Re: [PATCH V2] watchdog: mpcore: Add DT probing support for ARM mpcore watchdog

From: viresh kumar <viresh.linux@gmail.com>
To: "wim@iguana.be" <wim@iguana.be>, Marc Zyngier <marc.zyngier@arm.com>
Cc: "spear-devel@list.st.com" <spear-devel@list.st.com>,
	"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	Pawel Moll <Pawel.Moll@arm.com>,
	Viresh Kumar <viresh.kumar@st.com>
Subject: Re: [PATCH V2] watchdog: mpcore: Add DT probing support for ARM mpcore watchdog
Date: Mon, 23 Apr 2012 19:51:01 +0530	[thread overview]
Message-ID: <CAOh2x=kQvjP5SYfJsTXkZyNe3UsS-=pXUBKoQ=SsMUNcPGjzuA@mail.gmail.com> (raw)
In-Reply-To: <4F9547E3.4000709@arm.com>

On 4/23/12, Marc Zyngier <marc.zyngier@arm.com> wrote:
> Ah, that explains why it worked. I suppose you do have additional
> patches that fix the IRQ request bit?

Missed this earlier. That patchset is in review currently and have already
fixed that. :)

> Given that no in-tree platform seem to be using this watchdog (at least
> a quick grep didn't reveal anything), I'd be inclined to simply change
> the offset in smp_twd.h and let them break.

Even i can't find any users of it. :)

@Wim: Please apply following patch before this one.
Here we go:

From: Viresh Kumar <viresh.kumar@st.com>
Date: Mon, 23 Apr 2012 19:39:47 +0530
Subject: [PATCH] ARM: SMP_TWD: WDOG: Start registers from 0x00 instead of
 0x20

TWD_WDOG is at offset 0x20 from TWD base address. Current register offsets
contain this extra 0x20 offset, i.e. users were required to pass base address of
TWD instead of WDOG to WDOG driver.

Change this, so that users can pass base address of WDOG to WDOG driver instead
of TWD module. For this, subtract 0x20 from offsets of WDOG registers.

This could break any current users of TWD_WDOG, but i couldn't find any users of
this driver in current Linux tree. So, haven't fixed any platform code. If some
platforms are broken please report to me, so that we can get them fixed in this
patch only.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
 arch/arm/include/asm/smp_twd.h |   17 +++++++++++------
 1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h
index 57857d1..ff3f67e 100644
--- a/arch/arm/include/asm/smp_twd.h
+++ b/arch/arm/include/asm/smp_twd.h
@@ -6,12 +6,17 @@
 #define TWD_TIMER_CONTROL		0x08
 #define TWD_TIMER_INTSTAT		0x0C

-#define TWD_WDOG_LOAD			0x20
-#define TWD_WDOG_COUNTER		0x24
-#define TWD_WDOG_CONTROL		0x28
-#define TWD_WDOG_INTSTAT		0x2C
-#define TWD_WDOG_RESETSTAT		0x30
-#define TWD_WDOG_DISABLE		0x34
+/*
+ * TWD_WDOG is at offset 0x20 from TWD base address. Following register offsets
+ * doesn't contain this extra 0x20 offset, i.e. users of TWD_WDOG
must pass base
+ * address of WDOG to WDOG driver instead of TWD module.
+ */
+#define TWD_WDOG_LOAD			0x00
+#define TWD_WDOG_COUNTER		0x04
+#define TWD_WDOG_CONTROL		0x08
+#define TWD_WDOG_INTSTAT		0x0C
+#define TWD_WDOG_RESETSTAT		0x10
+#define TWD_WDOG_DISABLE		0x14

 #define TWD_WDOG_LOAD_MIN		0x00000000
 #define TWD_WDOG_LOAD_MAX		0xFFFFFFFF
