Re: [PATCH 1/2] mtd: spi-nor: Add support for EN25Q80A

From: Schrempf Frieder <frieder.schrempf@kontron.de>
To: "Tudor.Ambarus@microchip.com" <Tudor.Ambarus@microchip.com>,
	"marek.vasut@gmail.com" <marek.vasut@gmail.com>
Cc: "bbrezillon@kernel.org" <bbrezillon@kernel.org>,
	"richard@nod.at" <richard@nod.at>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
	"dwmw2@infradead.org" <dwmw2@infradead.org>
Subject: Re: [PATCH 1/2] mtd: spi-nor: Add support for EN25Q80A
Date: Thu, 7 Feb 2019 10:06:56 +0000	[thread overview]
Message-ID: <52338dfe-aca1-503d-6871-c4be09f1f3ac@kontron.de> (raw)
In-Reply-To: <f0b2c97b-419a-1e3e-4624-52c60fe32065@microchip.com>

Hi Tudor,

On 03.02.19 14:33, Tudor.Ambarus@microchip.com wrote:
> Hi, Frieder,
> 
> On 01/23/2019 09:56 AM, Schrempf Frieder wrote:
>> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>>
>> This adds support for the EON EN25Q80A, a 8Mb SPI NOR chip.
> 
> I would suggest to specify who is using this flash and how did you test it. This
> way we will not end up with support for flashes that are not actually used.

Ok. The flash is used by a board that I plan to upstream. Maybe I should 
just resubmit this together with the actual board support patches?

Likewise for my other patch (MX25V8035F), this is for another board I 
plan to upstream soon.

> 
>>
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
>> ---
>>   drivers/mtd/spi-nor/spi-nor.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index 6e13bbd1aaa5..aa8a04293a25 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -1737,6 +1737,8 @@ static const struct flash_info spi_nor_ids[] = {
>>   	/* EON -- en25xxx */
>>   	{ "en25f32",    INFO(0x1c3116, 0, 64 * 1024,   64, SECT_4K) },
>>   	{ "en25p32",    INFO(0x1c2016, 0, 64 * 1024,   64, 0) },
>> +	{ "en25q80a",   INFO(0x1c3014, 0, 64 * 1024,   16,
>> +			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> 
> I'm reading EN25Q80A Rev. H, Issue Date: 2012/10/23
>   datasheet. I don't see the bfpt table described, so probably it doesn't support
> it. The flash advertises SPINOR_OP_READ_1_4_4 (0xeb), but not
> SPINOR_OP_READ_1_1_4 (0x6b). In spi_nor_init_params(), when SPI_NOR_QUAD_READ is
> set, we assume that SNOR_HWCAPS_READ_1_1_4 is supported, so we will use 0x6b for
> quad reads. I can't see how the flash works with 0x6b, unless there is a bfpt
> table that indicates support for 0xebh.
> 
> If it does support bfpt, set just SECT_4K | SPI_NOR_DUAL_READ, the latter will
> trigger the bfpt parsing.

Thanks for explaining this. I missed the point, that SPI_NOR_QUAD_READ 
actually requires support for SPINOR_OP_READ_1_1_4.

> 
> If you will resubmit, please order the entry in alphabetical order, by name.

Ok.

Thanks,
Frieder
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/