Commit Graph

76 Commits

Author SHA1 Message Date
Fabio Estevam
6576bf009a
spi: spi-fsl-dspi: Switch to SPDX identifier
Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-24 15:37:36 +01:00
Andrey Smirnov
5f8f80356e
spi: spi-fsl-dspi: Fill actual_length when doing DMA transfer
Upper layer users of SPI device drivers may rely on 'actual_length',
so it is important that information is correctly reported. One such
example is spi_mem_exec_op() function that will fail if
'actual_length' of the data transferred is not what was requested. Add
necessary code to populate 'actual_length.

Cc: Mark Brown <broonie@kernel.org>
Cc: Sanchayan Maity <maitysanchayan@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: cphealy@gmail.com
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-17 12:56:49 +01:00
Krzysztof Kozlowski
d8ffee2f55
spi: spi-fsl-dspi: Fix imprecise abort on VF500 during probe
Registers of DSPI should not be accessed before enabling its clock.  On
Toradex Colibri VF50 on Iris carrier board this could be seen during
bootup as imprecise abort:

    Unhandled fault: imprecise external abort (0x1c06) at 0x00000000
    Internal error: : 1c06 [#1] ARM
    Modules linked in:
    CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.39-dirty #97
    Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
    Backtrace:
    [<804166a8>] (regmap_write) from [<80466b5c>] (dspi_probe+0x1f0/0x8dc)
    [<8046696c>] (dspi_probe) from [<8040107c>] (platform_drv_probe+0x54/0xb8)
    [<80401028>] (platform_drv_probe) from [<803ff53c>] (driver_probe_device+0x280/0x2f8)
    [<803ff2bc>] (driver_probe_device) from [<803ff674>] (__driver_attach+0xc0/0xc4)
    [<803ff5b4>] (__driver_attach) from [<803fd818>] (bus_for_each_dev+0x70/0xa4)
    [<803fd7a8>] (bus_for_each_dev) from [<803fee74>] (driver_attach+0x24/0x28)
    [<803fee50>] (driver_attach) from [<803fe980>] (bus_add_driver+0x1a0/0x218)
    [<803fe7e0>] (bus_add_driver) from [<803fffe8>] (driver_register+0x80/0x100)
    [<803fff68>] (driver_register) from [<80400fdc>] (__platform_driver_register+0x48/0x50)
    [<80400f94>] (__platform_driver_register) from [<8091cf7c>] (fsl_dspi_driver_init+0x1c/0x20)
    [<8091cf60>] (fsl_dspi_driver_init) from [<8010195c>] (do_one_initcall+0x4c/0x174)
    [<80101910>] (do_one_initcall) from [<80900e8c>] (kernel_init_freeable+0x144/0x1d8)
    [<80900d48>] (kernel_init_freeable) from [<805ff6a8>] (kernel_init+0x10/0x114)
    [<805ff698>] (kernel_init) from [<80107be8>] (ret_from_fork+0x14/0x2c)

Cc: <stable@vger.kernel.org>
Fixes: 5ee67b587a ("spi: dspi: clear SPI_SR before enable interrupt")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-02 11:02:42 +01:00
Gustavo A. R. Silva
80dc12cdfb
spi: spi-fsl-dspi: Fix copy-paste error in dspi_probe
It seems that the proper structure field to use in this particular
case is *regmap_pushr* instead of regmap.

Addresses-Coverity-ID: 1470126 ("Copy-paste error")
Fixes: 58ba07ec79 ("spi: spi-fsl-dspi: Add support for XSPI mode registers")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Esben Haabendal <eha@deif.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-21 16:30:22 +01:00
Esben Haabendal
3e7cc6252d
spi: spi-fsl-dspi: Enable extended SPI mode
Set the XSPI bit for devices configured for XSPI mode (currently LS1021A),
and thereby switch to extended SPI mode, allowing for SPI transfers using
from 4 to 32 bits per word instead of 4 to 16 bits per word.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:48:27 +01:00
Esben Haabendal
35c9d461a4
spi: spi-fsl-dspi: Advertise 32 bit for XSPI mode
Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:48:21 +01:00
Esben Haabendal
8fcd151d26
spi: spi-fsl-dspi: XSPI FIFO handling (in TCFQ mode)
This implements handling of split CMD and TX FIFO queues for XSPI when
running in TCFQ mode.

It should be simple to add it to EOQ mode also.  Currently, EOQ mode is
only used with coldfire.  So if coldfire DSPI supports XSPI, XSPI FIFO
handling should be added to EOQ mode also.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:48:17 +01:00
Esben Haabendal
51d583ae77
spi: spi-fsl-dspi: Framesize control for XSPI mode
Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:48:12 +01:00
Esben Haabendal
58ba07ec79
spi: spi-fsl-dspi: Add support for XSPI mode registers
This prepares for adding support for extended SPI mode (XSPI), by extending
the regmap with the extra SREX and CTAREx registers.

An additional register map is made for allowing 16 bit access to CMD and TX
FIFO of the PUSHR register separately, which is also needed for XSPI mode
support.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:48:02 +01:00
Mark Brown
071db7a675
Merge branch 'spi-4.18' into spi-4.19 for DSPI dep 2018-06-20 14:47:07 +01:00
Esben Haabendal
8570043e2c
spi: spi-fsl-dspi: Fixup regmap configuration
Mark volatile registers to avoid caching bugs.

Note: SPI_MCR is marked volatile because of CLR_TXF and CLR_RXF bits.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:46:55 +01:00
Esben Haabendal
d87e08f142
spi: spi-fsl-dspi: Fix MCR register handling
The MCR register is not changed, so initialize it in dspi_init().

The exception is the CLR_TXF and CLR_RXF bits, which should be written to
before each transfer to make sure we start with empty FIFOs.  With MCR
register now configured as volatile, the regmap_update_bits will do a real
read-modify-write cycle.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:46:15 +01:00
Esben Haabendal
dadcf4abd6
spi: spi-fsl-dspi: Support 4 to 16 bits per word transfers
This extends the driver with support for all SPI framesizes from 4 to 16
bits, and adds support for per transfer specific bits_per_word, while at
the same time reducing code size and complexity.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:46:08 +01:00
Esben Haabendal
0a4ec2c158
spi: spi-fsl-dspi: Simplify transfer counter handling
Simplify driver by avoiding counter wrapping by clearing transfer counter
on first SPI transfer per interrupt instead of tracking what it was before.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:46:03 +01:00
Esben Haabendal
9e1dc9bd09
spi: spi-fsl-dspi: Fix per transfer cs_change handling
As of 92dc20d83a, transfer->cs_change has
been supported for non-last transfers, but not for last transfer.

This change brings handling of cs_change in line with the specification in
spi.h, implementing handling of transfer->cs_change for all transfers.

The value for CMD FIFO is precalculated with transfer->cs_change field
taken into account, allowing for CS de-activate between transfers and
keeping CS activated after last transfer.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:45:46 +01:00
Esben Haabendal
4779f23d1a
spi: spi-fsl-dspi: Drop unneeded use of dataflags bits
Checking directly against pointer value should be at least as fast as doing
bitmasking and compare, so let's keep it simple.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:45:41 +01:00
Esben Haabendal
c87bdcc89d
spi: spi-fsl-dspi: Drop unreachable else if statement
The if statement just above this if/else statement triggers on the same
condition, and then invalidates it.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-06-20 14:45:36 +01:00
Julia Lawall
230c08b2ac
spi: spi-fsl-dspi: account for const type of of_device_id.data
This driver creates a number of const structures that it stores in the
data field of an of_device_id array.

The data field of an of_device_id structure has type const void *, so
there is no need for a const-discarding cast when putting const values
into such a structure.

Done using Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-01-03 12:19:24 +00:00
Kurt Kanzenbach
00ac956215
spi: spi-fsl-dspi: add SPI_LSB_FIRST to driver capabilities
The driver as well as the controller support the SPI lsb first
mode. However, it's not possible to configure it e.g. when using
spidev. Adding this flag to mode_bits resolves the issue and lsb first
mode can be used.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-11-16 12:01:08 +00:00
Angelo Dureghello
ec7ed7708e
spi: spi-fsl-dspi: enabling Coldfire mcf5441x dspi
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-11-03 12:53:16 +01:00
Nikita Yushchenko
cddebdd19c spi: spi-fsl-dspi: ensure non-zero return on error path
Propagate error return from dspi_request_dma() into probe routine's
return.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-05-22 16:14:22 +01:00
Christophe JAILLET
fbad6c2439 spi: spi-fsl-dspi: Fix error handling
According to error handling in this function, it is likely that going to
'out_master_put' was expected here.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-02-19 16:39:21 +00:00
Mark Brown
3bc1ad252d Merge remote-tracking branches 'spi/topic/delay', 'spi/topic/dw', 'spi/topic/fsl-dspi' and 'spi/topic/fsl-espi' into spi-next 2016-12-12 15:54:09 +00:00
Sanchayan Maity
ccf7d8ee3d spi: spi-fsl-dspi: Fix continuous selection format
Current DMA implementation was not handling the continuous selection
format viz. SPI chip select would be deasserted even between sequential
serial transfers.

Use existing dspi_data_to_pushr function to restructure the transmit
code path and set or reset the CONT bit on same lines as code path
in EOQ mode does. This correctly implements continuous selection format
while also correcting and cleaning up the transmit code path.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-22 16:47:25 +00:00
Sanchayan Maity
1eaccf210c spi: spi-fsl-dspi: Fix incorrect DMA setup
Currently dmaengine_prep_slave_single was being called with length
set to the complete DMA buffer size. This resulted in unwanted bytes
being transferred to the SPI register leading to clock and MOSI lines
having unwanted data even after chip select got deasserted and the
required bytes having been transferred.

While at it also clean up the use of curr_xfer_len which is central
to the DMA setup, from bytes to DMA transfers for every use.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-22 16:47:24 +00:00
Sanchayan Maity
27d21e9f98 spi: spi-fsl-dspi: Fix incorrect freeing of DMA allocated buffers
Buffers allocated with a call to dma_alloc_coherent should be
freed with dma_free_coherent instead of the currently used
devm_kfree.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-22 16:47:09 +00:00
Sanchayan Maity
9811430465 spi: spi-fsl-dspi: Fix SPI transfer issue when using multiple SPI_IOC_MESSAGE
Current DMA implementation had a bug where the DMA transfer would
exit the loop in dspi_transfer_one_message after the completion of
a single transfer. This results in a multi message transfer submitted
with SPI_IOC_MESSAGE to terminate incorrectly without an error.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-18 12:03:32 +00:00
Sanchayan Maity
90ba37033c spi: spi-fsl-dspi: Add DMA support for Vybrid
Add DMA support for Vybrid.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-11-11 12:21:00 +00:00
Yuan Yao
5ee67b587a spi: dspi: clear SPI_SR before enable interrupt
Once dspi is used in uboot, the SPI_SR have been set by some value.
At this time, if kernel enable the interrupt before clear the
status flag, that will trigger the wrong interrupt.

Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-29 12:51:29 -06:00
Wei Yongjun
6999aeabbb spi: spi-fsl-dspi: Drop extra spi_master_put in device remove function
The call sequence spi_alloc_master/spi_register_master/spi_unregister_master
is complete; it reduces the device reference count to zero, which and results
in device memory being freed. The subsequent call to spi_master_put is
unnecessary and results in an access to free memory. Drop it.

Fixes: 9298bc7273 ("spi: spi-fsl-dspi: Remove spi-bitbang")
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-22 17:45:22 +01:00
Fabio Estevam
1c5ea2b4de spi: spi-fsl-dspi: Check clk_prepare_enable() error
clk_prepare_enable() may fail, so we should better check its
return value and propagate it in the case of failure.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-22 17:32:42 +01:00
LABBE Corentin
53d8916075 spi: spi-fsl-dspi: fix a possible NULL dereference
of_match_device could return NULL, and so cause a NULL pointer
dereference later.

For fixing this problem, we use of_device_get_match_data(), this will
simplify the code a little by using a standard function for
getting the match data.

Reported-by: coverity (CID 1324129)
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-16 12:26:59 +01:00
LABBE Corentin
94b968b5a3 spi: spi-fsl-dspi: constify devtype_data
of_id->data is const, so instead of casting the pointer to drop its
const status, this patch constify the devtype_data pointer.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-08-16 12:26:59 +01:00
Mark Brown
c36581c9a5 Merge remote-tracking branches 'spi/topic/dw', 'spi/topic/flash-read', 'spi/topic/fsl-dspi', 'spi/topic/fsl-espi' and 'spi/topic/kconfig' into spi-next 2016-05-23 12:16:48 +01:00
Andrey Vostrikov
92dc20d83a spi: spi-fsl-dspi: Fix cs_change handling in message transfer
There are use cases when chip select should be triggered between transfers
in single SPI message. Current implementation does this only on last
transfer in message ignoring cs_change value provided in current transfer.

Signed-off-by: Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-05 12:12:42 -07:00
Bhuvanchandra DV
9419b2006c spi: fsl-dspi: Set max_speed_hz for master
Calculate and update max speed from bus clock for SoCs
using DSPI IP.

The bus clock factor's are taken from the data sheets
of respective SoCs.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-23 13:54:42 +00:00
Bhuvanchandra DV
ef22d1604c spi-fsl-dspi: Fix CTAR Register access
DSPI instances in Vybrid have a different amount of chip selects
and CTARs (Clock and transfer Attributes Register). In case of
DSPI1 we only have 2 CTAR registers and 4 CS. In present driver
implementation CTAR offset is derived from CS instance which will
lead to out of bound access if chip select instance is greater than
CTAR register instance, hence use single CTAR0 register for all CS
instances. Since we write the CTAR register anyway before each access,
there is no value in using the additional CTAR registers. Also one
should not program a value in CTAS for a CTAR register that is not
present, hence configure CTAS to use CTAR0.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-12 22:33:09 +00:00
Jarkko Nikula
fa14e47fc4 spi: spi-fsl-dspi: Remove duplicated register write
SPI core makes sure that transfer speed is always set so code here writes
the same register with the same value twice. Code has been doing this from
the beginning.

This looks to me some sort of copy paste error so I'm removing the second
write. If this is not the case we can bring it back with a comment.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-09-17 18:35:59 +01:00
Mirza Krak
432a17d77a spi: fsl-dspi: Use pinctrl PM helpers
Add support for "sleep" state of pinctrl.

Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-12 18:28:13 +01:00
Haikun Wang
c042af95a2 spi: spi-fsl-dspi: Change the way of increasing spi_message->actual_length
In current driver, we increase actual_length in the following way:
message->actual_length += dspi_xxx_transfer()
It has two defects.
First, transmitting maybe in process when the function call finished and
we don't know the transmitting result in this moment.
Secondly, the last sentence in function before returning is accessing the
SPI register and trigger the data transmitting. If we enable interrupt,
interrupt may be generated before function return and we also have the same
sentence "message->actual_length += dspi_xxx_transfer()"
in the IRQ handler.
And usually dspi_xxx_transfer will trigger a new IRQ.
The original dspi_xxx_transfer call may return when no new IRQ generate.
This may mess the variable spi_message->actual_length.
Now we increase the variable in the IRQ handler and only when we get the
TCF or EOQ interrupt
And we get the transmitted data length from the SPI transfer counter
instead of the function return value.

Signed-off-by: Haikun Wang <haikun.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09 18:35:54 +01:00
Haikun Wang
d1f4a38c81 spi: spi-fsl-dspi: Enable TCF interrupt mode support
DSPI module has two optional interrupts when complete data transfer.
One is EOQ interrupt, the other one is TCF interrupt.
EOQ indicates a queue of data frame has been transmitted.
TCF indicates a frame has been transmitted.
This patch enable support TCF mode.
Driver binds a correct interrupt mode to every compatible string.
User should use the correct compatible string in the dts node.

Signed-off-by: Haikun Wang <haikun.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09 18:35:54 +01:00
Mark Brown
6724af4869 Merge branch 'fix/fsl-dspi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-fsl-dspi 2015-06-09 18:35:46 +01:00
Haikun Wang
9deef024a1 spi: spi-fsl-dspi: Bug fix incorrect CS de-assert
SPI chip select signal need to keep asserted between several
spi_transfer in the same spi_message usually.
But the driver will de-assert CS signal and the assert it between
serval spi_transfer in the same spi_message under some condiations.
This patch fix the bug.

Here is an example:
Assume you have two variables like the following,
struct spi_transfer a;
struct spi_transfer b;
if you send a spi_message only includes 'a' first,
and then you send a spi_message includes 'a' and 'b'
but without resetting 'a'.
Driver will de-assert CS and then assert CS between 'a' and 'b'.

Signed-off-by: Haikun Wang <haikun.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-21 21:54:24 +01:00
Haikun Wang
d2233325e5 spi: spi-fsl-dspi: remove clk reference when regmap_mmio initialize
It is unnecessary for DSPI to enable/disable clk when access DSPI register.
And it will reduce efficiency.

Signed-off-by: Haikun Wang <haikun.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-24 12:32:38 +01:00
Mark Brown
63031ed6b8 Merge branch 'fix/fsl-dspi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-fsl-dspi
Conflicts:
	drivers/spi/spi-fsl-dspi.c
2015-04-07 11:54:40 +01:00
Aaron Brice
95bf15f386 spi: fsl-dspi: Add ~50ns delay between cs and sck
Add delay between chip select and clock signals, before clock starts and
after clock stops.

Signed-off-by: Aaron Brice <aaron.brice@datasoft.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-06 18:12:25 +01:00
Aaron Brice
e689d6df82 spi: fsl-dspi: Fix clock rate scale values
Previous algorithm had an outer loop with the values {2,3,5,7} and an
inner loop with {2,4,6,8,16,32,...,32768}, and would pick the first
value over the required scaling value (where the total scale was the two
numbers multiplied).

Since the inner loop went up to 32768 it would always pick a value of 2
for PBR and a much higher than necessary value for BR.  The desired
scale factor was being divided by two I believe to compensate for the
much higher scale factors (the divide by two not specified in the
reference manual).

Updated to check all values and find the smallest scale factor possible
without going over the desired clock rate.

Signed-off-by: Aaron Brice <aaron.brice@datasoft.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-06 18:11:19 +01:00
Aaron Brice
6fd63087d8 spi: fsl-dspi: Fix clock rate scale values
Previous algorithm had an outer loop with the values {2,3,5,7} and an
inner loop with {2,4,6,8,16,32,...,32768}, and would pick the first
value over the required scaling value (where the total scale was the two
numbers multiplied).

Since the inner loop went up to 32768 it would always pick a value of 2
for PBR and a much higher than necessary value for BR.  The desired
scale factor was being divided by two I believe to compensate for the
much higher scale factors (the divide by two not specified in the
reference manual).

Updated to check all values and find the smallest scale factor possible
without going over the desired clock rate.

Signed-off-by: Aaron Brice <aaron.brice@datasoft.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-31 12:13:03 +01:00
Bhuvanchandra DV
ceadfd8de0 spi: fsl-dspi: Remove possible memory leak of 'chip'
Move the check for spi->bits_per_word
before allocation, to avoid memory leak.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 20:05:19 +00:00
Chao Fu
9298bc7273 spi: spi-fsl-dspi: Remove spi-bitbang
DSPI module need cs change information in
a spi transfer. According to cs change, DSPI
will give last data the right flag. Bitbang
provide cs change behind the last data in
a transfer. So DSPI can not deal the last
data in every transfer properly, so remove
the bitbang in the driver.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:25:17 +00:00