From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:44620 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751703AbaJJTzg (ORCPT ); Fri, 10 Oct 2014 15:55:36 -0400 Received: from mailnull by bh-25.webhostbox.net with sa-checked (Exim 4.82) (envelope-from ) id 1XcgHo-002L35-0c for linux-watchdog@vger.kernel.org; Fri, 10 Oct 2014 19:55:36 +0000 Message-ID: <543839AA.8050808@roeck-us.net> Date: Fri, 10 Oct 2014 12:55:22 -0700 From: Guenter Roeck MIME-Version: 1.0 To: John Crispin , Wim Van Sebroeck CC: linux-watchdog@vger.kernel.org, linux-mips@linux-mips.org Subject: Re: [PATCH] watchdog: add MT7621 watchdog support References: <1412965669-5243-1-git-send-email-blogic@openwrt.org> In-Reply-To: <1412965669-5243-1-git-send-email-blogic@openwrt.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org On 10/10/2014 11:27 AM, John Crispin wrote: > This patch adds support for the watchdog core found on newer mediatek/ralink > Wifi SoCs. > > Signed-off-by: John Crispin Hi John, > --- > .../devicetree/bindings/watchdog/mt7621-wdt.txt | 12 ++ > drivers/watchdog/Kconfig | 7 + > drivers/watchdog/Makefile | 1 + > drivers/watchdog/mt7621_wdt.c | 185 ++++++++++++++++++++ > 4 files changed, 205 insertions(+) > create mode 100644 Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt > create mode 100644 drivers/watchdog/mt7621_wdt.c > > diff --git a/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt > new file mode 100644 > index 0000000..c15ef0e > --- /dev/null > +++ b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt > @@ -0,0 +1,12 @@ > +Ralink Watchdog Timers > + > +Required properties: > +- compatible: must be "mediatek,mt7621-wdt" > +- reg: physical base address of the controller and length of the register range > + > +Example: > + > + watchdog@100 { > + compatible = "mediatek,mt7621-wdt"; > + reg = <0x100 0x10>; > + }; > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index f57312f..84c911f 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1186,6 +1186,13 @@ config RALINK_WDT > help > Hardware driver for the Ralink SoC Watchdog Timer. > > +config MT7621_WDT > + tristate "Mediatek SoC watchdog" > + select WATCHDOG_CORE > + depends on SOC_MT7620 || SOC_MT7621 > + help > + Hardware driver for the Ralink SoC Watchdog Timer. > + The above claims to do the same. Should this be Mediatek ? > # PARISC Architecture > > # POWERPC Architecture > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 468c320..5b2031e 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -138,6 +138,7 @@ obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o > octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o > obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o > obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o > +obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o > > # PARISC Architecture > > diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c > new file mode 100644 > index 0000000..542ed97 > --- /dev/null > +++ b/drivers/watchdog/mt7621_wdt.c > @@ -0,0 +1,185 @@ > +/* > + * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer > + * The rt2880_wdt driver claims to do the same. Either the statement here or there or both is wrong. > + * Copyright (C) 2011 Gabor Juhos > + * Copyright (C) 2013 John Crispin > + * > + * This driver was based on: drivers/watchdog/softdog.c > + * Seems to be based on the rt2880 driver ? > + * 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. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include No longer needed. > +#include > +#include > + > +#include > + > +#define SYSC_RSTSTAT 0x38 > +#define WDT_RST_CAUSE BIT(1) > + > +#define RALINK_WDT_TIMEOUT 30 > + > +#define TIMER_REG_TMRSTAT 0x00 > +#define TIMER_REG_TMR1LOAD 0x24 > +#define TIMER_REG_TMR1CTL 0x20 > + > +#define TMR1CTL_ENABLE BIT(7) > +#define TMR1CTL_RESTART BIT(9) > + > +static void __iomem *mt7621_wdt_base; > + > +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) ")"); Please align continuation lines with '('. > + > +static inline void rt_wdt_w32(unsigned reg, u32 val) > +{ > + iowrite32(val, mt7621_wdt_base + reg); > +} > + > +static inline u32 rt_wdt_r32(unsigned reg) > +{ > + return ioread32(mt7621_wdt_base + reg); > +} > + > +static int mt7621_wdt_ping(struct watchdog_device *w) > +{ > + rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART); > + > + return 0; > +} > + > +static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t) > +{ > + w->timeout = t; > + rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000); > + mt7621_wdt_ping(w); > + > + return 0; > +} > + > +static int mt7621_wdt_start(struct watchdog_device *w) > +{ > + u32 t; > + > + rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << 16); Can you explain this a bit ? > + mt7621_wdt_set_timeout(w, w->timeout); > + > + t = rt_wdt_r32(TIMER_REG_TMR1CTL); > + t |= TMR1CTL_ENABLE; > + rt_wdt_w32(TIMER_REG_TMR1CTL, t); > + > + return 0; > +} > + > +static int mt7621_wdt_stop(struct watchdog_device *w) > +{ > + u32 t; > + > + mt7621_wdt_ping(w); > + > + t = rt_wdt_r32(TIMER_REG_TMR1CTL); > + t &= ~TMR1CTL_ENABLE; > + rt_wdt_w32(TIMER_REG_TMR1CTL, t); > + > + return 0; > +} > + > +static int mt7621_wdt_bootcause(void) > +{ > + if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) > + return WDIOF_CARDRESET; > + That concerns me a bit. What guarantees that rt_sysc_membase is set ? I understand that rt2880 driver has the same problem, but that doesn't really make it better. > + return 0; > +} > + > +static struct watchdog_info mt7621_wdt_info = { > + .identity = "Mediatek Watchdog", > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > +}; > + > +static struct watchdog_ops mt7621_wdt_ops = { > + .owner = THIS_MODULE, > + .start = mt7621_wdt_start, > + .stop = mt7621_wdt_stop, > + .ping = mt7621_wdt_ping, > + .set_timeout = mt7621_wdt_set_timeout, > +}; > + > +static struct watchdog_device mt7621_wdt_dev = { > + .info = &mt7621_wdt_info, > + .ops = &mt7621_wdt_ops, > + .min_timeout = 1, > +}; > + > +static int mt7621_wdt_probe(struct platform_device *pdev) > +{ > + struct resource *res; > + int ret; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(mt7621_wdt_base)) > + return PTR_ERR(mt7621_wdt_base); > + > + device_reset(&pdev->dev); > + Just wondering ... is this doing anything in the real world, or in other words is there a reset bit (or controller, for that matter) associated with the watchdog timer ? I see a reset controller registration for the rl2880, but not for the mt7621. > + mt7621_wdt_dev.dev = &pdev->dev; > + mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause(); > + mt7621_wdt_dev.max_timeout = (0xfffful / 1000); > + mt7621_wdt_dev.timeout = mt7621_wdt_dev.max_timeout; > + Why not just set max_timeout and timeout directly in the data structure ? Also, since the driver supports devicetree, would it make sense to use watchdog_init_timeout to support the timeout-sec property ? > + watchdog_set_nowayout(&mt7621_wdt_dev, nowayout); > + > + ret = watchdog_register_device(&mt7621_wdt_dev); > + if (!ret) > + dev_info(&pdev->dev, "Initialized\n"); > + Is that noise really necessary ? > + return 0; > +} > + > +static int mt7621_wdt_remove(struct platform_device *pdev) > +{ > + watchdog_unregister_device(&mt7621_wdt_dev); > + > + return 0; > +} > + > +static void mt7621_wdt_shutdown(struct platform_device *pdev) > +{ > + mt7621_wdt_stop(&mt7621_wdt_dev); > +} > + > +static const struct of_device_id mt7621_wdt_match[] = { > + { .compatible = "mediatek,mt7621-wdt" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, mt7621_wdt_match); > + > +static struct platform_driver mt7621_wdt_driver = { > + .probe = mt7621_wdt_probe, > + .remove = mt7621_wdt_remove, > + .shutdown = mt7621_wdt_shutdown, > + .driver = { > + .name = KBUILD_MODNAME, > + .owner = THIS_MODULE, > + .of_match_table = mt7621_wdt_match, > + }, > +}; > + > +module_platform_driver(mt7621_wdt_driver); > + > +MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver"); > +MODULE_AUTHOR("John Crispin +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); No longer needed. Thanks, Guenter