On Mon, Jul 16, 2018 at 09:25:10AM +0200, Johannes Thumshirn wrote:
> Add a driver for the MEN 16z069 Watchdog and Reset Controller IP-Core.
>
> Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de>
Reviewed-by: Michael Moese <mmo...@suse.de>
>
> ---
> Changes to v1:
> * Sorted includes alphabetically
> * Indented defines with tabs
> * Removed unnecessary timeout validation
> * Removed unnecessary masking of values
> * Fixed error return in .probe
> * Directly accessed drv->wdt
> * Removed leftover timeout resetting
> ---
> MAINTAINERS | 6 ++
> drivers/watchdog/Kconfig | 10 +++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/menz69_wdt.c | 170
> ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 187 insertions(+)
> create mode 100644 drivers/watchdog/menz69_wdt.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 07d1576fc766..67a76f740294 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9298,6 +9298,12 @@ F: drivers/leds/leds-menf21bmc.c
> F: drivers/hwmon/menf21bmc_hwmon.c
> F: Documentation/hwmon/menf21bmc
>
> +MEN Z069 WATCHDOG DRIVER
> +M: Johannes Thumshirn <j...@kernel.org>
> +L: linux-watch...@vger.kernel.org
> +S: Maintained
> +F: drivers/watchdog/menz069_wdt.c
> +
> MESON AO CEC DRIVER FOR AMLOGIC SOCS
> M: Neil Armstrong <narmstr...@baylibre.com>
> L: linux-me...@lists.freedesktop.org
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 9af07fd92763..df55d65bbb1c 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -161,6 +161,16 @@ config MENF21BMC_WATCHDOG
> This driver can also be built as a module. If so the module
> will be called menf21bmc_wdt.
>
> +config MENZ069_WATCHDOG
> + tristate "MEN 16Z069 Watchdog"
> + depends on MCB || COMPILE_TEST
> + select WATCHDOG_CORE
> + help
> + Say Y here to include support for the MEN 16Z069 Watchdog.
> +
> + This driver can also be built as a module. If so the module
> + will be called menz069_wdt.
> +
> config TANGOX_WATCHDOG
> tristate "Sigma Designs SMP86xx/SMP87xx watchdog"
> select WATCHDOG_CORE
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 1d3c6b094fe5..bf92e7bf9ce0 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -215,4 +215,5 @@ obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o
> obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o
> obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
> obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
> +obj-$(CONFIG_MENZ069_WATCHDOG) += menz69_wdt.o
> obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o
> diff --git a/drivers/watchdog/menz69_wdt.c b/drivers/watchdog/menz69_wdt.c
> new file mode 100644
> index 000000000000..ed18238c5407
> --- /dev/null
> +++ b/drivers/watchdog/menz69_wdt.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Watchdog driver for the MEN z069 IP-Core
> + *
> + * Copyright (C) 2018 Johannes Thumshirn <j...@kernel.org>
> + */
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mcb.h>
> +#include <linux/module.h>
> +#include <linux/watchdog.h>
> +
> +struct men_z069_drv {
> + struct watchdog_device wdt;
> + void __iomem *base;
> + struct resource *mem;
> +};
> +
> +#define MEN_Z069_WTR 0x10
> +#define MEN_Z069_WTR_WDEN BIT(15)
> +#define MEN_Z069_WTR_WDET_MASK 0x7fff
> +#define MEN_Z069_WVR 0x14
> +
> +#define MEN_Z069_TIMER_FREQ 500 /* 500 Hz */
> +#define MEN_Z069_WDT_COUNTER_MIN 1
> +#define MEN_Z069_WDT_COUNTER_MAX 0x7fff
> +#define MEN_Z069_DEFAULT_TIMEOUT 30
> +
> +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 int men_z069_wdt_start(struct watchdog_device *wdt)
> +{
> + struct men_z069_drv *drv = watchdog_get_drvdata(wdt);
> + u16 val;
> +
> + val = readw(drv->base + MEN_Z069_WTR);
> + val |= MEN_Z069_WTR_WDEN;
> + writew(val, drv->base + MEN_Z069_WTR);
> +
> + return 0;
> +}
> +
> +static int men_z069_wdt_stop(struct watchdog_device *wdt)
> +{
> + struct men_z069_drv *drv = watchdog_get_drvdata(wdt);
> + u16 val;
> +
> + val = readw(drv->base + MEN_Z069_WTR);
> + val &= ~MEN_Z069_WTR_WDEN;
> + writew(val, drv->base + MEN_Z069_WTR);
> +
> + return 0;
> +}
> +
> +static int men_z069_wdt_ping(struct watchdog_device *wdt)
> +{
> + struct men_z069_drv *drv = watchdog_get_drvdata(wdt);
> + u16 val;
> +
> + /* The watchdog trigger value toggles between 0x5555 and 0xaaaa */
> + val = readw(drv->base + MEN_Z069_WVR);
> + val ^= 0xffff;
> + writew(val, drv->base + MEN_Z069_WVR);
> +
> + return 0;
> +}
> +
> +static int men_z069_wdt_set_timeout(struct watchdog_device *wdt,
> + unsigned int timeout)
> +{
> + struct men_z069_drv *drv = watchdog_get_drvdata(wdt);
> + u16 reg, val, ena;
> +
> + wdt->timeout = timeout;
> + val = timeout * MEN_Z069_TIMER_FREQ;
> +
> + reg = readw(drv->base + MEN_Z069_WVR);
> + ena = reg & MEN_Z069_WTR_WDEN;
> + reg = ena | val;
> + writew(reg, drv->base + MEN_Z069_WTR);
> +
> + return 0;
> +}
> +
> +static const struct watchdog_info men_z069_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> + .identity = "MEN z069 Watchdog",
> +};
> +
> +static const struct watchdog_ops men_z069_ops = {
> + .owner = THIS_MODULE,
> + .start = men_z069_wdt_start,
> + .stop = men_z069_wdt_stop,
> + .ping = men_z069_wdt_ping,
> + .set_timeout = men_z069_wdt_set_timeout,
> +};
> +
> +static struct watchdog_device men_z069_wdt = {
> + .info = &men_z069_info,
> + .ops = &men_z069_ops,
> + .timeout = MEN_Z069_DEFAULT_TIMEOUT,
> + .min_timeout = 1,
> + .max_timeout = MEN_Z069_WDT_COUNTER_MAX / MEN_Z069_TIMER_FREQ,
> +};
> +
> +static int men_z069_probe(struct mcb_device *dev,
> + const struct mcb_device_id *id)
> +{
> + struct men_z069_drv *drv;
> + struct resource *mem;
> +
> + drv = devm_kzalloc(&dev->dev, sizeof(struct men_z069_drv), GFP_KERNEL);
> + if (!drv)
> + return -ENOMEM;
> +
> + mem = mcb_request_mem(dev, "z069-wdt");
> + if (IS_ERR(mem))
> + return PTR_ERR(mem);
> +
> + drv->base = devm_ioremap(&dev->dev, mem->start, resource_size(mem));
> + if (drv->base == NULL)
> + goto release_mem;
> +
> + drv->mem = mem;
> +
> + drv->wdt = men_z069_wdt;
> + watchdog_init_timeout(&drv->wdt, 0, &dev->dev);
> + watchdog_set_nowayout(&drv->wdt, nowayout);
> + watchdog_set_drvdata(&drv->wdt, drv);
> + drv->wdt.parent = &dev->dev;
> + mcb_set_drvdata(dev, drv);
> +
> + return watchdog_register_device(&men_z069_wdt);
> +
> +release_mem:
> + mcb_release_mem(mem);
> + return -ENOMEM;
> +}
> +
> +static void men_z069_remove(struct mcb_device *dev)
> +{
> + struct men_z069_drv *drv = mcb_get_drvdata(dev);
> +
> + watchdog_unregister_device(&drv->wdt);
> + mcb_release_mem(drv->mem);
> +}
> +
> +static const struct mcb_device_id men_z069_ids[] = {
> + { .device = 0x45 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(mcb, men_z069_ids);
> +
> +static struct mcb_driver men_z069_driver = {
> + .driver = {
> + .name = "z069-wdt",
> + .owner = THIS_MODULE,
> + },
> + .probe = men_z069_probe,
> + .remove = men_z069_remove,
> + .id_table = men_z069_ids,
> +};
> +module_mcb_driver(men_z069_driver);
> +
> +MODULE_AUTHOR("Johannes Thumshirn <j...@kernel.org>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("mcb:16z069");
> --
> 2.16.4
>
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