Commit graph

72 commits

Author SHA1 Message Date
Geert Uytterhoeven
85912a88c1 spi: rspi: Handle dmaengine_prep_slave_sg() failures gracefully
As typically a shmobile SoC has less DMA channels than devices that can use
DMA, we may want to prioritize access to the DMA channels in the future.
This means that dmaengine_prep_slave_sg() may start failing arbitrarily.

Handle dmaengine_prep_slave_sg() failures gracefully by falling back to
PIO.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-16 22:41:12 +01:00
Geert Uytterhoeven
afcc98dec9 spi: rspi: Pass spi_master pointer to rspi_release_dma()
rspi_release_dma() doesn't need access to any fields in the driver private
data, except for the pointer to the SPI master object. Hence just pass the
needed pointer.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-07 12:55:20 +02:00
Geert Uytterhoeven
95029a0088 spi: rspi: Remove unused variable in rspi_rz_transfer_one()
Introduced by commit 8b983e90ea ("spi: rspi:
Extract rspi_common_transfer()"), which removed its users.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-07 12:55:20 +02:00
Geert Uytterhoeven
8b983e90ea spi: rspi: Extract rspi_common_transfer()
Extract the common parts of rspi_transfer_one(), rspi_rz_transfer_one(),
and qspi_transfer_out_in() into the new function rspi_common_transfer().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:36 +01:00
Geert Uytterhoeven
e7fb921d9f spi: rspi: Add DMA support for RSPI on RZ/A1H
Enable DMA support for RSPI on r7s72100 (RZ/A1H).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:35 +01:00
Geert Uytterhoeven
4f12b5e529 spi: rspi: Add DMA support for QSPI on R-Car Gen2
Enable DMA support for QSPI on R-Car Gen2, for Single, Dual, and Quad SPI
Transfers.

Performance figures for reading from a QSPI FLASH driven at 24.375 MHz
on r8a7791/koelsch:
  - Single:  1.1 Mbps PIO, 23 Mbps DMA
  - Dual  : 12.7 Mbps PIO, 48 Mbps DMA
  - Quad  : 13   Mbps PIO, 70 Mbps DMA

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:35 +01:00
Geert Uytterhoeven
03e627c557 spi: rspi: Absorb rspi_rz_transfer_out_in() into rspi_rz_transfer_one()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:35 +01:00
Geert Uytterhoeven
c52fb6d634 spi: rspi: Merge rspi_*_dma() into rspi_dma_transfer()
rspi_send_dma() and rspi_send_receive_dma() are very similar. Consolidate
into a single function rspi_dma_transfer(), and add missing checks for
dmaengine_submit() failures.

Both sg_table pointer parameters can be NULL, as RSPI supports TX-only
mode, and unidirectional DMA transfers will also be needed later for
Dual/Quad DMA support.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:35 +01:00
Geert Uytterhoeven
e4b52dc462 spi: rspi: Pass sg_tables instead of spi_tranfer to rspi_*_dma()
The DMA routines only need access to the scatter-gather tables inside the
spi_transfer structures, hence just pass those.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:35 +01:00
Geert Uytterhoeven
8393fa787b spi: rspi: Move RSPI-specific setup out of DMA routines
Refactor RSPI (on SH) DMA handling to make it reusable for other RSPI
implementations:
  - Call the DMA routines after configuring the TX Mode bit and after
    calling rspi_receive_init(), so these RSPI-specific operations can be
    removed from the DMA routines,
  - Absorb rspi_transfer_out_in() into rspi_transfer_one().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:34 +01:00
Geert Uytterhoeven
2f777ec91a spi: rspi: Use SPI core DMA mapping framework
Use the SPI core DMA mapping framework instead of our own.
If available, DMA is used for transfers larger than the FIFO size
(8 or 32 bytes).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:34 +01:00
Geert Uytterhoeven
5f338d0ce0 spi: rspi: SPI DMA core needs both RX and TX DMA to function
The SPI DMA core framework needs both RX and TX DMA to function.  As a
preparation for converting the driver to use this framework, fall back to
PIO if no DMA channel or only one DMA channel is available.

This affects only RSPI, which could do DMA transfers for TX-only before.
RSPI-RZ and QSPI (at least for Single SPI Transfers) will need both RX and
TX DMA anyway.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:34 +01:00
Geert Uytterhoeven
fcdc49ae53 spi: rspi: Remove unneeded resource test in DMA setup
The resource is know to exist, as rspi_probe() already mapped it.
Remove the test, and just pass the resource.
Pass the device pointer instead of the platform device pointer, as the
latter is no longer needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:34 +01:00
Geert Uytterhoeven
65bf220571 spi: rspi: Extract rspi_request_dma_chan()
Setup of the receive and transmit DMA channels is very similar, so let's
consolidate.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:33 +01:00
Geert Uytterhoeven
27e105a600 spi: rspi: Don't consider DMA configuration failures fatal
Fall back to PIO if DMA configuration failed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:33 +01:00
Geert Uytterhoeven
6837b8e91d spi: rspi: Extract rspi_pio_transfer()
The various PIO loops are very similar. Consolidate into a single
function rspi_pio_transfer().

Both buffer pointers can be NULL, as RSPI supports TX-only mode, and
Dual/Quad SPI Transfers are unidirectional.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:33 +01:00
Geert Uytterhoeven
b42e03596d spi: rspi: Use core SPI_MASTER_MUST_[RT]X handling
RSPI needs dummy transfers to generate the SPI clock on receive.
RSPI-RZ and QSPI always do both transmit and receive.

Use the SPI core SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure
instead of checking for the presence of buffers and providing dummy data
ourselves (for PIO), or providing a dummy buffer (for DMA).

rspi_receive_dma() now provides full duplex DMA transfers on RSPI, and is
renamed to rspi_send_receive_dma().

As the SPI core will always provide a TX buffer, the logic to choose
between DMA send and DMA send/receive in rspi_transfer_one() now has to
check for the presence of an RX buffer. Likewise for the DMA availability
tests in rspi_is_dma().

The buffer tests in qspi_transfer_one() are now always true, so they're
removed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:32 +01:00
Geert Uytterhoeven
9c5de2c175 spi: rspi: Remove unused 16-bit DMA support
The 16-bit DMA support doesn't fit well within the SPI core DMA framework,
as it needs to manage its own double-sized temporary buffers, for handling
the interleaved data.
Remove it, as there is no in-tree board code that sets
rspi_plat_data.dma_width_16bit.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:32 +01:00
Geert Uytterhoeven
32c64261c6 spi: rspi: Do not call rspi_receive_init() for TX-only
Since commit 8449fd76de ("spi: rspi: Merge
rspi_send_pio() and rspi_receive_pio()"), rspi_receive_init() is called
for transmit-only transfers too, while this is not needed.
Only call rspi_receive_init() when receiving, to preserve behavior on
RSPI on SH.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:32 +01:00
Geert Uytterhoeven
5f684c34fc spi: rspi: Extract rspi_wait_for_{tx_empty,rx_full}()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 15:49:32 +01:00
Geert Uytterhoeven
3beb61dbfc spi: rspi: Round up division to avoid slave overclocking
The calculation of the bit rate divider used a standard C division, which
rounds down the quotient. This may lead to a higher bitrate than requested.
Round up to avoid this.

E.g. on Koelsch, the SPI flash (configured for 30 MHz) was driven at 48.75
MHz. After this patch it's driven at a safe 24.375 MHz.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-05-26 14:30:37 +01:00
Geert Uytterhoeven
490c97747d spi: rspi: Add runtime PM support, using spi core auto_runtime_pm
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-03-11 10:45:53 +00:00
Geert Uytterhoeven
ba824d4971 spi: rspi: Fix loopback mode for Dual/Quad SPI Transfers
While normal Dual and Quad SPI Transfers are unidirectional, we must do
a bidirectional transfer if loopback mode is enabled, else rx_buf is not
filled.

With spidev it seemed to work, as spidev uses the same buffer for
tranmission and reception.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-23 12:27:03 +09:00
Geert Uytterhoeven
ab98fcba96 spi: rspi: Remove empty rspi_cleanup()
If spi_master.cleanup() is not needed, it can be left unimplemented.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-23 12:27:03 +09:00
Geert Uytterhoeven
5dd1ad23af spi: rspi: Only enable interrupts when there's a need to wait
rspi_wait_for_interrupt() unconditionally enables interrupts, even when the
wait condition is already satisfied. This causes a high interrupt load (2
interrupts/byte for full-duplex Single SPI transfers, 1 interrupt/byte for
RSPI with TX Only mode, or QSPI in unidirectional Dual or Quad Transfer
mode).

Change this to return immediately when the wait condition is satisfied.
This dramatically reduces the interrupt load, especially in high-speed
Quad Transfer mode, and increases transfer speed, as no interrupts need to
be handled when there's space available in the output FIFO, or data
available in the input FIFO.

Benchmark results for QSPI on r8a7791 while reading 1 MiB from 30 MHz SPI
FLASH on the Koelsch development board:

Before:
                        Single SPI      Dual SPI        Quad SPI
    Interrupts:         2096856         1048592         1048594
    Mbps:               0.9             1.6             1.6

After:

                        Single SPI      Dual SPI        Quad SPI
    Interrupts:         1048569         21295           8
    Mbps:               0.7             10.8            12.9

I don't know why Single SPI slowed down a bit.

I've also verified functionality for RSPI-RZ on r7s72100, but don't have
benchmark results as there's no SPI FLASH connected to RSPI on the Genmai
development board. Unlike RSPI and QSPI, RSPI-RZ has separate interrupts
for RX and TX, which shows that Single SPI transfers now generate (mostly)
RX interrupts, as expected.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-04 11:11:46 +00:00
Shimoda, Yoshihiro
64b67defe4 spi: rspi: fix build error when CONFIG_OF is not set
This patch fixes an issue that the following build error happens when
the CONFIG_OF is not set:

drivers/spi/spi-rspi.c: In function 'rspi_probe':
drivers/spi/spi-rspi.c:1203:26: error: 'rspi_of_match' undeclared (first use in this function)

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-03 13:14:06 +00:00
Geert Uytterhoeven
880c6d114f spi: rspi: Add support for Quad and Dual SPI Transfers on QSPI
Add support for Quad and Dual SPI Transfers on the Renesas Quad Serial
Peripheral Interface, as found in R-Car Gen2 SoCs like R-Car H2 (r8a7790)
and R-Car M2 (r8a7791):
  - Add unidirectional transfer methods for Quad/Dual SPI Transfers.
  - Program the sequencer to handle SPI messages with multiple transfer
    modes when Quad or Dual transfers are enabled for an SPI slave.
    Up to 4 transfer modes per SPI message are supported by the hardware.
  - Advertise the availability of Quad and Dual SPI modes on QSPI.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-30 16:51:21 +00:00
Geert Uytterhoeven
426ef76dd8 spi: rspi: Add DT support
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-29 17:56:57 +00:00
Geert Uytterhoeven
29f397b739 spi: rspi: Use NULL as the clock ID
There's only one RSPI/QSPI clock, so we can use NULL as the clock ID

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:07:38 +00:00
Geert Uytterhoeven
17fe0d9a28 spi: rspi: Convert to clk_prepare_enable/disable_unprepare
Get the driver ready for the migration to the common clock framework by
calling clk_prepare_enable() and clk_disable_unprepare().

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:07:38 +00:00
Geert Uytterhoeven
06a7a3cff0 spi: rspi: Add support for loopback mode
Add support for specifying loopback mode.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:07:38 +00:00
Geert Uytterhoeven
862d357f84 spi: rspi: Add support for RSPI on RZ/A1H
Add support for the RSPI variant in the RZ/A1H (r7s72100) SoC.

Main differences with RSPI on SH are:
  - Lack of TX only mode, hence we always have to use full duplex
    transfers,
  - The Data Register must be accessed used 8-bit operations.

RSPI on RZ is matched using the new "rspi-rz" platform device name.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:07:07 +00:00
Geert Uytterhoeven
9372220678 spi: rspi: Add support for more than one interrupt
Add support for multiple interrupts, based on the SDK reference code.
This is needed for RZ/A1H, which supports 3 interrupts.

When using multiple interrupts, they must be called "rx" (SPRI) and "tx"
(SPTI). The error interrupt (SPEI) is not used, as it matters for slave
mode only.

When using a single interrupt, it may be called "mux". If it cannot be
found, the first interrupt in the device's resources will be used.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:05:34 +00:00
Geert Uytterhoeven
340a15e6f0 spi: rspi: Merge qspi_send_pio() and qspi_receive_pio()
qspi_send_pio() and qspi_receive_pio() are very similar: they both send
and receive full duplex data to/from the hardware, but ignore the data
stream in the unused direction.
Merge them into qspi_transfer_out_in(), now supporting real full duplex.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:10 +00:00
Geert Uytterhoeven
8449fd76de spi: rspi: Merge rspi_send_pio() and rspi_receive_pio()
rspi_send_pio() and rspi_receive_pio() are very similar:
  - the former only sends data, using TX Only Mode,
  - the latter sends and receives full duplex data to/from the hardware,
    but uses dummy transmit data.
Merge them into rspi_transfer_out_in(), now supporting full duplex if
needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:10 +00:00
Geert Uytterhoeven
eb557f7526 spi: rspi: Abstract transfer_one() for RSPI and QSPI
Split off qspi_transfer_one() (which doesn't support DMA yet) from
rspi_transfer_one().
Replace the abstraction of send_pio()/receive_pio() by the abstracrion of
transfer_one().

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:09 +00:00
Geert Uytterhoeven
35301c9960 spi: rspi: Add rspi_data_{out,in,out_in}() helpers
Add helpers rspi_data_{out,in,out_in}() to write, read, or write and
read data to/from the Data Register, taking care of waiting until data
or space is available in the buffers.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:09 +00:00
Geert Uytterhoeven
74da76865d spi: rspi: Abstract 8/16-bit Data Register access
Add rspi_{write,read}_data(), to abstract 8-bit (QSPI, and RSPI on RZ/A1H)
versus 16-bit (RSPI) Data Register access.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:09 +00:00
Geert Uytterhoeven
79d2349542 spi: rspi: Use core message handling
Let the generic SPI core handle SPI messages, calling into our
rspi_transfer_one() method.

rspi_assert_ssl() and rspi_negate_ssl() are absorbed into
rspi_prepare_message() and rspi_unprepare_message(), as they actually
enable/disable the whole SPI function, instead of just (de)asserting the
chip select line.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:09 +00:00
Geert Uytterhoeven
91949a2d4a spi: rspi: Remove unused mesg parameter from {send,receive}_pio()
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27 20:02:09 +00:00
Mark Brown
341e6df6c8 Merge commit 'spi/fix/rcar' into spi-linus 2014-01-23 13:13:30 +00:00
Axel Lin
23061f1eb8 spi: Remove duplicate code to set default bits_per_word setting
The implementation in spi_setup() already set spi->bits_per_word = 8 when
spi->bits_per_word is 0 before calling spi->master->setup.
So we don't need to do it again in setup() callback.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-17 15:54:22 +00:00
Geert Uytterhoeven
fcb4ed749c spi: rspi: Add missing clk_disable() calls in error and cleanup paths
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-14 14:14:54 +00:00
Mark Brown
13ea330010 Merge branch 'topic/rcar' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-rspi 2014-01-14 14:14:47 +00:00
Geert Uytterhoeven
b7ed6b88b2 spi: rspi: Spelling s/transmition/transmission/
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-14 14:02:11 +00:00
Geert Uytterhoeven
348e5153bc spi: rspi: Add support for specifying CPHA/CPOL
Add support for specifying the SPI clock phase and polarity, based on the
SDK reference code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-13 17:24:04 +00:00
Geert Uytterhoeven
fbe5072bbe spi: rspi: Add more QSPI register documentation
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-13 12:10:01 +00:00
Geert Uytterhoeven
6ab4865b7e spi: rspi: Add more RSPI register documentation
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-13 12:10:01 +00:00
Geert Uytterhoeven
97b95c1170 spi: rspi: Use u8 for 8-bit register values
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-24 13:19:55 +00:00
Geert Uytterhoeven
2aae80b27d spi: rspi: Use DUMMY_DATA macro instead of hardcoded value
Make it more obvious that this value is dummy data.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-24 13:19:55 +00:00