[PATCH v2 3/3] mtd: dataflash: Make use of "extened device information"

[Andrey Smirnov <andrew.smirnov@gmail.com>]

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 [v1]:

	- Formatting

[v1] http://lkml.kernel.org/r/20170411161722.11164-1-andrew.smirnov@gmail.com


 drivers/mtd/devices/mtd_dataflash.c | 113 +++++++++++++++++++++---------------
 1 file changed, 65 insertions(+), 48 deletions(-)

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 5b7a8c3..5d694a4 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -690,7 +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;
@@ -713,63 +713,34 @@ 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, i;
-	u8 code = OP_READ_ID;
-	u8 id[3];
-	u32 jedec;
+	int status, i;
 	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) {
-		pr_debug("%s: error %d reading JEDEC ID\n",
-			dev_name(&spi->dev), 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 (i = 0, info = dataflash_data;
 			i < ARRAY_SIZE(dataflash_data);
@@ -799,12 +770,58 @@ 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;
+	u8 id[8] = {0};
+	const unsigned int id_size = 5;
+	const unsigned int first_byte = sizeof(id) - id_size;
+	const u64 eid_mask = GENMASK_ULL(63, 16);
+	u64 jedec;
+	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 and try to find a match again */
+	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);
 }
 
-- 
2.9.3