[U-Boot] [PATCH v1 1/2] imx: add macro to detect whether USB has been initialized

[Stefan Agner]

On 2017-09-05 04:13, Fabio Estevam wrote:
> Hi Stefan,
> 
> On Mon, Sep 4, 2017 at 10:21 PM, Stefan Agner <stefan at agner.ch> wrote:
>> From: Stefan Agner <stefan.agner at 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 at toradex.com>
>> Acked-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> 
> This allows Serial Download Protocol to work on imx6q sabresd:
> 
> Tested-by: Fabio Estevam <fabio.estevam at nxp.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;
>>  };
>> +
>> +/*
>> + * 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)))
> 
> Minor nit: imx-regs.h is better suited for storing register layout definitions.
> 
> I think that arch/arm/include/asm/mach-imx/sys_proto.h  would be a
> more appropriate location for this macro.

Makes sense, will move it.


> 
> Also you could remove that tab between 'define' and the macro name.

Agreed.

--
Stefan