From d08a1baf617a8b7f1959c6b24c1ee7590a0c06a5 Mon Sep 17 00:00:00 2001 From: Jagannadha Sutradharudu Teki Date: Thu, 26 Dec 2013 13:54:57 +0530 Subject: 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. Currently added set quad enable bit for winbond and spansion flash devices. stmicro flash doesn't require to set as qeb is volatile. remaining flash devices support will add in future patches. Signed-off-by: Jagannadha Sutradharudu Teki --- drivers/mtd/spi/sf_ops.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/mtd/spi/sf_ops.c') diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c index 39e06ecae..827f71912 100644 --- a/drivers/mtd/spi/sf_ops.c +++ b/drivers/mtd/spi/sf_ops.c @@ -38,6 +38,7 @@ int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr) return 0; } +#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND) static int spi_flash_cmd_write_config(struct spi_flash *flash, u8 cr) { u8 data[2]; @@ -62,6 +63,31 @@ static int spi_flash_cmd_write_config(struct spi_flash *flash, u8 cr) return 0; } +int spi_flash_set_qeb_winspan(struct spi_flash *flash) +{ + u8 qeb_status; + u8 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_WINSPAN) { + debug("SF: Quad enable bit is already set\n"); + } else { + ret = spi_flash_cmd_write_config(flash, STATUS_QEB_WINSPAN); + if (ret < 0) + return ret; + } + + return ret; +} +#endif + #ifdef CONFIG_SPI_FLASH_BAR static int spi_flash_cmd_bankaddr_write(struct spi_flash *flash, u8 bank_sel) { -- cgit v1.2.3-70-g09d2