	spin_lock_init(&wdt->lock);
>  
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	wdt->base = devm_ioremap_resource(dev, res);
> -	if (IS_ERR(wdt->base))
> -		return PTR_ERR(wdt->base);
> +	wdt->base = pm->base;
>  
>  	watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
>  	watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
> @@ -211,8 +208,10 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> -	if (pm_power_off == NULL)
> +	if (pm_power_off == NULL) {
>  		pm_power_off = bcm2835_power_off;
> +		bcm2835_power_off_wdt = wdt;
> +	}
>  
>  	dev_info(dev, "Broadcom BCM2835 watchdog timer");
>  	return 0;
> @@ -226,18 +225,11 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static const struct of_device_id bcm2835_wdt_of_match[] = {
> -	{ .compatible = "brcm,bcm2835-pm-wdt", },
> -	{},
> -};
> -MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
> -
>  static struct platform_driver bcm2835_wdt_driver = {
>  	.probe		= bcm2835_wdt_probe,
>  	.remove		= bcm2835_wdt_remove,
>  	.driver = {
>  		.name =		"bcm2835-wdt",
> -		.of_match_table = bcm2835_wdt_of_match,
>  	},
>  };
>  module_platform_driver(bcm2835_wdt_driver);
> diff --git a/include/linux/mfd/bcm2835-pm.h b/include/linux/mfd/bcm2835-pm.h
> new file mode 100644
> index 000000000000..b7d0ee1feffa
> --- /dev/null
> +++ b/include/linux/mfd/bcm2835-pm.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +
> +#ifndef BCM2835_MFD_PM_H
> +#define BCM2835_MFD_PM_H
> +
> +#include <linux/regmap.h>
> +
> +struct bcm2835_pm {
> +	struct device *dev;
> +	void __iomem *base;
> +};
> +
> +#endif /* BCM2835_MFD_PM_H */
> -- 
> 2.20.0.rc1
>