From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VerWk-0003Xz-1F for linux-mtd@lists.infradead.org; Fri, 08 Nov 2013 19:15:31 +0000 Message-ID: <527D3835.1090702@ti.com> Date: Sat, 9 Nov 2013 00:45:01 +0530 From: Sourav Poddar MIME-Version: 1.0 To: Brian Norris Subject: Re: [PATCH v4] drivers: mtd: m25p80: add quad read support References: <1383935845-31116-1-git-send-email-computersforpeace@gmail.com> In-Reply-To: <1383935845-31116-1-git-send-email-computersforpeace@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: Marek Vasut , linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Saturday 09 November 2013 12:07 AM, Brian Norris wrote: > From: Sourav Poddar > > 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 > Signed-off-by: Brian Norris > --- > v3 -> v4 > > I made a few final tweaks to Sourav's patch. It got the precedence logic > wrong, where fast and normal read might override quad-read, and then > normal-read would in some cases override either of the others! > > drivers/mtd/devices/m25p80.c | 141 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 139 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c > index 04f8a24..f2f781d 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 { > @@ -136,6 +145,26 @@ static int read_sr(struct m25p *flash) > } > > /* > + * 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. > */ > @@ -225,6 +254,95 @@ static int wait_till_ready(struct m25p *flash) > } > > /* > + * 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"); > + 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"); > + 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"); > + 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"); > + return -EINVAL; > + } > + return status; > + default: > + status = spansion_quad_enable(flash); > + if (status) { > + dev_err(&flash->spi->dev, > + "Spansion quad-read not enabled"); > + return -EINVAL; > + } > + return status; > + } > +} > + > +/* > * Erase the whole flash memory > * > * Returns 0 if successful, non-zero otherwise. > @@ -363,6 +481,7 @@ 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 +846,7 @@ 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 +924,7 @@ 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 +944,7 @@ 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 +1086,7 @@ 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 +1214,21 @@ 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 +1250,9 @@ 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; Thanks Brian. This looks good to me. I cant test it now. I will test it once I go to office tommorow.