| Message ID | cover.1719686465.git.marcelo.schmitt@analog.com |
|---|---|
| Headers | show |
| Series | Add support for AD4000 series of ADCs | expand |
On Sat, 29 Jun 2024 16:04:40 -0300 Marcelo Schmitt <marcelo.schmitt@analog.com> wrote: > The behavior of an SPI controller data output line (SDO or MOSI or COPI > (Controller Output Peripheral Input) for disambiguation) is usually not > specified when the controller is not clocking out data on SCLK edges. > However, there do exist SPI peripherals that require specific MOSI line > state when data is not being clocked out of the controller. > > Conventional SPI controllers may set the MOSI line on SCLK edges then bring > it low when no data is going out or leave the line the state of the last > transfer bit. More elaborated controllers are capable to set the MOSI idle > state according to different configurable levels and thus are more suitable > for interfacing with demanding peripherals. > > Add SPI mode bits to allow peripherals to request explicit MOSI idle state > when needed. > > When supporting a particular MOSI idle configuration, the data output line > state is expected to remain at the configured level when the controller is > not clocking out data. When a device that needs a specific MOSI idle state > is identified, its driver should request the MOSI idle configuration by > setting the proper SPI mode bit. > > Acked-by: Nuno Sa <nuno.sa@analog.com> > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> I always like to see some nice ascii art. Very nice documentation. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index 93f59ebb5b79..c8ba5e490850 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -3950,6 +3956,7 @@ int spi_setup(struct spi_device *spi) > */ > bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | > SPI_NO_TX | SPI_NO_RX); > + Trivial grumpy comment. Don't touch white space in unrelated code! > ugly_bits = bad_bits & > (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | > SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
On Sat, 29 Jun 2024 16:05:33 -0300 Marcelo Schmitt <marcelo.schmitt@analog.com> wrote: > Implement MOSI idle low and MOSI idle high to better support peripherals > that request specific MOSI behavior. > > Acked-by: Nuno Sa <nuno.sa@analog.com> > Reviewed-by: David Lechner <dlechner@baylibre.com> > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> LGTM Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
On 06/30, Jonathan Cameron wrote: > On Sat, 29 Jun 2024 16:04:40 -0300 > Marcelo Schmitt <marcelo.schmitt@analog.com> wrote: > > > The behavior of an SPI controller data output line (SDO or MOSI or COPI > > (Controller Output Peripheral Input) for disambiguation) is usually not > > specified when the controller is not clocking out data on SCLK edges. > > However, there do exist SPI peripherals that require specific MOSI line > > state when data is not being clocked out of the controller. > > > > Conventional SPI controllers may set the MOSI line on SCLK edges then bring > > it low when no data is going out or leave the line the state of the last > > transfer bit. More elaborated controllers are capable to set the MOSI idle > > state according to different configurable levels and thus are more suitable > > for interfacing with demanding peripherals. > > > > Add SPI mode bits to allow peripherals to request explicit MOSI idle state > > when needed. > > > > When supporting a particular MOSI idle configuration, the data output line > > state is expected to remain at the configured level when the controller is > > not clocking out data. When a device that needs a specific MOSI idle state > > is identified, its driver should request the MOSI idle configuration by > > setting the proper SPI mode bit. > > > > Acked-by: Nuno Sa <nuno.sa@analog.com> > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> > > I always like to see some nice ascii art. Very nice documentation. > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > > index 93f59ebb5b79..c8ba5e490850 100644 > > --- a/drivers/spi/spi.c > > +++ b/drivers/spi/spi.c > > > @@ -3950,6 +3956,7 @@ int spi_setup(struct spi_device *spi) > > */ > > bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | > > SPI_NO_TX | SPI_NO_RX); > > + > > Trivial grumpy comment. Don't touch white space in unrelated code! Ouf, must have slipped through after messing around with spi_setup(). Didn't intend to add that. Fine if that can be removed when applying the patch. > > > ugly_bits = bad_bits & > > (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | > > SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
On Mon, 29 Jul 2024 19:02:23 +0100 Mark Brown <broonie@kernel.org> wrote: > On Sat, 29 Jun 2024 16:04:00 -0300, Marcelo Schmitt wrote: > > This patch series extends the SPI bitbang, gpio, and spi-engine controllers to > > support configurable MOSI line idle states. > > It then introduces the ad4000 driver which uses the MOSI idle configuration to > > provide improved support for the AD4000 series of ADCs. > > Documentation is added describing the new extension to the SPI protocol. > > The currently supported wiring modes for AD4000 devices were documented under > > IIO documentation directory. > > > > [...] > > Applied to > > https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next > > Thanks! > > [1/7] spi: Enable controllers to extend the SPI protocol with MOSI idle configuration > commit: f58872f45c36ded048bccc22701b0986019c24d8 > [2/7] spi: bitbang: Implement support for MOSI idle state configuration > commit: 320f6693097bf89d67f9cabad24a2b911e23073f > [3/7] spi: spi-gpio: Add support for MOSI idle state configuration > commit: 927d382c7efbcc2206c31fa2f672fa264c0f1d5b > [4/7] spi: spi-axi-spi-engine: Add support for MOSI idle configuration > commit: a62073f4b2164028fc7c5ae45ceba10c9326cd91 Hi Mark, Any chance of a tag + you seem to have also picked up the ADC dt binding. Patch 5/7. dt-bindings: iio: adc: Add AD4000 which I'm assuming was not intentional. I think I only need the definition of SPI_MOSI_IDLE_HIGH for 5-7 to build fine. If needed, I can use a local value for that in the driver and we can follow up with a patch using the main define once the trees come together upstream. Jonathan > > All being well this means that it will be integrated into the linux-next > tree (usually sometime in the next 24 hours) and sent to Linus during > the next merge window (or sooner if it is a bug fix), however if > problems are discovered then the patch may be dropped or reverted. > > You may get further e-mails resulting from automated or manual testing > and review of the tree, please engage with people reporting problems and > send followup patches addressing any issues that are reported if needed. > > If any updates are required or you are submitting further changes they > should be sent as incremental updates against current git, existing > patches will not be replaced. > > Please add any relevant lists and maintainers to the CCs when replying > to this mail. > > Thanks, > Mark >