[PATCH] mtd: spi-nor: Add support for S3AN spi-nor devices

Ricardo Ribalda Delgado ricardo.ribalda at gmail.com
Fri Jan 15 08:25:05 PST 2016


Xilinx Spartan-3AN contain an embedded spi device where they keep their
configuration data and optionally some user data.

The protocol of this flash follows most of the spi-nor standard. With
the following differences:

- Page size might not be a power of two.
- The address calculation.
- The spi nor commands used.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda at gmail.com>
---
 drivers/mtd/devices/m25p80.c  |  3 ++
 drivers/mtd/spi-nor/spi-nor.c | 97 +++++++++++++++++++++++++++++++++++++++++--
 include/linux/mtd/spi-nor.h   | 13 ++++++
 3 files changed, 110 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index c9c3b7fa3051..869576735978 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -49,6 +49,9 @@ static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
 
 static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
 {
+	if (nor->addr_convert)
+		addr = nor->addr_convert(nor, addr);
+
 	/* opcode is in cmd[0] */
 	cmd[1] = addr >> (nor->addr_width * 8 -  8);
 	cmd[2] = addr >> (nor->addr_width * 8 - 16);
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index ed0c19c558b5..90215f053916 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -69,6 +69,7 @@ struct flash_info {
 #define	SPI_NOR_DUAL_READ	0x20    /* Flash supports Dual Read */
 #define	SPI_NOR_QUAD_READ	0x40    /* Flash supports Quad Read */
 #define	USE_FSR			0x80	/* use flag status register */
+#define	SPI_S3AN		0x100	/* Xililnx S3AN Embedded SPI nor*/
 };
 
 #define JEDEC_MFR(info)	((info)->id[0])
@@ -211,6 +212,21 @@ static inline int set_4byte(struct spi_nor *nor, const struct flash_info *info,
 		return nor->write_reg(nor, SPINOR_OP_BRWR, nor->cmd_buf, 1);
 	}
 }
+
+static inline int s3an_sr_ready(struct spi_nor *nor)
+{
+	int ret;
+	u8 val;
+
+	ret = nor->read_reg(nor, SPINOR_OP_XRDSR, &val, 1);
+	if (ret < 0) {
+		pr_err("error %d reading SR\n", (int) ret);
+		return ret;
+	}
+
+	return !!(val & XSR_RDY);
+}
+
 static inline int spi_nor_sr_ready(struct spi_nor *nor)
 {
 	int sr = read_sr(nor);
@@ -232,7 +248,7 @@ static inline int spi_nor_fsr_ready(struct spi_nor *nor)
 static int spi_nor_ready(struct spi_nor *nor)
 {
 	int sr, fsr;
-	sr = spi_nor_sr_ready(nor);
+	sr = nor->sr_ready(nor);
 	if (sr < 0)
 		return sr;
 	fsr = nor->flags & SNOR_F_USE_FSR ? spi_nor_fsr_ready(nor) : 1;
@@ -328,6 +344,9 @@ static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
 	 * Default implementation, if driver doesn't have a specialized HW
 	 * control
 	 */
+	if (nor->addr_convert)
+		addr = nor->addr_convert(nor, addr);
+
 	for (i = nor->addr_width - 1; i >= 0; i--) {
 		buf[i] = addr & 0xff;
 		addr >>= 8;
@@ -362,7 +381,7 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 		return ret;
 
 	/* whole-chip erase? */
-	if (len == mtd->size) {
+	if (len == mtd->size && !(nor->flags & SNOR_NO_OP_CHIP_ERASE)) {
 		unsigned long timeout;
 
 		write_enable(nor);
@@ -680,6 +699,19 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 		.addr_width = (_addr_width),				\
 		.flags = (_flags),
 
+#define S3AN_INFO(_jedec_id, _n_sectors, _page_size)			\
+		.id = {							\
+			((_jedec_id) >> 16) & 0xff,			\
+			((_jedec_id) >> 8) & 0xff,			\
+			(_jedec_id) & 0xff				\
+			},						\
+		.id_len = 3,						\
+		.sector_size = (8*_page_size),				\
+		.n_sectors = (_n_sectors),				\
+		.page_size = _page_size,				\
+		.addr_width = 3,					\
+		.flags = SPI_NOR_NO_FR | SPI_S3AN,
+
 /* NOTE: double check command sets and memory organization when you add
  * more nor chips.  This current list focusses on newer chips, which
  * have been converging on command sets which including JEDEC ID.
@@ -877,6 +909,14 @@ static const struct flash_info spi_nor_ids[] = {
 	{ "cat25c17", CAT25_INFO( 256, 8, 32, 2, SPI_NOR_NO_ERASE | SPI_NOR_NO_FR) },
 	{ "cat25128", CAT25_INFO(2048, 8, 64, 2, SPI_NOR_NO_ERASE | SPI_NOR_NO_FR) },
 	{ },
+
+	/* Xilinx S3AN Internal Flash */
+	{ "3S50AN", S3AN_INFO(0x1f2200, 64, 264) },
+	{ "3S200AN", S3AN_INFO(0x1f2400, 256, 264) },
+	{ "3S400AN", S3AN_INFO(0x1f2400, 256, 264) },
+	{ "3S700AN", S3AN_INFO(0x1f2500, 512, 264) },
+	{ "3S1400AN", S3AN_INFO(0x1f2600, 512, 528) },
+	{ },
 };
 
 static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
@@ -1007,7 +1047,13 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	write_enable(nor);
 
-	page_offset = to & (nor->page_size - 1);
+	if (hweight32(nor->page_size) == 1)
+		page_offset = to & (nor->page_size - 1);
+	else {
+		uint64_t aux = to;
+
+		page_offset = do_div(aux, nor->page_size);
+	}
 
 	/* do all the bytes fit onto one page? */
 	if (page_offset + len <= nor->page_size) {
@@ -1179,6 +1225,43 @@ static int spi_nor_check(struct spi_nor *nor)
 	return 0;
 }
 
+static unsigned int s3an_addr_convert(struct spi_nor *nor, unsigned int addr)
+{
+	if (nor->page_size == 264)
+		return (addr / 264) * 512 + (addr % 264);
+
+	return (addr / 528) * 1024 + (addr % 528);
+}
+
+static int s3an_nor_scan(const struct flash_info *info, struct spi_nor *nor)
+{
+	int ret;
+	u8 val;
+
+	ret = nor->read_reg(nor, SPINOR_OP_XRDSR, &val, 1);
+	if (ret < 0) {
+		pr_err("error %d reading SR\n", (int) ret);
+		return ret;
+	}
+
+	nor->erase_opcode = SPINOR_OP_XSE;
+	nor->program_opcode = SPINOR_OP_XPP;
+	nor->read_opcode = SPINOR_OP_READ;
+	nor->sr_ready = s3an_sr_ready;
+	nor->flags |= SNOR_NO_OP_CHIP_ERASE;
+
+	/*Flash in Power of 2 mode*/
+	if (val & XSR_PAGESIZE) {
+		nor->page_size = (nor->page_size == 264) ? 256 : 512;
+		nor->mtd.writebufsize = nor->page_size;
+		nor->mtd.size = 8 * nor->page_size * info->n_sectors;
+		nor->mtd.erasesize = 8 * nor->page_size;
+	} else
+		nor->addr_convert = s3an_addr_convert;
+
+	return 0;
+}
+
 int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 {
 	const struct flash_info *info = NULL;
@@ -1339,6 +1422,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 	}
 
 	nor->program_opcode = SPINOR_OP_PP;
+	nor->sr_ready = spi_nor_sr_ready;
 
 	if (info->addr_width)
 		nor->addr_width = info->addr_width;
@@ -1379,6 +1463,13 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 
 	nor->read_dummy = spi_nor_read_dummy_cycles(nor);
 
+	if (info->flags & SPI_S3AN) {
+		ret = s3an_nor_scan(info, nor);
+
+		if (ret)
+			return ret;
+	}
+
 	dev_info(dev, "%s (%lld Kbytes)\n", info->name,
 			(long long)mtd->size >> 10);
 
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 62356d50815b..8946fa936b46 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -67,6 +67,15 @@
 #define SPINOR_OP_WRDI		0x04	/* Write disable */
 #define SPINOR_OP_AAI_WP	0xad	/* Auto address increment word program */
 
+/* Used for S3AN flashes only */
+#define SPINOR_OP_XSE		0x50	/* Sector erase */
+#define SPINOR_OP_XPP		0x82	/* Page program */
+#define SPINOR_OP_XRDSR		0xd7	/* Read status register */
+
+#define XSR_PAGESIZE		BIT(0)	/* Page size in Po2 or Linear */
+#define XSR_RDY			BIT(7)	/* Ready */
+
+
 /* Used for Macronix and Winbond flashes. */
 #define SPINOR_OP_EN4B		0xb7	/* Enter 4-byte mode */
 #define SPINOR_OP_EX4B		0xe9	/* Exit 4-byte mode */
@@ -116,6 +125,7 @@ enum spi_nor_ops {
 
 enum spi_nor_option_flags {
 	SNOR_F_USE_FSR		= BIT(0),
+	SNOR_NO_OP_CHIP_ERASE	= BIT(1),
 };
 
 /**
@@ -170,6 +180,9 @@ struct spi_nor {
 	int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
 	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
 
+	int (*sr_ready)(struct spi_nor *nor);
+	unsigned int (*addr_convert)(struct spi_nor *nor, unsigned int addr);
+
 	int (*read)(struct spi_nor *nor, loff_t from,
 			size_t len, size_t *retlen, u_char *read_buf);
 	void (*write)(struct spi_nor *nor, loff_t to,
-- 
2.6.4




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