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 <emillbrandt@dekaresearch.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c
index 6e905314ad5..41f3a7eda1d 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);