Re: [PATCH 2/2] Add two architectures which can detect the reset source

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Jun 21, 2012 at 11:16:18AM +0200, Juergen Beisert wrote:
> These are examples how to provide the reset source. Not really tested on
> the corresponding hardware yet.

I did. On i.MX1 it does not work. The reset source register is not
inside the watchdog module, but at 0x0021b800 (Reset source register,
RSR)

On i.MX27 it correctly detects a watchdog reset but not a power on
reset. On i.MX27 it must be:

#  define WDOG_WRSR_EXT (1 << 3)
#  define WDOG_WRSR_PWR (1 << 4)

i.MX51 does not seem to have a power-on-reset bit, at least not in the
watchdog module. I didn't check the other i.MXs

Sascha

> 
> Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
> ---
>  arch/arm/mach-imx/Makefile           |    1 +
>  arch/arm/mach-imx/reset_source.c     |   59 ++++++++++++++++++++++++++++++++++
>  arch/arm/mach-samsung/Makefile       |    1 +
>  arch/arm/mach-samsung/reset_source.c |   56 ++++++++++++++++++++++++++++++++
>  4 files changed, 117 insertions(+)
>  create mode 100644 arch/arm/mach-imx/reset_source.c
>  create mode 100644 arch/arm/mach-samsung/reset_source.c
> 
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index 03e2421..7da8cec 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -1,4 +1,5 @@
>  obj-y += clocksource.o gpio.o
> +obj-$(CONFIG_GLOBALVAR) += reset_source.o
>  obj-$(CONFIG_ARCH_IMX1)  += speed-imx1.o  imx1.o  iomux-v1.o
>  obj-$(CONFIG_ARCH_IMX25) += speed-imx25.o imx25.o iomux-v3.o
>  obj-$(CONFIG_ARCH_IMX21) += speed-imx21.o imx21.o iomux-v1.o
> diff --git a/arch/arm/mach-imx/reset_source.c b/arch/arm/mach-imx/reset_source.c
> new file mode 100644
> index 0000000..79e5337
> --- /dev/null
> +++ b/arch/arm/mach-imx/reset_source.c
> @@ -0,0 +1,59 @@
> +/*
> + * (C) Copyright 2012 Juergen Beisert - <kernel@pengutronix.de>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <io.h>
> +#include <reset_source.h>
> +#include <mach/imx-regs.h>
> +
> +#ifdef CONFIG_ARCH_IMX1
> +# define WDOG_WRSR 0x08
> +#  define WDOG_WRSR_TOUT (1 << 0)
> +/* let the compiler sort out useless code on this arch */
> +#  define WDOG_WRSR_SFTW 0
> +#  define WDOG_WRSR_EXT 0
> +#  define WDOG_WRSR_PWR 0
> +#else
> +# define WDOG_WRSR 0x04
> +#  define WDOG_WRSR_SFTW (1 << 0)
> +#  define WDOG_WRSR_TOUT (1 << 1)
> +#  define WDOG_WRSR_EXT (1 << 2)
> +#  define WDOG_WRSR_PWR (1 << 3)
> +#endif
> +
> +static int imx_detect_reset_source(void)
> +{
> +	u16 reg = readw(IMX_WDT_BASE + WDOG_WRSR);
> +
> +	if (reg & WDOG_WRSR_PWR) {
> +		set_reset_source(RESET_POR);
> +		return 0;
> +	}
> +
> +	if (reg & (WDOG_WRSR_EXT | WDOG_WRSR_SFTW)) {
> +		set_reset_source(RESET_RST);
> +		return 0;
> +	}
> +
> +	if (reg & WDOG_WRSR_TOUT) {
> +		set_reset_source(RESET_WDG);
> +		return 0;
> +	}
> +
> +	/* else keep the default 'unknown' state */
> +	return 0;
> +}
> +
> +device_initcall(imx_detect_reset_source);
> diff --git a/arch/arm/mach-samsung/Makefile b/arch/arm/mach-samsung/Makefile
> index d7344c8..74799c5 100644
> --- a/arch/arm/mach-samsung/Makefile
> +++ b/arch/arm/mach-samsung/Makefile
> @@ -1,4 +1,5 @@
>  obj-y += s3c-timer.o generic.o
> +obj-$(CONFIG_GLOBALVAR) += reset_source.o
>  obj-lowlevel-$(CONFIG_ARCH_S3C24xx) += lowlevel-s3c24x0.o
>  obj-lowlevel-$(CONFIG_ARCH_S5PCxx) += lowlevel-s5pcxx.o
>  obj-$(CONFIG_ARCH_S3C24xx) += gpio-s3c24x0.o s3c24xx-clocks.o mem-s3c24x0.o
> diff --git a/arch/arm/mach-samsung/reset_source.c b/arch/arm/mach-samsung/reset_source.c
> new file mode 100644
> index 0000000..2456e3f
> --- /dev/null
> +++ b/arch/arm/mach-samsung/reset_source.c
> @@ -0,0 +1,56 @@
> +/*
> + * (C) Copyright 2012 Juergen Beisert - <kernel@pengutronix.de>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <io.h>
> +#include <reset_source.h>
> +#include <mach/s3c-iomap.h>
> +
> +/* S3C2440 relevant */
> +#define S3C2440_GSTATUS2 0xb4
> +# define S3C2440_GSTATUS2_PWRST (1 << 0)
> +# define S3C2440_GSTATUS2_SLEEPRST (1 << 1)
> +# define S3C2440_GSTATUS2_WDRST (1 << 2)
> +
> +static int s3c_detect_reset_source(void)
> +{
> +	u32 reg = readl(S3C_GPIO_BASE + S3C2440_GSTATUS2);
> +
> +	if (reg & S3C2440_GSTATUS2_PWRST) {
> +		set_reset_source(RESET_POR);
> +		writel(S3C2440_GSTATUS2_PWRST,
> +					S3C_GPIO_BASE + S3C2440_GSTATUS2);
> +		return 0;
> +	}
> +
> +	if (reg & S3C2440_GSTATUS2_SLEEPRST) {
> +		set_reset_source(RESET_WKE);
> +		writel(S3C2440_GSTATUS2_SLEEPRST,
> +					S3C_GPIO_BASE + S3C2440_GSTATUS2);
> +		return 0;
> +	}
> +
> +	if (reg & S3C2440_GSTATUS2_WDRST) {
> +		set_reset_source(RESET_WDG);
> +		writel(S3C2440_GSTATUS2_WDRST,
> +					S3C_GPIO_BASE + S3C2440_GSTATUS2);
> +		return 0;
> +	}
> +
> +	/* else keep the default 'unknown' state */
> +	return 0;
> +}
> +
> +device_initcall(s3c_detect_reset_source);
> -- 
> 1.7.10
> 
> 
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