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powerpc/5200: tighten up ac97 reset timing

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Tighten up time timing around the gpio reset functionality.  Add a 200ns
delay before remuxing the pins back to ac97 to comply with the ac97 spec.

Signed-off-by: Eric Millbrandt <emillbrandt@dekaresearch.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Eric Millbrandt 2010-09-03 13:27:38 -04:00 committed by Grant Likely
parent 915b96191f
commit fa32154e47
1 changed files with 6 additions and 2 deletions
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8
arch/powerpc/platforms/52xx/mpc52xx_common.c
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@ -325,12 +325,16 @@ int mpc5200_psc_ac97_gpio_reset(int psc_number)
clrbits32(&simple_gpio->simple_dvo, sync | out);
clrbits8(&wkup_gpio->wkup_dvo, reset);
/* wait at lease 1 us */
udelay(2);
/* wait for 1 us */
udelay(1);
/* Deassert reset */
setbits8(&wkup_gpio->wkup_dvo, reset);
/* wait at least 200ns */
/* 7 ~= (200ns * timebase) / ns2sec */
__delay(7);
/* Restore pin-muxing */
out_be32(&simple_gpio->port_config, mux);