[PATCH 1/2] mtd: dataflash: Make use of "extened device information"

Marek Vasut marek.vasut at gmail.com
Tue Apr 11 11:29:28 PDT 2017


On 04/11/2017 06:17 PM, Andrey Smirnov wrote:
> In anticipation of supporting chips that need it, extend the size of
> struct flash_info's 'jedec_id' field to make room 2 byte of extended
> device information as well as add code to fetch this data during
> jedec_probe().
> 
> Cc: cphealy at gmail.com
> Cc: David Woodhouse <dwmw2 at infradead.org>
> Cc: Brian Norris <computersforpeace at gmail.com>
> Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
> Cc: Marek Vasut <marek.vasut at gmail.com>
> Cc: Richard Weinberger <richard at nod.at>
> Cc: Cyrille Pitchen <cyrille.pitchen at atmel.com>
> Cc: linux-kernel at vger.kernel.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
> ---
>  drivers/mtd/devices/mtd_dataflash.c | 113 +++++++++++++++++++++---------------
>  1 file changed, 66 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
> index f9e9bd1..9a98cdc 100644
> --- a/drivers/mtd/devices/mtd_dataflash.c
> +++ b/drivers/mtd/devices/mtd_dataflash.c
> @@ -689,7 +689,7 @@ struct flash_info {
>  	/* JEDEC id has a high byte of zero plus three data bytes:
>  	 * the manufacturer id, then a two byte device id.
>  	 */
> -	uint32_t	jedec_id;
> +	uint64_t	jedec_id;
>  
>  	/* The size listed here is what works with OP_ERASE_PAGE. */
>  	unsigned	nr_pages;
> @@ -712,61 +712,35 @@ static struct flash_info dataflash_data[] = {
>  	 * These newer chips also support 128-byte security registers (with
>  	 * 64 bytes one-time-programmable) and software write-protection.
>  	 */
> -	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
> -	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB011B",  0x1f22000000, 512, 264, 9, SUP_POW2PS},
> +	{ "at45db011d",  0x1f22000000, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
> -	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB021B",  0x1f23000000, 1024, 264, 9, SUP_POW2PS},
> +	{ "at45db021d",  0x1f23000000, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
> -	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB041x",  0x1f24000000, 2048, 264, 9, SUP_POW2PS},
> +	{ "at45db041d",  0x1f24000000, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
> -	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB081B",  0x1f25000000, 4096, 264, 9, SUP_POW2PS},
> +	{ "at45db081d",  0x1f25000000, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
> -	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB161x",  0x1f26000000, 4096, 528, 10, SUP_POW2PS},
> +	{ "at45db161d",  0x1f26000000, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
> +	{ "AT45DB321x",  0x1f27000000, 8192, 528, 10, 0},	/* rev C */
>  
> -	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
> -	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB321x",  0x1f27010000, 8192, 528, 10, SUP_POW2PS},
> +	{ "at45db321d",  0x1f27010000, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
>  
> -	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
> -	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
> +	{ "AT45DB642x",  0x1f28000000, 8192, 1056, 11, SUP_POW2PS},
> +	{ "at45db642d",  0x1f28000000, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
>  };
>  
> -static struct flash_info *jedec_probe(struct spi_device *spi)
> +static struct flash_info *jedec_lookup(struct spi_device *spi,
> +				       uint64_t jedec)

const u64 (not uint64_t , this is NOT userspace). Fix globally.

>  {
> -	int			tmp;
> -	uint8_t			code = OP_READ_ID;
> -	uint8_t			id[3];
> -	uint32_t		jedec;
> -	struct flash_info	*info;
> -	int status;
> -
> -	/* JEDEC also defines an optional "extended device information"
> -	 * string for after vendor-specific data, after the three bytes
> -	 * we use here.  Supporting some chips might require using it.
> -	 *
> -	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
> -	 * That's not an error; only rev C and newer chips handle it, and
> -	 * only Atmel sells these chips.
> -	 */
> -	tmp = spi_write_then_read(spi, &code, 1, id, 3);
> -	if (tmp < 0) {
> -		pr_debug("%s: error %d reading JEDEC ID\n",
> -			dev_name(&spi->dev), tmp);
> -		return ERR_PTR(tmp);
> -	}
> -	if (id[0] != 0x1f)
> -		return NULL;
> -
> -	jedec = id[0];
> -	jedec = jedec << 8;
> -	jedec |= id[1];
> -	jedec = jedec << 8;
> -	jedec |= id[2];
> +	int tmp, status;
> +	struct flash_info *info;
>  
>  	for (tmp = 0, info = dataflash_data;
>  			tmp < ARRAY_SIZE(dataflash_data);
> @@ -796,12 +770,57 @@ static struct flash_info *jedec_probe(struct spi_device *spi)
>  		}
>  	}
>  
> +	return NULL;
> +}
> +
> +static struct flash_info *jedec_probe(struct spi_device *spi)
> +{
> +	int			tmp;
> +	uint8_t			code = OP_READ_ID;
> +	uint8_t			id[8] = {0};
> +	const unsigned int	id_size = 5;
> +	const unsigned int	first_byte = sizeof(id) - id_size;
> +	const uint64_t		eid_mask = GENMASK_ULL(63, 16);

Can we have some macro, like DATAFLASH_ID_BYTES and derive all the masks
and crap from it instead of having this stack of variables ?

> +	uint64_t		jedec;
> +	struct flash_info	*info;

Replace the tab after the type with space please.

> +	/* JEDEC also defines an optional "extended device information"

Multi-line comment format:

/*
 * foo
 * bar
 */

> +	 * string for after vendor-specific data, after the three bytes
> +	 * we use here.  Supporting some chips might require using it.
> +	 *
> +	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
> +	 * That's not an error; only rev C and newer chips handle it, and
> +	 * only Atmel sells these chips.
> +	 */
> +	tmp = spi_write_then_read(spi, &code, 1, &id[first_byte], id_size);
> +	if (tmp < 0) {

Use ret instead of tmp.

> +		pr_debug("%s: error %d reading JEDEC ID\n",
> +			dev_name(&spi->dev), tmp);
> +		return ERR_PTR(tmp);
> +	}

newline

> +	if (id[first_byte] != 0x1f)

Use a macro, like CFI_MFR_ATMEL ?

> +		return NULL;
> +
> +	jedec = be64_to_cpup((__be64 *)id);
> +
> +	info = jedec_lookup(spi, jedec);
> +	if (info)
> +		return info;
> +	/*
> +	 * Clear extended id bits and try to find a match again
> +	 */

This could be a single-line comment.

> +	jedec &= eid_mask;
> +
> +	info = jedec_lookup(spi, jedec);
> +	if (info)
> +		return info;
> +
>  	/*
>  	 * Treat other chips as errors ... we won't know the right page
>  	 * size (it might be binary) even when we can tell which density
>  	 * class is involved (legacy chip id scheme).
>  	 */
> -	dev_warn(&spi->dev, "JEDEC id %06x not handled\n", jedec);
> +	dev_warn(&spi->dev, "JEDEC id %010llx not handled\n", jedec);
>  	return ERR_PTR(-ENODEV);
>  }
>  
> 


-- 
Best regards,
Marek Vasut



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