[PATCH v3 5/6] mtd: dataflash: Make use of "extened device information"

Andrey Smirnov
2017-04-19T15:23:53Z

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 [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

drivers/mtd/devices/mtd_dataflash.c | 115 +++++++++++++++++++++---------------
1 file changed, 68 insertions(+), 47 deletions(-)

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 2d3e403..941e8b7 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -687,7 +687,7 @@ 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;
@@ -710,62 +710,34 @@ 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, u64 jedec)
{
- 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];
+ struct flash_info *info;

for (info = dataflash_data;
info < dataflash_data + ARRAY_SIZE(dataflash_data);
@@ -793,12 +765,61 @@ static struct flash_info *jedec_probe(struct spi_device *spi)
}
}

+ return NULL;
+}
+
+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;
+ const unsigned int first_byte = sizeof(id) - id_size;
+ 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[first_byte], id_size);
+ if (ret < 0) {
+ pr_debug("%s: error %d reading JEDEC ID\n",
+ dev_name(&spi->dev), ret);
+ return ERR_PTR(ret);
+ }
+
+ if (id[first_byte] != CFI_MFR_ATMEL)
+ return NULL;
+
+ jedec = be64_to_cpup((__be64 *)id);
+
+ info = jedec_lookup(spi, jedec);
+ if (info)
+ return info;
+
+ /*
+ * Clear extended id bits (bits 0 through 15) and try to find
+ * a match again in case our chip does not support returning
+ * extended ID information and we got invalid bits instead
+ */
+ jedec &= GENMASK_ULL(63, 16);
+
+ 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);
}

--
2.9.3