Merge tag 'i2c-host-6.13-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-mergewindow

i2c-host updates for v6.13, part 1

Major Improvements and Refactoring:

 - All controllers using the 'remove_new' callback have been
   reverted to use the 'remove' callback.

 - Intel SCH controller underwent significant refactoring,
   this brings love and a modern look to the driver.

 - PIIX4 driver refactored to enable usage by other drivers
   (e.g., AMD ASF).

 - iMX/MXC improved message handling to reduce protocol overhead:
     Refactored DMA/non-DMA read/write and bus polling mechanisms
     to achieve this.

 - ACPI documentation for PIIX4.

New Features:

 - i2c-cadence added support for atomic transfers.
 - Qualcomm CII added support for a 32MHz serial engine clock.

Deprecated Features:

 - Dropped outdated support for AMD756 S4882 and NFORCE2 S4985. If
   somebody misses this, Jean will rewrite support using the proper
   i2c mux framework.

New Hardware Support:

 - Added support for:
   - Intel Panther Lake (new ID)
   - AMD ASF (new driver)
   - S32G2/S32G3 SoCs (new ID)
   - Realtek RTL I2C Controller (new driver)
   - HJMC01 DesignWare ACPI HID (new ID)
   - PIC64GX to Microchip Core (new ID)
   - Qualcomm SDM670 to Qualcomm CCI (new ID)

2 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/i2c/busses/i2c-i801.rst b/Documentation/i2c/busses/i2c-i801.rst
index c840b597912c..47e8ac5b7099 100644
--- a/Documentation/i2c/busses/i2c-i801.rst
+++ b/Documentation/i2c/busses/i2c-i801.rst
@@ -49,6 +49,7 @@ Supported adapters:
   * Intel Meteor Lake (SOC and PCH)
   * Intel Birch Stream (SOC)
   * Intel Arrow Lake (SOC)
+  * Intel Panther Lake (SOC)
 
    Datasheets: Publicly available at the Intel website
 
diff --git a/Documentation/i2c/busses/i2c-piix4.rst b/Documentation/i2c/busses/i2c-piix4.rst
index 07fe6f6f4b18..94e20b18c59a 100644
--- a/Documentation/i2c/busses/i2c-piix4.rst
+++ b/Documentation/i2c/busses/i2c-piix4.rst
@@ -109,3 +109,66 @@ which can easily get corrupted due to a state machine bug. These are mostly
 Thinkpad laptops, but desktop systems may also be affected. We have no list
 of all affected systems, so the only safe solution was to prevent access to
 the SMBus on all IBM systems (detected using DMI data.)
+
+
+Description in the ACPI code
+----------------------------
+
+Device driver for the PIIX4 chip creates a separate I2C bus for each of its
+ports::
+
+    $ i2cdetect -l
+    ...
+    i2c-7   unknown         SMBus PIIX4 adapter port 0 at 0b00      N/A
+    i2c-8   unknown         SMBus PIIX4 adapter port 2 at 0b00      N/A
+    i2c-9   unknown         SMBus PIIX4 adapter port 1 at 0b20      N/A
+    ...
+
+Therefore if you want to access one of these busses in the ACPI code, port
+subdevices are needed to be declared inside the PIIX device::
+
+    Scope (\_SB_.PCI0.SMBS)
+    {
+        Name (_ADR, 0x00140000)
+
+        Device (SMB0) {
+            Name (_ADR, 0)
+        }
+        Device (SMB1) {
+            Name (_ADR, 1)
+        }
+        Device (SMB2) {
+            Name (_ADR, 2)
+        }
+    }
+
+If this is not the case for your UEFI firmware and you don't have access to the
+source code, you can use ACPI SSDT Overlays to provide the missing parts. Just
+keep in mind that in this case you would need to load your extra SSDT table
+before the piix4 driver starts, i.e. you should provide SSDT via initrd or EFI
+variable methods and not via configfs.
+
+As an example of usage here is the ACPI snippet code that would assign jc42
+driver to the 0x1C device on the I2C bus created by the PIIX port 0::
+
+    Device (JC42) {
+        Name (_HID, "PRP0001")
+        Name (_DDN, "JC42 Temperature sensor")
+        Name (_CRS, ResourceTemplate () {
+            I2cSerialBusV2 (
+                0x001c,
+                ControllerInitiated,
+                100000,
+                AddressingMode7Bit,
+                "\\_SB.PCI0.SMBS.SMB0",
+                0
+            )
+        })
+
+        Name (_DSD, Package () {
+            ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+            Package () {
+                Package () { "compatible", Package() { "jedec,jc-42.4-temp" } },
+            }
+        })
+    }