> -----Original Message----- > From: Cédric Le Goater [mailto:c...@kaod.org] > Sent: Thursday, July 07, 2016 2:57 PM > To: Krzeminski, Marcin (Nokia - PL/Wroclaw) > <marcin.krzemin...@nokia.com>; qemu-devel@nongnu.org > Cc: crosthwaitepe...@gmail.com; rfsw-patc...@mlist.nokia.com; > peter.mayd...@linaro.org; c...@fr.ibm.com > Subject: Re: [PATCH] m25p80: Fix QIOR/DIOR handling for Winbond > > Hello Marcin, > > On 07/06/2016 02:43 PM, marcin.krzemin...@nokia.com wrote: > > From: Marcin Krzeminski <marcin.krzemin...@nokia.com> > > > > Winbond also support continuous read mode, but as an opposite for > > other flash type read mode clock cycles are included to dummy cycles > number. > > This path add proper handling of read mode byte and update needed > > dummy cycles. QPI mode and dummy cycles configuration are not > supported. > > > > Signed-off-by: Marcin Krzeminski <marcin.krzemin...@nokia.com> > > --- > > hw/block/m25p80.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c index > > d9b2793..a349544 100644 > > --- a/hw/block/m25p80.c > > +++ b/hw/block/m25p80.c > > @@ -149,6 +149,7 @@ typedef struct FlashPartInfo { */ > > > > #define SPANSION_CONTINUOUS_READ_MODE_CMD_LEN 1 > > +#define WINBOND_CONTINUOUS_READ_MODE_CMD_LEN 1 > > I checked the W25Q256FV datasheet and > > > static const FlashPartInfo known_devices[] = { > > /* Atmel -- some are (confusingly) marketed as "DataFlash" */ @@ > > -775,7 +776,7 @@ static void decode_dio_read_cmd(Flash *s) > > /* Dummy cycles modeled with bytes writes instead of bits */ > > switch (get_man(s)) { > > case MAN_WINBOND: > > - s->needed_bytes += 8; > > + s->needed_bytes += > WINBOND_CONTINUOUS_READ_MODE_CMD_LEN; > > this looks fine, > > > break; > > case MAN_SPANSION: > > s->needed_bytes += > SPANSION_CONTINUOUS_READ_MODE_CMD_LEN; > > @@ -814,7 +815,8 @@ static void decode_qio_read_cmd(Flash *s) > > /* Dummy cycles modeled with bytes writes instead of bits */ > > switch (get_man(s)) { > > case MAN_WINBOND: > > - s->needed_bytes += 8; > > + s->needed_bytes += > WINBOND_CONTINUOUS_READ_MODE_CMD_LEN; > > + s->needed_bytes += 4; > > but I don't understand the above. I see the address + M7-0 + 2 dummies. > Hello Cedric,
This is because the problematic interface in here. Generally you need to send 2 dummy bytes, but this is four clocks in this mode (Fig 24a). I want to send a proposal to change this dummy clock interface after 2.7 will be released, because now it is really confusing and unclear. Thanks, Marcin > Thanks, > > C. > > > break; > > case MAN_SPANSION: > > s->needed_bytes += > SPANSION_CONTINUOUS_READ_MODE_CMD_LEN; > >
