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.ag...@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.ag...@toradex.com> >> Acked-by: Marcel Ziswiler <marcel.ziswi...@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. > >> + >> +/* >> + * 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). 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/include/asm/arch-mx7/imx-regs.h?h=imx_v2016.03_4.1.15_2.0.0_ga#n1204 -- Stefan _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
