f58872f45c
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> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: David Lechner <dlechner@baylibre.com> Tested-by: David Lechner <dlechner@baylibre.com> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> Link: https://patch.msgid.link/9802160b5e5baed7f83ee43ac819cb757a19be55.1720810545.git.marcelo.schmitt@analog.com Signed-off-by: Mark Brown <broonie@kernel.org> |
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| asm-generic | ||
| drm | ||
| linux | ||
| misc | ||
| mtd | ||
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| xen | ||
| Kbuild | ||