Re: [RESEND][PATCH] watchdog: add support for Sigma Designs SMP86xx

[Guenter Roeck <linux@roeck-us.net>]

On 11/13/2015 05:14 AM, Mans Rullgard wrote:
> This adds support for the Sigma Designs SMP86xx family built-in
> watchdog.
>
> Signed-off-by: Mans Rullgard <mans@mansr.com>
> ---
>   drivers/watchdog/Kconfig      |   7 ++
>   drivers/watchdog/Makefile     |   1 +
>   drivers/watchdog/tangox_wdt.c | 185 ++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 193 insertions(+)
>   create mode 100644 drivers/watchdog/tangox_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 79e1aa1..0ed5ee8 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1337,6 +1337,13 @@ config RALINK_WDT
>   	help
>   	  Hardware driver for the Ralink SoC Watchdog Timer.
>
> +config TANGOX_WDT
> +	tristate "SMP86xx watchdog"
> +	select WATCHDOG_CORE
> +	depends on ARCH_TANGOX

Please make this "depends on ARCH_TANGOX | COMPILE_TEST" so the driver
can be compile-tested without ARCH_TANGOX.

One more comment below.

Thanks,
Guenter

> +	help
> +	  Watchdog driver for Sigma Designs SMP86xx.
> +
>   # PARISC Architecture
>
>   # POWERPC Architecture
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 0c616e3..ed00796 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -148,6 +148,7 @@ octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o
>   obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o
>   obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o
>   obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o
> +obj-$(CONFIG_TANGOX_WDT) += tangox_wdt.o
>
>   # PARISC Architecture
>
> diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
> new file mode 100644
> index 0000000..305759f
> --- /dev/null
> +++ b/drivers/watchdog/tangox_wdt.c
> @@ -0,0 +1,185 @@
> +/*
> + *  Copyright (C) 2014, Mans Rullgard <mans@mansr.com>
> + *  SMP86xx Watchdog driver
> + *
> + *  This program is free software; you can redistribute it and/or modify it
> + *  under  the terms of the GNU General  Public License as published by the
> + *  Free Software Foundation;  either version 2 of the License, or (at your
> + *  option) any later version.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/notifier.h>
> +#include <linux/delay.h>
> +#include <linux/reboot.h>
> +#include <linux/platform_device.h>
> +#include <linux/watchdog.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +
> +#define DEFAULT_TIMEOUT	30
> +#define MAX_TIMEOUT	120
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout,
> +		 "Watchdog cannot be stopped once started (default="
> +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +static unsigned int timeout = DEFAULT_TIMEOUT;
> +module_param(timeout, int, 0);
> +MODULE_PARM_DESC(watchdog_timeout, "Watchdog timeout");
> +
> +#define WD_COUNTER	0
> +#define WD_CONFIG	4
> +
> +struct tangox_wdt_device {
> +	struct watchdog_device wdt;
> +	void __iomem *base;
> +	unsigned int timeout;
> +	struct clk *clk;
> +	struct notifier_block restart;
> +};
> +
> +static int tangox_wdt_ping(struct watchdog_device *wdt)
> +{
> +	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
> +
> +	writel(dev->timeout, dev->base + WD_COUNTER);
> +
> +	return 0;
> +}
> +
> +static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
> +				  unsigned int new_timeout)
> +{
> +	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
> +
> +	wdt->timeout = new_timeout;
> +	dev->timeout = 1 + new_timeout * clk_get_rate(dev->clk);
> +
> +	tangox_wdt_ping(wdt);
> +
> +	return 0;
> +}
> +
> +static int tangox_wdt_start(struct watchdog_device *wdt)
> +{
> +	return tangox_wdt_set_timeout(wdt, wdt->timeout);
> +}
> +
> +static int tangox_wdt_stop(struct watchdog_device *wdt)
> +{
> +	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
> +
> +	writel(0, dev->base + WD_COUNTER);
> +
> +	return 0;
> +}
> +
> +static const struct watchdog_info tangox_wdt_info = {
> +	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> +	.identity = "tangox watchdog",
> +};
> +
> +static const struct watchdog_ops tangox_wdt_ops = {
> +	.start		= tangox_wdt_start,
> +	.stop		= tangox_wdt_stop,
> +	.ping		= tangox_wdt_ping,
> +	.set_timeout	= tangox_wdt_set_timeout,
> +};
> +
> +static int tangox_wdt_restart(struct notifier_block *nb, unsigned long action,
> +			      void *data)
> +{
> +	struct tangox_wdt_device *dev =
> +		container_of(nb, struct tangox_wdt_device, restart);
> +
> +	writel(1, dev->base + WD_COUNTER);
> +
> +	return NOTIFY_DONE;
> +}
> +
> +static int tangox_wdt_probe(struct platform_device *pdev)
> +{
> +	struct tangox_wdt_device *dev;
> +	struct resource *res;
> +	int err;
> +
> +	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> +	if (!dev)
> +		return -ENOMEM;
> +
> +	dev->wdt.parent = &pdev->dev;
> +	dev->wdt.info = &tangox_wdt_info;
> +	dev->wdt.ops = &tangox_wdt_ops;
> +	dev->wdt.timeout = timeout;
> +	dev->wdt.min_timeout = 1;
> +	dev->wdt.max_timeout = MAX_TIMEOUT;
> +	watchdog_set_nowayout(&dev->wdt, nowayout);
> +	watchdog_set_drvdata(&dev->wdt, dev);
> +
> +	dev->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(dev->clk))
> +		return PTR_ERR(dev->clk);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
> +
Unnecessary error check; devm_ioremap_resource() generates an error
if res is NULL.

> +	dev->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(dev->base))
> +		return PTR_ERR(dev->base);
> +
> +	writel(0, dev->base + WD_COUNTER);
> +	writel(1, dev->base + WD_CONFIG);
> +
> +	err = watchdog_register_device(&dev->wdt);
> +	if (err)
> +		return err;
> +
> +	platform_set_drvdata(pdev, dev);
> +
> +	dev->restart.notifier_call = tangox_wdt_restart;
> +	dev->restart.priority = 128;
> +	err = register_restart_handler(&dev->restart);
> +	if (err)
> +		dev_err(&pdev->dev, "failed to register restart handler\n");
> +
> +	dev_info(dev->wdt.dev, "SMP86xx watchdog registered\n");
> +
> +	return 0;
> +}
> +
> +static int tangox_wdt_remove(struct platform_device *pdev)
> +{
> +	struct tangox_wdt_device *dev = platform_get_drvdata(pdev);
> +
> +	tangox_wdt_stop(&dev->wdt);
> +	unregister_restart_handler(&dev->restart);
> +	watchdog_unregister_device(&dev->wdt);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id tangox_wdt_dt_ids[] = {
> +	{ .compatible = "sigma,smp8642-wdt" },
> +	{ }
> +};
> +
> +static struct platform_driver tangox_wdt_driver = {
> +	.probe	= tangox_wdt_probe,
> +	.remove	= tangox_wdt_remove,
> +	.driver	= {
> +		.name		= "tangox-wdt",
> +		.of_match_table	= tangox_wdt_dt_ids,
> +	},
> +};
> +
> +module_platform_driver(tangox_wdt_driver);
> +
> +MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
> +MODULE_DESCRIPTION("SMP86xx Watchdog driver");
> +MODULE_LICENSE("GPL");
>