Hi Simon, On Sun, Jun 9, 2013 at 7:43 PM, Simon Glass <[email protected]> wrote: > Hi Jagan, > > On Sat, Jun 8, 2013 at 7:44 AM, Jagan Teki <[email protected]> wrote: >> >> Hi Simon, >> >> On Sat, Jun 8, 2013 at 8:02 PM, Simon Glass <[email protected]> wrote: >> > Hi Jagan, >> > >> > On Sat, Jun 8, 2013 at 1:32 AM, Jagan Teki <[email protected]> >> > wrote: >> >> >> >> Hi Simon, >> >> >> >> Please let know your comments. >> >> >> >> I have changed the logic, but removed spi_flash_cmd_poll_bit() use >> >> poll code on spi_flash_cmd_wait_ready() >> >> as no other call for spi_flash_cmd_poll_bit() this. >> >> >> >> And also for read_status the check_status i assigned as 0,earlier it >> >> has direct 0 (w/o check_status variable). >> >> >> >> To add the support for flag status on the same code, i define this >> >> check_status. >> >> I don't see any coding functionality change for now, compared to >> >> before. >> > >> > >> > This is not the right patch, but in one of them you remove >> > spi_flash_cmd_poll_bit(), so that it no longer works the same way. You >> > will >> > get lots of individual SPI transactions on the bus instead of a single >> > one >> > that reads the status byte continuously. >> >> I couldn't understand you clearly. >> >> Earlier all erase/write they were calling spi_flash_cmd_wait_ready >> with flash, timeout values. >> spi_flash_cmd_wait_ready() is intern call to spi_flash_cmd_poll_bit() >> with CMD_READ_STATUS and STATUS_WIP. >> >> In my changes I have removed spi_flash_cmd_poll_bit() as there is no >> other caller except spi_flash_cmd_wait_ready() >> so all polling stuff on spi_flash_cmd_wait_ready() means, still >> erase/program can call spi_flash_cmd_wait_ready() with >> flash, timeout and CMD_READ_STATUS and STAUS_WIP were use directly >> used on spi_flash_cmd_wait_ready() instead >> of passing through spi_flash_cmd_poll_bit(). >> >> Any wrong here, please comment. > > > You have changed the implementation of spi_flash_cmd_wait_ready() so that > instead of polling for the bit within a single SPI transaction (CS staying > asserted) you are now doing multiple transactions. > > The old code for spi_flash_cmd_wait_ready() ended up with an algorithm like > this, when you look inside the nested functions: > > spi_claim_bus(spi); > ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, SPI_XFER_BEGIN); > do { > ret = spi_xfer(spi, 8, NULL, &status, 0); > ... > } > spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END); > spi_release_bus(spi); > > The new code is: > > do { > spi_claim_bus(spi); > ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, SPI_XFER_BEGIN); > ret = spi_xfer(spi, data_len * 8, data_out, data_in, SPI_XFER_END); > spi_release_bus(spi); > ... > } while (...) > > > Can you see the difference? The bus clain and SPI_XFER_BEGIN/END is now > inside the loop.
Understand, i thought as we do _END transfer in old code as well. It could be fine to go with using common function as it will do _BEGIN and _END. What could be the problem you see if we do _BEGIN and _END on loop...? > > Is there a reason why this change is needed? Does updating the bank address > not work with the old code? It doesn't effect with banking. Thanks, Jagan. > > It is find to move the spi_flash_cmd_poll_bit() function into > spi_flash_cmd_wait_ready() - I am not worried about that. I am only worried > about your change of algorithm as above. > > Regards, > Simon > >> >> >> Thanks, >> Jagan. >> >> > >> > Do we need to change this? >> > >> > >> >> >> >> >> >> -- >> >> Thanks, >> >> Jagan. >> >> >> >> On Fri, May 31, 2013 at 6:22 PM, Jagannadha Sutradharudu Teki >> >> <[email protected]> wrote: >> >> > Flag status register polling is required for micron 512Mb flash >> >> > devices onwards, for performing erase/program operations. >> >> > >> >> > Like polling for WIP(Write-In-Progress) bit in read status register, >> >> > spi_flash_cmd_wait_ready will poll for PEC(Program-Erase-Control) >> >> > bit in flag status register. >> >> > >> >> > Signed-off-by: Jagannadha Sutradharudu Teki <[email protected]> >> >> > --- >> >> > Changes for v2: >> >> > - none >> >> > >> >> > drivers/mtd/spi/spi_flash.c | 15 ++++++++++++--- >> >> > drivers/mtd/spi/spi_flash_internal.h | 3 +++ >> >> > 2 files changed, 15 insertions(+), 3 deletions(-) >> >> > >> >> > diff --git a/drivers/mtd/spi/spi_flash.c >> >> > b/drivers/mtd/spi/spi_flash.c >> >> > index 527423d..8cd2988 100644 >> >> > --- a/drivers/mtd/spi/spi_flash.c >> >> > +++ b/drivers/mtd/spi/spi_flash.c >> >> > @@ -195,25 +195,34 @@ int spi_flash_cmd_wait_ready(struct spi_flash >> >> > *flash, unsigned long timeout) >> >> > unsigned long timebase; >> >> > int ret; >> >> > u8 status; >> >> > + u8 check_status = 0x0; >> >> > u8 poll_bit = STATUS_WIP; >> >> > u8 cmd = CMD_READ_STATUS; >> >> > >> >> > + if ((flash->idcode0 == 0x20) && >> >> > + (flash->size >= SPI_FLASH_512MB_STMIC)) { >> >> > + poll_bit = STATUS_PEC; >> >> > + check_status = poll_bit; >> >> > + cmd = CMD_FLAG_STATUS; >> >> > + } >> >> > + >> >> > timebase = get_timer(0); >> >> > do { >> >> > WATCHDOG_RESET(); >> >> > >> >> > ret = spi_flash_read_common(flash, &cmd, 1, &status, >> >> > 1); >> >> > if (ret < 0) { >> >> > - debug("SF: fail to read read status >> >> > register\n"); >> >> > + debug("SF: fail to read %s status >> >> > register\n", >> >> > + cmd == CMD_READ_STATUS ? "read" : >> >> > "flag"); >> >> > return ret; >> >> > } >> >> > >> >> > - if ((status & poll_bit) == 0) >> >> > + if ((status & poll_bit) == check_status) >> >> > break; >> >> > >> >> > } while (get_timer(timebase) < timeout); >> >> > >> >> > - if ((status & poll_bit) == 0) >> >> > + if ((status & poll_bit) == check_status) >> >> > return 0; >> >> > >> >> > /* Timed out */ >> >> > diff --git a/drivers/mtd/spi/spi_flash_internal.h >> >> > b/drivers/mtd/spi/spi_flash_internal.h >> >> > index ac4530f..cb7a505 100644 >> >> > --- a/drivers/mtd/spi/spi_flash_internal.h >> >> > +++ b/drivers/mtd/spi/spi_flash_internal.h >> >> > @@ -13,6 +13,7 @@ >> >> > #define SPI_FLASH_SECTOR_ERASE_TIMEOUT (10 * CONFIG_SYS_HZ) >> >> > >> >> > #define SPI_FLASH_16MB_BOUN 0x1000000 >> >> > +#define SPI_FLASH_512MB_STMIC 0x4000000 >> >> > >> >> > /* Common commands */ >> >> > #define CMD_READ_ID 0x9f >> >> > @@ -24,6 +25,7 @@ >> >> > #define CMD_PAGE_PROGRAM 0x02 >> >> > #define CMD_WRITE_DISABLE 0x04 >> >> > #define CMD_READ_STATUS 0x05 >> >> > +#define CMD_FLAG_STATUS 0x70 >> >> > #define CMD_WRITE_ENABLE 0x06 >> >> > #define CMD_ERASE_4K 0x20 >> >> > #define CMD_ERASE_32K 0x52 >> >> > @@ -38,6 +40,7 @@ >> >> > >> >> > /* Common status */ >> >> > #define STATUS_WIP 0x01 >> >> > +#define STATUS_PEC 0x80 >> >> > >> >> > /* Send a single-byte command to the device and read the response */ >> >> > int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, >> >> > size_t >> >> > len); >> >> > -- >> >> > 1.8.3 >> >> > _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
