Patchwork [U-Boot,PATCHv3,3/7] drivers: mtd: :spi: Add quad read support

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Submitter Poddar, Sourav
Date Sept. 18, 2013, 12:21 p.m.
Message ID <1379506888-10040-4-git-send-email-sourav.poddar@ti.com>
Download mbox | patch
Permalink /patch/275695/
State Superseded
Delegated to: Jagannadha Sutradharudu Teki
Headers show

Comments

Poddar, Sourav - Sept. 18, 2013, 12:21 p.m.
From: Ravikumar Kattekola <rk@ti.com>

Some flash like S25fl256s supports quad read mode also.
This patch enables the quad read support based on
CONFIG_SF_QUAD_RD config.

Enabling quad read has the following components:
1. Enable the Quad mode bit in the flash device side.
2. Add a quad read mode read api. I have created a new
   api for quad mode as some flash has few more quad read
   command that can be supported. As of now, I have addded only
   QUAD OUTPUT READ command.
3. spi driver need to know that the read to be done is the
   quad read. Communicate this to the driver through a
   "SPI_QUAD" flag. This need to be done because quad read should 
only happen when quad command is sent. For reading status register
and other configuration register normal transfers should happen.

Signed-off-by: Ravikumar Kattekola <rk@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
---
 drivers/mtd/spi/spi_flash.c          |  109 +++++++++++++++++++++++++++++++++-
 drivers/mtd/spi/spi_flash_internal.h |    2 +
 include/spi.h                        |    2 +
 3 files changed, 112 insertions(+), 1 deletions(-)

Patch

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 5d5055f..993a9d4 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -42,8 +42,13 @@  static int spi_flash_read_write(struct spi_slave *spi,
 		debug("SF: Failed to send command (%zu bytes): %d\n",
 		      cmd_len, ret);
 	} else if (data_len != 0) {
+		if (spi->quad_enable)
+			flags = SPI_QUAD;
+		else
+			flags = 0;
+
 		ret = spi_xfer(spi, data_len * 8, data_out, data_in,
-					SPI_XFER_END);
+					flags | SPI_XFER_END);
 		if (ret)
 			debug("SF: Failed to transfer %zu bytes of data: %d\n",
 			      data_len, ret);
@@ -272,6 +277,58 @@  int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
 	return ret;
 }
 
+int spi_flash_cmd_read_quad(struct spi_flash *flash, u32 offset,
+		size_t len, void *data)
+{
+	struct spi_slave *spi = flash->spi;
+	u8 cmd[5], bank_sel = 0;
+	u32 remain_len, read_len;
+	int ret = -1;
+
+	/* Handle memory-mapped SPI */
+	if (flash->memory_map) {
+		memcpy(data, flash->memory_map + offset, len);
+		return 0;
+	}
+
+	spi->quad_enable = true;
+	cmd[0] = CMD_READ_ARRAY_QUAD;
+	cmd[4] = 0x00;
+
+	while (len) {
+#ifdef CONFIG_SPI_FLASH_BAR
+		bank_sel = offset / SPI_FLASH_16MB_BOUN;
+
+		ret = spi_flash_cmd_bankaddr_write(flash, bank_sel);
+		if (ret) {
+			debug("SF: fail to set bank%d\n", bank_sel);
+			return ret;
+		}
+#endif
+
+		remain_len = (SPI_FLASH_16MB_BOUN * (bank_sel + 1) - offset);
+		if (len < remain_len)
+			read_len = len;
+		else
+			read_len = remain_len;
+
+		spi_flash_addr(offset, cmd);
+
+		ret = spi_flash_read_common(flash, cmd, sizeof(cmd),
+						data, read_len);
+		if (ret < 0) {
+			debug("SF: read failed\n");
+			break;
+		}
+
+		offset += read_len;
+		len -= read_len;
+		data += read_len;
+	}
+
+	return ret;
+}
+
 int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 		size_t len, void *data)
 {
@@ -395,6 +452,48 @@  int spi_flash_bank_config(struct spi_flash *flash, u8 idcode0)
 }
 #endif
 
+int spi_flash_en_quad_mode(struct spi_flash *flash)
+{
+	u8 stat, con, cd;
+	u16 cr;
+	int ret;
+	cd = CMD_WRITE_STATUS;
+
+	ret = spi_flash_cmd_write_enable(flash);
+	if (ret < 0) {
+		debug("SF: enabling write failed\n");
+		goto out;
+	}
+	ret = spi_flash_cmd(flash->spi, CMD_READ_STATUS, &stat, 1);
+	ret = spi_flash_cmd(flash->spi, CMD_READ_CONFIG, &con, 1);
+	if (ret < 0) {
+		debug("%s: SF: read CR failed\n", __func__);
+		goto out;
+	}
+	/* Byte 1 - status reg, Byte 2 - config reg */
+	cr = ((con | (0x1 << 1)) << 8) | (stat << 0);
+
+	ret = spi_flash_cmd_write(flash->spi, &cd, 1, &cr, 2);
+	if (ret) {
+		debug("SF: fail to write conf register\n");
+		goto out;
+	}
+
+	ret = spi_flash_cmd_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+	if (ret < 0) {
+		debug("SF: write conf register timed out\n");
+		goto out;
+	}
+
+	ret = spi_flash_cmd_write_disable(flash);
+	if (ret < 0) {
+		debug("SF: disabling write failed\n");
+		goto out;
+	}
+out:
+	return ret;
+}
+
 #ifdef CONFIG_OF_CONTROL
 int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
 {
@@ -549,6 +648,10 @@  struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 		goto err_manufacturer_probe;
 #endif
 
+#ifdef CONFIG_SF_QUAD_RD
+	spi_flash_en_quad_mode(flash);
+#endif
+
 #ifdef CONFIG_OF_CONTROL
 	if (spi_flash_decode_fdt(gd->fdt_blob, flash)) {
 		debug("SF: FDT decode error\n");
@@ -601,7 +704,11 @@  void *spi_flash_do_alloc(int offset, int size, struct spi_slave *spi,
 	flash->name = name;
 	flash->poll_cmd = CMD_READ_STATUS;
 
+#ifdef CONFIG_SF_QUAD_RD
+	flash->read = spi_flash_cmd_read_quad;
+#else
 	flash->read = spi_flash_cmd_read_fast;
+#endif
 	flash->write = spi_flash_cmd_write_multi;
 	flash->erase = spi_flash_cmd_erase;
 
diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
index af1afa9..b388837 100644
--- a/drivers/mtd/spi/spi_flash_internal.h
+++ b/drivers/mtd/spi/spi_flash_internal.h
@@ -17,11 +17,13 @@ 
 
 #define CMD_READ_ARRAY_SLOW		0x03
 #define CMD_READ_ARRAY_FAST		0x0b
+#define CMD_READ_ARRAY_QUAD		0x6b
 
 #define CMD_WRITE_STATUS		0x01
 #define CMD_PAGE_PROGRAM		0x02
 #define CMD_WRITE_DISABLE		0x04
 #define CMD_READ_STATUS			0x05
+#define CMD_READ_CONFIG			0x35
 #define CMD_FLAG_STATUS			0x70
 #define CMD_WRITE_ENABLE		0x06
 #define CMD_ERASE_4K			0x20
diff --git a/include/spi.h b/include/spi.h
index c0dab57..9d4b2dc 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -27,6 +27,7 @@ 
 /* SPI transfer flags */
 #define SPI_XFER_BEGIN	0x01			/* Assert CS before transfer */
 #define SPI_XFER_END	0x02			/* Deassert CS after transfer */
+#define SPI_QUAD	0x04			/* Use QUAD read command */
 
 /* Header byte that marks the start of the message */
 #define SPI_PREAMBLE_END_BYTE	0xec
@@ -45,6 +46,7 @@  struct spi_slave {
 	unsigned int	bus;
 	unsigned int	cs;
 	unsigned int max_write_size;
+	bool quad_enable;
 };
 
 /*-----------------------------------------------------------------------