linux-stable/drivers/i2c
Benjamin Tissoires 4d5538f588 i2c: use an IRQ to report Host Notify events, not alert
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>
2016-11-24 16:22:06 +01:00
..
algos i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static 2016-05-11 17:16:30 +02:00
busses i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
muxes i2c: mux: mellanox: add driver 2016-11-17 23:19:00 +01:00
i2c-boardinfo.c i2c: remove __init from i2c_register_board_info() 2016-06-19 14:13:50 +02:00
i2c-core.c i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
i2c-core.h i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-dev.c i2c-dev: don't get i2c adapter via i2c_dev 2016-07-08 10:29:31 +09:00
i2c-mux.c i2c: move locking operations to their own struct 2016-08-30 22:56:14 +02:00
i2c-slave-eeprom.c i2c: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
i2c-smbus.c i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
i2c-stub.c i2c: i2c-stub: sort includes 2016-02-20 23:33:39 +01:00
Kconfig i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
Makefile i2c: slave-eeprom: add eeprom simulator driver 2014-12-11 22:25:54 +01:00