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path: root/include/linux/i2c.h
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2018-08-31i2c: refactor function to release a DMA safe bufferWolfram Sang1-1/+1
a) rename to 'put' instead of 'release' to match 'get' when obtaining the buffer b) change the argument order to have the buffer as first argument c) add a new argument telling the function if the message was transferred. This allows the function to be used also in cases where setting up DMA failed, so the buffer needs to be freed without syncing to the message buffer. Also convert the only user. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-24i2c: remove deprecated attach_adapter callbackWolfram Sang1-6/+0
There aren't any users left. Remove this callback from the 2.4 times. Phew, finally, that took years to reach... Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-08i2c: core: Parse SDA hold time from firmwareAndy Shevchenko1-0/+2
There are two drivers already using the SDA hold time setting. It might be more in the future, thus, make I2C core to parse the setting for us if provided by firmware. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-05i2c: quirks: add zero length checksWolfram Sang1-0/+4
Some adapters do not support a message length of 0. Add this as a quirk so drivers don't have to open code it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17i2c: recovery: add get_bus_free callbackWolfram Sang1-0/+3
Some IP cores have an internal 'bus free' logic which may be more advanced than just checking if SDA is high. Add a separate callback to get this status. Filling it is optional. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17i2c: recovery: require either get_sda or set_sdaWolfram Sang1-6/+6
For bus recovery, we either need to bail out early if we can read SDA or we need to send STOP after every pulse. Otherwise recovery might be misinterpreted as an unwanted write. So, require one of those SDA handling functions to avoid this problem. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-13Merge branch 'i2c/precise-locking-names_immutable' into i2c/for-4.19Wolfram Sang1-12/+0
2018-07-13i2c: remove i2c_lock_adapter and use i2c_lock_bus directlyPeter Rosin1-12/+0
The i2c_lock_adapter name is ambiguous since it is unclear if it refers to the root adapter or the adapter you name in the argument. The natural interpretation is the adapter you name in the argument, but there are historical reasons for that not being the case; it in fact locks the root adapter. Just remove the function and force users to spell out the I2C_LOCK_ROOT_ADAPTER name to indicate what is really going on. Also remove i2c_unlock_adapter, of course. This patch was generated with git grep -l 'i2c_\(un\)\?lock_adapter' \ | xargs sed -i 's/i2c_\(un\)\?lock_adapter(\([^)]*\))/'\ 'i2c_\1lock_bus(\2, I2C_LOCK_ROOT_ADAPTER)/g' followed by white-space touch-up. Signed-off-by: Peter Rosin <peda@axentia.se> Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com> Tested-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-03i2c: smbus: add unlocked __i2c_smbus_xfer variantPeter Rosin1-3/+8
Removes all locking from i2c_smbus_xfer and renames it to __i2c_smbus_xfer, then adds a new i2c_smbus_xfer function that simply grabs the lock while calling the unlocked variant. This is not perfectly equivalent, since i2c_smbus_xfer was callable from atomic/irq context if you happened to end up emulating SMBus with an I2C transfer, and that is no longer the case with this patch. It is unknown (to me) if anything depends on that quirk, but it seems fragile enough to simply break those cases and require them to call i2c_transfer directly instead. While at it, for consistency rename the 2nd to last argument (size) of the i2c_smbus_xfer declaration to protocol and remove the surplus extern marker. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-22i2c: Export of_i2c_get_board_info()Boris Brezillon1-0/+10
I3C busses have to know about all I2C devices connected on the I3C bus to properly initialize the I3C master, and I2C frames can't be sent on the bus until this initialization is done. We can't let the I2C core parse the DT and instantiate I2C devices as part of its i2c_add_adapter() procedure because, when done this way, I2C devices are directly registered to the device-model and might be attached to drivers which could in turn start sending frames on the bus, which won't work since, as said above, the bus is not yet initialized. Export of_i2c_register_device() in order to let the I3C core parse the I2C device nodes by itself and initialize the bus. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15i2c: Get rid of i2c_board_info->archdataBoris Brezillon1-2/+0
The only user of i2c_board_info->archdata is the OF parsing code and it just pass a zero-initialized object which has the same effect as leaving ->archdata to NULL since the client object is allocated with kzalloc(). Get rid of this useless field. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-06i2c: add i2c_get_device_id() to get the standard i2c device idPeter Rosin1-0/+30
Can be used during probe to double check that the probed device is what is expected. Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>. Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Peter Rosin <peda@axentia.se>
2018-01-16i2c: add 'set_sda' to bus_recovery_infoWolfram Sang1-0/+4
This will be needed when we want to create STOP conditions, too, later. Create the needed fields and populate them for the GPIO case if the GPIO is set to output. Tested-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-16i2c: add identifier in declarations for i2c_bus_recoveryWolfram Sang1-6/+6
No reason to have them undefined, so let's add them. Tested-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-16i2c: make kerneldoc about bus recovery more preciseWolfram Sang1-5/+5
"Used internally" is vague. What it actually means is that those fields are populated by the core if valid GPIOs are provided. Change the comments to reflect that. Tested-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-12-03i2c: add i2c_master_{send|recv}_dmasafeWolfram Sang1-0/+32
Use the new helper to create variants of i2c_master_{send|recv} which mark their buffers as DMA safe. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-12-03i2c: refactor i2c_master_{send_recv}Wolfram Sang1-4/+30
Those two functions are very similar, the only differences are that one needs the I2C_M_RD flag for its message while the other one needs the buffer casted to drop the const. Introduce a generic helper which allows to specify the flags (also needed later for DMA safe variants of these calls) and let the casting be done in the inlining functions which are now calling the new helper function. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-12-03i2c: add helpers to ease DMA handlingWolfram Sang1-0/+3
One helper checks if DMA is suitable and optionally creates a bounce buffer, if not. The other function returns the bounce buffer and makes sure the data is properly copied back to the message. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-27i2c: remove legacy integer scl/sda gpio for recoveryPhil Reid1-6/+1
Remove all reference to code related to using integer based ids for scl/sda gpio for bus recovery. All in tree drivers are now using the gpio descriptors to specific the required gpios. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Reid <preid@electromag.com.au> Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-27i2c: Switch to using gpiod interface for gpio bus recoveryPhil Reid1-0/+4
Currently the i2c gpio recovery code uses gpio integer interface instead of the gpiod. This change switch the core code to use the gpiod while still retaining compatibility with the gpio integer interface. This will allow individual driver to be updated and tested individual to switch to using the gpiod interface. Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-11-27i2c: use macro IS_ENABLED in header i2c.hStefan Lengfeld1-3/+3
Using the macro IS_ENABLED to check the option CONFIG_I2C=(y|m) makes the code nicer. No functional change. Signed-off-by: Stefan Lengfeld <contact@stefanchrist.eu> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-27i2c: Allow overriding dev_name through board_infoHans de Goede1-0/+2
For devices not instantiated through ACPI the i2c-client's device-name gets set to <busnr>-<addr> by default, e.g. "0-0022" this means that the device-name is dependent on the order in which the i2c-busses are enumerated. In some cases having a predictable constant device-name is desirable, for example on non device-tree platforms the link between a regulator and its consumers is specified by the platform code by setting regulator_init_data.consumers. This array identifies the regulator's consumers by dev_name and supply(-name). Which requires a constant dev_name. This commit adds a dev_name field to i2c_board_info allowing platform code to set a contstant dev_name so that the device can be identified by its dev_name in other platform code. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> (live at ELCE17) Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (live at ELCE17) Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31i2c: rephrase explanation of I2C_CLASS_DEPRECATEDWolfram Sang1-1/+2
Hopefully making clear that it is not needed for new drivers. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-08i2c: Provide a stub for i2c_detect_slave_mode()Andy Shevchenko1-0/+2
Drivers would like to call i2c_detect_slave_mode() even if !I2C_SLAVE. Give them what they want to, Otherwise kernel will not compile: drivers/i2c/busses/i2c-designware-platdrv.c: In function ‘dw_i2c_plat_probe’: drivers/i2c/busses/i2c-designware-platdrv.c:331:6: error: implicit declaration of function ‘i2c_detect_slave_mode’ [-Werror=implicit-function-declaration] if (i2c_detect_slave_mode(&pdev->dev)) ^~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors Fixes: 6e38cf3b4421 ("i2c: designware: Let slave adapter support be optional") Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-03Merge branch 'for-linus' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input subsystem updates from Dmitry Torokhov: - a big update from Mauro converting input documentation to ReST format - Synaptics PS/2 is now aware of SMBus companion devices, which means that we can now use native RMI4 protocol to handle touchpads, instead of relying on legacy PS/2 mode. - we removed support from BMA180 accelerometer from input devices as it is now handled properly by IIO - update to TSC2007 to corretcly report pressure - other miscellaneous driver fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (152 commits) Input: ar1021_i2c - use BIT to check for a bit Input: twl4030-pwrbutton - use input_set_capability() helper Input: twl4030-pwrbutton - use correct device for irq request Input: ar1021_i2c - enable touch mode during open Input: add uinput documentation dt-bindings: input: add bindings document for ar1021_i2c driver dt-bindings: input: rotary-encoder: fix typo Input: xen-kbdfront - add module parameter for setting resolution ARM: pxa/raumfeld: fix compile error in rotary controller resources Input: xpad - do not suggest writing to Dominic Input: xpad - don't use literal blocks inside footnotes Input: xpad - note that usb/devices is now at /sys/kernel/debug/ Input: docs - freshen up introduction Input: docs - split input docs into kernel- and user-facing Input: docs - note that MT-A protocol is obsolete Input: docs - update joystick documentation a bit Input: docs - remove disclaimer/GPL notice Input: fix "Game console" heading level in joystick documentation Input: rotary-encoder - remove references to platform data from docs Input: move documentation for Amiga CD32 ...
2017-04-16i2c: core: Allow drivers to disable i2c-core irq mappingHans de Goede1-0/+3
By default the i2c-core will try to get an irq with index 0 on ACPI / of instantiated devices. This is troublesome on some ACPI systems where the irq info at index 0 in the CRS table may contain nonsense and/or point to an irqchip for which there is no Linux driver. If this happens then before this commit the driver's probe method would never get called because i2c_device_probe will try to get an irq by calling acpi_dev_gpio_irq_get which will always return -EPROBE in this case, as it waits for a matching irqchip driver to load. Thus causing the driver to not get a chance to bind. This commit adds a new disable_i2c_core_irq_mapping flag to struct i2c_driver which a driver can set to tell the core to skip irq mapping. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-04-16i2c: core: Add new i2c_acpi_new_device helper functionHans de Goede1-0/+7
By default the i2c subsys creates an i2c-client for the first I2cSerialBus resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus resources and we may want to instantiate i2c-clients for the others. This commit adds a new i2c_acpi_new_device function which can be used to create an i2c-client for any I2cSerialBus resource of an acpi_device. Note that the other resources may even be on a different i2c bus, so just retrieving the client address is not enough. Here is an example DSDT excerpt from such a device: Device (WIDR) { Name (_HID, "INT33FE" /* XPOWER Battery Device */) Name (_CID, "INT33FE" /* XPOWER Battery Device */) Name (_DDN, "WC PMIC Battery Device") <snip> Name (RBUF, ResourceTemplate () { I2cSerialBusV2 (0x005E, ControllerInitiated, 0x000186A0, AddressingMode7Bit, "\\_SB.PCI0.I2C7", 0x00, ResourceConsumer, , Exclusive, ) I2cSerialBusV2 (0x0036, ControllerInitiated, 0x000186A0, AddressingMode7Bit, "\\_SB.PCI0.I2C1", 0x00, ResourceConsumer, , Exclusive, ) I2cSerialBusV2 (0x0022, ControllerInitiated, 0x00061A80, AddressingMode7Bit, "\\_SB.PCI0.I2C1", 0x00, ResourceConsumer, , Exclusive, ) I2cSerialBusV2 (0x0054, ControllerInitiated, 0x00061A80, AddressingMode7Bit, "\\_SB.PCI0.I2C1", 0x00, ResourceConsumer, , Exclusive, ) GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000, "\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, , ) { // Pin list 0x0012 } GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone, 0x0000, "\\_SB.GPO1", 0x00, ResourceConsumer, , ) { // Pin list 0x0005 } GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000, "\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, , ) { // Pin list 0x0013 } }) Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings { Return (RBUF) /* \_SB_.PCI0.I2C7.WIDR.RBUF */ } <snip> } Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-04-01i2c: allow attaching IRQ resources to i2c_board_infoDmitry Torokhov1-0/+4
Simple integer for interrupt number is not expressive enough, as it does not convey interrupt trigger type that should be used. Let's allow attaching array of resources to the board info and have i2c core parse first IRQ resource and set up interrupt trigger as needed. Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-04-01i2c: export i2c_client_type structureDmitry Torokhov1-0/+1
i2c bus has 2 different types of device belonging to the same bus and bus notifiers use device type to distinguish between adapters and clients. Previously we only had i2c_adapter_type exported, which made code wanting to work with i2c_client devices test for type not equal to adapter type. This unfortunately is not safe if we ever add another type to the bus, so let's export i2c_client_type as well. Reviewed-by: Jean Delvare <jdelvare@suse.de> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-03-02sched/headers: Prepare for the removal of <linux/rtmutex.h> from <linux/sched.h>Ingo Molnar1-0/+1
Fix up missing #includes in other places that rely on sched.h doing that for them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-26Merge branch 'i2c/for-4.11' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "I2C has for you two new drivers (Tegra BPMP and STM32F4), interrupt support for pca954x muxes, and a bunch of driver bugfixes and improvements. Nothing really special this cycle. A few commits have been added to my tree just recently. Those are the Tegra BPMP driver and a few straightforward bugfixes or cleanups which I prefer to have upstream rather soonish. The rest had proper linux-next exposure" * 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (25 commits) i2c: thunderx: Replace pci_enable_msix() i2c: exynos5: fix arbitration lost handling i2c: exynos5: disable fifo-almost-empty irq signal when necessary i2c: at91: ensure state is restored after suspending i2c: bcm2835: Avoid possible NULL ptr dereference i2c: Add Tegra BPMP I2C proxy driver dt-bindings: Add Tegra186 BPMP I2C binding misc: eeprom: at24: use device_property_*() functions instead of of_get_property() i2c: mux: pca954x: Add interrupt controller support dt: bindings: i2c-mux-pca954x: Add documentation for interrupt controller i2c: mux: pca954x: Add missing pca9542 definition to chip_desc i2c: riic: correctly finish transfers i2c: i801: Add support for Intel Gemini Lake i2c: mux: pca9541: Export OF device ID table as module aliases i2c: mux: pca954x: Export OF device ID table as module aliases i2c: mux: mlxcpld: remove unused including <linux/version.h> i2c: busses: constify i2c_algorithm structures i2c: i2c-mux-gpio: rename i2c-gpio-mux to i2c-mux-gpio i2c: sh_mobile: document support for r8a7796 (R-Car M3-W) i2c: i2c-cros-ec-tunnel: Reduce logging noise ...
2017-02-08i2c: allow specify device properties in i2c_board_infoDmitry Torokhov1-0/+3
With many drivers converting to using generic device properties, it is useful to provide array of device properties when instantiating new i2c client via i2c_board_info and have them automatically added to the device in question. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-29i2c: core: helper function to detect slave modeLuis Oliveira1-0/+1
This function has the purpose of mode detection by checking the device nodes for a reg matching with the I2C_OWN_SLAVE_ADDREESS flag. Currently only checks using OF functions (ACPI slave not supported yet). Signed-off-by: Luis Oliveira <lolivei@synopsys.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-12i2c: do not enable fall back to Host Notify by defaultDmitry Torokhov1-0/+1
Falling back unconditionally to HostNotify as primary client's interrupt breaks some drivers which alter their functionality depending on whether interrupt is present or not, so let's introduce a board flag telling I2C core explicitly if we want wired interrupt or HostNotify-based one: I2C_CLIENT_HOST_NOTIFY. For DT-based systems we introduce "host-notify" property that we convert to I2C_CLIENT_HOST_NOTIFY board flag. Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Pali Rohár <pali.rohar@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-24i2c: use an IRQ to report Host Notify events, not alertBenjamin Tissoires1-0/+4
The current SMBus Host Notify implementation relies on .alert() to relay its notifications. However, the use cases where SMBus Host Notify is needed currently is to signal data ready on touchpads. This is closer to an IRQ than a custom API through .alert(). Given that the 2 touchpad manufacturers (Synaptics and Elan) that use SMBus Host Notify don't put any data in the SMBus payload, the concept actually matches one to one. Benefits are multiple: - simpler code and API: the client will just have an IRQ, and nothing needs to be added in the adapter beside internally enabling it. - no more specific workqueue, the threading is handled by IRQ core directly (when required) - no more races when removing the device (the drivers are already required to disable irq on remove) - simpler handling for drivers: use plain regular IRQs - no more dependency on i2c-smbus for i2c-i801 (and any other adapter) - the IRQ domain is created automatically when the adapter exports the Host Notify capability - the IRQ are assign only if ACPI, OF and the caller did not assign one already - the domain is automatically destroyed on remove - fewer lines of code (minus 20, yeah!) Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17i2c: Provide a temporary .probe_new() call-back typeLee Jones1-1/+7
This will aid the seamless removal of the current probe()'s, more commonly unused than used second parameter. Most I2C drivers can simply switch over to the new interface, others which have DT support can use its own matching instead and others can call i2c_match_id() themselves. This brings I2C's device probe method into line with other similar interfaces in the kernel and prevents the requirement to pass an i2c_device_id table. Suggested-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> [Kieran: fix rebase conflicts and adapt for dev_pm_domain_{attach,detach}] Tested-by: Kieran Bingham <kieran@bingham.xyz> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Kieran Bingham <kieran@bingham.xyz> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17i2c: Export i2c_match_id() for direct use by device driversLee Jones1-0/+2
When there was no other way to match a I2C device to driver i2c_match_id() was exclusively used. However, now there are other types of tables which are commonly supplied, matching on an i2c_device_id table is used less frequently. Instead of _always_ calling i2c_match_id() from within the framework, we only need to do so from drivers which have no other way of matching. This patch makes i2c_match_id() available to the aforementioned device drivers. Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Tested-by: Kieran Bingham <kieran@bingham.xyz> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Kieran Bingham <kieran@bingham.xyz> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17i2c: Match using traditional OF methods, then by vendor-less compatible stringsLee Jones1-0/+12
This function provides a single call for all I2C devices which need to match firstly using traditional OF means i.e by of_node, then if that fails we attempt to match using the supplied I2C client name with a list of supplied compatible strings with the '<vendor>,' string removed. The latter is required due to the unruly naming conventions used currently by I2C devices. Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> [Kieran: Fix static inline usage on !CONFIG_OF] Tested-by: Kieran Bingham <kieran@bingham.xyz> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Kieran Bingham <kieran@bingham.xyz> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>