sf: Set quad enable bit support

This patch provides support to set the quad enable bit on flash.

quad enable bit needs to set before performing any quad IO
operations on respective SPI flashes.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index baed29b79570515c6f532ad147f650a7970fb704..6c266ac1a3656a04adfd810f31d82bf4b0d9999f 100644 (file)
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -407,6 +407,29 @@ int spi_flash_cmd_write_config(struct spi_flash *flash, u8 cr)
        return 0;
 }
 
+int spi_flash_set_qeb(struct spi_flash *flash)
+{
+       u8 qeb_status, cmd;
+       int ret;
+
+       cmd = CMD_READ_CONFIG;
+       ret = spi_flash_read_common(flash, &cmd, 1, &qeb_status, 1);
+       if (ret < 0) {
+               debug("SF: fail to read config register\n");
+               return ret;
+       }
+
+       if (qeb_status & STATUS_QEB) {
+               debug("SF: qeb is already set\n");
+       } else {
+               ret = spi_flash_cmd_write_config(flash, STATUS_QEB);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
 #ifdef CONFIG_SPI_FLASH_BAR
 int spi_flash_cmd_bankaddr_write(struct spi_flash *flash, u8 bank_sel)
 {
@@ -624,6 +647,15 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
                goto err_manufacturer_probe;
 #endif
 
+       /* set the quad enable bit - only for quad commands */
+       if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) ||
+           (flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
+               if (spi_flash_set_qeb(flash)) {
+                       debug("SF: Fail to set qeb\n");
+                       goto err_manufacturer_probe;
+               }
+       }
+
 #ifdef CONFIG_OF_CONTROL
        if (spi_flash_decode_fdt(gd->fdt_blob, flash)) {
                debug("SF: FDT decode error\n");

diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
index 1f105258b780af8af88cdf8597bc4d1e13882b30..4d4442343aae719ef0ec396f7d3d58b2a3610598 100644 (file)
--- a/drivers/mtd/spi/spi_flash_internal.h
+++ b/drivers/mtd/spi/spi_flash_internal.h
@@ -22,6 +22,7 @@
 #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
@@ -46,6 +47,7 @@
 
 /* Common status */
 #define STATUS_WIP                     0x01
+#define STATUS_QEB                     0x02
 #define STATUS_PEC                     0x80
 
 /* Send a single-byte command to the device and read the response */