Hi Stefan,
On 09/04/2017 09:50 PM, Stefan Agner wrote:
On 2017-09-04 19:57, Eric Nelson wrote:
On 09/04/2017 06:21 PM, Stefan Agner wrote:
<snip>
+/*
- If ROM fell back to USB recover mode, USBPH0_PWD will be clear to use USB
- If boot from the other mode, USB0_PWD will keep reset value
- */
+#define is_boot_from_usb(void) (!(readl(USB_PHY0_BASE_ADDR) & (1<<20)))
- #endif /* __ASSEMBLER__*/ #endif /* __ASM_ARCH_MX6_IMX_REGS_H__ */
If I'm reading your comment correctly, the RXPWDRX bit will be set (the PHY will be powered down) unless it was enabled by the Boot ROM.
Won't this also be clear if you've run 'usb start' under U-Boot?
Yes, this only works before a USB initialization...
Based on this, I'd recommend changing the macro name to something like "is_udc_active" to reflect it's true meaning.
This should be fine for the use case I have in mind (see patch 2).
Note this idea is borrowed from NXP downstream and seems to work here: http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/arch/arm/includ...
Understood.
Using this detection mechanism in SPL (where there isn't another path for initializing the UDC) makes sense.
Regards,
Eric