USB: ehci-fsl: Fix 'have_sysif_regs' detection

Previously a check was done on an ID register at the base of a CPU's
internal USB registers to determine if system interface regsiters were
present.  The check looked for an ID register that had the format
ID[0:5] == ~ID[8:13] as described in the MPC5121 User's Manual to
determine if a MPC5121 or MPC83xx/85xx was being used.

There are two issues with this method:
- The ID register is not defined on the MPC83xx/85xx CPUs, so its
  unclear what is being checked on them.
- Newer CPUs such as the P4080 also don't document the ID register, but
  do share the same format as the MPC5121.  Thus the previous code did
  not set 'have_sysif_regs' properly which results in the P4080 not
  properly initializing its USB ports.

Using the device tree 'compatible' node is a cleaner way to determine if
'have_sysif_regs' should be set and resolves the USB initialization issue
seen on the P4080.

Tested on a P4080-based system and compile tested on mpc512x_defconfig
with Freescale EHCI driver enabled.

Cc: Anatolij Gustschin <agust@denx.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 13 deletions

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 86e42892016d..5c761df7fa83 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -52,7 +52,6 @@ static int usb_hcd_fsl_probe(const struct hc_driver *driver,
         struct resource *res;
         int irq;
         int retval;
-        unsigned int temp;
 
         pr_debug("initializing FSL-SOC USB Controller\n");
 
@@ -126,18 +125,6 @@ static int usb_hcd_fsl_probe(const struct hc_driver *driver,
                 goto err3;
         }
 
-        /*
-         * Check if it is MPC5121 SoC, otherwise set pdata->have_sysif_regs
-         * flag for 83xx or 8536 system interface registers.
-         */
-        if (pdata->big_endian_mmio)
-                temp = in_be32(hcd->regs + FSL_SOC_USB_ID);
-        else
-                temp = in_le32(hcd->regs + FSL_SOC_USB_ID);
-
-        if ((temp & ID_MSK) != (~((temp & NID_MSK) >> 8) & ID_MSK))
-                pdata->have_sysif_regs = 1;
-
         /* Enable USB controller, 83xx or 8536 */
         if (pdata->have_sysif_regs)
                 setbits32(hcd->regs + FSL_SOC_USB_CTRL, 0x4);