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2016-09-24i2c: export i2c_adapter_depth()Bartosz Golaszewski1-0/+1
For crazy setups in which an i2c gpio expander is behind an i2c gpio multiplexer controlled by a gpio provided a second expander using the same device driver we need to explicitly tell lockdep how to handle nested locking. Export i2c_adapter_depth() as public API to be reused outside of i2c core code. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Peter Rosin <peda@axentia.se> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-30i2c: move locking operations to their own structPeter Rosin1-7/+18
This makes it trivial to constify them, so do that. Signed-off-by: Peter Rosin <peda@axentia.se> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-26i2c: core: Add function for finding the bus speed from ACPI, take 2Jarkko Nikula1-0/+9
ACPI 5 specification doesn't have property for the I2C bus speed but I2cSerialBus resource descriptor which define each controller-slave connection define the maximum speed supported by that connection. Thus finding the maximum safe speed for the bus is to walk through all I2cSerialBus resources that are associated to I2C controller and use the speed of slowest connection. Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter drivers can call prior registering itself to core. This implies two-step walk through the I2cSerialBus resources: call to i2c_acpi_find_bus_speed() does the first scan and finds the safe bus speed that adapter drivers can set up. Adapter driver registration does the second scan when i2c-core creates the I2C slaves by calling the i2c_acpi_register_devices(). In that way the bus speed is set in case slave device probe gets called during registration and does communication. Previous version commit 55d38d060e99 ("i2c: core: Add function for finding the bus speed from ACPI") got reverted due merge conflicts from commit 525e6fabeae2 ("i2c / ACPI: add support for ACPI reconfigure notifications"). This version is a bit bigger than previous version but is still sharing the lowest and complicated part of I2cSerialBus lookup routines with the existing code. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-25i2c: add i2c_trylock_bus wrapper, use itPeter Rosin1-0/+14
This unifies usage with i2c_lock_bus and i2c_unlock_bus, and paves the way for the next patch which looks a bit saner with this preparatory work taken care of beforehand. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-07-19Revert "i2c: core: Add function for finding the bus speed from ACPI"Wolfram Sang1-9/+0
This reverts commit 55d38d060e999ca1a3ea6eb132105a0301e4cd04. There were too heavy merge conflicts and the driver code making use of this was not ready yet anyhow. So, we wait one cycle. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-07-14i2c: core: Add function for finding the bus speed from ACPIJarkko Nikula1-0/+9
ACPI 5 specification doesn't have property for the I2C bus speed but I2cSerialBus resource descriptors which define each controller-slave connection define the maximum speed supported by that connection. Thus finding the maximum safe speed for the bus is to walk all I2cSerialBus resources that are associated to I2C controller and use the speed of slowest connection. Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter drivers can call prior registering itself to core. This implies two-step walk through the I2cSerialBus resources: call to i2c_acpi_find_bus_speed() does the first scan and finds the safe bus speed that adapter drivers can set up. Adapter driver registration does the second scan when i2c-core creates the I2C slaves by calling the i2c_acpi_register_devices(). In that way the bus speed is set in case slave device probe gets called during registration and does communication. Implement this by reusing the existing ACPI I2C walk routines in the i2c-core. Extend them so that slowest connection speed is saved during the walk and I2C slaves are registered only when calling through the i2c_acpi_register_devices() with the i2c_adapter pointer. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-06-17i2c: smbus: add SMBus Host Notify supportBenjamin Tissoires1-0/+3
SMBus Host Notify allows a slave device to act as a master on a bus to notify the host of an interrupt. On Intel chipsets, the functionality is directly implemented in the firmware. We just need to export a function to call .alert() on the proper device driver. i2c_handle_smbus_host_notify() behaves like i2c_handle_smbus_alert(). When called, it schedules a task that will be able to sleep to go through the list of devices attached to the adapter. The current implementation allows one Host Notification to be scheduled while an other is running. Tested-by: Andrew Duggan <aduggan@synaptics.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-06-17i2c: add a protocol parameter to the alert callbackBenjamin Tissoires1-1/+6
.alert() is meant to be generic, but there is currently no way for the device driver to know which protocol generated the alert. Add a parameter in .alert() to help the device driver to understand what is given in data. This patch is required to have the support of SMBus Host Notify protocol through .alert(). Tested-by: Andrew Duggan <aduggan@synaptics.com> For hwmon: Acked-by: Guenter Roeck <linux@roeck-us.net> For IPMI: Acked-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-06-13i2c: Add generic support passing secondary devices addressesJean-Michel Hautbois1-0/+5
Some I2C devices have multiple addresses assigned, for example each address corresponding to a different internal register map page of the device. So far drivers which need support for this have handled this with a driver specific and non-generic implementation, e.g. passing the additional address via platform data. This patch provides a new helper function called i2c_new_secondary_device() which is intended to provide a generic way to get the secondary address as well as instantiate a struct i2c_client for the secondary address. The function expects a pointer to the primary i2c_client, a name for the secondary address and an optional default address. The name is used as a handle to specify which secondary address to get. The default address is used as a fallback in case no secondary address was explicitly specified. In case no secondary address and no default address were specified the function returns NULL. For now the function only supports look-up of the secondary address from devicetree, but it can be extended in the future to for example support board files and/or ACPI. Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@veo-labs.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04i2c: mux: relax locking of the top i2c adapter during mux-locked muxingPeter Rosin1-0/+1
With a i2c topology like the following GPIO ---| ------ BAT1 | v / I2C -----+----------+---- MUX | \ EEPROM ------ BAT2 there is a locking problem with the GPIO controller since it is a client on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1) will lock the whole i2c bus prior to attempting to switch the mux to the correct i2c segment. In the above case, the GPIO device is an I/O expander with an i2c interface, and since the GPIO subsystem knows nothing (and rightfully so) about the lockless needs of the i2c mux code, this results in a deadlock when the GPIO driver issues i2c transfers to modify the mux. So, observing that while it is needed to have the i2c bus locked during the actual MUX update in order to avoid random garbage on the slave side, it is not strictly a must to have it locked over the whole sequence of a full select-transfer-deselect mux client operation. The mux itself needs to be locked, so transfers to clients behind the mux are serialized, and the mux needs to be stable during all i2c traffic (otherwise individual mux slave segments might see garbage, or worse). Introduce this new locking concept as "mux-locked" muxes, and call the pre-existing mux locking scheme "parent-locked". Modify the i2c mux locking so that muxes that are "mux-locked" locks only the muxes on the parent adapter instead of the whole i2c bus when there is a transfer to the slave side of the mux. This lock serializes transfers to the slave side of the muxes on the parent adapter. Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved gpio/pinctrl devices have a parent that is an i2c adapter in the same adapter tree that is muxed, and request a "mux-locked mux" if that is the case. Modify the select-transfer-deselect code for "mux-locked" muxes so that each of the select-transfer-deselect ops locks the mux parent adapter individually. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04i2c: allow adapter drivers to override the adapter lockingPeter Rosin1-2/+42
Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and unlock_bus ops in the adapter. These funcs/ops take an additional flags argument that indicates for what purpose the adapter is locked. There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they are both implemented the same. For now. Locking the root adapter means that the whole bus is locked, locking the segment means that only the current bus segment is locked (i.e. i2c traffic on the parent side of a mux is still allowed even if the child side of the mux is locked). Also support a trylock_bus op (but no function to call it, as it is not expected to be needed outside of the i2c core). Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag). Locking the root adapter and locking the segment is the same thing for all root adapters (e.g. in the normal case of a simple topology with no i2c muxes). The two locking variants are also the same for traditional muxes (aka parent-locked muxes). These muxes traverse the tree, locking each level as they go until they reach the root. This patch is preparatory for a later patch in the series introducing mux-locked muxes, which behave differently depending on the requested locking. Since all current users are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER, we only need to annotate the calls that will not need to lock the root adapter for mux-locked muxes. I.e. the instances that needs to use I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those instances are in the i2c_transfer and i2c_smbus_xfer functions, so that mux-locked muxes can single out normal i2c accesses to its slave side and adjust the locking for those accesses. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-11i2c: introduce helper function to get 8 bit address from a messageWolfram Sang1-0/+5
Drivers do this in various ways, let's use one standard way of doing it. Note: I2C_M_RD is bit 0, so the code could be simplified. To be extremly robust and to advertise good coding practices, I still use the ternary operator and let the compilers do the optimizing job. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-13i2c: create builtin_i2c_driver to avoid registration boilerplatePaul Gortmaker1-1/+12
In commit f309d4443130bf814e991f836e919dca22df37ae ("platform_device: better support builtin boilerplate avoidance") we introduced the builtin_driver macro. Here we use that support and extend it to I2C driver registration, so where a driver is clearly non-modular and builtin-only, we can register it in a similar fashion. And existing code that is clearly non-modular can be updated with the simple mapping of module_i2c_driver(...) ---> builtin_i2c_driver(...) We've essentially cloned the former to make the latter, and taken out the remove/module_exit parts since those never get used in a non-modular build of the code. A similar thing was done in commit b4eb6cdbbd13698704863f680c643c569909e1c2 ("PCI: Add builtin_pci_driver() to avoid registration boilerplate"). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-14i2c: add generic routine to parse DT for timing informationWolfram Sang1-0/+18
Inspired from the i2c-rk3x driver (thanks guys!) but refactored and extended. See built-in docs for further information. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-30i2c: add i2c_check_quirks helper functionNicola Corna1-0/+14
This patch adds a i2c_check_quirks helper function to check the quirk flags of an i2c adapter, in a similar way to i2c_check_functionality. Signed-off-by: Nicola Corna <nicola@corna.info> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-30i2c: add i2c quirk flag for unsupported clock stretchingNicola Corna1-0/+2
Add I2C_AQ_NO_CLK_STRETCH quirk flag, to be used when clock stretching is not supported. Signed-off-by: Nicola Corna <nicola@corna.info> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24i2c: core: Add support for best effort block read emulationIrina Tirdea1-0/+3
There are devices that need to handle block transactions regardless of the capabilities exported by the adapter. For performance reasons, they need to use i2c read blocks if available, otherwise emulate the block transaction with word or byte transactions. Add support for a helper function that would read a data block using the best transfer available: I2C_FUNC_SMBUS_READ_I2C_BLOCK, I2C_FUNC_SMBUS_READ_WORD_DATA or I2C_FUNC_SMBUS_READ_BYTE_DATA. Signed-off-by: Irina Tirdea <irina.tirdea@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24i2c: add a flag to mark clients as slavesWolfram Sang1-4/+5
And update indentation with one more tab, sigh... Tested-by: Andrey Danin <danindrey@mail.ru> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10i2c: core: add and export of_get_i2c_adapter_by_node() interfaceVladimir Zapolskiy1-0/+7
of_find_i2c_adapter_by_node() call requires quite often missing put_device(), and i2c_put_adapter() releases a device locked by i2c_get_adapter() only. In general module_put(adapter->owner) and put_device(dev) are not interchangeable. This is a common error reproduction scenario as a result of the misusage described above (for clearness this is run on iMX6 platform with HDMI and I2C bus drivers compiled as kernel modules): root@mx6q:~# lsmod | grep i2c i2c_imx 10213 0 root@mx6q:~# lsmod | grep dw_hdmi_imx dw_hdmi_imx 3631 0 dw_hdmi 11846 1 dw_hdmi_imx imxdrm 8674 3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb drm_kms_helper 113765 5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb root@mx6q:~# rmmod dw_hdmi_imx root@mx6q:~# lsmod | grep i2c i2c_imx 10213 -1 ^^^^^ root@mx6q:~# rmmod i2c_imx rmmod: ERROR: Module i2c_imx is in use To fix existing users of these interfaces and to avoid any further confusion and misusage in future, add one more interface of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in sense that an I2C bus device driver found and locked by user can be correctly unlocked by i2c_put_adapter(). Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-04-15Merge tag 'pm+acpi-4.1-rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups all over, although there are a few items that sort of fall into the new feature category. First off, we have new callbacks for PM domains that should help us to handle some issues related to device initialization in a better way. There also is some consolidation in the unified device properties API area allowing us to use that inferface for accessing data coming from platform initialization code in addition to firmware-provided data. We have some new device/CPU IDs in a few drivers, support for new chips and a new cpufreq driver too. Specifics: - Generic PM domains support update including new PM domain callbacks to handle device initialization better (Russell King, Rafael J Wysocki, Kevin Hilman) - Unified device properties API update including a new mechanism for accessing data provided by platform initialization code (Rafael J Wysocki, Adrian Hunter) - ARM cpuidle update including ARM32/ARM64 handling consolidation (Daniel Lezcano) - intel_idle update including support for the Silvermont Core in the Baytrail SOC and for the Airmont Core in the Cherrytrail and Braswell SOCs (Len Brown, Mathias Krause) - New cpufreq driver for Hisilicon ACPU (Leo Yan) - intel_pstate update including support for the Knights Landing chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi) - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann) - powernv cpufreq driver update (Shilpasri G Bhat) - devfreq update including Tegra support changes (Tomeu Vizoso, MyungJoo Ham, Chanwoo Choi) - powercap RAPL (Running-Average Power Limit) driver update including support for Intel Broadwell server chips (Jacob Pan, Mathias Krause) - ACPI device enumeration update related to the handling of the special PRP0001 device ID allowing DT-style 'compatible' property to be used for ACPI device identification (Rafael J Wysocki) - ACPI EC driver update including limited _DEP support (Lan Tianyu, Lv Zheng) - ACPI backlight driver update including a new mechanism to allow native backlight handling to be forced on non-Windows 8 systems and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede) - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu) - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger, Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki) - Fixes related to suspend-to-idle for the iTCO watchdog driver and the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu) - PM tracing support for the suspend phase of system suspend/resume transitions (Zhonghui Fu) - Configurable delay for the system suspend/resume testing facility (Brian Norris) - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)" * tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits) ACPI / scan: Fix NULL pointer dereference in acpi_companion_match() ACPI / scan: Rework modalias creation when "compatible" is present intel_idle: mark cpu id array as __initconst powercap / RAPL: mark rapl_ids array as __initconst powercap / RAPL: add ID for Broadwell server intel_pstate: Knights Landing support intel_pstate: remove MSR test cpufreq: fix qoriq uniprocessor build ACPI / scan: Take the PRP0001 position in the list of IDs into account ACPI / scan: Simplify acpi_match_device() ACPI / scan: Generalize of_compatible matching device property: Introduce firmware node type for platform data device property: Make it possible to use secondary firmware nodes PM / watchdog: iTCO: stop watchdog during system suspend cpufreq: hisilicon: add acpu driver ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler cpufreq: powernv: Report cpu frequency throttling intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs intel_idle: Update support for Silvermont Core in Baytrail SOC PM / devfreq: tegra: Register governor on module init ...
2015-04-10i2c: change input parameter to i2c_adapter for prepare/unprepare_recoveryGrygorii Strashko1-2/+2
This patch changes type of input parameter for prepare/unprepare_recovery() callbacks from struct i2c_bus_recovery_info * to struct i2c_adapter *. This allows to simplify implementation of these callbacks and avoid type conversations from i2c_bus_recovery_info to i2c_adapter. The i2c_bus_recovery_info can be simply retrieved from struct i2c_adapter which contains pointer on it. There are no users currently, so this is safe to do. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-27i2c: slave: rework the slave APIWolfram Sang1-4/+4
After more discussion, brave users, and additional datasheet evaluation, some API updates for the new I2C slave framework became imminent. The slave events now get some easier to understand naming. Also, the event handling has been simplified to only need a single call to the slave callback when an action by the backend is required. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-17driver core / ACPI: Represent ACPI companions using fwnode_handleRafael J. Wysocki1-2/+2
Now that we have struct fwnode_handle, we can use that to point to ACPI companions from struct device objects instead of pointing to struct acpi_device directly. There are two benefits from that. First, the somewhat ugly and hackish struct acpi_dev_node can be dropped and, second, the same struct fwnode_handle pointer can be used in the future to point to other (non-ACPI) firmware device node types. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Grant Likely <grant.likely@linaro.org>
2015-03-13i2c: add quirk structure to describe adapter flawsWolfram Sang1-0/+43
The number of I2C adapters which are not fully I2C compatible is rising, sadly. Drivers usually do handle the flaws, still the user receives only some errno for a transfer which normally can be expected to work. This patch introduces a formal description of flaws. One advantage is that the core can check before the actual transfer if the messages could be transferred at all. This is done in the next patch. Another advantage is that we can pass this information to the user so the restrictions are exactly known and further actions can be based on that. This will be done later after some stabilization period for this description. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Ray Jui <rjui@broadcom.com> Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com> Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
2015-02-21Merge branch 'i2c/for-3.20' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Summary: - legacy PM code removed from the core, there were no users anymore (thanks to Lars-Peter Clausen) - new driver for Broadcom iProc - bigger driver updates for designware, rk3x, cadence, ocores - a bunch of smaller updates and bugfixes" * 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (31 commits) i2c: ocores: rework clk code to handle NULL cookie i2c: designware-baytrail: another fixup for proper Kconfig dependencies i2c: fix reference to functionality constants definition i2c: iproc: Add Broadcom iProc I2C Driver i2c: designware-pci: update Intel copyright line i2c: ocores: add common clock support i2c: hix5hd2: add COMPILE_TEST i2c: clarify comments about the dev_released completion i2c: ocores: fix clock-frequency binding usage i2c: tegra: Maintain CPU endianness i2c: designware-baytrail: use proper Kconfig dependencies i2c: designware: Do not calculate SCL timing parameters needlessly i2c: do not try to load modules for of-registered devices i2c: designware: Add Intel Baytrail PMIC I2C bus support i2c: designware: Add i2c bus locking support of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver i2c: designware: use {readl|writel}_relaxed instead of readl/writel i2c: designware-pci: no need to provide clk_khz i2c: designware-pci: remove Moorestown support i2c: imx: whitespace and checkpatch cleanup ...
2015-01-27i2c: Only include slave support if selectedJean Delvare1-0/+6
Make the slave support depend on CONFIG_I2C_SLAVE. Otherwise it gets included unconditionally, even when it is not needed. I2C bus drivers which implement slave support must select I2C_SLAVE. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-22i2c: Remove support for legacy PMLars-Peter Clausen1-4/+0
There haven't been any I2C driver that use the legacy suspend/resume callbacks for a while now and new drivers are supposed to use PM ops. So remove support for legacy suspend/resume for I2C drivers. Since there aren't any special bus specific things to do during suspend/resume and since the PM core will automatically fallback directly to using the device's PM ops if no bus PM ops are specified there is no need to have any I2C bus PM ops. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-14Merge branch 'i2c/for-3.19' of ↵Linus Torvalds1-0/+29
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "For 3.19, the I2C subsystem has to offer special candy this time. Right in time for Christmas :) - I2C slave framework: finally, a generic mechanism for Linux being an I2C slave (if the bus driver supports that). Docs are still missing but will come later this cycle, the code is good enough to go. - I2C muxes represent their topology in sysfs much more detailed. This will help users to navigate around much easier. - irq population of i2c clients is now done at probe time, not device creation time, to have better support for deferred probing. - new drivers for Imagination SCB, Amlogic Meson - DMA support added for Freescale IMX, Renesas SHMobile - slightly bigger driver updates to OMAP, i801, AT91, and rk3x (mostly quirk handling, timing updates, and using better kernel interfaces) - eeprom driver can now write with byte-access (very slow, but OK to have) - and the bunch of smaller fixes, cleanups, ID updates..." * 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (56 commits) i2c: sh_mobile: remove unneeded DMA mask i2c: rcar: add slave support i2c: slave-eeprom: add eeprom simulator driver i2c: core changes for slave support MAINTAINERS: add I2C dt bindings also to I2C realm i2c: designware: Fix falling time bindings doc i2c: davinci: switch to use platform_get_irq Documentation: i2c: Use PM ops instead of legacy suspend/resume i2c: sh_mobile: optimize irq entry i2c: pxa: add support for SCCB devices omap: i2c: don't check bus state IP rev3.3 and earlier i2c: s3c2410: Handle i2c sys_cfg register in i2c driver i2c: rk3x: add Kconfig dependency on COMMON_CLK i2c: omap: add notes related to i2c multimaster mode i2c: omap: don't reset controller if Arbitration Lost detected i2c: omap: implement workaround for handling invalid BB-bit values i2c: omap: cleanup register definitions i2c: rk3x: handle dynamic clock rate changes correctly i2c: at91: enable probe deferring on dma channel request i2c: at91: remove legacy DMA support ...
2014-12-12i2c: core changes for slave supportWolfram Sang1-0/+29
Finally(!), make Linux support being an I2C slave. Most of the existing infrastructure is reused. We mainly add i2c_slave_register/unregister() calls which tells i2c bus drivers to activate the slave mode. Then, they also get a callback to report slave events to. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-03treewide: Fix typo in Documentation/DocBook/device-driversMasanari Iida1-1/+1
This patch fix speeling typo found in html files within Documentation/DocBook/device-drivers. It is because html files are generated from comments in source, so I have to fix comments in the source. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-09-25i2c: move acpi code back into the coreWolfram Sang1-16/+0
Commit 5d98e61d337c ("I2C/ACPI: Add i2c ACPI operation region support") renamed the i2c-core module. This may cause regressions for distributions, so put the ACPI code back into the core. Reported-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Lan Tianyu <tianyu.lan@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2014-08-19i2c: rework kernel config I2C_ACPILan Tianyu1-4/+8
Commit da3c6647(I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI config) adds a new kernel config I2C_ACPI and make I2C core built in when the config is selected. This is wrong because distributions etc generally compile I2C as a module and the commit broken that. This patch is to rename I2C_ACPI to ACPI_I2C_OPREGION. New config only controls ACPI I2C operation region code and depends on I2C=y. Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> [wsa: removed unrelated change for Kconfig] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-27I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI configLan Tianyu1-1/+3
Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI to enable I2C ACPI code. Current there is a race between removing I2C ACPI operation region and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI is set. Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-27I2C/ACPI: Add i2c ACPI operation region supportLan Tianyu1-0/+10
ACPI 5.0 spec(5.5.2.4.5) defines GenericSerialBus(i2c, spi, uart) operation region. It allows ACPI aml code able to access such kind of devices to implement some ACPI standard method. ACPI Spec defines some access attribute to associate with i2c protocol. AttribQuick Read/Write Quick Protocol AttribSendReceive Send/Receive Byte Protocol AttribByte Read/Write Byte Protocol AttribWord Read/Write Word Protocol AttribBlock Read/Write Block Protocol AttribBytes Read/Write N-Bytes Protocol AttribProcessCall Process Call Protocol AttribBlockProcessCall Write Block-Read Block Process Call Protocol AttribRawBytes Raw Read/Write N-BytesProtocol AttribRawProcessBytes Raw Process Call Protocol On the Asus T100TA, Bios use GenericSerialBus operation region to access i2c device to get battery info. Sample code From Asus T100TA Scope (_SB.I2C1) { Name (UMPC, ResourceTemplate () { I2cSerialBus (0x0066, ControllerInitiated, 0x00061A80, AddressingMode7Bit, "\\_SB.I2C1", 0x00, ResourceConsumer, , ) }) ... OperationRegion (DVUM, GenericSerialBus, Zero, 0x0100) Field (DVUM, BufferAcc, NoLock, Preserve) { Connection (UMPC), Offset (0x81), AccessAs (BufferAcc, AttribBytes (0x3E)), FGC0, 8 } ... } Device (BATC) { Name (_HID, EisaId ("PNP0C0A")) // _HID: Hardware ID Name (_UID, One) // _UID: Unique ID ... Method (_BST, 0, NotSerialized) // _BST: Battery Status { If (LEqual (AVBL, One)) { Store (FGC0, BFFG) If (LNotEqual (STAT, One)) { ShiftRight (CHST, 0x04, Local0) And (Local0, 0x03, Local0) If (LOr (LEqual (Local0, One), LEqual (Local0, 0x02))) { Store (0x02, Local1) } ... } The i2c operation region is defined under I2C1 scope. _BST method under battery device BATC read battery status from the field "FCG0". The request would be sent to i2c operation region handler. This patch is to add i2c ACPI operation region support. Due to there are only "Byte" and "Bytes" protocol access on the Asus T100TA, other protocols have not been tested. About RawBytes and RawProcessBytes protocol, they needs specific drivers to interpret reference data from AML code according ACPI 5.0 SPEC(5.5.2.4.5.3.9 and 5.5.2.4.5.3.10). So far, not found such case and will add when find real case. Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-05i2c: add deprecation warning for class based instantiationWolfram Sang1-0/+1
Class based instantiation can cause noticeable delays when booting. This mechanism is used when it is not possible to describe slaves on I2C busses. As we do have other mechanisms, most embedded I2C will not need classes and for embedded it is explicitly not recommended to use them. Add a deprecation warning for drivers which want to disable class based instantiation in the near future to gain boot-up time, so users relying on this technique can switch to something better. They really should. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-27i2c: update i2c_algorithm documentationBen Dooks1-1/+15
Add some kerneldoc style documentaton to the i2c_algorithm structure, and point the master_xfer return codes at the right place in Documentation/i2c/fault_codes Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-14i2c: Re-instate body of i2c_parent_is_i2c_adapter()Stephen Warren1-1/+1
The body of i2c_parent_is_i2c_adapter() is currently guarded by I2C_MUX. It should be CONFIG_I2C_MUX instead. Among potentially other problems, this resulted in i2c_lock_adapter() only locking I2C mux child adapters, and not the parent adapter. In turn, this could allow inter-mingling of mux child selection and I2C transactions, which could result in I2C transactions being directed to the wrong I2C bus, and possibly even switching between busses in the middle of a transaction. One concrete issue caused by this bug was corrupted HDMI EDID reads during boot on the NVIDIA Tegra Seaboard system, although this only became apparent in recent linux-next, when the boot timing was changed just enough to trigger the race condition. Fixes: 3923172b3d70 ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case") Cc: Phil Carmody <phil.carmody@partner.samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-04i2c: Remove redundant 'driver' field from the i2c_client structLars-Peter Clausen1-2/+0
The 'driver' field of the i2c_client struct is redundant. The same data can be accessed through to_i2c_driver(client->dev.driver). The generated code for both approaches in more or less the same. E.g. on ARM the expression client->driver->command(...) generates ... ldr r3, [r0, #28] ldr r3, [r3, #32] blx r3 ... and the expression to_i2c_driver(client->dev.driver)->command(...) generates ... ldr r3, [r0, #160] ldr r3, [r3, #-4] blx r3 ... Other architectures will generate similar code. All users of the 'driver' field outside of the I2C core have already been converted. So this only leaves the core itself. This patch converts the remaining few users in the I2C core and then removes the 'driver' field from the i2c_client struct. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23i2c: move ACPI helpers into the coreMika Westerberg1-6/+0
This follows what has already been done for the DeviceTree helpers. Move the ACPI helpers from drivers/acpi/acpi_i2c.c to the I2C core and update documentation accordingly. This also solves a problem reported by Jerry Snitselaar that we can't build the ACPI I2C helpers as a module. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23i2c: move OF helpers into the coreWolfram Sang1-0/+20
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>
2013-08-07i2c: reduce parent checking to a NOOP in non-I2C_MUX casePhil Carmody1-0/+2
In 0826374 - i2c: Multiplexed I2C bus core support core i2c code increased in size and complexity even when I2C_MUX wasn't selected. Turning this check into a constant NULL in the n case lets the client functions in be simplified too, not needing to include never-called calls to the mux-specific helpers. Signed-off-by: Phil Carmody <phil.carmody@partner.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02i2c: Make return type of i2c_del_adapter() voidLars-Peter Clausen1-1/+1
i2c_del_adapter() is usually called from a drivers remove callback. The Linux device driver model does not allow the remove callback to fail and all resources allocated in the probe callback need to be freed, as well as all resources which have been provided to the rest of the kernel(for example a I2C adapter) need to be revoked. So any function revoking such resources isn't allowed to fail either. i2c_del_adapter() adheres to this requirement and will never fail. But i2c_del_adapter()'s return type is int, which may cause driver authors to think that it can fail. This led to code constructs like: ret = i2c_del_adapter(...); BUG_ON(ret); Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially becomes dead code, which means it can be removed. Making the return type of i2c_del_adapter() void makes it explicit that the function will never fail and should prevent constructs like the above from re-appearing in the kernel code. All callers of i2c_del_adapter() have already been updated in a previous patch to ignore the return value, so the conversion of the return type from int to void can be done without causing any build failures. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02i2c: Remove detach_adapterLars-Peter Clausen1-5/+2
The detach_adapter callback has been deprecated for quite some time and has no user left. Keeping it alive blocks other cleanups, so remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24i2c: Add bus recovery infrastructureViresh Kumar1-0/+41
Add i2c bus recovery infrastructure to i2c adapters as specified in the i2c protocol Rev. 03 section 3.1.16 titled "Bus clear". http://www.nxp.com/documents/user_manual/UM10204.pdf Sometimes during operation i2c bus hangs and we need to give dummy clocks to slave device to start the transfer again. Now we may have capability in the bus controller to generate these clocks or platform may have gpio pins which can be toggled to generate dummy clocks. This patch supports both. This patch also adds in generic bus recovery routines gpio or scl line based which can be used by bus controller. In addition controller driver may provide its own version of the bus recovery routine. This doesn't support multi-master recovery for now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [wsa: changed gpio type to int and minor reformatting] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2012-11-23i2c / ACPI: add ACPI enumeration supportMika Westerberg1-0/+9
ACPI 5 introduced I2cSerialBus resource that makes it possible to enumerate and configure the I2C slave devices behind the I2C controller. This patch adds helper functions to support I2C slave enumeration. An ACPI enabled I2C controller driver only needs to call acpi_i2c_register_devices() in order to get its slave devices enumerated, created and bound to the corresponding ACPI handle. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells1-124/+1
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-10-06i2c: Correct struct i2c_driver doc about detectionVivien Didelot1-1/+1
s/address_data/address_list/ in addition to c3813d6. Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-31Merge branch 'v4l_for_linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: "This is the first part of the media patches for v3.6. This patch series contain: - new DVB frontend: rtl2832 - new video drivers: adv7393 - some unused files got removed - a selection API cleanup between V4L2 and V4L2 subdev API's - a major redesign at v4l-ioctl2, in order to clean it up - several driver fixes and improvements." * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (174 commits) v4l: Export v4l2-common.h in include/linux/Kbuild media: Revert "[media] Terratec Cinergy S2 USB HD Rev.2" [media] media: Use pr_info not homegrown pr_reg macro [media] Terratec Cinergy S2 USB HD Rev.2 [media] v4l: Correct conflicting V4L2 subdev selection API documentation [media] Feature removal: V4L2 selections API target and flag definitions [media] v4l: Unify selection flags documentation [media] v4l: Unify selection flags [media] v4l: Common documentation for selection targets [media] v4l: Unify selection targets across V4L2 and V4L2 subdev interfaces [media] v4l: Remove "_ACTUAL" from subdev selection API target definition names [media] V4L: Remove "_ACTIVE" from the selection target name definitions [media] media: dvb-usb: print mac address via native %pM [media] s5p-tv: Use module_i2c_driver in sii9234_drv.c file [media] media: gpio-ir-recv: add allowed_protos for platform data [media] s5p-jpeg: Use module_platform_driver in jpeg-core.c file [media] saa7134: fix spelling of detach in label [media] cx88-blackbird: replace ioctl by unlocked_ioctl [media] cx88: don't use current_norm [media] cx88: fix a number of v4l2-compliance violations ...
2012-07-24i2c: Add SCCB supportLaurent Pinchart1-0/+3
SCCB is a serial communication bus developed by Omnivision. Its 2-wire mode is very similar to SMBus byte data transactions, but requires the controller to ignore the ACK bit and to insert a stop condition after each message. Add a device SCCB flag and a message stop flag to be passed to controller drivers. [JD: Kill rogue definition in go7007 driver.] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-06-30[media] i2c: Export an unlocked flavor of i2c_transferJean Delvare1-0/+3
Some drivers (in particular for TV cards) need exclusive access to their I2C buses for specific operations. Export an unlocked flavor of i2c_transfer to give them full control. The unlocked flavor has the following limitations: * Obviously, caller must hold the i2c adapter lock. * No debug messages are logged. We don't want to log messages while holding a rt_mutex. * No check is done on the existence of adap->algo->master_xfer. It is thus the caller's responsibility to ensure that the function is OK to call. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>