Hi Carlo,
> This patch adds the driver for the watchdog found in the Allwinner A10 and
> A13 SoCs. It has DT-support and uses the new watchdog framework.
>
> Signed-off-by: Carlo Caione <carlo.caione@xxxxxxxxx>
> ---
> drivers/watchdog/Kconfig | 10 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/sunxi_wdt.c | 231 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 242 insertions(+)
> create mode 100644 drivers/watchdog/sunxi_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index e89fc31..8ad2238 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -299,6 +299,16 @@ config ORION_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called orion_wdt.
>
> +config SUNXI_WATCHDOG
> + tristate "Allwinner SoCs watchdog support"
> + depends on ARCH_SUNXI
> + select WATCHDOG_CORE
> + help
> + Say Y here to include support for the watchdog timer
> + in Allwinner SoCs.
> + To compile this driver as a module, choose M here: the
> + module will be called sunxi_wdt.
> +
> config COH901327_WATCHDOG
> bool "ST-Ericsson COH 901 327 watchdog"
> depends on ARCH_U300
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index a300b94..5012d5f 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -47,6 +47,7 @@ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
> obj-$(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_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/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
> new file mode 100644
> index 0000000..69d4d44
> --- /dev/null
> +++ b/drivers/watchdog/sunxi_wdt.c
> @@ -0,0 +1,231 @@
> +/*
> + * sunxi Watchdog Driver
> + *
> + * Copyright (c) 2013 Carlo Caione
> + * 2012 Henrik Nordstrom
> + *
> + * 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.
> + *
> + * Based on xen_wdt.c
> + * (c) Copyright 2010 Novell, Inc.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +
> +#define WDT_MAX_TIMEOUT 16
> +#define WDT_MIN_TIMEOUT 1
> +#define WDT_MODE_TIMEOUT(n) ((n) << 3)
> +#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
> +
> +#define WDT_CTRL 0x00
> +#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
> +
> +#define WDT_MODE 0x04
> +#define WDT_MODE_EN (1 << 0)
> +#define WDT_MODE_RST_EN (1 << 1)
> +
> +#define DRV_NAME "sunxi-wdt"
> +#define DRV_VERSION "1.0"
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +static int heartbeat = WDT_MAX_TIMEOUT;
heartbeat should be unsigned int.
I also prefer this to be called timeout. (heartbeat is what we use towards the watchdog, timeout is what we use for user-space. In this case heartbeat will be equal to timeout).
> +
> +struct sunxi_wdt_dev {
> + struct watchdog_device wdt_dev;
> + void __iomem *wdt_base;
> +};
> +
> +/*
> + * wdt_timeout_map maps the watchdog timer interval value in seconds to
> + * the value of the register WDT_MODE bit 3:6
> + *
> + * [timeout seconds] = register value
> + *
> + */
> +
> +static const int wdt_timeout_map[] = {
> + [1] = 0b0001, /* 1s */
> + [2] = 0b0010, /* 2s */
> + [3] = 0b0011, /* 3s */
> + [4] = 0b0100, /* 4s */
> + [5] = 0b0101, /* 5s */
> + [6] = 0b0110, /* 6s */
> + [8] = 0b0111, /* 8s */
> + [10] = 0b1000, /* 10s */
> + [12] = 0b1001, /* 12s */
> + [14] = 0b1010, /* 14s */
> + [16] = 0b1011, /* 16s */
> +};
> +
> +static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
> +{
> + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = sunxi_wdt->wdt_base;
> +
> + iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
> +
> + return 0;
> +}
> +
> +static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
> + unsigned int timeout)
> +{
> + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = sunxi_wdt->wdt_base;
> + u32 reg;
> +
> + if (timeout > WDT_MAX_TIMEOUT)
> + return -EINVAL;
> +
> + if (wdt_timeout_map[timeout] == 0)
> + timeout++;
> +
> + sunxi_wdt->wdt_dev.timeout = timeout;
> +
> + reg = ioread32(wdt_base + WDT_MODE);
> + reg &= ~WDT_TIMEOUT_MASK;
> + reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]);
> + iowrite32(reg, wdt_base + WDT_MODE);
> +
> + sunxi_wdt_ping(wdt_dev);
> +
> + return 0;
> +}
> +
> +static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
> +{
> + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = sunxi_wdt->wdt_base;
> +
> + iowrite32(0, wdt_base + WDT_MODE);
> +
> + return 0;
> +}
> +
> +static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
> +{
> + u32 reg;
> + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = sunxi_wdt->wdt_base;
> + int ret;
> +
> + ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
> + sunxi_wdt->wdt_dev.timeout);
> + if (ret < 0)
> + return ret;
> +
> + reg = ioread32(wdt_base + WDT_MODE);
> + reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);
> + iowrite32(reg, wdt_base + WDT_MODE);
> +
> + return 0;
> +}
> +
> +static const struct watchdog_info sunxi_wdt_info = {
> + .identity = DRV_NAME,
> + .options = WDIOF_SETTIMEOUT |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_MAGICCLOSE,
> +};
> +
> +static const struct watchdog_ops sunxi_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = sunxi_wdt_start,
> + .stop = sunxi_wdt_stop,
> + .ping = sunxi_wdt_ping,
> + .set_timeout = sunxi_wdt_set_timeout,
> +};
> +
> +static int __init sunxi_wdt_probe(struct platform_device *pdev)
> +{
> + struct sunxi_wdt_dev *sunxi_wdt;
> + struct resource *res;
> + int err;
> +
> + sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
> + if (!sunxi_wdt)
> + return -EINVAL;
> +
> + platform_set_drvdata(pdev, sunxi_wdt);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(sunxi_wdt->wdt_base))
> + return PTR_ERR(sunxi_wdt->wdt_base);
> +
> + sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
> + sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
> + sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
> + sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
> + sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
> + sunxi_wdt->wdt_dev.parent = &pdev->dev;
> +
> + watchdog_init_timeout(&sunxi_wdt->wdt_dev, heartbeat, &pdev->dev);
> + watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
> +
> + watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
Can the watchdog be running at startup before the driver loads?
If so you should make sure that you stop the watchdog.
> + err = watchdog_register_device(&sunxi_wdt->wdt_dev);
> + if (unlikely(err))
> + return err;
> +
> + dev_info(&pdev->dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)",
> + sunxi_wdt->wdt_dev.timeout, nowayout);
> +
> + return 0;
> +}
> +
> +static int __exit sunxi_wdt_remove(struct platform_device *pdev)
> +{
> + struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
> +
> + watchdog_unregister_device(&sunxi_wdt->wdt_dev);
> + watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id sunxi_wdt_dt_ids[] = {
> + { .compatible = "allwinner,sun4i-wdt" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
> +
> +static struct platform_driver sunxi_wdt_driver = {
> + .probe = sunxi_wdt_probe,
> + .remove = sunxi_wdt_remove,
May be interesting to add the shutdown method also... (so that the watchog doesn't get fired when, you are allready shutting down).
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = DRV_NAME,
> + .of_match_table = of_match_ptr(sunxi_wdt_dt_ids)
> + },
> +};
> +
> +module_platform_driver(sunxi_wdt_driver);
> +
> +module_param(heartbeat, int, 0);
> +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
Unsigned int and timeout is prefered name here.
> +
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
> + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Carlo Caione <carlo.caione@xxxxxxxxx>");
> +MODULE_AUTHOR("Henrik Nordstrom <henrik@xxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
> +MODULE_VERSION(DRV_VERSION);
For the rest: looks ok.
Kind regards,
Wim.
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