[U-Boot] board/freescale/mx6slevk: Add support for SPI NOR on the Freescale MCIMX6SLEVK Board

[Fabio Estevam]

On Thu, Apr 10, 2014 at 12:20 PM, Fabio Estevam <festevam at gmail.com> wrote:
> On Thu, Apr 10, 2014 at 12:05 PM, Sam Catch <dsblue.spam at gmail.com> wrote:
>> I hope this email is now in the right format.
>>
>> Hi All,
>>
>> I am trying to add support for the SPI NOR device on the  Freescale
>> MCIMX6SLEVK Board.  I have created a patch that should enable support but
>> the u-boot probe command still does not find the device.  The process fails
>> during the ECSPI transfer.
>>
>> I have tried the following patch to the latest git master of u-boot:
>>
>> http://pastebin.com/hamK7Ybb
>>
>> U-Boot Output:
>>
>> => sf probe
>> SF: Unsupported flash IDs: manuf 00, jedec 0000, ext_jedec 0000
>> Failed to initialize SPI flash at 0:27392
>>
>> Does anyone have any insight as to why the Probe may be failing?  I modeled
>> the changes on the mx6sabresd board.
>
> I see the same error here. I measured with a scope and the chip select
> signal behaves very differently compared to the mx6qsabresd board.
>
> When I do 'sf probe' on a mx6qsabresd the chip select line stays low
> for 10us and then stays high.
>
> On mx6slevk the chip select line stays low for 0.5us, then it goes
> high, goes low for 2us and they stays high.
>
> So there is something very wrong with the timings on mx6sl, but I
> haven't had a chance to debug this yet.

I have fixed the problem: just apply this one on top of the previous
patch I sent you:

--- a/arch/arm/include/asm/arch-mx6/mx6sl_pins.h
+++ b/arch/arm/include/asm/arch-mx6/mx6sl_pins.h
@@ -13,7 +13,7 @@ enum {
        MX6_PAD_ECSPI1_MISO__ECSPI_MISO                         =
IOMUX_PAD(0x0358, 0x0068, 0, 0x0684, 0, 0),
        MX6_PAD_ECSPI1_MOSI__ECSPI_MOSI                         =
IOMUX_PAD(0x035C, 0x006C, 0, 0x0688, 0, 0),
        MX6_PAD_ECSPI1_SCLK__ECSPI_SCLK                         =
IOMUX_PAD(0x0360, 0x0070, 0, 0x067C, 0, 0),
-       MX6_PAD_ECSPI1_SS0__GPIO4_IO11                          =
IOMUX_PAD(0x0364, 0x0074, 0, 0x0000, 5, 0),
+       MX6_PAD_ECSPI1_SS0__GPIO4_IO11                          =
IOMUX_PAD(0x0364, 0x0074, 5, 0x0000, 0, 0),
        MX6_PAD_SD2_CLK__USDHC2_CLK                             =
IOMUX_PAD(0x055C, 0x0254, 0, 0x0000, 0, 0),
        MX6_PAD_SD2_CMD__USDHC2_CMD                             =
IOMUX_PAD(0x0560, 0x0258, 0, 0x0000, 0, 0),
        MX6_PAD_SD2_DAT0__USDHC2_DAT0


Then it will work fine:

=> sf probe
SF: Detected M25P32 with page size 256 Bytes, erase size 64 KiB, total 4 MiB

I will submit a formal patch soon.

Regards,

Fabio Estevam