Hi Guenter, > -----Original Message----- > From: Guenter Roeck [mailto:linux@xxxxxxxxxxxx] > Sent: 2015年8月6日 18:00 > To: Yang, Wenyou; wim@xxxxxxxxx; robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; > mark.rutland@xxxxxxx; ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx > Cc: sylvain.rochet@xxxxxxxxxxxx; Ferre, Nicolas; boris.brezillon@free- > electrons.com; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > watchdog@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v5 1/2] drivers: watchdog: add a driver to support SAMA5D4 > watchdog timer > > Hi, > > On 08/06/2015 01:34 AM, Wenyou Yang wrote: > >>From SAMA5D4, the watchdog timer is upgrated with a new feature, > > Where does the additional ">" come from ? I don't know why, but it isn't inclusive in my received mail. > > > which is describled as in the datasheet, "WDT_MR can be written until > > a LOCKMR command is issued in WDT_CR". > > That is to say, as long as the bootstrap and u-boot don't issue a > > LOCKMR command, WDT_MR can be written more than once in the driver. > > > > So the SAMA5D4 watchdog driver's implementation is different from the > > at91sam9260 watchdog driver implemented in file at91sam9_wdt.c. > > The user application open the device file to enable the watchdog timer > > hardware, and close to disable it, and set the watchdog timer timeout > > by seting WDV and WDD fields of WDT_MR register, and ping the watchdog > > by issuing WDRSTT command to WDT_CR register with hard-coded key. > > > > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx> > > --- > > drivers/watchdog/Kconfig | 9 ++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/at91sam9_wdt.h | 2 + > > drivers/watchdog/sama5d4_wdt.c | 280 > +++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 292 insertions(+) > > create mode 100644 drivers/watchdog/sama5d4_wdt.c > > > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index > > e5e7c55..47ad39a 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -167,6 +167,15 @@ config AT91SAM9X_WATCHDOG > > Watchdog timer embedded into AT91SAM9X and AT91CAP9 chips. This > will > > reboot your system when the timeout is reached. > > > > +config SAMA5D4_WATCHDOG > > + tristate "Atmel SAMA5D4 Watchdog Timer" > > + depends on ARCH_AT91 > > + select WATCHDOG_CORE > > + help > > + Atmel SAMA5D4 watchdog timer is embedded into SAMA5D4 chips. > > + Its Watchdog Timer Mode Register can be written more than once. > > + This will reboot your system when the timeout is reached. > > + > > config CADENCE_WATCHDOG > > tristate "Cadence Watchdog Timer" > > select WATCHDOG_CORE > > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > > index 5c19294..f24b820 100644 > > --- a/drivers/watchdog/Makefile > > +++ b/drivers/watchdog/Makefile > > @@ -41,6 +41,7 @@ obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o > > obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o > > obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o > > obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o > > +obj-$(CONFIG_SAMA5D4_WATCHDOG) += sama5d4_wdt.o > > obj-$(CONFIG_DW_WATCHDOG) += dw_wdt.o > > obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o > > obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o diff --git > > a/drivers/watchdog/at91sam9_wdt.h b/drivers/watchdog/at91sam9_wdt.h > > index c6fbb2e6..b79a83b 100644 > > --- a/drivers/watchdog/at91sam9_wdt.h > > +++ b/drivers/watchdog/at91sam9_wdt.h > > @@ -22,11 +22,13 @@ > > > > #define AT91_WDT_MR 0x04 /* Watchdog > Mode Register */ > > #define AT91_WDT_WDV (0xfff << 0) /* > Counter Value */ > > +#define AT91_WDT_SET_WDV(x) ((x) & > AT91_WDT_WDV) > > #define AT91_WDT_WDFIEN (1 << 12) /* > Fault Interrupt Enable */ > > #define AT91_WDT_WDRSTEN (1 << 13) /* > Reset Processor */ > > #define AT91_WDT_WDRPROC (1 << 14) /* > Timer Restart */ > > #define AT91_WDT_WDDIS (1 << 15) /* > Watchdog Disable */ > > #define AT91_WDT_WDD (0xfff << 16) /* > Delta Value */ > > +#define AT91_WDT_SET_WDD(x) (((x) << 16) & > AT91_WDT_WDD) > > #define AT91_WDT_WDDBGHLT (1 << 28) /* > Debug Halt */ > > #define AT91_WDT_WDIDLEHLT (1 << 29) /* > Idle Halt */ > > > > diff --git a/drivers/watchdog/sama5d4_wdt.c > > b/drivers/watchdog/sama5d4_wdt.c new file mode 100644 index > > 0000000..a412215 > > --- /dev/null > > +++ b/drivers/watchdog/sama5d4_wdt.c > > @@ -0,0 +1,280 @@ > > +/* > > + * Driver for Atmel SAMA5D4 Watchdog Timer > > + * > > + * Copyright (C) 2015 Atmel Corporation > > + * > > + * Licensed under GPLv2. > > + */ > > + > > +#include <linux/interrupt.h> > > +#include <linux/io.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/of_irq.h> > > +#include <linux/platform_device.h> > > +#include <linux/reboot.h> > > +#include <linux/watchdog.h> > > + > > +#include "at91sam9_wdt.h" > > + > > +/* minimum and maximum watchdog timeout, in seconds */ > > +#define MIN_WDT_TIMEOUT 1 > > +#define MAX_WDT_TIMEOUT 16 > > +#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT > > + > > +#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0) > > + > > +struct sama5d4_wdt { > > + struct watchdog_device wdd; > > + void __iomem *reg_base; > > + u32 config; > > +}; > > + > > +static int wdt_timeout = WDT_DEFAULT_TIMEOUT; static bool nowayout = > > +WATCHDOG_NOWAYOUT; > > + > > +module_param(wdt_timeout, int, 0); > > +MODULE_PARM_DESC(wdt_timeout, > > + "Watchdog timeout in seconds. (default = " > > + __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); > > + > > +module_param(nowayout, bool, 0); > > +MODULE_PARM_DESC(nowayout, > > + "Watchdog cannot be stopped once started (default=" > > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > > + > > +#define wdt_read(wdt, field) \ > > + readl_relaxed((wdt)->reg_base + (field)) > > + > > +#define wdt_write(wtd, field, val) \ > > + writel_relaxed((val), (wdt)->reg_base + (field)) > > + > > +static int sama5d4_wdt_start(struct watchdog_device *wdd) { > > + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); > > + u32 reg; > > + > > + reg = wdt_read(wdt, AT91_WDT_MR); > > + reg &= ~AT91_WDT_WDDIS; > > + wdt_write(wdt, AT91_WDT_MR, reg); > > + > > + return 0; > > +} > > + > > +static int sama5d4_wdt_stop(struct watchdog_device *wdd) { > > + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); > > + u32 reg; > > + > > + reg = wdt_read(wdt, AT91_WDT_MR); > > + reg |= AT91_WDT_WDDIS; > > + wdt_write(wdt, AT91_WDT_MR, reg); > > + > > + return 0; > > +} > > + > > +static int sama5d4_wdt_ping(struct watchdog_device *wdd) { > > + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); > > + > > + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | > AT91_WDT_WDRSTT); > > + > > + return 0; > > +} > > + > > +static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd, > > + unsigned int timeout) > > +{ > > + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); > > + u32 value = WDT_SEC2TICKS(timeout); > > + u32 reg; > > + > > + reg = wdt_read(wdt, AT91_WDT_MR); > > + reg &= ~AT91_WDT_WDV; > > + reg &= ~AT91_WDT_WDD; > > + reg |= AT91_WDT_SET_WDV(value); > > + reg |= AT91_WDT_SET_WDD(value); > > + wdt_write(wdt, AT91_WDT_MR, reg); > > + > > + wdd->timeout = timeout; > > + > > + return 0; > > +} > > + > > +static const struct watchdog_info sama5d4_wdt_info = { > > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | > WDIOF_KEEPALIVEPING, > > + .identity = "Atmel SAMA5D4 Watchdog" > > +}; > > + > > +static struct watchdog_ops sama5d4_wdt_ops = { > > + .owner = THIS_MODULE, > > + .start = sama5d4_wdt_start, > > + .stop = sama5d4_wdt_stop, > > + .ping = sama5d4_wdt_ping, > > + .set_timeout = sama5d4_wdt_set_timeout > > You made another silent change in v4: You dropped the comma here, and above > after .identity. Now, while it makes sense to have no comma after "{ }", it does > make sense to have the comma here, because it avoids unnecessary conflicts > and build errors later on if a member is added at the end of the list. Please add > those commas back in. I will add those commas back in. > > Also, please stop making silent changes like this. You are making it really hard to > review your code - now I'll have to go through it line by line again and compare it > with your earlier patches to see if you made any other unannounced changes. Sorry for silent changes. I will double check it more careful before submitting the patch. > > Thanks, > Guenter Best Regards, Wenyou Yang ?韬{.n?????%??檩??w?{.n????z谵{???塄}?财??j:+v?? ? ???2??璀??摺?囤??z夸z罐?+?????w棹f
