Commit Graph

98 Commits

Author SHA1 Message Date
Geert Uytterhoeven
219a7bc577 spi: rspi: Use of_device_get_match_data() helper
Use the of_device_get_match_data() helper instead of open coding.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-10-04 15:47:38 +01:00
Mark Brown
e2a3b0df8d Merge remote-tracking branches 'spi/topic/rockchip', 'spi/topic/rspi', 'spi/topic/s3c64xx', 'spi/topic/sh-msiof' and 'spi/topic/slave' into spi-next 2017-02-19 16:41:05 +00:00
DongCV
ad16d4a83d spi: rspi: Replaces "n" by "len" in qspi_transfer_*()
This patch replaced "n" by "len" bytes of data in qspi_transfer_in() and
qspi_transfer_out() function. This will make improving readability.

Signed-off-by: DongCV <cv-dong@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-02-16 18:25:27 +00:00
DongCV
7264abc700 spi: rspi: Fixes bogus received byte in qspi_transfer_in()
In qspi_transfer_in(), when receiving the last n (or len) bytes of data,
one bogus byte was written in the receive buffer.
This code leads to a buffer overflow.

"jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found
at 0x03b40000: 0x1900 instead
jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found
at 0x03b40004: 0x000c instead"

The error message above happens when trying to mount, unmount,
and remount a jffs2-formatted device.
This patch removed the bogus write to fixes: 3be09bec42
"spi: rspi: supports 32bytes buffer for DUAL and QUAD"

And here is Geert's comment:

"spi: rspi: Fix bogus received byte in qspi_transfer_in()
When there are less than QSPI_BUFFER_SIZE remaining bytes to be received,
qspi_transfer_in() writes one bogus byte in the receive buffer, possibly
leading to a buffer overflow.
This can be reproduced by mounting, unmounting, and remounting a
jffs2-formatted device, causing lots of warnings like:

"jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found
at 0x03b40000: 0x1900 instead"

Remove the bogus write to fix this. "

Signed-off-by: DongCV <cv-dong@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-02-16 18:25:21 +00:00
Geert Uytterhoeven
ffcfae3823 spi: rspi: Remove useless memory allocation failure message
Printing an error on memory allocation failure is unnecessary.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-01-04 17:39:21 +00:00
Arnd Bergmann
db30083813 spi: rspi: avoid uninitialized variable access
The newly introduced rspi_pio_transfer_in_or_our() function must
take either a valid 'rx' or 'tx' pointer, and has undefined behavior
if both are NULL, as found by 'gcc -Wmaybe-unintialized':

drivers/spi/spi-rspi.c: In function 'rspi_pio_transfer_in_or_our':
drivers/spi/spi-rspi.c:558:5: error: 'len' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The analysis of the function is correct in principle, but the code
is currently safe because both callers always pass exactly one
of the two pointers.

Looking closer at this function shows that having a combined
method for rx and tx here actually increases the complexity
and the size of the file. This simplifies it again by keeping
the two separate, which then ends up avoiding that warning.

Fixes: 3be09bec42 ("spi: rspi: supports 32bytes buffer for DUAL and QUAD")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-09 13:05:19 +00:00
Hiep Cao Minh
3be09bec42 spi: rspi: supports 32bytes buffer for DUAL and QUAD
This patch supports 32bytes of buffer for DUAL and QUAD in QSPI by
Using Transmit/Receive Buffer Data Triggering Number.
In order to improve the DUAL and QUAD's performance of SPI
while transferring data in PIO mode, it sends/receives each 32bytes
data instead of each byte data as current situation.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-04 11:06:33 -06:00
Chris Brandt
aeb8f8cb15 spi: rspi: Increase accuracy of bit rate for RZ
When you leave the clock divider at 0, 130kHz is the lowest you can go.
Also, by adjusting the clock divider you can get more accurate resolutions
for clock speeds lower than 16MHz. This patch uses the clock divider as
part of the bit rate setup.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-08 11:56:46 +01:00
Geert Uytterhoeven
cb76b1ca91 spi: rspi: Make qspi_set_send_trigger() return "unsigned int"
qspi_set_send_trigger() returns an unsigned value, so make it return
"unsigned int".
Update the loop variables qspi_trigger_transfer_out_int() to match the
above.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-03 13:52:10 +01:00
Geert Uytterhoeven
5d4db691ed spi: rspi: Drop variable "error" in qspi_trigger_transfer_out_in()
Just use "ret" instead, for consistency with other similar functions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-03 13:52:10 +01:00
Hiep Cao Minh
cc2e9328ed spi: rspi: Re-do the returning value of qspi_transfer_out_in
To reduce complexity of code, drop "ret" then qspi_transfer_out_in function
should return the value of "qspi_trigger_transfer_out_in" directly.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-02 14:58:58 +01:00
Hiep Cao Minh
a91bbe7d3f spi: rspi: modify the name of "qspi_trigger_transfer_out_int" function
The name of "qspi_trigger_transfer_out_int" function should be
"qspi_trigger_transfer_out_in" without "t".

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-02 14:58:52 +01:00
Hiep Cao Minh
6310372dc3 spi: rspi: Re-do the returning value of rspi_dma_check_then_transfer
To reduce indentation and complexity of code, insteeds of returning zero
the function rspi_dma_check_then_transfer should return rspi_dma_transfer
directly after checking error.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-07 13:56:46 +01:00
Krzysztof Kozlowski
8634dafac6 spi: rspi: Constify platform_device_id
The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-01 17:37:50 +01:00
Linus Torvalds
d6a4c0e5d3 Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine updates from Vinod Koul:

 - new drivers for:
        - Ingenic JZ4780 controller
        - APM X-Gene controller
        - Freescale RaidEngine device
        - Renesas USB Controller

  - remove device_alloc_chan_resources dummy handlers

  - sh driver cleanups for peri peri and related emmc and asoc patches
    as well

  - fixes and enhancements spread over the drivers

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (59 commits)
  dmaengine: dw: don't prompt for DW_DMAC_CORE
  dmaengine: shdmac: avoid unused variable warnings
  dmaengine: fix platform_no_drv_owner.cocci warnings
  dmaengine: pch_dma: fix memory leak on failure path in pch_dma_probe()
  dmaengine: at_xdmac: unlock spin lock before return
  dmaengine: xgene: devm_ioremap() returns NULL on error
  dmaengine: xgene: buffer overflow in xgene_dma_init_channels()
  dmaengine: usb-dmac: Fix dereferencing freed memory 'desc'
  dmaengine: sa11x0: report slave capabilities to upper layers
  dmaengine: vdma: Fix compilation warnings
  dmaengine: fsl_raid: statify fsl_re_chan_probe
  dmaengine: Driver support for FSL RaidEngine device.
  dmaengine: xgene_dma_init_ring_mngr() can be static
  Documentation: dma: Add documentation for the APM X-Gene SoC DMA device DTS binding
  arm64: dts: Add APM X-Gene SoC DMA device and DMA clock DTS nodes
  dmaengine: Add support for APM X-Gene SoC DMA engine driver
  dmaengine: usb-dmac: Add Renesas USB DMA Controller (USB-DMAC) driver
  dmaengine: renesas,usb-dmac: Add device tree bindings documentation
  dmaengine: edma: fixed wrongly initialized data parameter to the edma callback
  dmaengine: ste_dma40: fix implicit conversion
  ...
2015-04-24 09:49:37 -07:00
Dan Carpenter
c9bc3e8bf0 spi: signedness bug in qspi_trigger_transfer_out_int()
We need "ret" to be unsigned for the error handling to work.  The
signedness of "i" and "n" don't matter but qspi_set_send_trigger()
returns an int so I've changed them to int as well.

Fixes: 4b6fe3edcb ('spi: Using Trigger number to transmit/receive data')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-06 17:20:07 +01:00
Hiep Cao Minh
4b6fe3edcb spi: Using Trigger number to transmit/receive data
In order to transmit and receive data when have 32 bytes of data that
ready has prepared on Transmit/Receive Buffer to transmit or receive.
Instead transmits/receives a byte data using Transmit/Receive Buffer
Data Triggering Number will improve the speed of transfer data.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-29 21:29:35 -07:00
Arnd Bergmann
118dad437f spi: rspi: remove slave_id settings for DMAEngine
Current rspi sets dma_slave_config :: slave_id field for DMAEngine,
but it is no longer needed. Let's remove it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-23 16:13:02 +05:30
Jarkko Nikula
2c658e212c spi: Remove FSF mailing addresses
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-12-22 15:32:42 +00:00
Wolfram Sang
14ac00e033 spi: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:36 +02:00
Geert Uytterhoeven
6089af775a spi: rspi: Add support for new R-Car Gen2 SoCs
Add support for QSPI in:
  - r8a7792 (R-Car V2H)
  - r8a7793 (R-Car M2-N)
  - r8a7794 (R-Car E2)

r8a7791 is now called "R-Car M2-W".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-28 15:33:17 +01:00
Geert Uytterhoeven
e825b8dd2b spi: rspi: Add DT support to DMA setup
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:14:09 -05:00
Geert Uytterhoeven
a30b95a7d8 spi: rspi: Configure DMA slave bus width to 8 bit
The new Renesas R-Car Gen2 DMA Controller driver (rcar-dmac) requires
explicit configuration of the DMA slave bus width.
Hardcode the DMA transfer size to 1 byte for both directions, as that's
the only supported configuration (16-bit DMA support was removed in
commit 9c5de2c175 ("spi: rspi: Remove
unused 16-bit DMA support")).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:14:09 -05:00
Geert Uytterhoeven
43937455c9 spi: rspi: Use devm_kasprintf()
Use the devm_kasprintf() helper function instead of open coding
error-prone buffer handling and string formatting.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:14:09 -05:00
Geert Uytterhoeven
d64b472678 spi: rspi: Remove unneeded semicolon
Introduced by commit 426ef76dd8 ("spi:
rspi: Add DT support").

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:14:09 -05:00
Geert Uytterhoeven
3819bc8752 spi: rspi: Fix leaking of unused DMA descriptors
If dmaengine_prep_slave_sg() or dmaengine_submit() fail, we may leak
unused DMA descriptors.

As per Documentation/dmaengine.txt, once a DMA descriptor has been
obtained, it must be submitted. Hence:
  - First prepare and submit all DMA descriptors,
  - Prepare the SPI controller for DMA,
  - Start DMA by calling dma_async_issue_pending(),
  - Make sure to call dmaengine_terminate_all() on all descriptors that
    haven't completed.

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:13:53 -05:00
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