[PATCH] ARM/MXS: free the watchdog from acting as a system reset source on demand

[PATCH] ARM/MXS: free the watchdog from acting as a system reset source on demand

[Juergen Beisert]

Currently the watchdog is occupied for system reset. This usage collides with
the dedicated usage of a watchdog. This patch series changes the behaviour of
at least i.MX23/i.MX28 where the chipset supports a simple and powerful
alternative to reset the whole SoC (including the PMIC).

Comments are welcome.

Juergen

The following changes since commit 2761ef4d4ae401887f0832d1fd496f26cdf11f20:

  Merge branch 'for-next/resource-size' into next (2012-06-20 10:30:40 +0200)

are available in the git repository at:

  git://git.pengutronix.de/git/jbe/barebox.git mxs_next_release_watchdog

for you to fetch changes up to c2acb4d57a6e79f633f69926bac03368dac2f8c5:

  ARM/MXS: remove the now obsolete mxs reset routine (2012-06-20 15:02:54 +0200)

----------------------------------------------------------------
Juergen Beisert (2):
      ARM/MXS: add new way to reset the whole SoC
      ARM/MXS: remove the now obsolete mxs reset routine

 arch/arm/mach-mxs/Makefile    |    6 ++--
 arch/arm/mach-mxs/reset-imx.c |   61 -----------------------------------------
 arch/arm/mach-mxs/soc-imx23.c |   37 +++++++++++++++++++++++++
 arch/arm/mach-mxs/soc-imx28.c |   37 +++++++++++++++++++++++++
 4 files changed, 77 insertions(+), 64 deletions(-)
 delete mode 100644 arch/arm/mach-mxs/reset-imx.c
 create mode 100644 arch/arm/mach-mxs/soc-imx23.c
 create mode 100644 arch/arm/mach-mxs/soc-imx28.c

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[PATCH 1/2] ARM/MXS: add new way to reset the whole SoC

[Juergen Beisert]

Currently the watchdog is occupied for system reset. This usage collides with
the dedicated usage of a watchdog. This patch change the behaviour of at least
i.MX23/i.MX28 where the chipset supports a simple and powerful alternative
to reset the whole SoC (including the PMIC).

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 arch/arm/mach-mxs/soc-imx23.c |   37 +++++++++++++++++++++++++++++++++++++
 arch/arm/mach-mxs/soc-imx28.c |   37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 arch/arm/mach-mxs/soc-imx23.c
 create mode 100644 arch/arm/mach-mxs/soc-imx28.c

diff --git a/arch/arm/mach-mxs/soc-imx23.c b/arch/arm/mach-mxs/soc-imx23.c
new file mode 100644
index 0000000..964b722
--- /dev/null
+++ b/arch/arm/mach-mxs/soc-imx23.c
@@ -0,0 +1,37 @@
+/*
+ * (c) 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.
+ *
+ * Collection of some SoC specific functions
+ */
+
+#include <common.h>
+#include <init.h>
+#include <mach/imx-regs.h>
+#include <io.h>
+
+#define HW_CLKCTRL_RESET 0x120
+# define HW_CLKCTRL_RESET_CHIP (1 << 1)
+
+/* Reset the full i.MX23 SoC via a chipset feature */
+void __noreturn reset_cpu (unsigned long addr)
+{
+	u32 reg;
+
+	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
+	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
+
+	while (1)
+		;
+	/*NOTREACHED*/
+}
+EXPORT_SYMBOL(reset_cpu);
diff --git a/arch/arm/mach-mxs/soc-imx28.c b/arch/arm/mach-mxs/soc-imx28.c
new file mode 100644
index 0000000..c7a34a8
--- /dev/null
+++ b/arch/arm/mach-mxs/soc-imx28.c
@@ -0,0 +1,37 @@
+/*
+ * (c) 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.
+ *
+ * Collection of some SoC specific functions
+ */
+
+#include <common.h>
+#include <init.h>
+#include <mach/imx-regs.h>
+#include <io.h>
+
+#define HW_CLKCTRL_RESET 0x1e0
+# define HW_CLKCTRL_RESET_CHIP (1 << 1)
+
+/* Reset the full i.MX28 SoC via a chipset feature */
+void __noreturn reset_cpu (unsigned long addr)
+{
+	u32 reg;
+
+	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
+	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
+
+	while (1)
+		;
+	/*NOTREACHED*/
+}
+EXPORT_SYMBOL(reset_cpu);
-- 
1.7.10


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Re: [PATCH 1/2] ARM/MXS: add new way to reset the whole SoC

[Uwe Kleine-König]

Hello Jürgen,

On Wed, Jun 20, 2012 at 03:49:12PM +0200, Juergen Beisert wrote:
> Currently the watchdog is occupied for system reset. This usage collides with
> the dedicated usage of a watchdog. This patch change the behaviour of at least
> i.MX23/i.MX28 where the chipset supports a simple and powerful alternative
> to reset the whole SoC (including the PMIC).
> 
> Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
> ---
>  arch/arm/mach-mxs/soc-imx23.c |   37 +++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-mxs/soc-imx28.c |   37 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 74 insertions(+)
>  create mode 100644 arch/arm/mach-mxs/soc-imx23.c
>  create mode 100644 arch/arm/mach-mxs/soc-imx28.c
> 
> diff --git a/arch/arm/mach-mxs/soc-imx23.c b/arch/arm/mach-mxs/soc-imx23.c
> new file mode 100644
> index 0000000..964b722
> --- /dev/null
> +++ b/arch/arm/mach-mxs/soc-imx23.c
> @@ -0,0 +1,37 @@
> +/*
> + * (c) 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.
> + *
> + * Collection of some SoC specific functions
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <mach/imx-regs.h>
> +#include <io.h>
> +
> +#define HW_CLKCTRL_RESET 0x120
> +# define HW_CLKCTRL_RESET_CHIP (1 << 1)
> +
> +/* Reset the full i.MX23 SoC via a chipset feature */
> +void __noreturn reset_cpu (unsigned long addr)
coding style ---------------^, no space here.

> +{
> +	u32 reg;
> +
> +	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
> +	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
> +
> +	while (1)
> +		;
> +	/*NOTREACHED*/
> +}
> +EXPORT_SYMBOL(reset_cpu);
> diff --git a/arch/arm/mach-mxs/soc-imx28.c b/arch/arm/mach-mxs/soc-imx28.c
> new file mode 100644
> index 0000000..c7a34a8
> --- /dev/null
> +++ b/arch/arm/mach-mxs/soc-imx28.c
> @@ -0,0 +1,37 @@
> +/*
> + * (c) 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.
> + *
> + * Collection of some SoC specific functions
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <mach/imx-regs.h>
> +#include <io.h>
> +
> +#define HW_CLKCTRL_RESET 0x1e0
> +# define HW_CLKCTRL_RESET_CHIP (1 << 1)
> +
> +/* Reset the full i.MX28 SoC via a chipset feature */
> +void __noreturn reset_cpu (unsigned long addr)
> +{
> +	u32 reg;
> +
> +	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
> +	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
> +
> +	while (1)
> +		;
> +	/*NOTREACHED*/
> +}
> +EXPORT_SYMBOL(reset_cpu);
Is it worth to introduce a common function 

	void __noreturn sensiblename(unsigned long clkctrl_reset_offset, unsigned long unused)
	{
		...
	}

and make the reset_cpu functions for imx23 and imx28 just call
sensiblename()?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [PATCH 1/2] ARM/MXS: add new way to reset the whole SoC

[Juergen Beisert]

Hi Uwe,

Uwe Kleine-König wrote:
> On Wed, Jun 20, 2012 at 03:49:12PM +0200, Juergen Beisert wrote:
> > Currently the watchdog is occupied for system reset. This usage collides
> > with the dedicated usage of a watchdog. This patch change the behaviour
> > of at least i.MX23/i.MX28 where the chipset supports a simple and
> > powerful alternative to reset the whole SoC (including the PMIC).
> >
> > Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
> > ---
> >  arch/arm/mach-mxs/soc-imx23.c |   37
> > +++++++++++++++++++++++++++++++++++++ arch/arm/mach-mxs/soc-imx28.c |  
> > 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 74
> > insertions(+)
> >  create mode 100644 arch/arm/mach-mxs/soc-imx23.c
> >  create mode 100644 arch/arm/mach-mxs/soc-imx28.c
> >
> > diff --git a/arch/arm/mach-mxs/soc-imx23.c
> > b/arch/arm/mach-mxs/soc-imx23.c new file mode 100644
> > index 0000000..964b722
> > --- /dev/null
> > +++ b/arch/arm/mach-mxs/soc-imx23.c
> > @@ -0,0 +1,37 @@
> > +/*
> > + * (c) 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.
> > + *
> > + * Collection of some SoC specific functions
> > + */
> > +
> > +#include <common.h>
> > +#include <init.h>
> > +#include <mach/imx-regs.h>
> > +#include <io.h>
> > +
> > +#define HW_CLKCTRL_RESET 0x120
> > +# define HW_CLKCTRL_RESET_CHIP (1 << 1)
> > +
> > +/* Reset the full i.MX23 SoC via a chipset feature */
> > +void __noreturn reset_cpu (unsigned long addr)
>
> coding style ---------------^, no space here.

Okay.

> > +{
> > +	u32 reg;
> > +
> > +	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
> > +	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
> > +
> > +	while (1)
> > +		;
> > +	/*NOTREACHED*/
> > +}
> > +EXPORT_SYMBOL(reset_cpu);
> > diff --git a/arch/arm/mach-mxs/soc-imx28.c
> > b/arch/arm/mach-mxs/soc-imx28.c new file mode 100644
> > index 0000000..c7a34a8
> > --- /dev/null
> > +++ b/arch/arm/mach-mxs/soc-imx28.c
> > @@ -0,0 +1,37 @@
> > +/*
> > + * (c) 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.
> > + *
> > + * Collection of some SoC specific functions
> > + */
> > +
> > +#include <common.h>
> > +#include <init.h>
> > +#include <mach/imx-regs.h>
> > +#include <io.h>
> > +
> > +#define HW_CLKCTRL_RESET 0x1e0
> > +# define HW_CLKCTRL_RESET_CHIP (1 << 1)
> > +
> > +/* Reset the full i.MX28 SoC via a chipset feature */
> > +void __noreturn reset_cpu (unsigned long addr)
> > +{
> > +	u32 reg;
> > +
> > +	reg = readl(IMX_CCM_BASE + HW_CLKCTRL_RESET);
> > +	writel(reg | HW_CLKCTRL_RESET_CHIP, IMX_CCM_BASE + HW_CLKCTRL_RESET);
> > +
> > +	while (1)
> > +		;
> > +	/*NOTREACHED*/
> > +}
> > +EXPORT_SYMBOL(reset_cpu);
>
> Is it worth to introduce a common function
>
> 	void __noreturn sensiblename(unsigned long clkctrl_reset_offset, unsigned
> long unused) {
> 		...
> 	}
>
> and make the reset_cpu functions for imx23 and imx28 just call
> sensiblename()?

Refer "http://www.spinics.net/lists/u-boot-v2/msg07681.html"

jbe

-- 
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Re: [PATCH 1/2] ARM/MXS: add new way to reset the whole SoC

[Uwe Kleine-König]

Hello Jürgen,

On Wed, Jun 20, 2012 at 09:04:09PM +0200, Juergen Beisert wrote:
> > Is it worth to introduce a common function
> >
> > 	void __noreturn sensiblename(unsigned long clkctrl_reset_offset, unsigned
> > long unused) {
> > 		...
> > 	}
> >
> > and make the reset_cpu functions for imx23 and imx28 just call
> > sensiblename()?
> 
> Refer "http://www.spinics.net/lists/u-boot-v2/msg07681.html"
I don't see how this answers my question. To combine both answers, put
sensiblename into arch/arm/mach-mxs/common.c and the imx23 and the imx28
specific call to sensiblename into imx23.c and imx28.c respectively.

Uwe

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Re: [PATCH 1/2] ARM/MXS: add new way to reset the whole SoC

[Juergen Beisert]

Hi Uwe,

Uwe Kleine-König wrote:
> On Wed, Jun 20, 2012 at 09:04:09PM +0200, Juergen Beisert wrote:
> > > Is it worth to introduce a common function
> > >
> > > 	void __noreturn sensiblename(unsigned long clkctrl_reset_offset,
> > > unsigned long unused) {
> > > 		...
> > > 	}
> > >
> > > and make the reset_cpu functions for imx23 and imx28 just call
> > > sensiblename()?
> >
> > Refer "http://www.spinics.net/lists/u-boot-v2/msg07681.html"
>
> I don't see how this answers my question. To combine both answers, put
> sensiblename into arch/arm/mach-mxs/common.c and the imx23 and the imx28
> specific call to sensiblename into imx23.c and imx28.c respectively.

What would be the advantage? You add one more indirection but almost the same 
amount of code.

jbe

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[PATCH 2/2] ARM/MXS: remove the now obsolete mxs reset routine

[Juergen Beisert]

Remove the old reset routine from the buildsystem and build the new one
instead according to the selected architecture

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 arch/arm/mach-mxs/Makefile    |    6 ++--
 arch/arm/mach-mxs/reset-imx.c |   61 -----------------------------------------
 2 files changed, 3 insertions(+), 64 deletions(-)
 delete mode 100644 arch/arm/mach-mxs/reset-imx.c

diff --git a/arch/arm/mach-mxs/Makefile b/arch/arm/mach-mxs/Makefile
index 9255d15..73ce1c8 100644
--- a/arch/arm/mach-mxs/Makefile
+++ b/arch/arm/mach-mxs/Makefile
@@ -1,6 +1,6 @@
-obj-y += imx.o iomux-imx.o reset-imx.o common.o power.o
+obj-y += imx.o iomux-imx.o common.o power.o
 obj-$(CONFIG_DRIVER_VIDEO_STM) += imx_lcd_clk.o
-obj-$(CONFIG_ARCH_IMX23) += speed-imx23.o clocksource-imx23.o usb.o
-obj-$(CONFIG_ARCH_IMX28) += speed-imx28.o clocksource-imx28.o
+obj-$(CONFIG_ARCH_IMX23) += speed-imx23.o clocksource-imx23.o usb.o  soc-imx23.o
+obj-$(CONFIG_ARCH_IMX28) += speed-imx28.o clocksource-imx28.o soc-imx28.o
 obj-$(CONFIG_MXS_OCOTP) += ocotp.o
 obj-$(CONFIG_MXS_CMD_BCB) += bcb.o
diff --git a/arch/arm/mach-mxs/reset-imx.c b/arch/arm/mach-mxs/reset-imx.c
deleted file mode 100644
index cfb3548..0000000
--- a/arch/arm/mach-mxs/reset-imx.c
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * (C) Copyright 2010 Juergen Beisert - Pengutronix
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- */
-
-#include <common.h>
-#include <init.h>
-#include <notifier.h>
-#include <mach/imx-regs.h>
-#include <io.h>
-
-#define HW_RTC_CTRL     0x000
-# define BM_RTC_CTRL_WATCHDOGEN (1 << 4)
-#define HW_RTC_CTRL_SET 0x004
-#define HW_RTC_CTRL_CLR 0x008
-#define HW_RTC_CTRL_TOG 0x00C
-
-#define HW_RTC_WATCHDOG     0x050
-#define HW_RTC_WATCHDOG_SET 0x054
-#define HW_RTC_WATCHDOG_CLR 0x058
-#define HW_RTC_WATCHDOG_TOG 0x05C
-
-#define WDOG_COUNTER_RATE	1000 /* 1 kHz clock */
-
-#define HW_RTC_PERSISTENT1     0x070
-# define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
-#define HW_RTC_PERSISTENT1_SET 0x074
-#define HW_RTC_PERSISTENT1_CLR 0x078
-#define HW_RTC_PERSISTENT1_TOG 0x07C
-
-/*
- * Reset the cpu by setting up the watchdog timer and let it time out
- *
- * TODO There is a much easier way to reset the CPU: Refer bit 2 in
- *       the HW_CLKCTRL_RESET register, data sheet page 106/4-30
- */
-void __noreturn reset_cpu (unsigned long addr)
-{
-	writel(WDOG_COUNTER_RATE, IMX_WDT_BASE + HW_RTC_WATCHDOG);
-	writel(BM_RTC_CTRL_WATCHDOGEN, IMX_WDT_BASE + HW_RTC_CTRL_SET);
-	writel(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER, IMX_WDT_BASE + HW_RTC_PERSISTENT1);
-
-	while (1)
-		;
-	/*NOTREACHED*/
-}
-EXPORT_SYMBOL(reset_cpu);
-- 
1.7.10


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