user/sven/linux.git/include/linux/i2c.h, branch v3.18.98

i2c: move acpi code back into the core

2014-09-25T14:07:15Z

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 Signed-off-by: Wolfram Sang Tested-by: Lan Tianyu Tested-by: Mika Westerberg

i2c: rework kernel config I2C_ACPI

2014-08-19T15:19:39Z

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 Reviewed-by: Mika Westerberg [wsa: removed unrelated change for Kconfig] Signed-off-by: Wolfram Sang

I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI config

2014-06-27T12:50:41Z

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 Signed-off-by: Lan Tianyu Signed-off-by: Wolfram Sang

I2C/ACPI: Add i2c ACPI operation region support

2014-06-27T12:50:40Z

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 Reviewed-by: Mika Westerberg Signed-off-by: Wolfram Sang

i2c: add deprecation warning for class based instantiation

2014-03-05T16:16:45Z

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

i2c: update i2c_algorithm documentation

2014-01-26T21:48:35Z

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 Signed-off-by: Wolfram Sang

i2c: Re-instate body of i2c_parent_is_i2c_adapter()

2014-01-14T16:11:13Z

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 Cc: Signed-off-by: Stephen Warren Signed-off-by: Wolfram Sang

i2c: Remove redundant 'driver' field from the i2c_client struct

2013-10-03T20:28:31Z

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 Signed-off-by: Wolfram Sang

i2c: move ACPI helpers into the core

2013-08-23T08:22:29Z

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 Acked-by: Rafael J. Wysocki Signed-off-by: Wolfram Sang

i2c: move OF helpers into the core

2013-08-23T08:22:20Z

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