Re: using mmc2 on panda [was: Regression 3.11-rc1: omap4panda: nousb and consequently no ethernet]

[Roger Quadros]

On 10/01/2013 12:49 PM, Roger Quadros wrote:
> Hi Arend,
> 
> On 10/01/2013 11:05 AM, Arend van Spriel wrote:
>> On 07/19/2013 12:57 PM, Arend van Spriel wrote:
>>> On 07/19/2013 12:49 PM, Roger Quadros wrote:
>>>> On 07/19/2013 01:36 PM, Arend van Spriel wrote:
>>>>> On 07/18/2013 10:59 AM, Tony Lindgren wrote:
>>>>>> Then for the SDIO with device tree, take a look at the following
>>>>>> patches:
>>>>>>
>>>>>> [PATCH 0/3] WLAN support for omap4 when booted with devicetree
>>>>>> http://comments.gmane.org/gmane.linux.ports.arm.omap/97522#
>>>>>
>>>>> I have been looking at the pandaboard patch in the series above and I
>>>>> do have a question. Among other things the patch adds these dt entries.
>>>>>
>>>>> +            0x108 0x118    /* sdmmc5_clk.sdmmc5_clk INPUT_PULLUP |
>>>>> MODE0 */
>>>>> +            0x10a 0x118    /* sdmmc5_cmd.sdmmc5_cmd INPUT_PULLUP |
>>>>> MODE0 */
>>>>>
>>>>> If I look at the similar names in the deceased board-omap4panda.c:
>>>>>
>>>>> board-omap4panda.c:    OMAP4_MUX(SDMMC5_CMD, OMAP_MUX_MODE0 |
>>>>> OMAP_PIN_INPUT_PULLUP),
>>>>> board-omap4panda.c:    OMAP4_MUX(SDMMC5_CLK, OMAP_MUX_MODE0 |
>>>>> OMAP_PIN_INPUT_PULLUP),
>>>>>
>>>>> and in mux44xx.h:
>>>>>
>>>>> mux44xx.h:#define OMAP4_CTRL_MODULE_PAD_SDMMC5_CLK_OFFSET    0x0148
>>>>> mux44xx.h:#define OMAP4_CTRL_MODULE_PAD_SDMMC5_CMD_OFFSET    0x014a
>>>>>
>>>>> So how did 0x0148 get 0x0108 in DT and 0x014a get 0x010a. There is
>>>>> probably an explanation to it and it would help my understanding to
>>>>> know where this difference comes from. Hope you can help me out here.
>>>>>
>>>>
>>>> If you see omap4.dtsi, omap4_pmx_core starts at register address
>>>> 0x4a100040.
>>>>
>>>> So, you need to subtract 0x40 from the offsets defined in mux44xx.h
>>>> for pmx_core registers.
>>>
>>> That was what I was looking for. Thanks!
>>
>> Hi Roger,
>>
>> It has been a while, but I would like to pickup this thread. We have a couple of pandaboards used as test setup. These have an SDIO adapter hooked up to expansion connector A using MMC2. I have attached the patch file (just ignore platform_data stuff). Now on one board it works, but not for the other. I suspect a board issue so listing the two types that we use:
>>
>> PandaBoard rev A2 (dmesg: OMAP4430 ES2.1): works
>> PandaBoardES rev B1 (dmesg: OMAP4460 ES1.1): nope
>>
>> Any hints for me.
> 
> Does your PandaboardES have the WLAN chip (U4) mounted? If yes, how do you isolate
> it from your external SDIO adapter?

OK, just realized that the expansion connector uses different pads for MMC2. However, you still
need to make sure that the other pins (connected to on board WLAN chip) are not muxed as MMC2.
> 
> Most likely your Pandaboard (A2) doesn't have the WLAN chip (U3) on board so there is no problem there.
> 

cheers,
-roger

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