Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/Documentation/firmware-guide/acpi/i2c-muxes.rst b/Documentation/firmware-guide/acpi/i2c-muxes.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+ACPI I2C Muxes
+==============
+
+Describing an I2C device hierarchy that includes I2C muxes requires an ACPI
+Device () scope per mux channel.
+
+Consider this topology::
+
+    +------+   +------+
+    | SMB1 |-->| MUX0 |--CH00--> i2c client A (0x50)
+    |      |   | 0x70 |--CH01--> i2c client B (0x50)
+    +------+   +------+
+
+which corresponds to the following ASL::
+
+    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,,)
+                    }
+                }
+            }
+        }
+    }