From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 04/15] ARM: smp_twd: add device tree support
Date: Thu, 12 Jan 2012 09:42:49 -0600 [thread overview]
Message-ID: <4F0EFF79.8060606@gmail.com> (raw)
In-Reply-To: <4F0EEFEA.1020305@arm.com>
On 01/12/2012 08:36 AM, Marc Zyngier wrote:
> Hi Rob,
>
> On 11/01/12 21:05, Rob Herring wrote:
>> On 01/11/2012 07:08 AM, Marc Zyngier wrote:
>>> Add bindings to support DT discovery of the ARM Timer Watchdog
>>> (aka TWD). Only the timer side is converted by this patch.
>>>
>>> Cc: Rob Herring <rob.herring@calxeda.com>
>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>> ---
>>> Documentation/devicetree/bindings/arm/twd.txt | 29 +++++++++++
>>> arch/arm/include/asm/smp_twd.h | 1 +
>>> arch/arm/kernel/smp_twd.c | 68 ++++++++++++++++++++-----
>>> 3 files changed, 85 insertions(+), 13 deletions(-)
>>> create mode 100644 Documentation/devicetree/bindings/arm/twd.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/arm/twd.txt b/Documentation/devicetree/bindings/arm/twd.txt
>>> new file mode 100644
>>> index 0000000..a9d5587
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/arm/twd.txt
>>> @@ -0,0 +1,29 @@
>>> +* ARM Timer Watchdog
>>> +
>>> +ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
>>> +Timer-Watchdog (aka TWD), which provides both a per-cpu local timer
>>> +and watchdog.
>>> +
>>> +The TWD is usually attached to a GIC to deliver its two per-processor
>>> +interrupts.
>>> +
>>> +Main node required properties:
>>> +
>>> +- compatible : Should be one of:
>>> + "arm,cortex-a9-twd"
>>> + "arm,cortex-a5-twd"
>>> + "arm,arm11mp-twd"
>>> + "arm,smp-twd"
>>> +
>>> +- interrupts : Two interrupts to each core, the first one for the
>>> + timer, the second one for the watchdog.
>>> +
>>> +- reg : Specify the base address and the size of the TWD.
>>> +
>>> +Example:
>>> +
>>> + twd at 2c000600 {
>>> + compatible = "arm,arm11mp-twd", "arm,smp-twd";
>>> + reg = <0x2c000600 0x100>;
>>> + interrupts = <1 13 0xf01 1 14 0xf01>;
>>> + };
>>
>> Why not split the watchdog and timer into 2 nodes? It may not matter
>> since there is no driver for the timer. If there was, we would have a
>> problem as you can't match 2 drivers to 1 node.
>
> Don't we hit the opposite problem - two nodes with the same address?
No, because the timer is at 0x600-0x61f and the watchdog is at
0x620-0x63f. There's no DT requirement on address range start or size.
However, the current watchdog driver includes 0x20 in its register
offsets, so changing the base address would require a change to the
driver (but that shouldn't really influence the decision).
Rob
next prev parent reply other threads:[~2012-01-12 15:42 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 13:08 [PATCH 00/15] Runtime registration for local timers Marc Zyngier
2012-01-11 13:08 ` [PATCH 01/15] ARM: smp_twd: make local_timer_stop a symbol instead of a #define Marc Zyngier
2012-01-11 13:08 ` [PATCH 02/15] ARM: local timers: introduce a new registration interface Marc Zyngier
2012-01-11 13:08 ` [PATCH 03/15] ARM: smp_twd: add runtime registration support Marc Zyngier
2012-01-11 13:08 ` [PATCH 04/15] ARM: smp_twd: add device tree support Marc Zyngier
2012-01-11 21:05 ` Rob Herring
2012-01-12 14:36 ` Marc Zyngier
2012-01-12 15:42 ` Rob Herring [this message]
2012-01-12 16:00 ` Marc Zyngier
2012-01-12 16:27 ` Rob Herring
2012-01-12 17:58 ` Marc Zyngier
2012-01-11 13:08 ` [PATCH 05/15] ARM: OMAP4: convert to twd_local_timer_register() interface Marc Zyngier
2012-01-11 13:14 ` Shilimkar, Santosh
2012-01-11 13:08 ` [PATCH 06/15] ARM: plat-versatile: " Marc Zyngier
2012-01-12 9:14 ` Russell King - ARM Linux
2012-01-12 11:53 ` Marc Zyngier
2012-01-11 13:08 ` [PATCH 07/15] ARM: tegra: " Marc Zyngier
2012-01-11 21:49 ` Stephen Warren
2012-01-11 13:08 ` [PATCH 08/15] ARM: shmobile: " Marc Zyngier
2012-01-12 9:19 ` Russell King - ARM Linux
2012-01-12 11:24 ` Marc Zyngier
2012-01-12 12:00 ` Marc Zyngier
2012-01-11 13:08 ` [PATCH 09/15] ARM: ux500: " Marc Zyngier
2012-01-11 23:53 ` Linus Walleij
2012-01-12 13:59 ` Marc Zyngier
2012-01-14 11:43 ` Linus Walleij
2012-01-12 9:16 ` Russell King - ARM Linux
2012-01-12 10:55 ` Marc Zyngier
2012-01-11 13:08 ` [PATCH 10/15] ARM: highbank: " Marc Zyngier
2012-01-11 13:08 ` [PATCH 11/15] ARM: imx6q: " Marc Zyngier
2012-01-12 9:21 ` Shawn Guo
2012-01-11 13:08 ` [PATCH 12/15] ARM: smp_twd: remove old local timer interface Marc Zyngier
2012-01-11 13:08 ` [PATCH 13/15] ARM: local timers: convert exynos to runtime registration interface Marc Zyngier
2012-01-11 13:08 ` [PATCH 14/15] ARM: local timers: convert MSM " Marc Zyngier
2012-01-13 0:13 ` David Brown
2012-01-13 0:27 ` David Brown
2012-01-13 10:11 ` Marc Zyngier
2012-01-11 13:08 ` [PATCH 15/15] ARM: local timers: make the runtime registration interface mandatory Marc Zyngier
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