[U-Boot] [V4 1/2] sf: Add clear flag status register operation on Micron chips

[Hou Zhiqiang]

> -----Original Message-----
> From: Jagan Teki [mailto:jteki at openedev.com]
> Sent: 2015年8月7日 16:22
> To: Hou Zhiqiang-B48286
> Cc: u-boot at lists.denx.de; Hu Mingkai-B21284
> Subject: Re: [U-Boot] [V4 1/2] sf: Add clear flag status register
> operation on Micron chips
> 
> On 23 July 2015 at 15:24, Zhiqiang Hou <B48286 at freescale.com> wrote:
> > From: Hou Zhiqiang <B48286 at freescale.com>
> >
> > Add clear flag status register operation that was required by Micron
> > SPI flash chips after reading the flag status register to check if the
> > erase and program operations complete or an error occur.
> 
> Flag status requires N25Q512 + parts, so clear flag status we need add
> only in this scenario is that true?
> 

Yes, so the clear FSR operation will work only if the chip supports FSR.
And if the chip supports FSR, it will support both read and clear FSR.
So there is a condition branch "if (cmd == CMD_FLAG_STATUS)".

> >
> > Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
> > Signed-off-by: Mingkai.Hu <Mingkai.Hu at freescale.com>
> > ---
> >  drivers/mtd/spi/sf_internal.h |  9 +++++++++
> >  drivers/mtd/spi/sf_ops.c      | 40 ++++++++++++++++++++++++++++++++---
> -----
> >  2 files changed, 41 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/mtd/spi/sf_internal.h
> > b/drivers/mtd/spi/sf_internal.h index 9fb5557..703d4a7 100644
> > --- a/drivers/mtd/spi/sf_internal.h
> > +++ b/drivers/mtd/spi/sf_internal.h
> > @@ -73,6 +73,7 @@ enum {
> >  #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
> > @@ -96,6 +97,8 @@ enum {
> >  #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)
> > @@ -182,6 +185,12 @@ 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_slave
> > +*spi) {
> > +       return spi_flash_cmd(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
> > 38592f5..cbb9f00 100644
> > --- a/drivers/mtd/spi/sf_ops.c
> > +++ b/drivers/mtd/spi/sf_ops.c
> > @@ -160,6 +160,7 @@ static int spi_flash_poll_status(struct spi_slave
> *spi, 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;
> >
> > @@ -182,22 +183,45 @@ static int spi_flash_poll_status(struct spi_slave
> *spi, 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");
> > +               if (cmd == CMD_FLAG_STATUS) {
> > +                       if (spi_flash_cmd_clear_flag_status(spi) < 0)
> > +                               debug("SF: clear flag status failed\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(spi) < 0) {
> > +                       debug("SF: clear flag status failed\n");
> > +                       ret = -1;
> > +               }
> > +       }
> > +#endif
> > +       return ret;
> >  }
> >
> >  int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long
> > timeout) @@ -252,7 +276,7 @@ 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;
> > --
> > 2.1.0.27.g96db324
> >
> > _______________________________________________
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> > U-Boot at lists.denx.de
> > http://lists.denx.de/mailman/listinfo/u-boot
> 
> 
> 
> --
> Jagan | openedev.