Commit graph

136 commits

Author SHA1 Message Date
Mika Westerberg a7ae81952c i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR
Many Intel systems the BIOS declares a SystemIO OpRegion below the SMBus
PCI device as can be seen in ACPI DSDT table from Lenovo Yoga 900:

  Device (SBUS)
  {
      OperationRegion (SMBI, SystemIO, (SBAR << 0x05), 0x10)
      Field (SMBI, ByteAcc, NoLock, Preserve)
      {
          HSTS,   8,
          Offset (0x02),
          HCON,   8,
          HCOM,   8,
          TXSA,   8,
          DAT0,   8,
          DAT1,   8,
          HBDR,   8,
          PECR,   8,
          RXSA,   8,
          SDAT,   16
      }

There are also bunch of AML methods that that the BIOS can use to access
these fields. Most of the systems in question AML methods accessing the
SMBI OpRegion are never used.

Now, because of this SMBI OpRegion many systems fail to load the SMBus
driver with an error looking like one below:

  ACPI Warning: SystemIO range 0x0000000000003040-0x000000000000305F
       conflicts with OpRegion 0x0000000000003040-0x000000000000304F
       (\_SB.PCI0.SBUS.SMBI) (20160108/utaddress-255)
  ACPI: If an ACPI driver is available for this device, you should use
       it instead of the native driver

The reason is that this SMBI OpRegion conflicts with the PCI BAR used by
the SMBus driver.

It turns out that we can install a custom SystemIO address space handler
for the SMBus device to intercept all accesses through that OpRegion. This
allows us to share the PCI BAR with the AML code if it for some reason is
using it. We do not expect that this OpRegion handler will ever be called
but if it is we print a warning and prevent all access from the SMBus
driver itself.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=110041
Reported-by: Andy Lutomirski <luto@kernel.org>
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
2016-06-09 21:38:57 +02:00
Jarkko Nikula a7401ca559 i2c: i801: Add runtime PM support with autosuspend
Allow runtime PM so that PM and PCI core can put the device into low-power
state when idle and resume it back when needed in those platforms that
support PM for i801 device.

Enable also autosuspend with 1 second delay in order to not needlessly
toggle power state on and off if there are multiple transactions during
short time.

Device is resumed at the beginning of bus access and marked idle ready
for autosuspend at the end of it.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-12 23:21:25 +02:00
Jarkko Nikula 2ee73c484d i2c: i801: Convert to struct dev_pm_ops for suspend/resume
Stop using legacy PCI PM support and convert to standard dev_pm_ops.
This provides more straightforward path to add runtime PM.

While at it remove explicit PCI power state control and configuration space
save/restore as the PCI core does it.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-12 23:18:53 +02:00
Linus Torvalds b852495908 Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Mostly usual driver updates and improvements.  The changelog should
  give an idea.  Standing out is the i2c-qup driver with lots of new
  capabilities and we also have now an i2c-demuxer.

  I'd especially like to welcome Peter Rosin as the i2c-mux maintainer.
  He has an interesting series for muxes in the queue and agreed to look
  after this part of the subsystem.  Thank you, Peter, and welcome
  again!

  The octeon changes were applied pretty recently before the merge
  window.  I am aware.  They are the first (and relatively simple)
  patches of a larger overhaul to this driver.  In case something goes
  wrong with them, they are easy to fix (or revert).  The advantage I
  see is that they are out of the way, and I can concentrate on the next
  block of patches.  I really would like to apply the overhaul in
  smaller batches to avoid regressions.  And waiting a cycle for the
  introductory patches seemed too much of a delay for me"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits)
  i2c: octeon: Support I2C_M_RECV_LEN
  i2c: octeon: Cleanup resource allocation code
  i2c: octeon: Cleanup i2c-octeon driver
  MAINTAINERS: add Peter Rosin as i2c mux maintainer
  dt-bindings: i2c: Spelling s/propoerty/property/
  i2c: immediately mark ourselves as registered
  i2c: i801: sort IDs alphabetically
  MAINTAINERS: Mika and me are designated reviewers for I2C DESIGNWARE
  i2c: octeon: Cleanup kerneldoc comments
  i2c: do not use internal data from driver core
  i2c: cadence: Fix the kernel-doc warnings
  i2c: imx: remove extra spaces.
  i2c: rcar: don't open code of_device_get_match_data()
  i2c: qup: Fix fifo handling after adding V2 support
  i2c: xiic: Implement power management
  i2c: piix4: Pre-shift the port number
  i2c: piix4: Always use the same type for port
  i2c: piix4: Support alternative port selection register
  i2c: tegra: don't open code of_device_get_match_data()
  i2c: riic, sh_mobile, rcar: Use ARCH_RENESAS
  ...
2016-03-22 12:47:40 -07:00
Andy Shevchenko 34b57f40a6 i2c: i801: sort IDs alphabetically
Sort the list to have a faster search for a certain PCI ID.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-03-12 16:59:18 +01:00
Alexandra Yates 1a1503c539 i2c: i801: Adding Intel Lewisburg support for iTCO
Starting from Intel Sunrisepoint (Skylake PCH) the iTCO watchdog
resources have been moved to reside under the i801 SMBus host
controller whereas previously they were under the LPC device.

This patch adds Intel lewisburg SMBus support for iTCO device.
It allows to load watchdog dynamically when the hardware is
present.

Fixes: cdc5a3110e ("i2c: i801: add Intel Lewisburg device IDs")
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2016-02-18 13:18:48 +01:00
Alexandra Yates cdc5a3110e i2c: i801: add Intel Lewisburg device IDs
Adding Intel codename Lewisburg platform device IDs for SMBus.

Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-20 16:22:21 +01:00
Dustin Byford 8eb5c87a92 i2c: add ACPI support for I2C mux ports
Although I2C mux devices are easily enumerated using ACPI (_HID/_CID or
device property compatible string match), enumerating I2C client devices
connected through an I2C mux needs a little extra work.

This change implements a method for describing an I2C device hierarchy that
includes mux devices by using an ACPI Device() for each mux channel along
with an _ADR to set the channel number for the device.  See
Documentation/acpi/i2c-muxes.txt for a simple example.

To make this work the ismt, i801, and designware pci/platform devs now
share an ACPI companion with their I2C adapter dev similar to how it's done
in OF.  This is done on the assumption that power management functions will
not be called directly on the I2C dev that is sharing the ACPI node.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-25 15:49:46 +01:00
Jarkko Nikula dd77f423e5 i2c: i801: Add support for Intel Broxton
This patch adds the SMBUS PCI ID of Intel Broxton.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-23 22:11:58 +02:00
Mika Westerberg 84d7f2ebd7 i2c: i801: Add support for Intel DNV
Intel DNV SoC has the same legacy SMBus host controller than Intel
Sunrisepoint PCH. It also has same iTCO watchdog on the bus.

Add DNV PCI ID to the list of supported devices.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-23 22:10:31 +02:00
Mika Westerberg 9424693035 i2c: i801: Create iTCO device on newer Intel PCHs
Starting from Intel Sunrisepoint (Skylake PCH) the iTCO watchdog resources
have been moved to reside under the i801 SMBus host controller whereas
previously they were under the LPC device.

In order to support the iTCO watchdog on newer PCHs we need to create the
platform device here in the SMBus driver and pass all known resources using
platform data.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-08-11 15:03:51 +01:00
Jarkko Nikula fef220da43 i2c: i801: Use managed pcim_* PCI device initialization and reservation
Simplifies the code a bit and makes easier to disable PCI device on driver
detach by removing the pcim_pin_device() call in the future if needed.

Reason why i2c-i801.c doesn't ever call pci_disable_device() was because it
made some systems to hang during power-off. See commit d6fcb3b9cf
("[PATCH] i2c-i801.c: don't pci_disable_device() after it was just enabled")
and
http://marc.info/?l=linux-kernel&m=115160053309535&w=2

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09 10:51:59 +01:00
Jarkko Nikula f85da3f5de i2c: i801: Remove pci_enable_device() call from i801_resume()
Since pci_disable_device() is not called from i801_suspend() and power
state is set already it means that subsequent pci_enable_device() calls do
practically nothing but monotonically increase struct pci_dev enable_cnt.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09 10:51:59 +01:00
Jarkko Nikula 1621c59d94 i2c: i801: Use managed devm_* memory and irq allocation
This simplifies the error and remove paths.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09 10:51:59 +01:00
Jarkko Nikula 256493c586 i2c: i801: Remove i801_driver forward declaration
struct pci_driver i801_driver forward declaration is needed only for
accessing the name field. Remove it and use dev_driver_string() instead.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09 10:51:58 +01:00
Jarkko Nikula 9cbbf3dc99 i2c: i801: Don't break user-visible strings
It makes more difficult to grep these error prints from sources if they are
split to multiple source lines.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09 10:51:58 +01:00
Devin Ryles 3eee1799ae i2c: i801: Add DeviceIDs for SunrisePoint LP
Signed-off-by: Devin Ryles <devin.ryles@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 17:19:13 +01:00
Jean Delvare 550d0407a8 i2c: i801: Drop useless debug message
Don't log the host status register value in i801_isr(), it has very
little value and fills up the log when debugging is enabled.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 16:26:49 +01:00
Jean Delvare aeb8a3d16a i2c: i801: Check if interrupts are disabled
There is a control bit in the PCI configuration space which disables
interrupts. If this bit is set, the driver should not try to make use
of interrupts, it won't receive any.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 16:26:41 +01:00
Jean Delvare ae94471717 i2c: i801: Fallback to polling if request_irq() fails
The i2c-i801 driver can work without interrupts, so there is no reason
to make a request_irq failure fatal. Instead we can simply fallback
to polling.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 16:26:32 +01:00
Jean Delvare b3b8df9772 i2c: i801: Use wait_event_timeout to wait for interrupts
Some systems have been reported to have trouble with interrupts. Use
wait_event_timeout() instead of wait_event() so we don't get stuck in
that case, and log the problem.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 16:06:38 +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
james.d.ralston@intel.com 3e27a8445c i2c: i801: Add Device IDs for Intel Sunrise Point PCH
This patch adds the I2C/SMBus Device IDs for the Intel Sunrise Point PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-16 09:16:22 +02:00
Alan Cox 39e8e30ee5 i2c: i801: Add PCI ID for Intel Braswell
The SMBus host controller is the same as used in Baytrail so add the new
PCI ID to the driver's list of supported IDs.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-08-19 10:19:47 -05:00
Jean Delvare b299de8391 i2c: i801: Add device ID for Intel Wildcat Point PCH
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17 19:56:23 +02:00
Jean Delvare ce3161106a i2c: i801: Fix the alignment of the device table
A long name broke the alignment, shift the columns a bit to fix it and
make the table look nice again. While we're here, switch to the
standard comment style to make checkpatch happy, and use tabs instead
of spaces for column alignment.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17 19:56:19 +02:00
Jingoo Han 392debf116 i2c: remove DEFINE_PCI_DEVICE_TABLE macro
Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is not preferred.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-13 09:44:59 +01:00
Chew, Kean ho 1b31e9b76e i2c: i801: enable Intel BayTrail SMBUS
Add Device ID of Intel BayTrail SMBus Controller.

Signed-off-by: Chew, Kean ho <kean.ho.chew@intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-09 21:40:25 +01:00
Jean Delvare 7c81c60f37 Update Jean Delvare's e-mail address
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2014-01-29 20:40:08 +01:00
James Ralston afc6592412 i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCH
This patch adds the SMBus Device IDs for the Intel Wildcat Point-LP PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-11-14 18:38:04 +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
Seth Heasley f39901c1be i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDs
This patch adds the i801 SMBus Controller DeviceIDs for the Intel Coleto Creek PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-20 21:32:27 +02:00
Jean Delvare 5322934550 i2c: i801: Document feature bits in modinfo
Duplicate the feature bits documentation in modinfo, as not every user
will read the driver's source code or documentation file.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-17 22:49:30 +02:00
Doug Anderson 55827f4aa6 i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls
There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.

Reported-by: Wolfram Sang <wsa@the-dreams.de>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-22 00:25:50 +01:00
James Ralston a3fc0ff00a i2c: i801: Add Device IDs for Intel Wellsburg PCH
This patch adds the SMBus Device IDs for the Intel Wellsburg PCH

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-15 20:46:01 +01:00
Seth Heasley c2db409cbc i2c: i801: SMBus patch for Intel Avoton DeviceIDs
This patch adds the PCU SMBus DeviceID for the Intel Avoton SOC.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-02-08 20:06:29 +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
Jean Delvare 6676a847d4 i2c-i801: Enable interrupts for all post-ICH5 chips
I did not receive a single bug report after interrupt support was
added for a limited number of chips. So I'd say the code is good and
should be enabled for all supported chips, that is: ICH5 and later.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
2012-12-16 21:11:55 +01:00
Thierry Reding f6afc8b158 i2c-i801: Add device tree support
Add support for probing slave devices parsed from the device tree.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-12-16 21:11:54 +01:00
Jean Delvare 28901f5794 i2c-i801: Fix comment
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-28 21:37:01 +01:00
Jean Delvare 79e3e5b894 i2c-i801: Simplify dependency towards GPIOLIB
Arbitrarily selecting GPIOLIB causes trouble on some architectures,
so don't do that. Instead, just make the optional multiplexing code
depend on CONFIG_I2C_MUX_GPIO instead of CONFIG_I2C_MUX for now. We
can revisit if the i2c-i801 driver ever supports other multiplexing
flavors.

Also make that optional code depend on DMI, as it won't do anything
without that.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
2012-10-28 21:37:01 +01:00
Jean Delvare f82b86267a i2c-i801: Let i2c-mux-gpio find the GPIO chip
Now that i2c-mux-gpio is able to find the GPIO chip by itself, we can
delegate this task. The great thing here is that i2c-mux-gpio can
defer device probing until the gpio chip is available, so we no longer
depend on the module loading order.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05 22:23:54 +02:00
Jean Delvare 3ad7ea18ae i2c-i801: Support SMBus multiplexing on Asus Z8 series
Add support for SMBus multiplexing on Asus Z8 motherboard series. On
these boards, the memory slots are behind a GPIO-controlled I2C
multiplexer. Models with 6 or 12 memory slots have 2 segments behind
the multiplexer, while models with 18 memory slots have 3 such
segments.

On these boards, only the memory slots are behind the multiplexer,
so it is possible to keep the autodetection mechanism.

The code is generic enough so it could work on other boards as long as
the multiplexer is controlled by GPIO pins. For other forms of
multiplexing (for example using an I2C device) additional code will be
needed.

Thanks to Asus for providing a board to develop and test this feature,
as well as all the technical information required.

At the moment, the GPIO driver must be loaded before the i2c-i801
driver, but I hope to solve this soon, using deferred probing on
the i2c-mux-gpio side.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05 22:23:53 +02:00
James Ralston 4a8f1ddde9 i2c-i801: Add Device IDs for Intel Lynx Point-LP PCH
Add the SMBus Device IDs for the Intel Lynx Point-LP PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-09-10 10:14:02 +02:00
Daniel Kurtz d3ff6ce400 i2c-i801: Enable IRQ for byte_by_byte transactions
Byte-by-byte transactions are used primarily for accessing I2C devices
with an SMBus controller.  For these transactions, for each byte that is
read or written, the SMBus controller generates a BYTE_DONE IRQ.  The isr
reads/writes the next byte, and clears the IRQ flag to start the next byte.
On the penultimate IRQ, the isr also sets the LAST_BYTE flag.

There is no locking around the cmd/len/count/data variables, since the
I2C adapter lock ensures there is never multiple simultaneous transactions
for the same device, and the driver thread never accesses these variables
while interrupts might be occurring.

The end result is faster I2C block read and write transactions.

Note: This patch has only been tested and verified by doing I2C read and
write block transfers on Cougar Point 6 Series PCH, as well as I2C read
block transfers on ICH5.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:59 +02:00
Jean Delvare 29b608540b i2c-i801: Enable interrupts on ICH5/7/8/9/10
Enable interrupts on more devices. ICH5, ICH7(-M) and ICH10 have been
tested to work OK. ICH8 and ICH9 are expected to work just fine as
they are very close to ICH7 and ICH10.

Ultimately we want to enable this feature on at least every device
since the ICH5, but for now we limit the exposure. We'll enable it for
other devices if we don't get negative feedback.

As a bonus, let the user know when interrupts are used.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24 14:13:59 +02:00
Daniel Kurtz 636752bcb5 i2c-i801: Enable IRQ for SMBus transactions
Add a new 'feature' to i2c-i801 to enable using PCI interrupts.
When the feature is enabled, then an isr is installed for the device's
PCI IRQ.

An I2C/SMBus transaction is always terminated by one of the following
interrupt sources: FAILED, BUS_ERR, DEV_ERR, or on success: INTR.

When the isr fires for one of these cases, it sets the ->status variable
and wakes up the waitq.  The waitq then saves off the status code, and
clears ->status (in preparation for some future transaction).
The SMBus controller generates an INTR irq at the end of each
transaction where INTREN was set in the HST_CNT register.

No locking is needed around accesses to priv->status since all writes to
it are serialized: it is only ever set once in the isr at the end of a
transaction, and cleared while no interrupts can occur.  In addition, the
I2C adapter lock guarantees that entire I2C transactions for a single
adapter are always serialized.

For this patch, the INTREN bit is set only for SMBus block, byte and word
transactions, but not for I2C reads or writes.  The use of the DS
(BYTE_DONE) interrupt with byte-by-byte I2C transactions is implemented in
a subsequent patch.

The interrupt feature has only been enabled for COUGARPOINT hardware.
In addition, it is disabled if SMBus is using the SMI# interrupt.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:58 +02:00
Jean Delvare 6cad93c4bb i2c-i801: Consolidate polling
(Based on earlier work by Daniel Kurtz.)

Come up with a consistent, driver-wide strategy for event polling. For
intermediate steps of byte-by-byte block transactions, check for
BYTE_DONE or any error flag being set. At the end of every transaction
(regardless of PEC being used), check for both BUSY being cleared and
INTR or any error flag being set. This ensures proper action for all
transaction types.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24 14:13:58 +02:00
Daniel Kurtz 37af871112 i2c-i801: Drop ENABLE_INT9
Later patches enable interrupts.  This preliminary patch removes the older
unsupported ENABLE_INT9 flag.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:58 +02:00
Daniel Kurtz edbeea6383 i2c-i801: Rename some SMBHSTCNT bit constants
Rename the SMBHSTCNT register bit access constants to match the style of
other register bits.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:58 +02:00