Hi Jagan, On Thu, Jun 13, 2013 at 10:46 AM, Willis, Max <max.wil...@spansion.com>wrote:
> Hi Jagan, Simon - Adding Bacem and Gernot from Spansion. Would you be able > to add them to the other open threads as well? --Max > > ------------------------------------------------- > Max Willis, PhD > Division Marketing Manager > Software Marketing > Spansion Inc. > ------------------------------------------------- > > -----Original Message----- > From: Jagan Teki [mailto:jagannadh.t...@gmail.com] > Sent: Wednesday, June 12, 2013 10:32 PM > To: Simon Glass > Cc: Jagannadha Sutradharudu Teki; U-Boot Mailing List; Michal Simek; Tom > Rini; Rajeshwari Shinde; Syed Hussain; Willis, Max; Todd Legler (tlegler); > Jagannadha Sutradharudu Teki > Subject: Re: [PATCH v3 17/17] sf: Add Flag status register polling support > > Hi Simon, > > On Thu, Jun 13, 2013 at 4:12 AM, Simon Glass <s...@chromium.org> wrote: > > Hi Jagan, > > > > On Tue, Jun 11, 2013 at 12:23 PM, Jagannadha Sutradharudu Teki > > <jagannadha.sutradharudu-t...@xilinx.com> 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 <jaga...@xilinx.com> > >> > >> --- > >> Changes for v3: > >> - define the flag status code on CONFIG_SPI_FLASH_STMICRO > >> Changes for v2: > >> - none > >> > >> drivers/mtd/spi/spi_flash.c | 16 +++++++++++++--- > >> drivers/mtd/spi/spi_flash_internal.h | 2 ++ > >> 2 files changed, 15 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/mtd/spi/spi_flash.c > >> b/drivers/mtd/spi/spi_flash.c index bb37f54..4f97fab0 100644 > >> --- a/drivers/mtd/spi/spi_flash.c > >> +++ b/drivers/mtd/spi/spi_flash.c > >> @@ -200,12 +200,22 @@ 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; > >> > >> +#ifdef CONFIG_SPI_FLASH_STMICRO > >> + if (flash->size >= 0x4000000) { > >> + poll_bit = STATUS_PEC; > >> + check_status = poll_bit; > >> + cmd = CMD_FLAG_STATUS; > >> + } > >> +#endif > >> + > > > > > > Similarly to the bank addressing I think this might be better done as > > a 'poll method' rather than a hack for a particular flash type. > > > > You mean to say read_status cmd and flag_status cmd need to find it on > probe it self.? > Can you please explain "better done as a 'poll method' ' > What I mean is that spi_flash_cmd_wait_ready() is in generic code. CONFIG_SPI_FLASH_STMICRO means that U-Boot will support that flash, but it does not mean that it is the only flash. You have added a device-specific thing into generic code. If someone compiles a U-Boot with ST and Winbond flash, then both types of flash will use the code you added (the ST code above). > > > Also I worry that in a system with more than one type of flash, this > > code will fire for all flash types. > > Even if the system has multiple flashes of different size, we can probe > once at a time, right? > > -- > Thanks, > Jagan. > Regards, Simon
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