[U-Boot] [PATCH v2 1/2] imx: add macro to detect whether USB PHY is active

[Stefan Agner]

From: Stefan Agner <stefan.agner at toradex.com>

This macro allows to detect whether the USB PHY is active. This
is helpful to detect if the boot ROM has previously started the
USB serial downloader.

The idea is taken from the mfgtool support in the NXP U-Boot:
http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/commit/?h=imx_v2016.03_4.1.15_2.0.0_ga&id=a352ed3c5184b95c4c9f7468f5fbb5f43de5e412

Signed-off-by: Stefan Agner <stefan.agner at toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
Tested-by: Fabio Estevam <fabio.estevam at nxp.com>
---

Changes in v2:
- Move macro to sys_proto.h
- Renamed from is_boot_from_usb() to is_usbphy_active()
- Use defines for register offset and field
- Remove tab after define
- Remove comment since the actual "magic" is happening and
  documented at usage side

 arch/arm/include/asm/arch-mx6/sys_proto.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/include/asm/arch-mx6/sys_proto.h b/arch/arm/include/asm/arch-mx6/sys_proto.h
index 14f5d948c9..9d4b1d6768 100644
--- a/arch/arm/include/asm/arch-mx6/sys_proto.h
+++ b/arch/arm/include/asm/arch-mx6/sys_proto.h
@@ -6,3 +6,10 @@
  */
 
 #include <asm/mach-imx/sys_proto.h>
+
+#define USBPHY_PWD		0x00000000
+
+#define USBPHY_PWD_RXPWDRX	(1 << 20) /* receiver block power down */
+
+#define is_usbphy_active(void)	(!(readl(USB_PHY0_BASE_ADDR + USBPHY_PWD) & \
+				   USBPHY_PWD_RXPWDRX))
-- 
2.14.1