Commit Graph

30 Commits

Author SHA1 Message Date
Mark Brown
165f2288e1 Merge remote-tracking branches 'spi/topic/qup', 'spi/topic/rockchip', 'spi/topic/rspi', 'spi/topic/s3c64xx' and 'spi/topic/sc18is602' into spi-next 2015-04-11 23:09:25 +01:00
Julius Werner
76b17e6e49 spi/rockchip: Add device tree property to configure Rx Sample Delay
We have found that we can sometimes see read failures on boards with
high-capacitance SPI lines. It seems that the controller samples the Rx
data line too early, and its register interface has an "Rx Sample Delay"
setting to fine-tune against this issue.

This patch adds a new optional device tree entry that can configure this
delay in terms of nanoseconds. The kernel will calculate the
best-fitting amount of parent clock ticks to program the controller with
based on that.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-26 17:42:21 -07:00
Julius Werner
754ec43c01 spi/rockchip: Round up clock rate divisor to err on the safe side
The Rockchip SPI driver currently calculates its clock rate divisor by
integer dividing the parent rate by the target rate, and then rounding
the result up to the next even number (since the divisor must be
even).

Clock rate divisors should always be rounded up, so that the resulting
frequency is lower or equal to the target. This is correctly done in the
second step here but not in the first, so we still have a risk of
exceeding the desired target frequency (e.g. setting spi-max-frequency
to 40000000 with a parent clock of 99000000 could lead to a divisor of
99000000 / 40000000 == 2 (which is even) that then results in an
effective frequency of 99000000 / 2 == 49500000 (potentially exceeding
the flash chip's specifications).

This patch changes the division to round up to fix this problem.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-26 17:41:52 -07:00
Andy Shevchenko
2291793cc4 spi/rockchip: do an error handling in proper time
There was handle_err() callback introduced that is dedicated for error
handling. The patch moves error handling to this callback.

Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-rockchip@lists.infradead.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-06 19:41:57 +00:00
Arnd Bergmann
97cf56697a spi/rockchip: avoid uninitialized-use warning
We currently get a warning about potentially uninitialized variables
in the rockchip spi driver, at least in certain toolchain versions:

spi/spi-rockchip.c: In function 'rockchip_spi_prepare_dma':
include/linux/dmaengine.h:796:2: warning: 'txdesc' may be used uninitialized in this function
include/linux/dmaengine.h:796:2: warning: 'rxdesc' may be used uninitialized in this function

The reason seems to be that gcc cannot know whether the value
of the rs->rx and rs->tx variables change between the two points
these are accessed.

The code is actually correct, but to make this clearer to the
compiler, this changes the conditionals to test for the local
rxdesc/txdesc variables instead, which it knows won't change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 17:36:37 +00:00
Linus Torvalds
c0f486fde3 More ACPI and power management updates for 3.19-rc1
- Fix a regression in leds-gpio introduced by a recent commit that
    inadvertently changed the name of one of the properties used by
    the driver (Fabio Estevam).
 
  - Fix a regression in the ACPI backlight driver introduced by a
    recent fix that missed one special case that had to be taken
    into account (Aaron Lu).
 
  - Drop the level of some new kernel messages from the ACPI core
    introduced by a recent commit to KERN_DEBUG which they should
    have used from the start and drop some other unuseful KERN_ERR
    messages printed by ACPI (Rafael J Wysocki).
 
  - Revert an incorrect commit modifying the cpupower tool
    (Prarit Bhargava).
 
  - Fix two regressions introduced by recent commits in the OPP
    library and clean up some existing minor issues in that code
    (Viresh Kumar).
 
  - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout
    the tree (or drop it where that can be done) in order to make
    it possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki,
    Ulf Hansson, Ludovic Desroches).  There will be one more
    "CONFIG_PM_RUNTIME removal" batch after this one, because some
    new uses of it have been introduced during the current merge
    window, but that should be sufficient to finally get rid of it.
 
  - Make the ACPI EC driver more robust against race conditions
    related to GPE handler installation failures (Lv Zheng).
 
  - Prevent the ACPI device PM core code from attempting to
    disable GPEs that it has not enabled which confuses ACPICA
    and makes it report errors unnecessarily (Rafael J Wysocki).
 
  - Add a "force" command line switch to the intel_pstate driver
    to make it possible to override the blacklisting of some
    systems in that driver if needed (Ethan Zhao).
 
  - Improve intel_pstate code documentation and add a MAINTAINERS
    entry for it (Kristen Carlson Accardi).
 
  - Make the ACPI fan driver create cooling device interfaces
    witn names that reflect the IDs of the ACPI device objects
    they are associated with, except for "generic" ACPI fans
    (PNP ID "PNP0C0B").  That's necessary for user space thermal
    management tools to be able to connect the fans with the
    parts of the system they are supposed to be cooling properly.
    From Srinivas Pandruvada.
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJUk0IDAAoJEILEb/54YlRx7fgP/3+yF/0TnEW93j2ALDAQFiLF
 tSv2A2vQC8vtMJjjWx0z/HqPh86gfaReEFZmUJD/Q/e2LXEnxNZJ+QMjcekPVkDM
 mTvcIMc2MR8vOA/oMkgxeaKregrrx7RkCfojd+NWZhVukkjl+mvBHgAnYjXRL+NZ
 unDWGlbHG97vq/3kGjPYhDS00nxHblw8NHFBu5HL5RxwABdWoeZJITwqxXWyuPLw
 nlqNWlOxmwvtSbw2VMKz0uof1nFHyQLykYsMG0ZsyayCRdWUZYkEqmE7GGpCLkLu
 D6yfmlpen6ccIOsEAae0eXBt50IFY9Tihk5lovx1mZmci2SNRg29BqMI105wIn0u
 8b8Ej7MNHp7yMxRpB5WfU90p/y7ioJns9guFZxY0CKaRnrI2+BLt3RscMi3MPI06
 Cu2/WkSSa09fhDPA+pk+VDYsmWgyVawigesNmMP5/cvYO/yYywVRjOuO1k77qQGp
 4dSpFYEHfpxinejZnVZOk2V9MkvSLoSMux6wPV0xM0IE1iD0ulVpHjTJrwp80ph4
 +bfUFVr/vrD1y7EKbf1PD363ZKvJhWhvQWDgETsM1vgLf21PfWO7C2kflIAsWsdQ
 1ukD5nCBRlP4K73hG7bdM6kRztXhUdR0SHg85/t0KB/ExiVqtcXIzB60D0G1lENd
 QlKbq3O4lim1WGuhazQY
 =5fo2
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...
2014-12-18 20:28:33 -08:00
Linus Torvalds
e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlSOD20ACgkQMUfUDdst+ylLPACg2QrW1oHhdTMT9WI8jihlHVRM
 53kAoLeteByQ3iVwWurwwseRPiWa8+MI
 =OVRS
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Rafael J. Wysocki
ec83305032 spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so #ifdef blocks
depending on CONFIG_PM_RUNTIME may now be changed to depend on
CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM everywhere under
drivers/spi/.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
2014-12-13 00:41:15 +01:00
Mark Brown
f56be67b19 Merge remote-tracking branches 'spi/topic/mxs', 'spi/topic/pxa', 'spi/topic/rockchip', 'spi/topic/samsung' and 'spi/topic/sirf' into spi-next 2014-12-08 12:17:17 +00:00
Laurentiu Palcu
dfcc2e3549 spi/rockchip: remove redundant call to spi_master_put()
The call to spi_master_put() in rockchip_spi_remove() is redundant since
the master is registered using devm_. This patch removes it.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-11-12 15:04:18 +00:00
Greg Kroah-Hartman
a8a93c6f99 Merge branch 'platform/remove_owner' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux into driver-core-next
Remove all .owner fields from platform drivers
2014-11-03 19:53:56 -08:00
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
Addy Ke
2c2bc7489e spi/rockchip: spi controller must be disabled in tx callback too
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-17 14:29:22 +02:00
Addy Ke
c28be31b11 spi/rockchip: fix bug that cause spi transfer timed out in DMA duplex mode
In rx mode, dma must be prepared before spi is enabled.
But in tx and tr mode, spi must be enabled first.

Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-15 15:05:38 +02:00
Addy Ke
f9cfd52262 spi/rockchip: fix bug that case spi can't go as fast as slave request
Because the minimum divisor in rk3x's spi controller is 2,
if spi_clk is less than 2 * sclk_out, we can't get the right divisor.
So we must set spi_clk again to match slave request.

Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-15 15:05:38 +02:00
Mark Brown
62d02e41ea Merge remote-tracking branch 'spi/fix/rockchip' into spi-linus 2014-10-03 16:33:35 +01:00
Addy Ke
a24e70c0ac spi/rockchip: fix bug that cause the failure to read data in DMA mode
In my test on RK3288-pinky board, if spi is enabled, it will begin to
read data from slave regardless of whether the DMA is ready. So we
need prepare DMA before spi is enable.

Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2014-09-25 14:14:44 +01:00
Mark Brown
94b0955ddd Merge remote-tracking branches 'spi/fix/davinci', 'spi/fix/dw', 'spi/fix/fsl', 'spi/fix/pl022', 'spi/fix/rockchip' and 'spi/fix/sirf' into spi-linus 2014-09-16 16:20:19 -07:00
Doug Anderson
62946172c8 spi/rockchip: Don't warn if SPI is busy but disabled
The reference manual from Rockchip claims this about the BSF (SPI Busy
Flag):
* 0 - SPI is idle or disabled
* 1 - SPI is actively transferring data

The above doesn't quite appear to be true.  Specifically I found the
busy bit set when SPI was disabled.  Let's change the WARN_ON() so we
only check the busy bit if the controller was enabled.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-09-04 23:54:11 +01:00
Doug Anderson
64bc0110f1 spi/rockchip: Fix the wait_for_idle() timeout
The wait_for_idle() could get unlucky and timeout too quickly.
Specifically, the old calculation was effectively:
  timeout = jiffies + 1;
  if (jiffies >= timeout) print warning;

From the above it should be obvious that if jiffies ticks in just the
wrong place then we'll have an effective timeout of 0.

Fix this by effectively changing the above ">=" to a ">".  That gives
us an extra jiffy to finish.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-09-04 23:54:11 +01:00
Doug Anderson
5d1d150d7d spi/rockchip: Avoid accidentally turning off the clock
If our client is requesting a clock that is above the maximum clock
then the following division will result in 0:
  rs->max_freq / rs->speed

We'll then program 0 into the SPI_BAUDR register.  The Rockchip TRM
says: "If the value is 0, the serial output clock (sclk_out) is
disabled."

It's much better to end up with the fastest possible clock rather than
a clock that is off, so enforce a minimum value.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-08-29 12:07:38 +01:00
Addy Ke
0ac7a4904a spi/rockchip: fixup incorrect dma direction setting
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-20 10:31:17 -05:00
Wei Yongjun
db7e8d90ca spi/rockchip: fix error return code in rockchip_spi_probe()
Fix to return -EINVAL from the error handling case instead of 0 when
failed to get fifo length.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-25 18:25:59 +01:00
Wei Yongjun
4e6fafee02 spi/rockchip: remove redundant dev_err call in rockchip_spi_probe()
There is a error message within devm_ioremap_resource
already, so remove the dev_err call to avoid redundant
error message.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-25 18:25:59 +01:00
Wei Yongjun
c4950143fc spi/rockchip: remove duplicated include from spi-rockchip.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-25 18:25:58 +01:00
Addy Ke
b839b78518 spi/rockchip: add compatible strings for RK3188 and RK3288
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Addy Ke <addy.ke@rockchip.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-11 13:59:58 +01:00
Addy Ke
ee78099764 spi/rockchip: master->mode_bits: remove SPI_CS_HIGH bit
Suggested-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Addy Ke <addy.ke@rockchip.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-11 13:59:57 +01:00
Addy Ke
2df08e7890 spi/rockchip: call wait_for_idle() for the transfer to complete
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Addy Ke <addy.ke@rockchip.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-11 13:59:57 +01:00
Addy Ke
5dcc44ed91 spi/rockchip: cleanup some coding issues and uncessary output
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Addy Ke <addy.ke@rockchip.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-11 13:59:57 +01:00
addy ke
64e36824b3 spi/rockchip: add driver for Rockchip RK3xxx SoCs integrated SPI
In order to facilitate understanding, rockchip SPI controller IP design
looks similar in its registers to designware. But IC implementation
is different from designware, So we need a dedicated driver for Rockchip
RK3XXX SoCs integrated SPI. The main differences:

- dma request line: rockchip SPI controller have two DMA request line
  for tx and rx.

- Register offset:
                  RK3288        dw
  SPI_CTRLR0      0x0000        0x0000
  SPI_CTRLR1      0x0004        0x0004
  SPI_SSIENR      0x0008        0x0008
  SPI_MWCR        NONE          0x000c
  SPI_SER         0x000c        0x0010
  SPI_BAUDR       0x0010        0x0014
  SPI_TXFTLR      0x0014        0x0018
  SPI_RXFTLR      0x0018        0x001c
  SPI_TXFLR       0x001c        0x0020
  SPI_RXFLR       0x0020        0x0024
  SPI_SR          0x0024        0x0028
  SPI_IPR         0x0028        NONE
  SPI_IMR         0x002c        0x002c
  SPI_ISR         0x0030        0x0030
  SPI_RISR        0x0034        0x0034
  SPI_TXOICR      NONE          0x0038
  SPI_RXOICR      NONE          0x003c
  SPI_RXUICR      NONE          0x0040
  SPI_MSTICR      NONE          0x0044
  SPI_ICR         0x0038        0x0048
  SPI_DMACR       0x003c        0x004c
  SPI_DMATDLR     0x0040        0x0050
  SPI_DMARDLR     0x0044        0x0054
  SPI_TXDR        0x0400        NONE
  SPI_RXDR        0x0800        NONE
  SPI_IDR         NONE          0x0058
  SPI_VERSION     NONE          0x005c
  SPI_DR          NONE          0x0060

- register configuration:
  such as SPI_CTRLRO in rockchip SPI controller:
    cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
        | (CR0_SSD_ONE << CR0_SSD_OFFSET);
    cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
    cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
    cr0 |= (rs->tmode << CR0_XFM_OFFSET);
    cr0 |= (rs->type << CR0_FRF_OFFSET);
  For more information, see RK3288 chip manual.

- Wait for idle: Must ensure that the FIFO data has been sent out
  before the next transfer.

Signed-off-by: addy ke <addy.ke@rock-chips.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-04 19:32:29 +01:00