[U-Boot] [PATCH v10 20/27] mtd: spi-nor: Add 4-byte addresswidth support

Jagan Teki
2017-12-28T06:12:26Z

Add 4-byte address supports, so-that SPI-NOR chips
has > 16MiB should accessible.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
drivers/mtd/spi-nor/m25p80.c | 1 +
drivers/mtd/spi-nor/spi-nor.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/mtd/spi-nor.h | 6 +++++-
3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/m25p80.c b/drivers/mtd/spi-nor/m25p80.c
index 5465921..7af6f59 100644
--- a/drivers/mtd/spi-nor/m25p80.c
+++ b/drivers/mtd/spi-nor/m25p80.c
@@ -35,6 +35,7 @@ static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
cmd[1] = addr >> (nor->addr_width * 8 - 8);
cmd[2] = addr >> (nor->addr_width * 8 - 16);
cmd[3] = addr >> (nor->addr_width * 8 - 24);
+ cmd[4] = addr >> (nor->addr_width * 8 - 32);
}

static int m25p_cmdsz(struct spi_nor *nor)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 8bf9e67..e0085cf 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -632,6 +632,38 @@ static int stm_unlock(struct udevice *dev, loff_t ofs, uint64_t len)
}
#endif

+/* Enable/disable 4-byte addressing mode. */
+static int set_4byte(struct udevice *dev, const struct spi_nor_info *info,
+ int enable)
+{
+ struct spi_nor *nor = spi_nor_get_spi_nor_dev(dev);
+ const struct spi_nor_ops *ops = spi_nor_get_ops(dev);
+ int status;
+ bool need_wren = false;
+ u8 cmd;
+
+ switch (JEDEC_MFR(info)) {
+ case SNOR_MFR_MICRON:
+ /* Some Micron need WREN command; all will accept it */
+ need_wren = true;
+ case SNOR_MFR_MACRONIX:
+ case SNOR_MFR_WINBOND:
+ if (need_wren)
+ write_enable(dev);
+
+ cmd = enable ? SNOR_OP_EN4B : SNOR_OP_EX4B;
+ status = ops->write_reg(dev, cmd, NULL, 0);
+ if (need_wren)
+ write_disable(dev);
+
+ return status;
+ default:
+ /* Spansion style */
+ nor->cmd_buf[0] = enable << 7;
+ return ops->write_reg(dev, SNOR_OP_BRWR, nor->cmd_buf, 1);
+ }
+}
+
#ifdef CONFIG_SPI_NOR_MACRONIX
static int macronix_quad_enable(struct udevice *dev)
{
@@ -873,6 +905,12 @@ int spi_nor_scan(struct spi_nor *nor)
}

nor->addr_width = 3;
+ if (mtd->size > SNOR_16MB_BOUN) {
+ nor->addr_width = 4;
+ ret = set_4byte(nor->dev, info, true);
+ if (ret)
+ goto err;
+ }

/* Dummy cycles for read */
switch (nor->read_opcode) {
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index e1688e2..fc4a649 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -63,6 +63,10 @@
#define SNOR_OP_BP 0x02 /* Byte program */
#define SNOR_OP_AAI_WP 0xad /* Auto addr increment word program */

+/* Used for Macronix and Winbond flashes. */
+#define SNOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
+#define SNOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
+
/* Status Register bits. */
#define SR_WIP BIT(0) /* Write in progress */
#define SR_WEL BIT(1) /* Write enable latch */
@@ -84,7 +88,7 @@
/* Flash timeout values */
#define SNOR_READY_WAIT_PROG (2 * CONFIG_SYS_HZ)
#define SNOR_READY_WAIT_ERASE (5 * CONFIG_SYS_HZ)
-#define SNOR_MAX_CMD_SIZE 4
+#define SNOR_MAX_CMD_SIZE 6
#define SNOR_16MB_BOUN 0x1000000

/**
--
2.7.4