> > Hi, Pekon > > 2013/8/26 Gupta, Pekon <pekon@xxxxxx>: > >> > >> fix one thing in patch: > >> commit id:f477b7fb13df2b843997559ff34e87d054ba6538 > >> > >> change property spi-tx-nbits and spi-rx-nbits to optional. > >> If User don't set spi-tx-nbits or spi-rx-nbits, spi device mode > >> should be regarded as SINGLE, not return an error. > >> > >> Signed-off-by: wangyuhang <wangyuhang2014@xxxxxxxxx> > >> --- > >> drivers/spi/spi.c | 68 +++++++++++++++++++++++++---------------------- > ---- > >> -- > >> 1 file changed, 32 insertions(+), 36 deletions(-) > >> > >> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > >> index 50f7fc3..46a55f0 100644 > >> --- a/drivers/spi/spi.c > >> +++ b/drivers/spi/spi.c > >> @@ -872,46 +872,42 @@ static void of_register_spi_devices(struct > >> spi_master *master) > >> /* Device DUAL/QUAD mode */ > >> prop = of_get_property(nc, "spi-tx-nbits", &len); > >> if (!prop || len < sizeof(*prop)) { > >> - dev_err(&master->dev, "%s has no 'spi-tx-nbits' > >> property\n", > >> - nc->full_name); > >> - spi_dev_put(spi); > >> - continue; > >> - } > >> - switch (be32_to_cpup(prop)) { > >> - case SPI_NBITS_SINGLE: > >> - break; > >> - case SPI_NBITS_DUAL: > >> - spi->mode |= SPI_TX_DUAL; > >> - break; > >> - case SPI_NBITS_QUAD: > >> - spi->mode |= SPI_TX_QUAD; > >> - break; > >> - default: > >> - dev_err(&master->dev, "spi-tx-nbits value is not > >> supported\n"); > >> - spi_dev_put(spi); > >> - continue; > >> + /* set tx mode in SINGLE as default */ > > [Pekon]: I think you should explicitly set, and not trust spi->mode defaults. > > spi->mode |= SPI_TX_SINGLE; > > > Now @spi_device->mode [bit8: SPI_TX_DUAL] [bit9: SPI_TX_QUAD] [bit10: > SPI_RX_DUAL] [bit11: SPI_RX_QUAD]. Because to every spi controller, > SPI SINGLE must be supported, so I did not add that as a mode. My > initial thought is if user don't select SPI_TX_DUAL and SPI_TX_QUAD, > then it is TX_SINGLE mode[bit8: 0 bit9: 0]. > Now 2 approaches as follows: > 1) #define SPI_TX_SINGLE ~(SPI_TX_DUAL | SPI_TX_QUAD) > case SPI_NBITS_SINGLE: > spi->mode & SPI_TX_SINGLE; > break; > 2)Adding a new bit in mode to specify SPI_SINGLE. But this bit also > should be reflected to @master->mode_bits. To the probe of each spi > controller driver, it is necessary to do "master->mode_bits |= > SPI_TX_SINGLE | SPI_RX_SINGLE;", in such case, it's not like a > selected mode, it's like a compulsary condition. Since all controller > do support, there's no need to make it a mode. > > So I prefer the previous correction, what's your idea. > [Pekon]: Ok makes sense.. (1) is preferred, as it is compatible to existing layout with regards, pekon ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f