[U-Boot] [PATCH] sf: Add support for flag status register on Micron chips

[B48286 at freescale.com]

> -----Original Message-----
> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> Sent: Friday, August 29, 2014 5:43 PM
> To: Hou Zhiqiang-B48286
> Cc: u-boot at lists.denx.de; Hu Mingkai-B21284; Sun York-R58495
> Subject: Re: [U-Boot] [PATCH] sf: Add support for flag status register 
> on Micron chips
> 
> On 29 August 2014 12:24, Hou Zhiqiang <B48286 at freescale.com> wrote:
> > Add clear flag status register operation that some Micron SPI flash 
> > chips required after reading the flag status register to check some 
> > operations completion.
> >
> > Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
> > ---
> > Based on git://git.denx.de/u-boot.git.
> > It also can be applied to git://www.denx.de/git/u-boot-mpc85xx.git.
> > Tested on board T2080QDS and T2080RDB.
> 
> Flag status register support is been added for stmicro flashes which 
> are >= 512MB sizes.
> 
> #ifdef CONFIG_SPI_FLASH_STMICRO
>         if (params->flags & E_FSR)
>                 flash->poll_cmd = CMD_FLAG_STATUS; #endif
> 
> Please check the condition on current tree bases, and let me know for 
> any questions.

First, this patch is generated base on the updated git://git.denx.de/u-boot.git.
Yes, the read operation of flag status register has been added, but I find the erase operation failed for SPI flash N25Q512A due to missing to clear the flag status register.

> 
> >
> >  drivers/mtd/spi/sf_internal.h |  9 +++++++++
> >  drivers/mtd/spi/sf_ops.c      | 36 ++++++++++++++++++++++++++++-------
> -
> >  2 files changed, 37 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/mtd/spi/sf_internal.h 
> > b/drivers/mtd/spi/sf_internal.h index 6bcd522..162dd87 100644
> > --- a/drivers/mtd/spi/sf_internal.h
> > +++ b/drivers/mtd/spi/sf_internal.h
> > @@ -36,6 +36,7 @@
> >  #define CMD_WRITE_ENABLE               0x06
> >  #define CMD_READ_CONFIG                        0x35
> >  #define CMD_FLAG_STATUS                        0x70
> > +#define CMD_CLEAR_FLAG_STATUS          0x50
> >
> >  /* Read commands */
> >  #define CMD_READ_ARRAY_SLOW            0x03
> > @@ -59,6 +60,8 @@
> >  #define STATUS_QEB_WINSPAN             (1 << 1)
> >  #define STATUS_QEB_MXIC                        (1 << 6)
> >  #define STATUS_PEC                     (1 << 7)
> > +#define STATUS_PROT                    (1 << 1)
> > +#define STATUS_ERASE                   (1 << 5)
> >
> >  /* Flash timeout values */
> >  #define SPI_FLASH_PROG_TIMEOUT         (2 * CONFIG_SYS_HZ)
> > @@ -120,6 +123,12 @@ static inline int
> spi_flash_cmd_write_disable(struct spi_flash *flash)
> >         return spi_flash_cmd(flash->spi, CMD_WRITE_DISABLE, NULL, 
> > 0); }
> >
> > +/* Clear flag status register */
> > +static inline int spi_flash_cmd_clear_flag_status(struct spi_flash
> > +*flash) {
> > +       return spi_flash_cmd(flash->spi, CMD_CLEAR_FLAG_STATUS, 
> > +NULL, 0); }
> > +
> >  /*
> >   * Send the read status command to the device and wait for the wip
> >   * (write-in-progress) bit to clear itself.
> > diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c 
> > index 85cf22d..08ff1df 100644
> > --- a/drivers/mtd/spi/sf_ops.c
> > +++ b/drivers/mtd/spi/sf_ops.c
> > @@ -160,6 +160,7 @@ int spi_flash_cmd_wait_ready(struct spi_flash
> *flash, unsigned long timeout)
> >         unsigned long timebase;
> >         unsigned long flags = SPI_XFER_BEGIN;
> >         int ret;
> > +       int out_of_time = 1;
> >         u8 status;
> >         u8 check_status = 0x0;
> >         u8 poll_bit = STATUS_WIP;
> > @@ -186,22 +187,41 @@ int spi_flash_cmd_wait_ready(struct spi_flash
> *flash, unsigned long timeout)
> >                 WATCHDOG_RESET();
> >
> >                 ret = spi_xfer(spi, 8, NULL, &status, 0);
> > -               if (ret)
> > +               if (ret) {
> > +                       spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
> >                         return -1;
> > +               }
> >
> > -               if ((status & poll_bit) == check_status)
> > +               if ((status & poll_bit) == check_status) {
> > +                       out_of_time = 0;
> >                         break;
> > +               }
> >
> >         } while (get_timer(timebase) < timeout);
> >
> >         spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
> >
> > -       if ((status & poll_bit) == check_status)
> > -               return 0;
> > +       if (out_of_time) {
> > +               /* Timed out */
> > +               debug("SF: time out!\n");
> > +               ret = -1;
> > +       }
> > +#ifdef CONFIG_SPI_FLASH_STMICRO
> > +       else if (cmd == CMD_FLAG_STATUS) {
> > +               if (!(status & (STATUS_PROT | STATUS_ERASE))) {
> > +                       ret = 0;
> > +               } else {
> > +                       debug("SF: flag status error");
> > +                       ret = -1;
> > +               }
> >
> > -       /* Timed out */
> > -       debug("SF: time out!\n");
> > -       return -1;
> > +               if (spi_flash_cmd_clear_flag_status(flash) < 0) {
> > +                       debug("SF: clear flag status failed\n");
> > +                       ret = -1;
> > +               }
> > +       }
> > +#endif
> > +       return ret;
> >  }
> >
> >  int spi_flash_write_common(struct spi_flash *flash, const u8 *cmd, 
> > @@
> > -234,7 +254,7 @@ int spi_flash_write_common(struct spi_flash *flash, 
> > const u8 *cmd,
> >
> >         ret = spi_flash_cmd_wait_ready(flash, timeout);
> >         if (ret < 0) {
> > -               debug("SF: write %s timed out\n",
> > +               debug("SF: write %s failed\n",
> >                       timeout == SPI_FLASH_PROG_TIMEOUT ?
> >                         "program" : "page erase");
> >                 return ret;
> > --
> > 1.8.5
> 
> thanks!
> --
> Jagan.