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From 96b232d03a0c4462eacf879ed80b0cfd235e65c4 Mon Sep 17 00:00:00 2001
From: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Date: Fri, 8 Jan 2016 17:02:17 +0100
Subject: [PATCH 20/33] mtd: spi-nor: fix support of Winbond memories
This patch fixes the support of Winbond memories. Indeed, before
performing any Quad SPI command, the Quad Enable (QE) non-volatile bit
MUST be set in the Status Register 2.
According to the w25q16fw datasheet from Winbond:
"When QE=1, the /WP pin becomes IO2 and /HOLD pin becomes IO3."
Quad SPI instructions requires the bidirectional IO2 and IO3 pins.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
---
drivers/mtd/spi-nor/spi-nor.c | 100 ++++++++++++++++++++++++++++++++++++++++++
include/linux/mtd/spi-nor.h | 6 +++
2 files changed, 106 insertions(+)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 1b1f5a6..aa7d26d 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1166,6 +1166,40 @@ static int spansion_quad_enable(struct spi_nor *nor)
return 0;
}
+static int winbond_quad_enable(struct spi_nor *nor)
+{
+ int ret;
+ u8 sr2;
+
+ ret = nor->read_reg(nor, SPINOR_OP_RDSR2_WINB, &sr2, 1);
+ if (ret < 0)
+ return ret;
+
+ if (likely(sr2 & SR2_QUAD_EN_WINB))
+ return 0;
+ dev_warn(nor->dev, "Winbond Quad mode disabled, enable it\n");
+
+ write_enable(nor);
+
+ sr2 |= SR2_QUAD_EN_WINB;
+ ret = nor->write_reg(nor, SPINOR_OP_WRSR2_WINB, &sr2, 1);
+ if (ret < 0)
+ return ret;
+
+ if (spi_nor_wait_till_ready(nor))
+ return -EIO;
+
+ ret = nor->read_reg(nor, SPINOR_OP_RDSR2_WINB, &sr2, 1);
+ if (ret < 0)
+ return ret;
+ if (!(sr2 & SR2_QUAD_EN_WINB)) {
+ dev_err(nor->dev, "Winbond Quad bit not set\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int macronix_set_quad_mode(struct spi_nor *nor)
{
int status;
@@ -1226,6 +1260,63 @@ static int macronix_set_single_mode(struct spi_nor *nor)
return 0;
}
+static int winbond_set_quad_mode(struct spi_nor *nor)
+{
+ int status;
+
+ /* Check whether the QPI mode is enabled. */
+ if (nor->read_proto == SNOR_PROTO_4_4_4) {
+ /* Since the QPI mode is enabled, the Quad Enabled (QE)
+ * non-volatile bit is already set.
+ * If the Fast Read 1-4-4 (0xeb) were used, we should
+ * take care about the value M7-M0 written during
+ * dummy/mode cycles to avoid entering the continuous
+ * read mode by mistake.
+ * Also the Fast Read 1-1-4 (0x6b) op code is not
+ * supported in QPI mode.
+ * Hence the Fast Read 1-1-1 (0x0b) op code is chosen.
+ */
+ nor->read_opcode = SPINOR_OP_READ_FAST;
+ return 0;
+ }
+
+ /*
+ * The QPI mode is disabled but we still need to set the QE bit:
+ * when QE=1, the /WP pin becomes IO2 and /HOLD pin becomes IO3.
+ * If the Fast Read 1-4-4 (0xeb) were used, we should take care
+ * about the value M7-M0 written during dummy/mode cycles to
+ * avoid entering the continuous read mode by mistake.
+ * Hence the Fast Read 1-1-4 (0x6b) op code is preferred.
+ */
+ status = winbond_quad_enable(nor);
+ if (status) {
+ dev_err(nor->dev, "Winbond quad-read nor enabled\n");
+ return status;
+ }
+ nor->read_proto = SNOR_PROTO_1_1_4;
+ nor->read_opcode = SPINOR_OP_READ_1_1_4;
+ return 0;
+}
+
+/*
+ * For both Winbond Dual and Single modes, we don't care about the value of
+ * the Quad Enabled (QE) bit since the memory still replies to Dual or Single
+ * SPI commands.
+ */
+
+static int winbond_set_dual_mode(struct spi_nor *nor)
+{
+ nor->read_proto = SNOR_PROTO_1_1_2;
+ nor->read_opcode = SPINOR_OP_READ_1_1_2;
+ return 0;
+}
+
+static int winbond_set_single_mode(struct spi_nor *nor)
+{
+ nor->read_proto = SNOR_PROTO_1_1_1;
+ return 0;
+}
+
static int set_quad_mode(struct spi_nor *nor, const struct flash_info *info)
{
int status;
@@ -1234,6 +1325,9 @@ static int set_quad_mode(struct spi_nor *nor, const struct flash_info *info)
case SNOR_MFR_MACRONIX:
return macronix_set_quad_mode(nor);
+ case SNOR_MFR_WINBOND:
+ return winbond_set_quad_mode(nor);
+
case SNOR_MFR_MICRON:
/* Check whether Micron Quad mode is enabled. */
if (nor->read_proto != SNOR_PROTO_4_4_4)
@@ -1263,6 +1357,9 @@ static int set_dual_mode(struct spi_nor *nor, const struct flash_info *info)
case SNOR_MFR_MACRONIX:
return macronix_set_dual_mode(nor);
+ case SNOR_MFR_WINBOND:
+ return winbond_set_dual_mode(nor);
+
case SNOR_MFR_MICRON:
/* Check whether Micron Dual mode is enabled. */
if (nor->read_proto != SNOR_PROTO_2_2_2)
@@ -1284,6 +1381,9 @@ static int set_single_mode(struct spi_nor *nor, const struct flash_info *info)
case SNOR_MFR_MACRONIX:
return macronix_set_single_mode(nor);
+ case SNOR_MFR_WINBOND:
+ return winbond_set_single_mode(nor);
+
default:
nor->read_proto = SNOR_PROTO_1_1_1;
break;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 89e3228..46343f5 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -75,6 +75,12 @@
#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
+/* Used for Winbond flashes only. */
+#define SPINOR_OP_RDSR2_WINB 0x35 /* Read status register 2 */
+#define SPINOR_OP_WRSR2_WINB 0x31 /* Write status register 2 */
+
+#define SR2_QUAD_EN_WINB BIT(1) /* Quad Enable bit */
+
/* Used for Spansion flashes only. */
#define SPINOR_OP_BRWR 0x17 /* Bank register write */
--
2.8.1
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