[U-Boot] [NEXT PATCH v1 2/7] NAND: added NAND type to nand_ids

[Stefano Babic]

On 07/09/2012 20:56, Scott Wood wrote:

Hi Scott,

>>>
>>>>>  drivers/mtd/nand/nand_ids.c |    2 ++
>>>>>  1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/drivers/mtd/nand/nand_ids.c b/drivers/mtd/nand/nand_ids.c
>>>>> index 3953549..fe75686 100644
>>>>> --- a/drivers/mtd/nand/nand_ids.c
>>>>> +++ b/drivers/mtd/nand/nand_ids.c
>>>>> @@ -131,6 +131,8 @@ const struct nand_flash_dev nand_flash_ids[] = {
>>>>>  	/* 128 Gigabit */
>>>>>  	{"NAND 16GiB 1,8V 8-bit",	0x1A, 0, 16384, 0, LP_OPTIONS},
>>>>>  	{"NAND 16GiB 3,3V 8-bit",	0x3A, 0, 16384, 0, LP_OPTIONS},
>>>>> +	{"NAND 16GiB 3,3V 8-bit",	0x48, 4096, 16384, 0x100000,
>>>>> +		LP_OPTIONS},
>>>>>  	{"NAND 16GiB 1,8V 16-bit",	0x2A, 0, 16384, 0, LP_OPTIONS16},
>>>>>  	{"NAND 16GiB 3,3V 16-bit",	0x4A, 0, 16384, 0, LP_OPTIONS16},
>>>>>  
>>>>>
>>>>
>>>> Why does this NAND chip need things specified that are zeroes for other
>>>> chips?
>>>
>>> At least on this board with MX35, the chip cannot be recognized.
>>> Manufacturer ID and device ID are read flawlessly, but then u-boot fails
>>> to get the correct geometry. Setting explicitely the values, I can then
>>> read / write into the NAND without any problem. It can be more a problem
>>> related to the specific MXC NAND driver (mxc_nand.c).
>>
>> It seems to me that the values returned by this flash cannot be
>> interpreted in nand_get_flash_type().
>>
>> The values returned from a READ-ID command with address 0x00 are:
>>
>> 	0x2C 0x48 0x04 0x4A 0xA5,
>>
>> I can really get these values from the flash, so the MXC controller gets
>> the correct data.
>>
>> However, the code in nand_base.c (lines from 2718, so not-Samsung case)
>> parses the answer setting the NAND as a 16-bit device, but this is
>> really a 8bit device. I do not know the meaning of the answer, it is not
>> described in the datasheet.
> 
> Does the datasheet say anything about what the ID data is supposed to
> look like and how to interpret it?  I tried to download it and Micron
> shoved an NDA in my face.

I find no description in the datasheet.

> 
> What kind of chip is this?  Is the datasheet publicly available?
> 
> These threads seem relevant:
> http://patchwork.ozlabs.org/patch/60042/
> http://old.nabble.com/-U-Boot--Add-new-NAND-flash-td29858370.html

It is the same case,  as I can see, with the same chip.

> 
> Does the chip support ONFI?

The chip supports ONFI, but it seems the i.MX driver does not. Quite as
described in http://patchwork.ozlabs.org/patch/60042/. READ-ID is always
sent with address 0, I do not know if we can convince the driver to send
the address.

Regards,
Stefano

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