[PATCH v2 0/1] i2c: acpi: scan ACPI enumerated I2C mux channels

From: Dustin Byford
Date: Mon Oct 19 2015 - 05:02:18 EST


The following patch adds support for describing ACPI enumerated I2C mux ports
like this (added as Documentation/acpi/i2c-muxes.txt):

+------+ +------+
| SMB1 |-->| MUX0 |--CH00--> i2c client A (0x50)
| | | 0x70 |--CH01--> i2c client B (0x50)
+------+ +------+

Device (SMB1)
{
Name (_HID, ...)
Device (MUX0)
{
Name (_HID, ...)
Name (_CRS, ResourceTemplate () {
I2cSerialBus (0x70, ControllerInitiated, I2C_SPEED,
AddressingMode7Bit, "^SMB1", 0x00,
ResourceConsumer,,)
}

Device (CH00)
{
Name (_ADR, 0)

Device (CLIA)
{
Name (_HID, ...)
Name (_CRS, ResourceTemplate () {
I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED,
AddressingMode7Bit, "^CH00", 0x00,
ResourceConsumer,,)
}
}
}

Device (CH01)
{
Name (_ADR, 1)

Device (CLIB)
{
Name (_HID, ...)
Name (_CRS, ResourceTemplate () {
I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED,
AddressingMode7Bit, "^CH01", 0x00,
ResourceConsumer,,)
}
}
}
}
}

v2:
- Drop duplicate patch already submitted by Andy Shevchenko (i2c / ACPI:
Rework I2C device scanning)
- Whitespace cleanup suggested by Mika
- Implement a acpi_preset_companion() stub for when CONFIG_ACPI is not set.
- Instead of special casing I2C muxes with regards to enumerating client
devices, make sure adap->dev always has an ACPI companion.

I based this on linux-pm/bleeding-edge, but now it depends on Andy's change
(i2c / ACPI: Rework I2C device scanning) and I don't know where the rest of
his patch set is going. Let me know if there's a more appropriate branch
and I'll be happy to rebase.

Dustin Byford (1):
i2c: add ACPI support for I2C mux ports

Documentation/acpi/i2c-muxes.txt | 58 ++++++++++++++++++++++++++++++++++++++++
drivers/i2c/i2c-core.c | 14 ++++++++--
drivers/i2c/i2c-mux.c | 8 ++++++
include/linux/acpi.h | 6 +++++
4 files changed, 84 insertions(+), 2 deletions(-)
create mode 100644 Documentation/acpi/i2c-muxes.txt

--
2.1.4

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