From: Martin Kaiser martin@kaiser.cx
The USBOH module on imx25 chips contains two USB controllers which are called USB OTG Controller and USB Host Controller. Each one has its EHCI root hub. The OTG Controller's EHCI registers start at offset 0, the Host Controller's registers start at offset 0x400.
We set CONFIG_MXC_USB_PORT=0 to select the OTG Controller and 1 for the Host Controller. Therefore, IMX_USB_PORT_OFFSET must be 0x400. Using this setting, the Host Controller starts working on my imx25 board.
Please note that the imx25 reference manual claims that the Host Controller's registers start at 0x200. This is not correct. The Linux Kernel uses the correct offset 0x400 in imx25.dtsi.
Signed-off-by: Martin Kaiser martin@kaiser.cx Reviewed-by: Fabio Estevam fabio.estevam@nxp.com --- Changes in v3: - reformat the multi-line comment
Changes in v2: - add a comment about the incorrect info in the reference manual
arch/arm/include/asm/arch-mx25/imx-regs.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/arch-mx25/imx-regs.h b/arch/arm/include/asm/arch-mx25/imx-regs.h index 1b00ed7..d64ca82 100644 --- a/arch/arm/include/asm/arch-mx25/imx-regs.h +++ b/arch/arm/include/asm/arch-mx25/imx-regs.h @@ -360,7 +360,12 @@ struct cspi_regs { #define IMX_IIM_BASE (0x53FF0000) #define IIM_BASE_ADDR IMX_IIM_BASE #define IMX_USB_BASE (0x53FF4000) -#define IMX_USB_PORT_OFFSET 0x200 +/* + * This is in contradiction to the imx25 reference manual, which says that + * port 1's registers start at 0x53FF4200. The correct base address for + * port 1 is 0x53FF4400. The kernel uses 0x53FF4400 as well. + */ +#define IMX_USB_PORT_OFFSET 0x400 #define IMX_CSI_BASE (0x53FF8000) #define IMX_DRYICE_BASE (0x53FFC000)