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Message-ID: <20140827190135.GA18849@roeck-us.net>
Date: Wed, 27 Aug 2014 12:01:35 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Beniamino Galvani <b.galvani@...il.com>
Cc: linux-kernel@...r.kernel.org, Lee Jones <lee.jones@...aro.org>,
Samuel Ortiz <sameo@...ux.intel.com>,
Mark Brown <broonie@...nel.org>,
Liam Girdwood <lgirdwood@...il.com>,
Wim Van Sebroeck <wim@...ana.be>,
linux-watchdog@...r.kernel.org, devicetree@...r.kernel.org,
Rob Herring <robh+dt@...nel.org>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>,
Grant Likely <grant.likely@...aro.org>,
Carlo Caione <carlo@...one.org>
Subject: Re: [PATCH 3/4] watchdog: add driver for Ricoh RN5T618 watchdog
On Wed, Aug 27, 2014 at 12:13:56AM +0200, Beniamino Galvani wrote:
> This adds a driver for the watchdog timer available in Ricoh RN5T618
> PMIC. The device supports a programmable expiration time of 1, 8, 32
> or 128 seconds.
>
> Signed-off-by: Beniamino Galvani <b.galvani@...il.com>
> ---
> drivers/watchdog/Kconfig | 11 +++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/rn5t618_wdt.c | 196 ++++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/rn5t618.h | 4 +
> 4 files changed, 212 insertions(+)
> create mode 100644 drivers/watchdog/rn5t618_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index f57312f..9eba6af 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -309,6 +309,17 @@ config ORION_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called orion_wdt.
>
> +config RN5T618_WATCHDOG
> + tristate "Ricoh RN5T618 watchdog"
> + depends on MFD_RN5T618
> + select WATCHDOG_CORE
> + help
> + If you say yes here you get support for watchdog on the Ricoh
> + RN5T618 PMIC.
> +
> + This driver can also be built as a module. If so, the module
> + will be called rn5t618_wdt.
> +
> config SUNXI_WATCHDOG
> tristate "Allwinner SoCs watchdog support"
> depends on ARCH_SUNXI
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 468c320..0afa343 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -47,6 +47,7 @@ obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
> obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
> obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
> obj-$(CONFIG_SUNXI_WATCHDOG) += sunxi_wdt.o
> +obj-$(CONFIG_RN5T618_WATCHDOG) += rn5t618_wdt.o
> obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
> obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
> obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
> diff --git a/drivers/watchdog/rn5t618_wdt.c b/drivers/watchdog/rn5t618_wdt.c
> new file mode 100644
> index 0000000..3a76ad7
> --- /dev/null
> +++ b/drivers/watchdog/rn5t618_wdt.c
> @@ -0,0 +1,196 @@
> +/*
> + * Watchdog driver for Ricoh RN5T618 PMIC
> + *
> + * Copyright (C) 2014 Beniamino Galvani <b.galvani@...il.com>
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/mfd/rn5t618.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/watchdog.h>
> +
> +#define DRIVER_NAME "rn5t618-wdt"
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +static unsigned int heartbeat = -1;
I'd be surprised if this doesn't cause a compiler warning.
Why not just initialize the variable with 0 ?
> +
> +module_param(heartbeat, int, 0);
> +MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
> +
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +struct rn5t618_wdt {
> + struct watchdog_device wdt_dev;
> + struct rn5t618 *rn5t618;
> +};
> +
> +/*
> + * This array encodes the values of WDOGTIM field for the supported
> + * watchdog expiration times. If the watchdog is not accessed before
> + * the timer expiration, the PMU generates an interrupt and if the CPU
> + * doesn't clear it within one second the system is restarted.
> + */
> +static const struct {
> + u8 reg_val;
> + int time;
> +} rn5t618_wdt_map[] = {
> + { 0, 1 },
> + { 1, 8 },
> + { 2, 32 },
> + { 3, 128 },
> +};
> +
> +static int rn5t618_wdt_set_timeout(struct watchdog_device *wdt_dev,
> + unsigned int timeout)
> +{
> + struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> + int ret, i;
> +
> + for (i = 0; i < ARRAY_SIZE(rn5t618_wdt_map); i++) {
> + if (rn5t618_wdt_map[i].time + 1 >= timeout)
> + break;
> + }
> +
> + if (i == ARRAY_SIZE(rn5t618_wdt_map))
> + ret = -EINVAL;
Can you simplify this a bit ? If you use
if (i == ARRAY_SIZE(rn5t618_wdt_map))
return -EINVAL;
> + else
You can drop this else statement.
Thanks,
Guenter
> + ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> + RN5T618_WATCHDOG_WDOGTIM_M,
> + rn5t618_wdt_map[i].reg_val);
> + if (!ret)
> + wdt_dev->timeout = rn5t618_wdt_map[i].time;
> +
> + return ret;
> +}
> +
> +static int rn5t618_wdt_start(struct watchdog_device *wdt_dev)
> +{
> + struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> + int ret;
> +
> + ret = rn5t618_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
> + if (ret)
> + return ret;
> +
> + /* enable repower-on */
> + ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_REPCNT,
> + RN5T618_REPCNT_REPWRON,
> + RN5T618_REPCNT_REPWRON);
> + if (ret)
> + return ret;
> +
> + /* enable watchdog */
> + ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> + RN5T618_WATCHDOG_WDOGEN,
> + RN5T618_WATCHDOG_WDOGEN);
> + if (ret)
> + return ret;
> +
> + /* enable watchdog interrupt */
> + return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIREN,
> + RN5T618_PWRIRQ_IR_WDOG,
> + RN5T618_PWRIRQ_IR_WDOG);
> +}
> +
> +static int rn5t618_wdt_stop(struct watchdog_device *wdt_dev)
> +{
> + struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> +
> + return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> + RN5T618_WATCHDOG_WDOGEN, 0);
> +}
> +
> +static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev)
> +{
> + struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> + unsigned int val;
> + int ret;
> +
> + /* The counter is restarted after a R/W access to watchdog register */
> + ret = regmap_read(wdt->rn5t618->regmap, RN5T618_WATCHDOG, &val);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(wdt->rn5t618->regmap, RN5T618_WATCHDOG, val);
> + if (ret)
> + return ret;
> +
> + /* Clear pending watchdog interrupt */
> + return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIRQ,
> + RN5T618_PWRIRQ_IR_WDOG, 0);
> +}
> +
> +static struct watchdog_info rn5t618_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
> + WDIOF_KEEPALIVEPING,
> + .identity = DRIVER_NAME,
> +};
> +
> +static struct watchdog_ops rn5t618_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = rn5t618_wdt_start,
> + .stop = rn5t618_wdt_stop,
> + .ping = rn5t618_wdt_ping,
> + .set_timeout = rn5t618_wdt_set_timeout,
> +};
> +
> +static int rn5t618_wdt_probe(struct platform_device *pdev)
> +{
> + struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
> + struct rn5t618_wdt *wdt;
> + int min_timeout, max_timeout;
> +
> + wdt = devm_kzalloc(&pdev->dev, sizeof(struct rn5t618_wdt), GFP_KERNEL);
> + if (!wdt)
> + return -ENOMEM;
> +
> + min_timeout = rn5t618_wdt_map[0].time;
> + max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time;
> +
> + wdt->rn5t618 = rn5t618;
> + wdt->wdt_dev.info = &rn5t618_wdt_info;
> + wdt->wdt_dev.ops = &rn5t618_wdt_ops;
> + wdt->wdt_dev.min_timeout = min_timeout;
> + wdt->wdt_dev.max_timeout = max_timeout;
> + wdt->wdt_dev.timeout = max_timeout;
> + wdt->wdt_dev.parent = &pdev->dev;
> +
> + watchdog_set_drvdata(&wdt->wdt_dev, wdt);
> + watchdog_init_timeout(&wdt->wdt_dev, heartbeat, &pdev->dev);
> + watchdog_set_nowayout(&wdt->wdt_dev, nowayout);
> +
> + return watchdog_register_device(&wdt->wdt_dev);
> +}
> +
> +static int rn5t618_wdt_remove(struct platform_device *pdev)
> +{
> + struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
> +
> + watchdog_unregister_device(wdt_dev);
> +
> + return 0;
> +}
> +
> +static struct platform_driver rn5t618_wdt_driver = {
> + .probe = rn5t618_wdt_probe,
> + .remove = rn5t618_wdt_remove,
> + .driver = {
> + .name = DRIVER_NAME,
> + },
> +};
> +
> +module_platform_driver(rn5t618_wdt_driver);
> +
> +MODULE_AUTHOR("Beniamino Galvani <b.galvani@...il.com>");
> +MODULE_DESCRIPTION("RN5T618 watchdog driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/rn5t618.h b/include/linux/mfd/rn5t618.h
> index e3571d1..c72d534 100644
> --- a/include/linux/mfd/rn5t618.h
> +++ b/include/linux/mfd/rn5t618.h
> @@ -202,6 +202,10 @@
>
> #define RN5T618_REPCNT_REPWRON BIT(0)
> #define RN5T618_SLPCNT_SWPWROFF BIT(0)
> +#define RN5T618_WATCHDOG_WDOGEN BIT(2)
> +#define RN5T618_WATCHDOG_WDOGTIM_M (BIT(0) | BIT(1))
> +#define RN5T618_WATCHDOG_WDOGTIM_S 0
> +#define RN5T618_PWRIRQ_IR_WDOG BIT(6)
>
> enum {
> RN5T618_DCDC1,
> --
> 1.7.10.4
>
> --
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