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

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

[Nikolay Dimitrov]

Hi,

 From what I remember when working with imx6d, the ecspi controller had 
a special behavior that it
insisted on toggling the CS line for each 8-bit transfer. U-Boot has a 
workaround for this: using
additional pin as "bit-banged CS". Here's how it worked on a project of 
mine:

static iomux_v3_cfg_t const spi1_pads[] =
{
     MX6_PAD_KEY_ROW1__GPIO4_IO09 | MUX_PAD_CTRL(NO_PAD_CTRL), // <= 
this is the new CS
     MX6_PAD_KEY_COL1__ECSPI1_MISO | MUX_PAD_CTRL(SPI_PAD_CTRL),
     MX6_PAD_KEY_ROW0__ECSPI1_MOSI | MUX_PAD_CTRL(SPI_PAD_CTRL),
     MX6_PAD_KEY_COL0__ECSPI1_SCLK | MUX_PAD_CTRL(SPI_PAD_CTRL)
};

...and here's what I defined in my board-config-file:

#define CONFIG_SF_DEFAULT_CS            (0 | (IMX_GPIO_NR(4, 9) << 8))

Then you need to double-check your ecspi config options, like speed, 
mode. You can check with
a scope whether the clock pulses are within supported timing of your SPI 
chip.

Kind regards,
Nikolay


On 4/11/2014 8:55 AM, u-boot-request@lists.denx.de wrote:
> Message: 28 Date: Thu, 10 Apr 2014 12:20:58 -0300 From: Fabio Estevam 
> <festevam@gmail.com> Subject: Re: [U-Boot] board/freescale/mx6slevk: 
> Add support for SPI NOR on the Freescale MCIMX6SLEVK Board To: Sam 
> Catch <dsblue.spam@gmail.com> Cc: Marek Va?ut <marex@denx.de>, 
> U-Boot-Denx <u-boot@lists.denx.de> Message-ID: 
> <CAOMZO5DvBqqAAzb5LwDNajMDj=+jm-nTz+FjQyGYLPXgKq-A2g@mail.gmail.com> 
> Content-Type: text/plain; charset=UTF-8 On Thu, Apr 10, 2014 at 12:05 
> PM, Sam Catch <dsblue.spam@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.
>
> Regards,
>
> Fabio Estevam

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

[Sam Catch]

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.

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

[Fabio Estevam]

On Thu, Apr 10, 2014 at 12:05 PM, Sam Catch <dsblue.spam@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.

Regards,

Fabio Estevam

[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@gmail.com> wrote:
> On Thu, Apr 10, 2014 at 12:05 PM, Sam Catch <dsblue.spam@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