arm: mach-k3: am6_init: Do USB fixups to facilitate host and device boot modes

U-boot only supports either USB host or device mode for a node at a
time in dts. To support both host and dfu bootmodes, set "peripheral"
as the default dr_mode but fixup property to "host" if host bootmode
is detected.

This needs to happen before the dwc3 generic layer binds the usb device
to a host or device driver. Therefore, add an fdtdec_setup_board()
implementation to fixup the dt based on the boot mode.

Also use the same fixup function to set the USB-PCIe Serdes mux to PCIe
in both the host and device cases. This is required for accessing the
interface at USB 2.0 speeds.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>

diff --git a/arch/arm/mach-k3/am6_init.c b/arch/arm/mach-k3/am6_init.c
index 42d13a3..c6d4f05 100644 (file)
--- a/arch/arm/mach-k3/am6_init.c
+++ b/arch/arm/mach-k3/am6_init.c
@@ -7,6 +7,7 @@
  */
 
 #include <common.h>
+#include <fdt_support.h>
 #include <init.h>
 #include <asm/io.h>
 #include <spl.h>
@@ -22,6 +23,8 @@
 #include <mmc.h>
 #include <stdlib.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #ifdef CONFIG_SPL_BUILD
 #ifdef CONFIG_K3_LOAD_SYSFW
 #ifdef CONFIG_TI_SECURE_DEVICE
@@ -119,7 +122,44 @@ void k3_mmc_restart_clock(void)
 void k3_mmc_stop_clock(void) {}
 void k3_mmc_restart_clock(void) {}
 #endif
+#if CONFIG_IS_ENABLED(DFU) || CONFIG_IS_ENABLED(USB_STORAGE)
+#define CTRLMMR_SERDES0_CTRL   0x00104080
+#define PCIE_LANE0             0x1
+static int fixup_usb_boot(void)
+{
+       int ret;
 
+       switch (spl_boot_device()) {
+       case BOOT_DEVICE_USB:
+               /*
+                * If bootmode is Host bootmode, fixup the dr_mode to host
+                * before the dwc3 bind takes place
+                */
+               ret = fdt_find_and_setprop((void *)gd->fdt_blob,
+                               "/interconnect@100000/dwc3@4000000/usb@10000",
+                               "dr_mode", "host", 11, 0);
+               if (ret)
+                       printf("%s: fdt_find_and_setprop() failed:%d\n", __func__,
+                              ret);
+               fallthrough;
+       case BOOT_DEVICE_DFU:
+               /*
+                * The serdes mux between PCIe and USB3 needs to be set to PCIe for
+                * accessing the interface at USB 2.0
+                */
+               writel(PCIE_LANE0, CTRLMMR_SERDES0_CTRL);
+       default:
+               break;
+       }
+
+       return 0;
+}
+
+int fdtdec_board_setup(const void *fdt_blob)
+{
+       return fixup_usb_boot();
+}
+#endif
 void board_init_f(ulong dummy)
 {
 #if defined(CONFIG_K3_LOAD_SYSFW) || defined(CONFIG_K3_AM654_DDRSS)