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path: root/drivers/i2c/i2c-core.c
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2014-03-13i2c: Add message transfer tracepoints for SMBUS [ver #2]David Howells
The SMBUS tracepoints can be enabled thusly: echo 1 >/sys/kernel/debug/tracing/events/i2c/enable and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace that look like: ... smbus_read: i2c-0 a=051 f=0000 c=fa BYTE_DATA ... smbus_reply: i2c-0 a=051 f=0000 c=fa BYTE_DATA l=1 [39] ... smbus_result: i2c-0 a=051 f=0000 c=fa BYTE_DATA rd res=0 formatted as: i2c-<adapter-nr> a=<addr> f=<flags> c=<command> <protocol-name> <rd|wr> res=<result> l=<data-len> [<data-block>] The adapters to be traced can be selected by something like: echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter Note that this shares the same filter and enablement as i2c. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-13i2c: Add message transfer tracepoints for I2CDavid Howells
Add tracepoints into the I2C message transfer function to retrieve the message sent or received. The following config options must be turned on to make use of the facility: CONFIG_FTRACE CONFIG_ENABLE_DEFAULT_TRACERS The I2C tracepoint can be enabled thusly: echo 1 >/sys/kernel/debug/tracing/events/i2c/enable and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace that look like: ... i2c_write: i2c-5 #0 a=044 f=0000 l=2 [02-14] ... i2c_read: i2c-5 #1 a=044 f=0001 l=4 ... i2c_reply: i2c-5 #1 a=044 f=0001 l=4 [33-00-00-00] ... i2c_result: i2c-5 n=2 ret=2 formatted as: i2c-<adapter-nr> #<message-array-index> a=<addr> f=<flags> l=<datalen> n=<message-array-size> ret=<result> [<data>] The operation is done between the i2c_write/i2c_read lines and the i2c_reply and i2c_result lines so that if the hardware hangs, the trace buffer can be consulted to determine the problematic operation. The adapters to be traced can be selected by something like: echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter These changes are based on code from Steven Rostedt. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> [wsa: adapted path for 'enable' in the commit msg] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-05i2c: add deprecation warning for class based instantiationWolfram Sang
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>
2014-01-29Merge branch 'i2c/for-current' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull more i2c updates from Wolfram Sang: "Mostly bugfixes, small but wanted cleanups, and Paul's init.h removal applied" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: rcar: fix NACK error code i2c: update i2c_algorithm documentation i2c: rcar: use devm_clk_get to ensure clock is properly ref-counted i2c: rcar: do not print error if device nacks transfer i2c: rely on driver core when sanitizing devices i2c: delete non-required instances of include <linux/init.h> i2c: acorn: is tristate and should use module.h i2c: piix4: Standardize log messages i2c: piix4: Use different message for AMD Auxiliary SMBus Controller i2c: piix4: Add support for AMD ML and CZ SMBus changes
2014-01-29Merge branch 'hwmon-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging Pull hwmon updates from Jean Delvare: "This include it87 driver improvements, and a tree-wide change of my e-mail address" * 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: Update Jean Delvare's e-mail address hwmon: (it87) Print proper names for the IT8771E and IT8772E hwmon: (it87) Add support for the ITE IT8603E
2014-01-29Update Jean Delvare's e-mail addressJean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2014-01-24i2c: rely on driver core when sanitizing devicesWolfram Sang
Commit 0998d0631001 (device-core: Ensure drvdata = NULL when no driver is bound) modified the driver core to always clear .driver and .drvdata on remove or probe error. No need for the I2C core to do it. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-16ACPI: fix module autoloading for ACPI enumerated devicesZhang Rui
ACPI enumerated devices has ACPI style _HID and _CID strings, all of these strings can be used for both driver loading and matching. Currently, in Platform, I2C and SPI bus, the ACPI style driver matching is supported by invoking acpi_driver_match_device() in bus .match() callback. But, the module autoloading is still broken. For example, there is any ACPI device with _HID "INTABCD" that is enumerated to platform bus, and we have a driver that can probe it. The driver exports its module_alias as "acpi:INTABCD" use the following code static const struct acpi_device_id xxx_acpi_match[] = { { "INTABCD", 0 }, { } }; MODULE_DEVICE_TABLE(acpi, xxx_acpi_match); But, unfortunately, the device' modalias is shown as "platform:INTABCD:00", please refer to modalias_show() and platform_uevent() in drivers/base/platform.c. This results in that the driver will not be loaded automatically when the device node is created, because their modalias do not match. This also applies to I2C and SPI bus. With this patch, the device' modalias will be shown as "acpi:INTABCD" as well. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Mark Brown <broonie@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-20Merge tag 'pm+acpi-2-3.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI and power management updates from Rafael Wysocki: - ACPI-based device hotplug fixes for issues introduced recently and a fix for an older error code path bug in the ACPI PCI host bridge driver - Fix for recently broken OMAP cpufreq build from Viresh Kumar - Fix for a recent hibernation regression related to s2disk - Fix for a locking-related regression in the ACPI EC driver from Puneet Kumar - System suspend error code path fix related to runtime PM and runtime PM documentation update from Ulf Hansson - cpufreq's conservative governor fix from Xiaoguang Chen - New processor IDs for intel_idle and turbostat and removal of an obsolete Kconfig option from Len Brown - New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg - Removal of several ACPI video DMI blacklist entries that are not necessary any more from Aaron Lu - Rework of the ACPI companion representation in struct device and code cleanup related to that change from Rafael J Wysocki, Lan Tianyu and Jarkko Nikula - Fixes for assigning names to ACPI-enumerated I2C and SPI devices from Jarkko Nikula * tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits) PCI / hotplug / ACPI: Drop unused acpiphp_debug declaration ACPI / scan: Set flags.match_driver in acpi_bus_scan_fixed() ACPI / PCI root: Clear driver_data before failing enumeration ACPI / hotplug: Fix PCI host bridge hot removal ACPI / hotplug: Fix acpi_bus_get_device() return value check cpufreq: governor: Remove fossil comment in the cpufreq_governor_dbs() ACPI / video: clean up DMI table for initial black screen problem ACPI / EC: Ensure lock is acquired before accessing ec struct members PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() ACPI / AC: Remove struct acpi_device pointer from struct acpi_ac spi: Use stable dev_name for ACPI enumerated SPI slaves i2c: Use stable dev_name for ACPI enumerated I2C slaves ACPI: Provide acpi_dev_name accessor for struct acpi_device device name ACPI / bind: Use (put|get)_device() on ACPI device objects too ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node cpufreq: OMAP: Fix compilation error 'r & ret undeclared' PM / Runtime: Fix error path for prepare PM / Runtime: Update documentation around probe|remove|suspend cpufreq: conservative: set requested_freq to policy max when it is over policy max ...
2013-11-18Merge branch 'i2c/for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c changes from Wolfram Sang: - new drivers for exynos5, bcm kona, and st micro - bigger overhauls for drivers mxs and rcar - typical driver bugfixes, cleanups, improvements - got rid of the superfluous 'driver' member in i2c_client struct This touches a few drivers in other subsystems. All acked. * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (38 commits) i2c: bcm-kona: fix error return code in bcm_kona_i2c_probe() i2c: i2c-eg20t: do not print error message in syslog if no ACK received i2c: bcm-kona: Introduce Broadcom I2C Driver i2c: cbus-gpio: Fix device tree binding i2c: wmt: add missing clk_disable_unprepare() on error i2c: designware: add new ACPI IDs i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCH i2c: exynos5: Remove incorrect clk_disable_unprepare i2c: i2c-st: Add ST I2C controller i2c: exynos5: add High Speed I2C controller driver i2c: rcar: fixup rcar type naming i2c: scmi: remove some bogus NULL checks i2c: sh_mobile & rcar: Enable the driver on all ARM platforms i2c: sh_mobile: Convert to clk_prepare/unprepare i2c: mux: gpio: use reg value for i2c_add_mux_adapter i2c: mux: gpio: use gpio_set_value_cansleep() i2c: Include linux/of.h header i2c: mxs: Fix PIO mode on i.MX23 i2c: mxs: Rework the PIO mode operation i2c: mxs: distinguish i.MX23 and i.MX28 based I2C controller ...
2013-11-14i2c: Use stable dev_name for ACPI enumerated I2C slavesJarkko Nikula
Current I2C adapter id - client address "x-00yy" based device naming scheme is not always stable enough to be used in name based matching, for instance within ALSA SoC subsystem. This is problematic in PC kind of platforms where I2C adapter numbers can change due variable amount of bus controllers, probe order, add-on cards or just because of BIOS settings. This patch addresses the problem by using the ACPI device name with "i2c-" prefix for ACPI enumerated I2C slaves. For them device name "x-00yz" becomes "i2c-INTABCD:ij" after this patch. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-14ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_nodeRafael J. Wysocki
Modify struct acpi_dev_node to contain a pointer to struct acpi_device associated with the given device object (that is, its ACPI companion device) instead of an ACPI handle corresponding to it. Introduce two new macros for manipulating that pointer in a CONFIG_ACPI-safe way, ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the ACPI_HANDLE() macro to take the above changes into account. Drop the ACPI_HANDLE_SET() macro entirely and rework its users to use ACPI_COMPANION_SET() instead. For some of them who used to pass the result of acpi_get_child() directly to ACPI_HANDLE_SET() introduce a helper routine acpi_preset_companion() doing an equivalent thing. The main motivation for doing this is that there are things represented by struct acpi_device objects that don't have valid ACPI handles (so called fixed ACPI hardware features, such as power and sleep buttons) and we would like to create platform device objects for them and "glue" them to their ACPI companions in the usual way (which currently is impossible due to the lack of valid ACPI handles). However, there are more reasons why it may be useful. First, struct acpi_device pointers allow of much better type checking than void pointers which are ACPI handles, so it should be more difficult to write buggy code using modified struct acpi_dev_node and the new macros. Second, the change should help to reduce (over time) the number of places in which the result of ACPI_HANDLE() is passed to acpi_bus_get_device() in order to obtain a pointer to the struct acpi_device associated with the given "physical" device, because now that pointer is returned by ACPI_COMPANION() directly. Finally, the change should make it easier to write generic code that will build both for CONFIG_ACPI set and unset without adding explicit compiler directives to it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> # on Haswell Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Aaron Lu <aaron.lu@intel.com> # for ATA and SDIO part
2013-10-28Merge branch 'acpi-pm'Rafael J. Wysocki
* acpi-pm: spi: attach/detach SPI device to the ACPI power domain i2c: attach/detach I2C client device to the ACPI power domain ACPI / PM: allow child devices to ignore parent power state
2013-10-11i2c: attach/detach I2C client device to the ACPI power domainLv Zheng
If the I2C client device is enumerated from ACPI namespace it might have ACPI methods that needs to be called in order to transition the device to different power states (such as _PSx). Implement this for I2C client devices by checking if the device has an ACPI handle and if that's the case, attach it to the ACPI power domain. In addition we make sure that the device is fully powered when its ->probe() function gets called. For non-ACPI devices this patch is a no-op. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-10i2c: Not all adapters have a parentJean Delvare
The code in acpi_i2c_register_devices() assumes that all i2c adapters have a parent. This is not necessarily the case, for example the i2c-stub driver instantiate a virtual i2c adapter without a parent. Check for this to avoid a NULL pointer deference. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-03i2c: Remove redundant 'driver' field from the i2c_client structLars-Peter Clausen
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 Westerberg
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 Sang
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>
2013-08-15i2c: Improve logging on failure to probe for ->class devicesAndy Lutomirski
While writing the i2c-imc driver, I noticed that the warning message when the i2c core can't figure out how to probe is mostly useless. This trivial patch improves it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-07i2c: add sanity check to i2c_put_adapterSebastian Hesselbarth
i2c_put_adapter dereferences i2c_adapter pointer passed without check for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter called with NULL and behave the same way i2c_release_client does already. It allows to simplify drivers where you need to release the adapter during probe failures. Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-03PM / Runtime: Rework the "runtime idle" helper routineRafael J. Wysocki
The "runtime idle" helper routine, rpm_idle(), currently ignores return values from .runtime_idle() callbacks executed by it. However, it turns out that many subsystems use pm_generic_runtime_idle() which checks the return value of the driver's callback and executes pm_runtime_suspend() for the device unless that value is not 0. If that logic is moved to rpm_idle() instead, pm_generic_runtime_idle() can be dropped and its users will not need any .runtime_idle() callbacks any more. Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle() routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and ata_port_runtime_idle(), respectively, as well as a few drivers' ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has been returned by the .runtime_idle() callback executed by it. To reduce overall code bloat, make the changes described above. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Kevin Hilman <khilman@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Alan Stern <stern@rowland.harvard.edu>
2013-05-17i2c: suppress lockdep warning on delete_deviceAlexander Sverdlin
i2c: suppress lockdep warning on delete_device Since commit 846f99749ab68bbc7f75c74fec305de675b1a1bf the following lockdep warning is thrown in case i2c device is removed (via delete_device sysfs attribute) which contains subdevices (e.g. i2c multiplexer): ============================================= [ INFO: possible recursive locking detected ] 3.8.7-0-sampleversion-fct #8 Tainted: G O --------------------------------------------- bash/3743 is trying to acquire lock: (s_active#110){++++.+}, at: [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8 but task is already holding lock: (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(s_active#110); lock(s_active#110); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by bash/3743: #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff802b3c3c>] sysfs_write_file+0x4c/0x208 #1: (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208 #2: (&adap->userspace_clients_lock/1){+.+.+.}, at: [<ffffffff80454a18>] i2c_sysfs_delete_device+0x90/0x238 #3: (&__lockdep_no_validate__){......}, at: [<ffffffff803dcc24>] device_release_driver+0x24/0x48 stack backtrace: Call Trace: [<ffffffff80575cc8>] dump_stack+0x8/0x34 [<ffffffff801b50fc>] __lock_acquire+0x161c/0x2110 [<ffffffff801b5c3c>] lock_acquire+0x4c/0x70 [<ffffffff802b60cc>] sysfs_addrm_finish+0x19c/0x1e0 [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8 [<ffffffff802b7d8c>] sysfs_remove_group+0x64/0x148 [<ffffffff803d990c>] device_remove_attrs+0x9c/0x1a8 [<ffffffff803d9b1c>] device_del+0x104/0x1d8 [<ffffffff803d9c18>] device_unregister+0x28/0x70 [<ffffffff8045505c>] i2c_del_adapter+0x1cc/0x328 [<ffffffff8045802c>] i2c_del_mux_adapter+0x14/0x38 [<ffffffffc025c108>] pca954x_remove+0x90/0xe0 [pca954x] [<ffffffff804542f8>] i2c_device_remove+0x80/0xe8 [<ffffffff803dca9c>] __device_release_driver+0x74/0xf8 [<ffffffff803dcc2c>] device_release_driver+0x2c/0x48 [<ffffffff803dbc14>] bus_remove_device+0x13c/0x1d8 [<ffffffff803d9b24>] device_del+0x10c/0x1d8 [<ffffffff803d9c18>] device_unregister+0x28/0x70 [<ffffffff80454b08>] i2c_sysfs_delete_device+0x180/0x238 [<ffffffff802b3cd4>] sysfs_write_file+0xe4/0x208 [<ffffffff8023ddc4>] vfs_write+0xbc/0x160 [<ffffffff8023df6c>] SyS_write+0x54/0xd8 [<ffffffff8013d424>] handle_sys64+0x44/0x64 The problem is already known for USB and PCI subsystems. The reason is that delete_device attribute is defined statically in i2c-core.c and used for all devices in i2c subsystem. Discussion of original USB problem: http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html Commit 356c05d58af05d582e634b54b40050c73609617b introduced new macro to suppress lockdep warnings for this special case and included workaround for USB code. LKML discussion of the workaround: http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html As i2c case is in principle the same, the same workaround could be used here. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-09i2c: remove CONFIG_HOTPLUG ifdefsYijing Wang
CONFIG_HOTPLUG is going away as an option, cleanup CONFIG_HOTPLUG ifdefs in i2c files. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02i2c: Make return type of i2c_del_adapter() voidLars-Peter Clausen
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: i2c_del_adapter: Don't treat removing a non-registered adapter as errorLars-Peter Clausen
Currently i2c_del_adapter() returns -EINVAL when it gets an adapter which is not registered. But none of the users of i2c_del_adapter() depend on this behavior, so for the sake of being able to sanitize the return type of i2c_del_adapter argue, that the purpose of i2c_del_adapter() is to remove an I2C adapter from the system. If the adapter is not registered in the first place this becomes a no-op. So we can return success without having to do anything. 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 Clausen
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 Kumar
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>
2013-03-24i2c: core: Pick i2c bus number from dt alias if presentDoug Anderson
This allows you to get the equivalent functionality of i2c_add_numbered_adapter() with all data in the device tree and no special case code in your driver. This is a common device tree technique. For quick reference, the FDT syntax for using an alias to provide an ID looks like: aliases { i2c0 = &i2c_0; i2c1 = &i2c_1; }; Signed-off-by: Doug Anderson <dianders@chromium.org> [wsa: removed one check from static function. We know our callers] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-02-27idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.cTejun Heo
MAX_IDR_MASK is another weirdness in the idr interface. As idr covers whole positive integer range, it's defined as 0x7fffffff or INT_MAX. Its usage in idr_find(), idr_replace() and idr_remove() is bizarre. They basically mask off the sign bit and operate on the rest, so if the caller, by accident, passes in a negative number, the sign bit will be masked off and the remaining part will be used as if that was the input, which is worse than crashing. The constant is visible in idr.h and there are several users in the kernel. * drivers/i2c/i2c-core.c:i2c_add_numbered_adapter() Basically used to test if adap->nr is a negative number which isn't -1 and returns -EINVAL if so. idr_alloc() already has negative @start checking (w/ WARN_ON_ONCE), so this can go away. * drivers/infiniband/core/cm.c:cm_alloc_id() drivers/infiniband/hw/mlx4/cm.c:id_map_alloc() Used to wrap cyclic @start. Can be replaced with max(next, 0). Note that this type of cyclic allocation using idr is buggy. These are prone to spurious -ENOSPC failure after the first wraparound. * fs/super.c:get_anon_bdev() The ID allocated from ida is masked off before being tested whether it's inside valid range. ida allocated ID can never be a negative number and the masking is unnecessary. Update idr_*() functions to fail with -EINVAL when negative @id is specified and update other MAX_IDR_MASK users as described above. This leaves MAX_IDR_MASK without any user, remove it and relocate other MAX_IDR_* constants to lib/idr.c. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com> Cc: Jack Morgenstein <jackm@dev.mellanox.co.il> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Wolfram Sang <wolfram@the-dreams.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27i2c: convert to idr_alloc()Tejun Heo
Convert to the much saner new idr interface. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Wolfram Sang <wolfram@the-dreams.de> Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-28i2c: core: Remove definition of i2c_smbus_process_callTushar Behera
i2c_smbus_process_call has no users in the kernel, so this can be removed. Documentation for the same has been updated accordingly. Fixes following sparse warning. drivers/i2c/i2c-core.c:1871:5: warning: symbol 'i2c_smbus_process_call' was not declared. Should it be static? [wsa: updated the documentation] Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-23i2c / ACPI: add ACPI enumeration supportMika Westerberg
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>
2012-10-05i2c: Convert struct i2c_msg initialization to C99 formatShubhrajyoti D
Convert the struct i2c_msg initialization to C99 format. This makes maintaining and editing the code simpler. Also helps once other fields like transferred are added in future. Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-06idr: rename MAX_LEVEL to MAX_IDR_LEVELFengguang Wu
To avoid name conflicts: drivers/video/riva/fbdev.c:281:9: sparse: preprocessor token MAX_LEVEL redefined While at it, also make the other names more consistent and add parentheses. [akpm@linux-foundation.org: repair fallout] [sfr@canb.auug.org.au: IB/mlx4: fix for MAX_ID_MASK to MAX_IDR_MASK name change] Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: walter harms <wharms@bfs.de> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Roland Dreier <roland@purestorage.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-10i2c-core: Fix for lockdep validatorJean Delvare
If kernel is compiled with CONFIG_PROVE_LOCKING the validator raises an error when a multiplexer is removed via sysfs and sub-clients are connected to it. This is a false positive. Documentation/lockdep-design.txt recommends to handle this via calls to mutex_lock_nested(). Based on an earlier fix from Michael Lawnick. Note that the extra code resolves to nothing unless CONFIG_DEBUG_LOCK_ALLOC=y. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Michael Lawnick <ml.lawnick@gmx.de>
2012-07-30Merge branch 'v4l_for_linus' of ↵Linus Torvalds
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: Fall back to emulated SMBus if the operation isn't supported nativelyLaurent Pinchart
Adapter drivers might support only a subset of the SMBus operations natively. Those drivers currently have to manually emulate unsupported operations using I2C. Make the i2c_smbus_xfer() function fall back to i2c_smbus_xfer_emulated() when the adapter's .smbus_xfer() operation returns -EOPNOTSUPP, like it already does when the .smbus_xfer() operation isn't available at all. [JD: Minor optimization.] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c: Add SCCB supportLaurent Pinchart
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>
2012-06-29[media] i2c: Export an unlocked flavor of i2c_transferJean Delvare
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>
2012-05-12i2c: implement i2c_verify_adapterStephen Warren
This converts a struct device * to a struct i2c_adapter * while verifying that the device really is an I2C adapter. Just like i2c_verify_client. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-03-26i2c: Update the FSF addressJean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-03-15i2c-core: Comment says "transmitted" but means "received"Wolfram Sang
Fix that. Also convert this and the related comment to proper commenting style. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-11-23i2c: Fix device name for 10-bit slave addressJean Delvare
10-bit addresses overlap with traditional 7-bit addresses, leading in device name collisions. Add an arbitrary offset to 10-bit addresses to prevent this collision. The offset was chosen so that the address is still easily recognizable. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-25i2c: Allow i2c_add_numbered_adapter() to assign a bus idGrant Likely
Currently, if an i2c bus driver supports both static and dynamic bus ids, it needs to choose between calling i2c_add_numbered_adapter() and i2c_add_adapter(). This patch makes i2c_add_numbered_adapter() redirect to i2c_add_adapter() if the requested bus id is -1. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-04-17i2c: Improve deprecation warningsJean Delvare
When warning on the use of deprecated i2c_driver methods attach_adapter and detach_adapter, mention the name of the driver which needs to be updated. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-20i2c: Deprecate i2c_driver.attach_adapter and .detach_adapterJean Delvare
The last legitimate user of i2c_driver.attach_adapter and .detach_adapter is gone, so we can finally deprecate these callbacks. The last few drivers which still use these will have to be updated to make use of standard I2C device instantiation ways instead. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20i2c: Export i2c_for_each_devJean Delvare
Introduce i2c_for_each_dev(), an i2c device iterator with proper locking for use by i2c-dev. This is needed so that we can get rid of the attach_adapter and detach_adapter legacy callback functions. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20i2c: make i2c_get_adapter prototype clearerJean Delvare
Rename the parameter of i2c_get_adapter() to "nr", to make it clear we are passing an adapter number and not an adapter ID (which have gone away by now.) Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-21driver-core: remove conditionals around devicetree pointersGrant Likely
Having conditional around the of_match_table and the of_node pointers turns out to make driver code use ugly #ifdef blocks. Drop the conditionals and remove the #ifdef blocks from the affected drivers. Also tidy up minor whitespace issues within the same hunks. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>