Re: [PATCH V2] Add support for flag status register on Micron chips.

From: Harini Katakam
Date: Mon Apr 14 2014 - 11:42:26 EST


Hi,

On Fri, Apr 11, 2014 at 8:33 PM, <grmoore@xxxxxxxxxx> wrote:
> From: Graham Moore <grmoore@xxxxxxxxxx>
>
> Some new Micron flash chips require reading the flag
> status register to determine when operations have completed.
>
> Furthermore, chips with multi-die stacks of the 65nm 256Mb QSPI also
> require reading the status register before reading the flag status register.
>
> This patch adds support for the flag status register in the n25q512a1 and n25q00
> Micron QSPI flash chips.
>
> Signed-off-by: Graham Moore <grmoore@xxxxxxxxxx>

<snip>

> #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags) \
> @@ -941,6 +999,8 @@ static const struct spi_device_id m25p_ids[] = {
> { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256, 0) },
> { "n25q256a", INFO(0x20ba19, 0, 64 * 1024, 512, SECT_4K) },
> { "n25q512a", INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K) },
> + { "n25q512a1", INFO(0x20ba20, 0, 64 * 1024, 1024, USE_FSR) },
> + { "n25q00", INFO(0x20ba21, 0, 64 * 1024, 2048, USE_FSR) },
>

I understand that "n25q512a1" was added to distinguish between
0x20bb20 and 0x20ba20,
which is essentially 1.8V and 3V parts.
(The actual part numbers are n25q512a11 and n25q512a13 respectively)
But USE_FSR is required for both parts.

Sorry for posting this question here but it seemed relevant:
When such devices differ only in supply voltages (and return different
response to READ ID),
which we don't act on, is there a way to use the same string?

Regards,
Harini
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