From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv3 5/9] ARM: OMAP2+: AM33XX: Add assembly code for PM operations
Date: Thu, 8 Aug 2013 11:22:34 -0400 [thread overview]
Message-ID: <5203B7BA.9020206@ti.com> (raw)
In-Reply-To: <CA+Bv8XY9kziMftrEAnJkenzg6yS+DUYeVy+NQaPTKygJDWNnWw@mail.gmail.com>
On Thursday 08 August 2013 11:16 AM, Russ Dill wrote:
> On Thu, Aug 8, 2013 at 7:50 AM, Santosh Shilimkar
> <santosh.shilimkar@ti•com> wrote:
>> On Tuesday 06 August 2013 01:49 PM, Dave Gerlach wrote:
>>> From: Vaibhav Bedia <vaibhav.bedia@ti•com>
>>>
>>> In preparation for suspend-resume support for AM33XX, add
>>> the assembly file with the code which is copied to internal
>>> memory (OCMC RAM) during bootup and runs from there.
>>>
>>> As part of the low power entry (DeepSleep0 mode in AM33XX TRM),
>>> the code running from OCMC RAM does the following
>>> 1. Stores the EMIF configuration
>>> 2. Puts external memory in self-refresh
>>> 3. Disables EMIF clock
>>> 4. Executes WFI after writing to MPU_CLKCTRL register.
>>>
>>> If no interrupts have come, WFI execution on MPU gets registered
>>> as an interrupt with the WKUP-M3. WKUP-M3 takes care of disabling
>>> some clocks which MPU should not (L3, L4, OCMC RAM etc) and takes
>>> care of clockdomain and powerdomain transitions as part of the
>>> DeepSleep0 mode entry.
>>>
>>> In case a late interrupt comes in, WFI ends up as a NOP and MPU
>>> continues execution from internal memory. The 'abort path' code
>>> undoes whatever was done as part of the low power entry and indicates
>>> a suspend failure by passing a non-zero value to the cpu_resume routine.
>>>
>>> The 'resume path' code is similar to the 'abort path' with the key
>>> difference of MMU being enabled in the 'abort path' but being
>>> disabled in the 'resume path' due to MPU getting powered off.
>>>
>>> Signed-off-by: Vaibhav Bedia <vaibhav.bedia@ti•com>
>>> Signed-off-by: Dave Gerlach <d-gerlach@ti•com>
>>> Cc: Santosh Shilimkar <santosh.shilimkar@ti•com>
>>> Cc: Kevin Hilman <khilman@linaro•org>
>>> ---
>>> arch/arm/mach-omap2/sleep33xx.S | 350 +++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 350 insertions(+)
>>> create mode 100644 arch/arm/mach-omap2/sleep33xx.S
>>>
>>> diff --git a/arch/arm/mach-omap2/sleep33xx.S b/arch/arm/mach-omap2/sleep33xx.S
>>> new file mode 100644
>>> index 0000000..834c7d4
>>> --- /dev/null
>>> +++ b/arch/arm/mach-omap2/sleep33xx.S
>>> @@ -0,0 +1,350 @@
>>> +/*
>>> + * Low level suspend code for AM33XX SoCs
>>> + *
>>> + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
>>> + * Vaibhav Bedia <vaibhav.bedia@ti•com>
>>> + *
>>> + * 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 version 2.
>>> + *
>>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>>> + * kind, whether express or implied; without even the implied warranty
>>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/linkage.h>
>>> +#include <linux/ti_emif.h>
>>> +#include <asm/memory.h>
>>> +#include <asm/assembler.h>
>>> +
>>> +#include "cm33xx.h"
>>> +#include "pm33xx.h"
>>> +#include "prm33xx.h"
>>> +
>>> + .text
>>> + .align 3
>>> +
>>> +/*
>>> + * This routine is executed from internal RAM and expects some
>>> + * parameters to be passed in r0 _strictly_ in following order:
>>> + * 1) emif_addr_virt - ioremapped EMIF address
>>> + * 2) mem_type - 2 -> DDR2, 3-> DDR3
>>> + * 3) dram_sync_word - uncached word in SDRAM
>>> + *
>>> + * The code loads these values taking r0 value as reference to
>>> + * the array in registers starting from r0, i.e emif_addr_virt
>>> + * goes to r1, mem_type goes to r2 and and so on. These are
>>> + * then saved into memory locations before proceeding with the
>>> + * sleep sequence and hence registers r0, r1 etc can still be
>>> + * used in the rest of the sleep code.
>>> + */
>>> +
>>> +ENTRY(am33xx_do_wfi)
>>> + stmfd sp!, {r4 - r11, lr} @ save registers on stack
>>> +
>>> + ldm r0, {r1-r3} @ gather values passed
>>> +
>>> + /* Save the values passed */
>>> + str r1, emif_addr_virt
>>> + str r2, mem_type
>>> + str r3, dram_sync_word
>>
>> None of this parameter are going to change for every suspend entry and
>> exit so saving them once and accessing them should be fine. Just
>> create a structure with above, save them in init from C code and
>> then access that structure where you need to.
>
> It isn't possible to do so since the structure would be in SDRAM and
> at resume time, we don't have access to SDRAM. Additionally, I'd like
> to expand the mem_type parameter to a bit field in the future to allow
> this code path to be shared with CPU idle.
>
You can copy the structure in SRAM. So how does memtype need
changes for CPUIDLE ?
I have several comments on this patch so I assume you are
going to address them then.
Regards,
Santosh
next prev parent reply other threads:[~2013-08-08 15:22 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-06 17:49 [PATCHv3 0/9] ARM: OMAP2+: AM33XX: Add suspend-resume support Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 1/9] memory: emif: Move EMIF register defines to include/linux/ Dave Gerlach
2013-08-08 0:48 ` Russ Dill
2013-08-08 13:35 ` Santosh Shilimkar
2013-08-12 19:32 ` Greg Kroah-Hartman
2013-08-12 19:33 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 2/9] ARM: OMAP2+: AM33XX: control: Add some control module registers and APIs Dave Gerlach
2013-08-08 0:52 ` Russ Dill
2013-08-08 13:44 ` Santosh Shilimkar
2013-08-08 16:16 ` Dave Gerlach
2013-08-09 5:11 ` Tony Lindgren
2013-08-09 20:55 ` Dave Gerlach
2013-08-12 7:54 ` Tony Lindgren
2013-08-12 19:17 ` Kevin Hilman
2013-08-12 21:40 ` Dave Gerlach
2013-08-13 14:29 ` Kevin Hilman
2013-08-13 15:08 ` Santosh Shilimkar
2013-08-13 16:19 ` Kevin Hilman
2013-08-13 18:18 ` Santosh Shilimkar
2013-08-13 18:30 ` Russ Dill
2013-08-13 18:40 ` Santosh Shilimkar
2013-08-13 19:11 ` Kevin Hilman
2013-08-14 17:27 ` Suman Anna
2013-08-14 19:16 ` Russ Dill
2013-08-20 23:39 ` Paul Walmsley
2013-08-21 17:32 ` Suman Anna
2013-08-06 17:49 ` [PATCHv3 3/9] ARM: OMAP: DTB: Update IRQ data for WKUP_M3 Dave Gerlach
2013-08-08 0:53 ` Russ Dill
2013-08-08 13:46 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 4/9] ARM: OMAP2+: AM33XX: Reserve memory to comply with EMIF spec Dave Gerlach
2013-08-08 2:30 ` Russ Dill
2013-08-08 14:19 ` Santosh Shilimkar
2013-08-08 18:16 ` Kevin Hilman
2013-08-08 19:31 ` Santosh Shilimkar
2013-08-08 20:05 ` Kevin Hilman
2013-08-08 20:11 ` Santosh Shilimkar
2013-08-09 15:11 ` Kevin Hilman
2013-08-09 16:25 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 5/9] ARM: OMAP2+: AM33XX: Add assembly code for PM operations Dave Gerlach
2013-08-08 7:02 ` Russ Dill
2013-08-08 14:50 ` Santosh Shilimkar
2013-08-08 15:16 ` Russ Dill
2013-08-08 15:22 ` Santosh Shilimkar [this message]
2013-08-08 16:03 ` Russ Dill
2013-08-19 12:54 ` Gururaja Hebbar
2013-08-19 17:51 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 6/9] ARM: OMAP2+: timer: Add suspend-resume callbacks for clkevent device Dave Gerlach
2013-08-08 7:03 ` Russ Dill
2013-08-08 14:23 ` Santosh Shilimkar
2013-08-08 16:09 ` Dave Gerlach
2013-08-08 18:25 ` Kevin Hilman
2013-08-08 19:49 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 7/9] ARM: OMAP: omap_device: Add APIs to enable and idle hwmods Dave Gerlach
2013-08-08 7:05 ` Russ Dill
2013-08-08 14:26 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 8/9] ARM: OMAP2+: AM33XX: Basic suspend resume support Dave Gerlach
2013-08-07 16:22 ` Nishanth Menon
2013-08-07 18:12 ` Dave Gerlach
2013-08-07 19:16 ` Nishanth Menon
2013-08-08 8:45 ` Russ Dill
2013-08-08 12:26 ` Nishanth Menon
2013-08-08 15:03 ` Santosh Shilimkar
2013-08-08 16:06 ` Dave Gerlach
2013-08-08 16:22 ` Nishanth Menon
2013-08-08 21:14 ` Kevin Hilman
2013-08-08 21:32 ` Nishanth Menon
2013-08-08 23:04 ` Kevin Hilman
2013-08-09 15:11 ` Nishanth Menon
2013-08-09 16:12 ` Kevin Hilman
2013-08-09 16:36 ` Nishanth Menon
2013-08-09 20:34 ` Kevin Hilman
2013-08-09 21:35 ` Nishanth Menon
2013-08-09 22:28 ` Russ Dill
2013-08-12 16:09 ` Kevin Hilman
2013-08-30 17:29 ` Vaibhav Bedia
2013-08-20 22:48 ` Paul Walmsley
2013-08-23 14:56 ` Dave Gerlach
2013-08-13 7:43 ` Russ Dill
2013-08-13 14:59 ` Kevin Hilman
2013-08-27 21:45 ` Kevin Hilman
2013-08-29 21:41 ` Dave Gerlach
2013-08-29 22:02 ` Kevin Hilman
2013-08-30 17:39 ` Vaibhav Bedia
2013-08-30 21:18 ` Kevin Hilman
2013-08-06 17:49 ` [PATCHv3 9/9] ARM: OMAP2+: AM33XX: Hookup AM33XX PM code into OMAP builds Dave Gerlach
2013-08-08 8:47 ` Russ Dill
2013-08-08 14:53 ` Santosh Shilimkar
2013-08-08 13:31 ` [PATCHv3 0/9] ARM: OMAP2+: AM33XX: Add suspend-resume support Santosh Shilimkar
2013-08-11 11:53 ` Daniel Mack
2013-08-12 18:59 ` Dave Gerlach
2013-08-13 12:39 ` Daniel Mack
2013-08-13 15:33 ` Dave Gerlach
2013-08-13 15:51 ` Daniel Mack
2013-08-19 9:23 ` Gururaja Hebbar
2013-08-19 17:47 ` Dave Gerlach
2013-08-27 20:23 ` Kevin Hilman
2013-08-29 21:30 ` Dave Gerlach
2013-08-29 21:52 ` Kevin Hilman
2013-08-29 22:20 ` Dave Gerlach
2013-08-29 22:20 ` Kevin Hilman
2013-08-29 22:43 ` Russ Dill
2013-08-29 23:02 ` Kevin Hilman
2013-09-03 17:24 ` Dave Gerlach
2013-09-04 15:01 ` Kevin Hilman
2013-09-04 15:12 ` Russ Dill
2013-09-04 15:18 ` Kevin Hilman
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