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

From: Ricardo Ribalda Delgado
Date: Fri Jan 15 2016 - 11:25:18 EST


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@xxxxxxxxx>
---
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