ppc4xx: Fix USB 2.0 phy reset sequence

This patch fixes USB 2.0 communication issues on some DU440 boards.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: Stefan Roese <sr@denx.de>

diff --git a/board/esd/du440/du440.c b/board/esd/du440/du440.c
index 7df2adb238e52d42369cd2c93bbcd509926b0776..6dca35d6267ee093ee1146da3d1e55500b1f761d 100644 (file)
--- a/board/esd/du440/du440.c
+++ b/board/esd/du440/du440.c
@@ -169,6 +169,7 @@ int misc_init_r(void)
        unsigned long usb2d0cr = 0;
        unsigned long usb2phy0cr, usb2h0cr = 0;
        unsigned long sdr0_pfc1;
+       unsigned long sdr0_srst0, sdr0_srst1;
        int i, j;
 
        /* adjust flash start and offset */
@@ -223,10 +224,38 @@ int misc_init_r(void)
        mtsdr(SDR0_USB2PHY0CR, usb2phy0cr);
        mtsdr(SDR0_USB2H0CR, usb2h0cr);
 
-       /* clear resets */
-       udelay (1000);
+       /*
+        * Take USB out of reset:
+        * -Initial status = all cores are in reset
+        * -deassert reset to OPB1, P4OPB0, OPB2, PLB42OPB1 OPB2PLB40 cores
+        * -wait 1 ms
+        * -deassert reset to PHY
+        * -wait 1 ms
+        * -deassert  reset to HOST
+        * -wait 4 ms
+        * -deassert all other resets
+        */
+       mfsdr(SDR0_SRST1, sdr0_srst1);
+       sdr0_srst1 &= ~(SDR0_SRST1_OPBA1 |              \
+                       SDR0_SRST1_P4OPB0 |             \
+                       SDR0_SRST1_OPBA2 |              \
+                       SDR0_SRST1_PLB42OPB1 |          \
+                       SDR0_SRST1_OPB2PLB40);
+       mtsdr(SDR0_SRST1, sdr0_srst1);
+       udelay(1000);
+
+       mfsdr(SDR0_SRST1, sdr0_srst1);
+       sdr0_srst1 &= ~SDR0_SRST1_USB20PHY;
+       mtsdr(SDR0_SRST1, sdr0_srst1);
+       udelay(1000);
+
+       mfsdr(SDR0_SRST0, sdr0_srst0);
+       sdr0_srst0 &= ~SDR0_SRST0_USB2H;
+       mtsdr(SDR0_SRST0, sdr0_srst0);
+       udelay(4000);
+
+       /* finally all the other resets */
        mtsdr(SDR0_SRST1, 0x00000000);
-       udelay (1000);
        mtsdr(SDR0_SRST0, 0x00000000);
 
        printf("USB:   Host(int phy)\n");