TI:OMAP: [PATCH 7/7] Add 720Mhz support for Beagle Rev C4

GoogleGroups
1

From c0bdd7fbdf343ada1ecc65541ec3de1a5fdbfe79 Mon Sep 17 00:00:00 2001

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Dear Khasim,
can you please make the patches available for download somewhere (e.g.
some archive)?
I could not manage to copy them correctly from Google Groups.

Thank you very much,
Nikolaus

3

Hello all,

I’ve tested your patches with an IGEP v2 at 720MHz and an IGEP v2 at 600MHz and looks great.

I see in your beagleboard file you check for C4 revision and then set up CPU to 720MHz. Is ok, but I think should be better create a more generic function and read the PROD_ID register. If you see at

spruf98d.pdf (page 171)
1.5.2.1 720MHz Device Identification
Read device ID to be able to identify if this device is 720MHz capable or not. There is SKU ID that is blown in efuse and that it readable from following the memory location.
Register 0x4830A20C [ProdID.SKUID] [0:3]:
• 0x0 for normal 600/430MHz device.
• 0x8 for 720/520MHz device.

— snip —
#define PRODUCT_ID_SKUID 0x4830A20C
#define CPU_35XX_PID_MASK 0x0000000F
#define CPU_35XX_600MHZ_DEV 0x0
#define CPU_35XX_720MHZ_DEV 0x8
static u32 get_prod_id(void)
{
u32 p;
/* get production ID */
p = __raw_readl(PRODUCT_ID_SKUID);
return (p & CPU_35XX_PID_MASK);
}
— snip —

Best regards,
Enric

2010/1/20 hns@computer.org <hns@computer.org>

4

Hello all,

I've tested your patches with an IGEP v2 at 720MHz and an IGEP v2 at 600MHz
and looks great.

I see in your beagleboard file you check for C4 revision and then set up CPU
to 720MHz. Is ok, but I think should be better create a more generic
function and read the PROD_ID register. If you see at

spruf98d.pdf (page 171)
1.5.2.1 720MHz Device Identification
Read device ID to be able to identify if this device is 720MHz capable
or not. There is SKU ID that is blown in efuse and that it readable from
following the memory location.
Register 0x4830A20C [ProdID.SKUID] [0:3]:
• 0x0 for normal 600/430MHz device.
• 0x8 for 720/520MHz device.

Thanks for the pointers, lets work on these after the current patch
set acceptance.

Regards,
Khasim

5

Khasim Syed Mohammed wrote:

From c0bdd7fbdf343ada1ecc65541ec3de1a5fdbfe79 Mon Sep 17 00:00:00 2001
From: Syed Mohammed Khasim <khasim@ti.com>
Date: Mon, 18 Jan 2010 18:51:04 +0530
Subject: [PATCH] Add 720Mhz support for Beagle Rev C4

Use the Generic TWL and Clock APIs to get beagle
Rev C4 running at 720Mhz

Why is it necessary to run mpu at 720 ?
If this is to support display, this patch should be before display

Make it clear in your commit which omap clk is changing and why.

Tom

6

Khasim Syed Mohammed wrote:

From c0bdd7fbdf343ada1ecc65541ec3de1a5fdbfe79 Mon Sep 17 00:00:00 2001
From: Syed Mohammed Khasim<khasim@ti.com>
Date: Mon, 18 Jan 2010 18:51:04 +0530
Subject: [PATCH] Add 720Mhz support for Beagle Rev C4

Use the Generic TWL and Clock APIs to get beagle
Rev C4 running at 720Mhz

Why is it necessary to run mpu at 720 ?
If this is to support display, this patch should be before display

New BeagleBoard Rev C4 uses a new OMAP3 revision which is able to run with higher frequency. Switching to 720MHz (from 500MHz) base clock is to use this general performance improvement. It's independent of display support.

Best regards

Dirk

7

I too want to see the Revision C4 implemented at the fastest possible speed. There will be folks with applications that need to wring all the processor speed they can get.

Thanks

Bob

8

And those people can set 'mpurate=720' in bootargs to make the kernel switch to 720MHz, you don't need uboot for that[1]

regards,

Koen

[1] only to set said bootargs