This patch series refactors the Renesas SPI driver and adds DMA support
using the SPI DMA framework for QSPI on R-Car Gen2, for Single, Dual, and
Quad SPI Transfers.
It also adds DMA support for RZ/A1H, but this was untested.
Apart from refactorings that don't change behavior:
- [02/18] reverts a (harmless?) behavioral change for RSPI on SH,
- [03/18] removes 16-bit DMA support, which has no in-tree users.
16-bit DMA support requires using a double-sized buffer to
accomodate the interleaved data format.
If there's a strong requirement to keep this, I think it's best
to re-add support after this series.
- [09/18] drops the ability of RSPI on SH to work with a single DMA
channel, as the SPI DMA framework needs both RX and TX DMA
to function,
- [15/18] Adds DMA support for QSPI on R-Car Gen2,
- [16/18] Adds DMA support for RSPI on RZ/A1H,
- [18/18] adds DT preliminary DT support, as the format of the DMA
specifiers depends on the DT bindings for SHDMA, which are still
under development.
This was tested on r8a7791/koelsch (PIO and DMA), and r7s72100/genmai (PIO
only).
Performance figures for reading from a QSPI FLASH driven at 24.375 MHz
on r8a7791/koelsch are:
- Single: 1.1 Mbps PIO, 23 Mbps DMA
- Dual : 12.7 Mbps PIO, 48 Mbps DMA
- Quad : 13 Mbps PIO, 70 Mbps DMA
Thanks for your comments!
[01/18] spi: rspi: Extract rspi_wait_for_{tx_empty,rx_full}()
[02/18] spi: rspi: Do not call rspi_receive_init() for TX-only
[03/18] [RFC] spi: rspi: Remove unused 16-bit DMA support
[04/18] spi: rspi: Use core SPI_MASTER_MUST_[RT]X handling
[05/18] spi: rspi: Extract rspi_pio_transfer()
[06/18] spi: rspi: Don't consider DMA configuration failures fatal
[07/18] spi: rspi: Extract rspi_request_dma_chan()
[08/18] spi: rspi: Remove unneeded resource test in DMA setup
[09/18] spi: rspi: SPI DMA core needs both RX and TX DMA to function
[10/18] spi: rspi: Use SPI core DMA mapping framework
[11/18] spi: rspi: Move RSPI-specific setup out of DMA routines
[12/18] spi: rspi: Pass sg_tables instead of spi_tranfer to rspi_*_dma()
[13/18] spi: rspi: Merge rspi_*_dma() into rspi_dma_transfer()
[14/18] spi: rspi: Absorb rspi_rz_transfer_out_in() into
spi_rz_transfer_one()
[15/18] spi: rspi: Add DMA support for QSPI on R-Car Gen2
[16/18] spi: rspi: Add DMA support for RSPI on RZ/A1H
[17/18] spi: rspi: Extract rspi_common_transfer()
[18/18] [RFC] spi: rspi: Add DT support to DMA setup
Documentation/devicetree/bindings/spi/spi-rspi.txt | 6 +
drivers/spi/spi-rspi.c | 604 ++++++++-------------
include/linux/spi/rspi.h | 2 -
3 files changed, 228 insertions(+), 384 deletions(-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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