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SubjectRe: [PATCH v4 5/6] mtd: dataflash: Make use of "extened device information"
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On 04/20/2017 06:29 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@gmail.com
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
> Cc: Marek Vasut <marek.vasut@gmail.com>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>
> Changes since [v3]:
>
> - Convert patch to use SUP_EXTID flag and avoid patching
> dataflash_data table
>
> Changes since [v2]:
>
> - Make 'id' have same size as 'jedec'
>
> - Get rid of eid_mask variable in favour of using GENMASK
> in-place
>
> Changes since [v1]:
>
> - Formatting
>
> [v1] http://lkml.kernel.org/r/20170411161722.11164-1-andrew.smirnov@gmail.com
> [v2] http://lkml.kernel.org/r/20170418142127.23301-3-andrew.smirnov@gmail.com
> [v3] http://lkml.kernel.org/r/20170419152305.17226-5-andrew.smirnov@gmail.com
>
> drivers/mtd/devices/mtd_dataflash.c | 88 ++++++++++++++++++++++++-------------
> 1 file changed, 57 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
> index 2d3e403..9342cc47 100644
> --- a/drivers/mtd/devices/mtd_dataflash.c
> +++ b/drivers/mtd/devices/mtd_dataflash.c
> @@ -84,6 +84,9 @@
>
> #define CFI_MFR_ATMEL 0x1F
>
> +#define DATAFLASH_SHIFT_EXTID 24
> +#define DATAFLASH_SHIFT_ID 40
> +
> struct dataflash {
> u8 command[4];
> char name[24];
> @@ -687,7 +690,7 @@ struct flash_info {
> /* JEDEC id has a high byte of zero plus three data bytes:
> * the manufacturer id, then a two byte device id.
> */
> - u32 jedec_id;
> + u64 jedec_id;
>
> /* The size listed here is what works with OP_ERASE_PAGE. */
> unsigned nr_pages;
> @@ -695,6 +698,7 @@ struct flash_info {
> u16 pageoffset;
>
> u16 flags;
> +#define SUP_EXTID BIT(3)

Two nits, can we keep things consistent please ? In this case, 0x0004 .
Also, you wanted to use BIT(2)=0x4 here, not BIT(3)=0x8 .

Other than that,
Acked-by: Marek Vasut <marek.vasut@gmail.com>

> #define SUP_POW2PS 0x0002 /* supports 2^N byte pages */
> #define IS_POW2PS 0x0001 /* uses 2^N byte pages */
> };
> @@ -734,42 +738,18 @@ static struct flash_info dataflash_data[] = {
> { "at45db642d", 0x1f2800, 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,
> + u64 jedec, bool use_extid)
> {
> - int ret;
> - u8 code = OP_READ_ID;
> - u8 id[3];
> - u32 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.
> - */
> - ret = spi_write_then_read(spi, &code, 1, id, 3);
> - if (ret < 0) {
> - dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);
> - return ERR_PTR(ret);
> - }
> -
> - if (id[0] != CFI_MFR_ATMEL)
> - return NULL;
> -
> - jedec = id[0];
> - jedec = jedec << 8;
> - jedec |= id[1];
> - jedec = jedec << 8;
> - jedec |= id[2];
> -
> for (info = dataflash_data;
> info < dataflash_data + ARRAY_SIZE(dataflash_data);
> info++) {
> + if (use_extid && !(info->flags & SUP_EXTID))
> + continue;
> +
> if (info->jedec_id == jedec) {
> dev_dbg(&spi->dev, "OTP, sector protect%s\n",
> (info->flags & SUP_POW2PS) ?
> @@ -793,12 +773,58 @@ static struct flash_info *jedec_probe(struct spi_device *spi)
> }
> }
>
> + return ERR_PTR(-ENODEV);
> +}
> +
> +static struct flash_info *jedec_probe(struct spi_device *spi)
> +{
> + int ret;
> + u8 code = OP_READ_ID;
> + u64 jedec;
> + u8 id[sizeof(jedec)] = {0};
> + const unsigned int id_size = 5;
> + struct flash_info *info;
> +
> + /*
> + * 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.
> + */
> + ret = spi_write_then_read(spi, &code, 1, id, id_size);
> + if (ret < 0) {
> + dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);
> + return ERR_PTR(ret);
> + }
> +
> + if (id[0] != CFI_MFR_ATMEL)
> + return NULL;
> +
> + jedec = be64_to_cpup((__be64 *)id);
> +
> + /*
> + * First, try to match device using extended device
> + * information
> + */
> + info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_EXTID, true);
> + if (!IS_ERR(info))
> + return info;
> + /*
> + * If that fails, make another pass using regular ID
> + * information
> + */
> + info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_ID, false);
> + if (!IS_ERR(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 %016llx not handled\n", jedec);
> return ERR_PTR(-ENODEV);
> }
>
>


--
Best regards,
Marek Vasut

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