From fa32154e47a203688453e53c1369fcbc63b06a21 Mon Sep 17 00:00:00 2001 From: Eric Millbrandt Date: Fri, 3 Sep 2010 13:27:38 -0400 Subject: powerpc/5200: tighten up ac97 reset timing 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 Signed-off-by: Grant Likely --- arch/powerpc/platforms/52xx/mpc52xx_common.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c index 6e905314ad5d..41f3a7eda1de 100644 --- a/arch/powerpc/platforms/52xx/mpc52xx_common.c +++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c @@ -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); -- cgit v1.2.1