Commit Graph

66 Commits

Author SHA1 Message Date
Bhumika Goyal 92d9d0dfb0 i2c: busses: constify i2c_algorithm structures
Declare i2c_algorithm structures as const as they are only stored in the
algo field of an i2c_adapter structure. This field is of type const, so
i2c_algorithm structures having this property can be made const too.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> for
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-02-09 17:06:52 +01:00
Simon Horman b880ccaf17 i2c: sh_mobile: Add per-Generation fallback bindings
Add per-Generation fallback bindings for R-Car SoCs.

This is in keeping with the compatibility string scheme is being adopted
for drivers for Renesas SoCs.

Also, improve readability by listing the rmobile fallback compatibility
string after the more-specific compatibility strings they provide a
fallback for.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-12-11 22:52:28 +01:00
Linus Torvalds 87840a2b7e Merge branch 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Here is the 4.9 pull request from I2C including:

   - centralized error messages when registering to the core
   - improved lockdep annotations to prevent false positives
   - DT support for muxes, gates, and arbitrators
   - bus speeds can now be obtained from ACPI
   - i2c-octeon got refactored and now supports ThunderX SoCs, too
   - i2c-tegra and i2c-designware got a bigger bunch of updates
   - a couple of standard driver fixes and improvements"

* 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits)
  i2c: axxia: disable clks in case of failure in probe
  i2c: octeon: thunderx: Limit register access retries
  i2c: uniphier-f: fix misdetection of incomplete STOP condition
  gpio: pca953x: variable 'id' was used twice
  i2c: i801: Add support for Kaby Lake PCH-H
  gpio: pca953x: fix an incorrect lockdep warning
  i2c: add a warning to i2c_adapter_depth()
  lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible
  i2c: export i2c_adapter_depth()
  i2c: rk3x: Fix variable 'min_total_ns' unused warning
  i2c: rk3x: Fix sparse warning
  i2c / ACPI: Do not touch an I2C device if it belongs to another adapter
  i2c: octeon: Fix high-level controller status check
  i2c: octeon: Avoid sending STOP during recovery
  i2c: octeon: Fix set SCL recovery function
  i2c: rcar: add support for r8a7796 (R-Car M3-W)
  i2c: imx: make bus recovery through pinctrl optional
  i2c: meson: add gxbb compatible string
  i2c: uniphier-f: set the adapter to master mode when probing
  i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path
  ...
2016-10-07 14:12:21 -07:00
Wolfram Sang 488d69ea72 i2c: sh_mobile: use proper device with dma_mapping_error
We must use the same device we used for mapping.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-25 18:48:12 +02:00
Wolfram Sang ea734404f3 i2c: don't print error when adding adapter fails
The core will do this for us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-22 08:19:55 +02:00
Wolfram Sang 3f8a57bb6d i2c: sh_mobile: use new 8 bit address helper function
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-11 18:54:59 +02:00
Wolfram Sang 7bb6da5a3d i2c: sh_mobile: add support for r8a7795 (R-Car H3)
Enable the I2C core for this SoC. It is compitable to Gen2 SoCs, so
reuse the settings.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-20 18:10:20 +02:00
Wolfram Sang 365322fb32 i2c: sh_mobile: use proper type for timeout
wait_event_timeout returns long, not int.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-23 19:50:27 +02:00
Wolfram Sang 41bdbd2887 i2c: sh_mobile: use adapter default for timeout
5 seconds is a very large timeout, and it is hardcoded. Use the default
timeout from 'struct adapter' which is 1 second. It can also be modified
from userspace for specific workloads via i2c-dev.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-23 19:50:24 +02:00
Wolfram Sang 3ded3743a0 i2c: sh_mobile: add errata workaround
This used to be in platform init code. We want it to do in the driver
now. This is basically a code move and a new compatible added.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-17 12:40:38 +02:00
Wolfram Sang 32e224090f i2c: sh_mobile: terminate DMA reads properly
DMA read requests could miss proper termination, so two more bytes would
have been read via PIO overwriting the end of the buffer with wrong
data. Make DMA stop handling more readable while we are here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-01-30 17:58:43 +01:00
Wolfram Sang fe07adec73 i2c: sh_mobile: fix uninitialized var when debug is enabled
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-20 09:28:09 +01:00
Wolfram Sang 55f5f9862a i2c: sh_mobile: rework deferred probing
DMA is opt-in for this driver. So, we can't use deferred probing for
requesting DMA channels in probe, because our driver would get endlessly
deferred if DMA support is compiled in AND the DMA driver is missing.
Because we can't know when the DMA driver might show up, we always try
again when a DMA transfer would be possible. The downside is that there
is more overhead for setting up PIO transfers under the above scenario.
But well, having DMA enabled and the proper DMA driver missing looks
like a broken or test config anyhow.

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-17 19:26:08 +01:00
Wolfram Sang e844a7997d i2c: sh_mobile: refactor DMA setup
Refactor DMA setup to keep the errno so we can implement better
deferred probe support in the next step.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-17 19:26:07 +01:00
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>
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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
Wolfram Sang 6cf710d476 i2c: sh_mobile: remove unneeded DMA mask
We don't need the mask since we obtain the channels via DT.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-11 22:28:22 +01:00
Wolfram Sang 530834b13f i2c: sh_mobile: optimize irq entry
We can simply pass the pointer to the private structure to the irq
routine instead of passing the platform device and looking up its
driver_data.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-04 18:49:54 +01:00
Wolfram Sang 8cfcae9f05 i2c: sh_mobile: use proper device for mapping DMA memory
It should be the DMA device, not the platform device.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-19 15:17:16 +01:00
Wolfram Sang 7ca0186468 i2c: sh_mobile: improve success message
No user needs magic hex values, makes this debug output. Add DMA info.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 17:09:06 +01:00
Wolfram Sang 2d09581b4c i2c: sh_mobile: add DMA support
Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address is still handled using the old state
machine, it is sending the actual data that is done via DMA. This is
least intrusive and allows us to work with the message buffers directly
instead of preparing a custom buffer which involves copying the data
around.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed an uninitialized var problem]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 17:08:40 +01:00
Wolfram Sang 5bbe687912 i2c: sh_mobile: sort includes alphabetically
Improves readability and reduces chances of duplicates.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 16:53:10 +01:00
Geert Uytterhoeven 78df445e78 i2c: sh_mobile: Add support for r8a73a4 and sh73a0
Add support for r8a73a4 (R-Mobile APE6) and sh73a0 (SH-Mobile AG5).
On these SoCs, the operating clock runs faster that on previous SoCs,
and the internal SCL clock counter gets incremented every 2 clocks of
the operating clock, just like on R-Car Gen2.

Cfr. the "/2" in the calculation of ICCL/ICCH in section "I2C Bus
Interface (IIC)", subsection "Transfer Rate" of the datasheets.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-10 09:34:56 +01:00
Wolfram Sang ca1f8da9ac i2c: remove FSF address
We have a central copy of the GPL for that. Some addresses were already
outdated.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2014-11-07 18:35:33 +01:00
Wolfram Sang 1ecc4335eb i2c: busses: 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 16:20:37 +02:00
Wolfram Sang 90104d0637 i2c: sh_mobile: add compatibles for additional SoC
Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-01 22:22:08 +02:00
Wolfram Sang 67240dfcb8 i2c: sh_mobile: fix clock calculation for newer SoCs
Newer SoCs have so fast input clocks that the ICCL/H registers only
count every second clock to have a meaningful 9-bit range. The driver
was already prepared for that happening, but didn't use it so far.
Add the proper DT configuration for SoCs that need it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:25 +02:00
Wolfram Sang 7663ebefca i2c: sh_mobile: check timing parameters for valid range
Due to misconfiguration, it can happen that the calculated timing
parameters are out of range. Bail out if that happens. We can also
simplify some logic later because of the verified value. Also, make the
printouts of the values more precise by adding the hex-prefixes.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:24 +02:00
Wolfram Sang 6ed7053c22 i2c: sh_mobile: bail out on errors when initializing
sh_mobile_i2c_init() could detect wrong settings, but didn't bail out,
so it would continue unconfigured. Fix this.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:24 +02:00
Wolfram Sang ed4121e129 i2c: sh_mobile: remove superfluous offset parameter
Following the KISS principle, remove unneeded stuff.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:24 +02:00
Wolfram Sang 7fe8a99933 i2c: sh_mobile: devm conversion, irq setup
This is what devm was made for. No rollback mechanism needed, remove the
hook parameter from the irq setup function and simplify it. While we are
here change some variables to proper types.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:23 +02:00
Wolfram Sang 4fd31c2eb7 i2c: sh_mobile: devm conversion, low hanging fruits
Convert the easy parts to devm. irqs will be converted in a seperate
patch to keep diffs readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:23 +02:00
Wolfram Sang 88c289ec28 i2c: sh_mobile: honor DT bus speed settings
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:23 +02:00
Wolfram Sang 5a72b25e78 i2c: sh_mobile: improve error handling
Use standard i2c error codes for i2c failures. Also, don't print
something on timeout since it happens regularly with i2c. Simplify some,
logic, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:22 +02:00
Wolfram Sang a78f6a4140 i2c: sh_mobile: replace magic hex values with constants
No functional change, binaries are identical.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-05-22 10:09:22 +02:00
Laurent Pinchart f887605d25 i2c: sh_mobile: Convert to clk_prepare/unprepare
Turn clk_enable() and clk_disable() calls into clk_prepare_enable() and
clk_disable_unprepare() to get ready for the migration to the common
clock framework.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-31 12:45:44 +01:00
Wolfram Sang 687b81d083 i2c: move OF helpers into the core
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:22:20 +02:00
Jingoo Han 6d4028c644 i2c: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-19 19:46:30 +02:00
Guennadi Liakhovetski e789029761 i2c: sh_mobile: don't send a stop condition by default inside transfers
By default there should be no stop bit on I2C between single messages
within transfers. Fix the driver to comply and only send a stop bit at
the end of transfers or if I2C_M_STOP is set.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-10 19:55:24 +01:00
Guennadi Liakhovetski 4b3823184f i2c: sh_mobile: eliminate an open-coded "goto" loop
Eliminate an open-coded "goto" loop by introducing a function.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-10 19:55:23 +01:00
Guennadi Liakhovetski 5687265b31 i2c: sh_mobile: fix timeout error handling
In a timeout case return an error immediately from the driver's
.master_xfer() method, instead of continuing and letting higher layers
fail.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-10 19:55:23 +01:00
Guennadi Liakhovetski 05cf936846 i2c: sh_mobile: cosmetic: trivially simplify 2 functions
Reduce 2 boolean functions from "if (condition) return 1; return 0;" to
"return condition;"

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-10 19:55:22 +01:00
Bill Pemberton 0b255e927d i2c: remove __dev* attributes from subsystem
CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: Jean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-12-22 20:13:45 +01:00
Shinya Kuribayashi 29fb08c300 i2c: i2c-sh_mobile: fix spurious transfer request timed out
Ensure that any of preceding register write operations to the I2C
hardware block reached the module, and the write data is reflected
in the registers, before leaving the interrupt handler.

Otherwise, we'll suffer from spurious WAIT interrupts that lead to
'Transfer request timed out' message, and the transaction failed.

Reported-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16 09:09:13 +01:00
Shinya Kuribayashi ebd5ac165f i2c: i2c-sh_mobile: support I2C hardware block with a faster operating clock
On newer SH-/R-Mobile SoCs, a clock supply to the I2C hardware block,
which is used to generate the SCL clock output, is getting faster than
before, while on the other hand, the SCL clock control registers, ICCH
and ICCL, stay unchanged in 9-bit-wide (8+1).

On such silicons, the internal SCL clock counter gets incremented every
2 clocks of the operating clock.

This patch makes it configurable through platform data.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16 09:09:12 +01:00
Shinya Kuribayashi 23a612916a i2c: i2c-sh_mobile: optimize ICCH/ICCL values according to I2C bus speed
ICCH/ICCL values is supposed to be calculated/optimized to strictly meet
the timing specs required by the I2C standard. The resulting I2C bus
speed does not matter at all, if it's less than 100 or 400 kHz.

With this change, sh_mobile_i2c_icch() is virtually identical to
sh_mobile_i2c_iccl(), but they're providing good descriptions of
SH-/R-Mobile I2C hardware spec, and I'd leave them as separated.

Also fix a typo in the comment, print icch/iccl values at probe, etc.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>

[wsa: squashed two patches for bisectability]

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16 09:07:43 +01:00
Shinya Kuribayashi 7b0e62920a i2c: i2c-sh_mobile: calculate clock parameters at driver probing time
Currently SCL clock parameters (ICCH/ICCL) are calculated in
activate_ch(), which gets called every time sh_mobile_i2c_xfer() is
processed, while each I2C bus speed is system-defined and in general
those parameters do not have to be updated over I2C transactions.

The only reason I could see having it transaction-time is to adjust
ICCH/ICCL values according to the operating frequency of the I2C
hardware block, in the face of DFS (Dynamic Frequency Scaling).

However, this won't be necessary.

The operating frequency of the I2C hardware block can change _even_
in the middle of I2C transactions.  There is no way to prevent it
from happening, and I2C hardware block can work with such dynamic
frequency change, of course.

Another is that ICCH/ICCL clock parameters optimized for the faster
operating frequency, can also be applied to the slower operating
frequency, as long as slave devices work.  However, the converse is
not true.  It would violate SCL timing specs of the I2C standard.

What we can do now is to calculate the ICCH/ICCL clock parameters
according to the fastest operating clock of the I2C hardware block.
And if that's the case, that calculation should be done just once
at driver-module-init time.

This patch moves ICCH/ICCL calculating part from activate_ch() into
sh_mobile_i2c_init(), and call it from sh_mobile_i2c_probe().

Note that sh_mobile_i2c_init() just prepares clock parameters using
the clock rate and platform data provided, but does _not_ make any
hardware I/O accesses.  We don't have to care about run-time PM
maintenance here.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16 08:57:16 +01:00
Magnus Damm ad33707417 i2c: sh_mobile: add device tree support
This patch enables DT support for the IIC driver
used on SH-based SoCs such as sh7722 and sh7724
among others as well as SH-Mobile SoCs such as
sh7367, sh7377, sh7372, sh73a0 and r8a7740.

Tested with out-of-tree DT support code on the
sh7372 Mackerel board.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-12 14:28:12 +02:00
Yong Zhang 4311051c35 i2c: irq: Remove IRQF_DISABLED
Since commit [c58543c8: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29 09:55:45 +01:00
Ben Dooks 5bdfdfeed5 Merge branches 'for-2639/i2c-eg20t', 'for-2639/i2c-shmobile', 'for-2639/i2c-tegra' and 'for-2639/i2c-nomadik2' into for-linus/2640/i2c 2011-05-25 00:25:55 +01:00
Magnus Damm 81f8115305 i2c: i2c-sh_mobile bus speed platform data V2
Add support to the i2c-sh_mobile driver for setting
the I2C bus speed using platform data.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-05-11 07:08:13 +01:00