Commit 68f6be65 authored Jun 14, 2017 by Anatolij Gustschin Committed by Greg Kroah-Hartman Jul 17, 2017

fpga: Add flag to indicate SPI bitstream is bit-reversed



Add a flag that is passed to the write_init() callback,
indicating that the SPI bitstream starts with LSB first.
SPI controllers usually send data with MSB first. If an
FPGA expects bitstream data as LSB first, the data must
be reversed either by the SPI controller or by the driver.

Alternatively the bitstream could be prepared as bit-reversed
to avoid the bit-swapping while sending. This flag indicates
such bit-reversed SPI bitstream. The low-level driver will
deal with the flag and perform bit-reversing if needed.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 50fa0285

include/linux/fpga/fpga-mgr.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -67,10 +67,12 @@ enum fpga_mgr_states {
		* FPGA Manager flags
		* FPGA_MGR_PARTIAL_RECONFIG: do partial reconfiguration if supported
		* FPGA_MGR_EXTERNAL_CONFIG: FPGA has been configured prior to Linux booting
		* FPGA_MGR_BITSTREAM_LSB_FIRST: SPI bitstream bit order is LSB first
		*/
		#define FPGA_MGR_PARTIAL_RECONFIG BIT(0)
		#define FPGA_MGR_EXTERNAL_CONFIG BIT(1)
		#define FPGA_MGR_ENCRYPTED_BITSTREAM BIT(2)
		#define FPGA_MGR_BITSTREAM_LSB_FIRST BIT(3)

		/**
		* struct fpga_image_info - information specific to a FPGA image