Hi Jagan, On 10 October 2014 11:31, Jagan Teki <jagannadh.t...@gmail.com> wrote: > Hi Simon, > > Can you please see my comments below, I'm relating more about cs and bus > valid scenario which is available on current drivers wrt dm-spi. > > On 30 September 2014 01:05, Simon Glass <s...@chromium.org> wrote: >> Add a uclass which provides access to SPI buses and includes operations >> required by SPI. >> >> For a time driver model will need to co-exist with the legacy SPI interface >> so some parts of the header file are changed depending on which is in use. >> The exports are adjusted also since some functions are not available with >> driver model. >> >> Boards must define CONFIG_DM_SPI to use driver model for SPI. >> >> Signed-off-by: Simon Glass <s...@chromium.org> >> --- >> >> Changes in v3: >> - Add a cs_info() method to the driver model SPI API > > I think this gives the enough info regarding cs on particular controller what > about the bus usage - which is also specific to controller it self, right? > > Say - spi controller on a particular soc, have spi0, spi1 means two buses > and 4 cs lines, cs0-cs3. How is this works in that case? > > And also I saw tegra20_sflash.c validates only cs > > int tegra20_sflash_cs_info(struct udevice *bus, unsigned int cs, > struct spi_cs_info *info) > > What about bus number check this particular tegra spi controller is concern.
The bus device is passed in as a pointer. The bus number gets looked up to find the device for that bus number. See spi_get_bus_and_cs() for that. This is good because drivers no longer need to validate the bus number. > >> - Add a uclass for a generic SPI device (for use with the 'sspi' command) >> - Add missing comments to spi.h >> - Correct typo where 'slave' should say 'bus' >> - Fix two comment typos >> - Put the cs member back into spi_slave >> - Use an explicit chip select value instead of reusing device sequence number >> >> Changes in v2: >> - Add missing comments for struct spi_slave >> - Fix code nits from Daniel Schwierzeck >> - Use 'bus' instead of 'dev' to make the API clearer >> >> common/exports.c | 4 +- >> drivers/spi/Makefile | 4 + >> drivers/spi/spi-uclass.c | 390 >> +++++++++++++++++++++++++++++++++++++++++++++++ >> include/dm/uclass-id.h | 2 + >> include/spi.h | 254 +++++++++++++++++++++++++++++- >> 5 files changed, 650 insertions(+), 4 deletions(-) >> create mode 100644 drivers/spi/spi-uclass.c >> >> +int spi_cs_is_valid(unsigned int busnum, unsigned int cs) > > Who is the caller for this? This can be called by boards, or anywhere really. It replaces the function with the same purpose in the old SPI framework. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
