From 548cd3ab54da10f896daa7ca422236847a915734 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bean=20Huo=20=E9=9C=8D=E6=96=8C=E6=96=8C=20=28beanhuo=29?= Date: Wed, 17 Dec 2014 07:35:45 +0000 Subject: [PATCH] mtd: spi-nor: Add quad I/O support for Micron SPI NOR This patch adds code which enables Quad I/O mode on Micron SPI NOR flashes. For Micron SPI NOR flash, enabling or disabling quad I/O protocol can be done By two methods, which are to use EVCR (Enhanced Volatile Configuration Register) and the ENTER QUAD I/O MODE command. There is no difference between these two methods. Unfortunately, for some Micron SPI NOR flashes, there no ENTER Quad I/O command (35h), such as n25q064. But for all current Micron SPI NOR, if it support quad I/O mode, using EVCR definitely be supported. It is a recommended method to enable Quad I/O mode by EVCR, Quad I/O protocol bit 7. When EVCR bit 7 is reset to 0, the SPI NOR flash will operate in quad I/O mode. This patch has been tested on N25Q512A and MT25TL256BAA1ESF. Micron SPI NOR of spi_nor_ids[] table all support this method. Signed-off-by: Bean Huo Acked-by: Marek Vasut Signed-off-by: Brian Norris --- drivers/mtd/spi-nor/spi-nor.c | 62 +++++++++++++++++++++++++++++++++++++------ include/linux/mtd/spi-nor.h | 7 +++++ 2 files changed, 61 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 0f8ec3c2d015..ea196c18dec9 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -560,14 +560,14 @@ static const struct spi_device_id spi_nor_ids[] = { { "mx66l1g55g", INFO(0xc2261b, 0, 64 * 1024, 2048, SPI_NOR_QUAD_READ) }, /* Micron */ - { "n25q032", INFO(0x20ba16, 0, 64 * 1024, 64, 0) }, - { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, 0) }, - { "n25q128a11", INFO(0x20bb18, 0, 64 * 1024, 256, 0) }, - { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256, 0) }, - { "n25q256a", INFO(0x20ba19, 0, 64 * 1024, 512, SECT_4K) }, - { "n25q512a", INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K) }, - { "n25q512ax3", INFO(0x20ba20, 0, 64 * 1024, 1024, USE_FSR) }, - { "n25q00", INFO(0x20ba21, 0, 64 * 1024, 2048, USE_FSR) }, + { "n25q032", INFO(0x20ba16, 0, 64 * 1024, 64, SPI_NOR_QUAD_READ) }, + { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, SPI_NOR_QUAD_READ) }, + { "n25q128a11", INFO(0x20bb18, 0, 64 * 1024, 256, SPI_NOR_QUAD_READ) }, + { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256, SPI_NOR_QUAD_READ) }, + { "n25q256a", INFO(0x20ba19, 0, 64 * 1024, 512, SECT_4K | SPI_NOR_QUAD_READ) }, + { "n25q512a", INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) }, + { "n25q512ax3", INFO(0x20ba20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) }, + { "n25q00", INFO(0x20ba21, 0, 64 * 1024, 2048, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) }, /* PMC */ { "pm25lv512", INFO(0, 0, 32 * 1024, 2, SECT_4K_PMC) }, @@ -891,6 +891,45 @@ static int spansion_quad_enable(struct spi_nor *nor) return 0; } +static int micron_quad_enable(struct spi_nor *nor) +{ + int ret; + u8 val; + + ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1); + if (ret < 0) { + dev_err(nor->dev, "error %d reading EVCR\n", ret); + return ret; + } + + write_enable(nor); + + /* set EVCR, enable quad I/O */ + nor->cmd_buf[0] = val & ~EVCR_QUAD_EN_MICRON; + ret = nor->write_reg(nor, SPINOR_OP_WD_EVCR, nor->cmd_buf, 1, 0); + if (ret < 0) { + dev_err(nor->dev, "error while writing EVCR register\n"); + return ret; + } + + ret = spi_nor_wait_till_ready(nor); + if (ret) + return ret; + + /* read EVCR and check it */ + ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1); + if (ret < 0) { + dev_err(nor->dev, "error %d reading EVCR\n", ret); + return ret; + } + if (val & EVCR_QUAD_EN_MICRON) { + dev_err(nor->dev, "Micron EVCR Quad bit not clear\n"); + return -EINVAL; + } + + return 0; +} + static int set_quad_mode(struct spi_nor *nor, struct flash_info *info) { int status; @@ -903,6 +942,13 @@ static int set_quad_mode(struct spi_nor *nor, struct flash_info *info) return -EINVAL; } return status; + case CFI_MFR_ST: + status = micron_quad_enable(nor); + if (status) { + dev_err(nor->dev, "Micron quad-read not enabled\n"); + return -EINVAL; + } + return status; default: status = spansion_quad_enable(nor); if (status) { diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index 63aeccf9ddc8..4720b86ee73d 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -56,6 +56,10 @@ /* Used for Spansion flashes only. */ #define SPINOR_OP_BRWR 0x17 /* Bank register write */ +/* Used for Micron flashes only. */ +#define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */ +#define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */ + /* Status Register bits. */ #define SR_WIP 1 /* Write in progress */ #define SR_WEL 2 /* Write enable latch */ @@ -67,6 +71,9 @@ #define SR_QUAD_EN_MX 0x40 /* Macronix Quad I/O */ +/* Enhanced Volatile Configuration Register bits */ +#define EVCR_QUAD_EN_MICRON 0x80 /* Micron Quad I/O */ + /* Flag Status Register bits */ #define FSR_READY 0x80 -- 2.11.0