From 3487a63955c34ea508bcf4ca5131ddd953876e2d Mon Sep 17 00:00:00 2001 From: Sourav Poddar Date: Wed, 6 Nov 2013 20:05:35 +0530 Subject: [PATCH] drivers: mtd: m25p80: add quad read support Some flash also support quad read mode. Adding support for quad read mode in m25p80 for Spansion and Macronix flash. [Tweaked by Brian] With this patch, quad-read support will override fast-read and normal-read, if the SPI controller and flash chip both support it. Signed-off-by: Sourav Poddar Tested-by: Sourav Poddar Reviewed-by: Marek Vasut Signed-off-by: Brian Norris --- drivers/mtd/devices/m25p80.c | 139 ++++++++++++++++++++++++++++++++++- 1 file changed, 137 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index 04f8a245ffef..7dc2c147720a 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -41,6 +41,7 @@ #define OPCODE_WRSR 0x01 /* Write status register 1 byte */ #define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */ #define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */ +#define OPCODE_QUAD_READ 0x6b /* Read data bytes */ #define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */ #define OPCODE_BE_4K 0x20 /* Erase 4KiB block */ #define OPCODE_BE_4K_PMC 0xd7 /* Erase 4KiB block on PMC chips */ @@ -48,10 +49,12 @@ #define OPCODE_CHIP_ERASE 0xc7 /* Erase whole flash chip */ #define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */ #define OPCODE_RDID 0x9f /* Read JEDEC ID */ +#define OPCODE_RDCR 0x35 /* Read configuration register */ /* 4-byte address opcodes - used on Spansion and some Macronix flashes. */ #define OPCODE_NORM_READ_4B 0x13 /* Read data bytes (low frequency) */ #define OPCODE_FAST_READ_4B 0x0c /* Read data bytes (high frequency) */ +#define OPCODE_QUAD_READ_4B 0x6c /* Read data bytes */ #define OPCODE_PP_4B 0x12 /* Page program (up to 256 bytes) */ #define OPCODE_SE_4B 0xdc /* Sector erase (usually 64KiB) */ @@ -76,6 +79,11 @@ #define SR_BP2 0x10 /* Block protect 2 */ #define SR_SRWD 0x80 /* SR write protect */ +#define SR_QUAD_EN_MX 0x40 /* Macronix Quad I/O */ + +/* Configuration Register bits. */ +#define CR_QUAD_EN_SPAN 0x2 /* Spansion Quad I/O */ + /* Define max times to check status register before we give up. */ #define MAX_READY_WAIT_JIFFIES (40 * HZ) /* M25P16 specs 40s max chip erase */ #define MAX_CMD_SIZE 6 @@ -87,6 +95,7 @@ enum read_type { M25P80_NORMAL = 0, M25P80_FAST, + M25P80_QUAD, }; struct m25p { @@ -135,6 +144,26 @@ static int read_sr(struct m25p *flash) return val; } +/* + * Read configuration register, returning its value in the + * location. Return the configuration register value. + * Returns negative if error occured. + */ +static int read_cr(struct m25p *flash) +{ + u8 code = OPCODE_RDCR; + int ret; + u8 val; + + ret = spi_write_then_read(flash->spi, &code, 1, &val, 1); + if (ret < 0) { + dev_err(&flash->spi->dev, "error %d reading CR\n", ret); + return ret; + } + + return val; +} + /* * Write status register 1 byte * Returns negative if error occurred. @@ -224,6 +253,93 @@ static int wait_till_ready(struct m25p *flash) return 1; } +/* + * Write status Register and configuration register with 2 bytes + * The first byte will be written to the status register, while the + * second byte will be written to the configuration register. + * Return negative if error occured. + */ +static int write_sr_cr(struct m25p *flash, u16 val) +{ + flash->command[0] = OPCODE_WRSR; + flash->command[1] = val & 0xff; + flash->command[2] = (val >> 8); + + return spi_write(flash->spi, flash->command, 3); +} + +static int macronix_quad_enable(struct m25p *flash) +{ + int ret, val; + u8 cmd[2]; + cmd[0] = OPCODE_WRSR; + + val = read_sr(flash); + cmd[1] = val | SR_QUAD_EN_MX; + write_enable(flash); + + spi_write(flash->spi, &cmd, 2); + + if (wait_till_ready(flash)) + return 1; + + ret = read_sr(flash); + if (!(ret > 0 && (ret & SR_QUAD_EN_MX))) { + dev_err(&flash->spi->dev, "Macronix Quad bit not set\n"); + return -EINVAL; + } + + return 0; +} + +static int spansion_quad_enable(struct m25p *flash) +{ + int ret; + int quad_en = CR_QUAD_EN_SPAN << 8; + + write_enable(flash); + + ret = write_sr_cr(flash, quad_en); + if (ret < 0) { + dev_err(&flash->spi->dev, + "error while writing configuration register\n"); + return -EINVAL; + } + + /* read back and check it */ + ret = read_cr(flash); + if (!(ret > 0 && (ret & CR_QUAD_EN_SPAN))) { + dev_err(&flash->spi->dev, "Spansion Quad bit not set\n"); + return -EINVAL; + } + + return 0; +} + +static int set_quad_mode(struct m25p *flash, u32 jedec_id) +{ + int status; + + switch (JEDEC_MFR(jedec_id)) { + case CFI_MFR_MACRONIX: + status = macronix_quad_enable(flash); + if (status) { + dev_err(&flash->spi->dev, + "Macronix quad-read not enabled\n"); + return -EINVAL; + } + return status; + default: + status = spansion_quad_enable(flash); + if (status) { + dev_err(&flash->spi->dev, + "Spansion quad-read not enabled\n"); + return -EINVAL; + } + return status; + } +} + /* * Erase the whole flash memory * @@ -363,6 +479,7 @@ static inline int m25p80_dummy_cycles_read(struct m25p *flash) { switch (flash->flash_read) { case M25P80_FAST: + case M25P80_QUAD: return 1; case M25P80_NORMAL: return 0; @@ -727,6 +844,7 @@ struct flash_info { #define SST_WRITE 0x04 /* use SST byte programming */ #define M25P_NO_FR 0x08 /* Can't do fastread */ #define SECT_4K_PMC 0x10 /* OPCODE_BE_4K_PMC works uniformly */ +#define M25P80_QUAD_READ 0x20 /* Flash supports Quad Read */ }; #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags) \ @@ -804,7 +922,7 @@ static const struct spi_device_id m25p_ids[] = { { "mx25l12855e", INFO(0xc22618, 0, 64 * 1024, 256, 0) }, { "mx25l25635e", INFO(0xc22019, 0, 64 * 1024, 512, 0) }, { "mx25l25655e", INFO(0xc22619, 0, 64 * 1024, 512, 0) }, - { "mx66l51235l", INFO(0xc2201a, 0, 64 * 1024, 1024, 0) }, + { "mx66l51235l", INFO(0xc2201a, 0, 64 * 1024, 1024, M25P80_QUAD_READ) }, /* Micron */ { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, 0) }, @@ -824,7 +942,7 @@ static const struct spi_device_id m25p_ids[] = { { "s25sl032p", INFO(0x010215, 0x4d00, 64 * 1024, 64, 0) }, { "s25sl064p", INFO(0x010216, 0x4d00, 64 * 1024, 128, 0) }, { "s25fl256s0", INFO(0x010219, 0x4d00, 256 * 1024, 128, 0) }, - { "s25fl256s1", INFO(0x010219, 0x4d01, 64 * 1024, 512, 0) }, + { "s25fl256s1", INFO(0x010219, 0x4d01, 64 * 1024, 512, M25P80_QUAD_READ) }, { "s25fl512s", INFO(0x010220, 0x4d00, 256 * 1024, 256, 0) }, { "s70fl01gs", INFO(0x010221, 0x4d00, 256 * 1024, 256, 0) }, { "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024, 64, 0) }, @@ -966,6 +1084,7 @@ static int m25p_probe(struct spi_device *spi) unsigned i; struct mtd_part_parser_data ppdata; struct device_node *np = spi->dev.of_node; + int ret; /* Platform data helps sort out which chip type we have, as * well as how this board partitions it. If we don't have @@ -1093,8 +1212,21 @@ static int m25p_probe(struct spi_device *spi) if (info->flags & M25P_NO_FR) flash->flash_read = M25P80_NORMAL; + /* Quad-read mode takes precedence over fast/normal */ + if (spi->mode & SPI_RX_QUAD && info->flags & M25P80_QUAD_READ) { + ret = set_quad_mode(flash, info->jedec_id); + if (ret) { + dev_err(&flash->spi->dev, "quad mode not supported\n"); + return ret; + } + flash->flash_read = M25P80_QUAD; + } + /* Default commands */ switch (flash->flash_read) { + case M25P80_QUAD: + flash->read_opcode = OPCODE_QUAD_READ; + break; case M25P80_FAST: flash->read_opcode = OPCODE_FAST_READ; break; @@ -1116,6 +1248,9 @@ static int m25p_probe(struct spi_device *spi) if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) { /* Dedicated 4-byte command set */ switch (flash->flash_read) { + case M25P80_QUAD: + flash->read_opcode = OPCODE_QUAD_READ; + break; case M25P80_FAST: flash->read_opcode = OPCODE_FAST_READ_4B; break;