Hi Stefan, Eric,
On 05/09/2017 06:50, Stefan Agner wrote:
On 2017-09-04 19:57, Eric Nelson wrote:
Hi Stefan,
On 09/04/2017 06:21 PM, Stefan Agner wrote:
From: Stefan Agner stefan.agner@toradex.com
This macro allows to detect whether the boot ROM initialized USB already (serial downloader). This is helpful to reliably detect if the system has been recovered via USB serial downloader.
Signed-off-by: Stefan Agner stefan.agner@toradex.com Acked-by: Marcel Ziswiler marcel.ziswiler@toradex.com
Hi Stefano,
I noted already in my initial post that detection of serial downloader mode is somewhat brittle: https://lists.denx.de/pipermail/u-boot/2017-August/301952.html
This came up quite fast now also for other boards: https://www.mail-archive.com/u-boot@lists.denx.de/msg262234.html
We use this patches since quite some time. Also NXP uses this detection method to start their mfgr tools... Altough a hack, maybe we should still add it upstream?
-- Stefan
arch/arm/include/asm/arch-mx6/imx-regs.h | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h index 86e267087a..895ef4de83 100644 --- a/arch/arm/include/asm/arch-mx6/imx-regs.h +++ b/arch/arm/include/asm/arch-mx6/imx-regs.h @@ -985,5 +985,12 @@ struct pwm_regs { u32 pr; u32 cnr; };
It seems as if you've already named a constant, so you might as well #define and use it (USBPH0_PWD or USB0_PWD).
Agreed.
The reference manual seems to call it RXPWDRX though.
I guess taking the latest naming from the manual make sense. Will update in v2.
Before I send out v2, I'd like to know from Stefano whether he agrees with the general direction of the patch.
Green light from my side :-)
+/*
- 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...
This should be fine for the use case I have in mind (see patch 2).
Agree. We want to detect just in SPL which was the (last) bootdevice and rather we cannot detect them from SCR/GPR that just reflect the configured booting device and not a fallback.
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...
Regards, Stefano