Re: [PATCH V2] watchdog: add MT7621 watchdog support

[John Crispin <blogic@openwrt.org>]

Hi



On 16/10/2014 15:48, Guenter Roeck wrote:
> On 10/16/2014 03:08 AM, John Crispin wrote:
>> This patch adds support for the watchdog core found on newer 
>> mediatek/ralink Wifi SoCs.
>> 
>> Signed-off-by: John Crispin <blogic@openwrt.org> --- Changes 
>> since V1
>> 
>> * fix the comments identifying the driver * add a comment to the 
>> code setting the prescaler * use watchdog_init_timeout * use 
>> devm_reset_control_get * get rid of the miscdev code
>> 
>> .../devicetree/bindings/watchdog/mt7621-wdt.txt    |   12 ++ 
>> drivers/watchdog/Kconfig                           |    7 + 
>> drivers/watchdog/Makefile                          |    1 + 
>> drivers/watchdog/mt7621_wdt.c                      |  186 
>> ++++++++++++++++++++ 4 files changed, 206 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..9ee0d32 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
> 
> There is no SOC_MT7621 symbol, at least not in the current kernel.

the answer has not changed since last time. the patches are sitting in
the linux-mips patchwork.



> 
>> +    help +      Hardware driver for the Mediatek/Ralink SoC 
>> Watchdog Timer. +
> How about mentioning the supported chips (7620 ? 7621 ? 7628 ?)

ok

> 
>> # 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..0cb9e0b --- /dev/null +++ 
>> b/drivers/watchdog/mt7621_wdt.c @@ -0,0 +1,186 @@ +/* + * Ralink 
>> MT7621/MT7628 built-in hardware watchdog timer + *
> MT7628 or MT7620 ?
> 

MT7621 and MT7628 as it says there. the mt7628 is a subtype of mt7620.
it is the same core with slightly different peripherals. this is
covered by the SOC_MT7620. there i a patch for this inside the
linux-mips patchwork.

shall i resend a V3 only with the "How about mentioning the supported
chips (7620 ? 7621 ? 7628 ?)" fixed ?

Thanks,
	John



> Thanks, Guenter
> 
>> + * Copyright (C) 2014 John Crispin <blogic@openwrt.org> + * + * 
>> This driver was based on: drivers/watchdog/rt2880_wdt.c + * + * 
>> 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 <linux/clk.h> +#include <linux/reset.h> +#include 
>> <linux/module.h> +#include <linux/kernel.h> +#include 
>> <linux/watchdog.h> +#include <linux/moduleparam.h> +#include 
>> <linux/platform_device.h> + +#include 
>> <asm/mach-ralink/ralink_regs.h> + +#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) +#define 
>> TMR1CTL_PRESCALE_SHIFT        16 + +static void __iomem 
>> *mt7621_wdt_base; +static struct reset_control *mt7621_wdt_reset;
>> + +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 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; + + /* set the prescaler to
>> 1ms == 1000us */ + rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 <<
>> TMR1CTL_PRESCALE_SHIFT); + +    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; + +    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, +    .max_timeout =
>> 0xfffful / 1000, +}; + +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); + +    mt7621_wdt_reset = 
>> devm_reset_control_get(&pdev->dev, NULL); +    if 
>> (!IS_ERR(mt7621_wdt_reset)) + 
>> reset_control_deassert(mt7621_wdt_reset); + + mt7621_wdt_dev.dev
>> = &pdev->dev; +    mt7621_wdt_dev.bootstatus = 
>> mt7621_wdt_bootcause(); + + 
>> watchdog_init_timeout(&mt7621_wdt_dev, 
>> mt7621_wdt_dev.max_timeout, &pdev->dev); + 
>> watchdog_set_nowayout(&mt7621_wdt_dev, nowayout); + +    ret = 
>> watchdog_register_device(&mt7621_wdt_dev); + +    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 <blogic@openwrt.org"); 
>> +MODULE_LICENSE("GPL v2");
>> 
> 
> 
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