[PATCH v4 0/2] i2c: acpi: scan ACPI enumerated I2C mux channels

From: Dustin Byford
Date: Thu Oct 22 2015 - 05:18:46 EST


The following series 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,,)
}
}
}
}
}

v4:
- Moved the acpi_preset_companion() stub to a separate patch.
- Moved ACPI companion set from i2c-core to i801, ismt, and designware
drivers. With a minor rearrangement it was much easier to verify the
drivers are all consistent (hopefully a little extra churn is warranted)

I was able to test i801 and ismt myself, but I could use some help making
sure the designware driver is OK since I don't have the hardware.

v3:
- Correct to and cc list (sorry git-send-email trouble again)

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.

Thanks,

--Dustin

Dustin Byford (2):
acpi: add acpi_preset_companion() stub
i2c: add ACPI support for I2C mux ports

Documentation/acpi/i2c-muxes.txt | 58 +++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-designware-pcidrv.c | 1 +
drivers/i2c/busses/i2c-designware-platdrv.c | 6 ++-
drivers/i2c/busses/i2c-i801.c | 9 ++---
drivers/i2c/busses/i2c-ismt.c | 8 +---
drivers/i2c/i2c-core.c | 4 +-
drivers/i2c/i2c-mux.c | 8 ++++
include/linux/acpi.h | 6 +++
8 files changed, 84 insertions(+), 16 deletions(-)
create mode 100644 Documentation/acpi/i2c-muxes.txt

--
2.1.4

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