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path: root/drivers/spi/rk_spi.h
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2018-05-07SPDX: Convert all of our single license tags to Linux Kernel styleTom Rini
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
2017-05-10rockchip: spi: rk_spi: dynamically select an module input ratePhilipp Tomsich
The original clock/bitrate selection code for the rk_spi driver was a bit limited, as it always selected a 99MHz input clock rate (which would allow for a maximum bitrate of 49.5MBit/s), but returned -EINVAL if a bitrate higher than 48MHz was requested. To give us better control over the bitrate (i.e. add more operating points, especially at "higher" bitrate---such as above 9MBit/s), we try to choose 4x the maximum frequency (clamped to 50MBit) from the DTS instead of 99MHz... for most use-cases this will yield a frequency of 198MHz, but is flexible to go beyond this in future configurations. This also rewrites the check to allow frequencies of up to half the SPI module rate as bitrates and then clamps to whatever the DTS allows as a maximum (board-specific) frequency and does away with the -EINVAL when trying to select a bitrate (for cases that exceeded the hard limit) and instead consistently clamps to the lower of the hard limit, the soft limit for the SPI bus (from the DTS) or the soft limit for the SPI slave device. This replaces "rockchip: spi: rk_spi: select 198MHz input to the SPI module for the RK3399" "rockchip: spi: rk_spi: improve clocking code for the RK3399" from earlier versions of this series. Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2015-09-02rockchip: Add SPI driverSimon Glass
Add a SPI driver for the Rockchip RK3288, using driver model. It should work for other Rockchip SoCs also. Signed-off-by: Simon Glass <sjg@chromium.org>