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i.MX25 GPT clock fix: ensure correct the clock source

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From: T. Mehnert <t.mehnert@eckelmann.de>
Date: Mon, 4 Jul 2011 15:53:30 +0200
Subject: [PATCH] i.MX25 GPT clock fix: ensure correct the clock source

This patch ensures, that Linux will take the correct clock source (AHB_DIV)
for gpt in the ARM i.MX25 implementation. The currect code depends on the reset
defaults of the CCM_MCR register. So on some boards it could happen that the
UPLL is used for clock source, which results in faulty time behavior in Linux.
In this case all delays or sleeps will will be faktor 1.8 too long.

Signed-off-by: Torsten Mehnert <t.mehnert@eckelmann.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Mehnert, Torsten 2011-08-01 08:02:07 +00:00 committed by Sascha Hauer
parent 1c4b45d8f6
commit 2012d9ca2a
1 changed files with 3 additions and 0 deletions
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3
arch/arm/mach-imx/clock-imx25.c
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@ -328,6 +328,9 @@ int __init mx25_clocks_init(void)
__raw_writel(__raw_readl(CRM_BASE+0x64) | (1 << 7) | (1 << 0),
CRM_BASE + 0x64);
/* Clock source for gpt is ahb_div */
__raw_writel(__raw_readl(CRM_BASE+0x64) & ~(1 << 5), CRM_BASE + 0x64);
mxc_timer_init(&gpt_clk, MX25_IO_ADDRESS(MX25_GPT1_BASE_ADDR), 54);
return 0;