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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-16 07:10:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-16 07:10:39 +0300
commit273cbf61c3ddee9574ef1f4959b9bc6db5b24271 (patch)
tree1eb8a54d416453ad7c6adbf57ab05dce2587a012 /Documentation/i2c
parent5fe7b600a116187e10317d83fb56922c4ef6b76d (diff)
parentcc6b9dfb2c5769afeb3335048173c730bdf8dbe1 (diff)
downloadlinux-273cbf61c3ddee9574ef1f4959b9bc6db5b24271.tar.xz
Merge branch 'i2c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang: "New stuff from the I2C world: - in the core, getting irqs from ACPI is now similar to OF - new driver for MediaTek MT7621/7628/7688 SoCs - bcm2835, i801, and tegra drivers got some more attention - GPIO API cleanups - cleanups in the core headers - lots of usual driver updates" * 'i2c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (74 commits) i2c: mt7621: Fix platform_no_drv_owner.cocci warnings i2c: cpm: remove casting dma_alloc dt-bindings: i2c: sun6i-p2wi: Fix the binding example dt-bindings: i2c: mv64xxx: Fix the example compatible i2c: i801: Documentation update i2c: i801: Add support for Intel Tiger Lake i2c: i801: Fix PCI ID sorting dt-bindings: i2c-stm32: document optional dmas i2c: i2c-stm32f7: Add I2C_SMBUS_I2C_BLOCK_DATA support i2c: core: Tidy up handling of init_irq i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq i2c: core: Move ACPI IRQ handling to probe time i2c: acpi: Factor out getting the IRQ from ACPI i2c: acpi: Use available IRQ helper functions i2c: core: Allow whole core to use i2c_dev_irq_from_resources eeprom: at24: modify a comment referring to platform data dt-bindings: i2c: omap: Add new compatible for J721E SoCs dt-bindings: i2c: mv64xxx: Add YAML schemas dt-bindings: i2c: sun6i-p2wi: Add YAML schemas i2c: mt7621: Add MediaTek MT7621/7628/7688 I2C driver ...
Diffstat (limited to 'Documentation/i2c')
-rw-r--r--Documentation/i2c/busses/i2c-i80120
1 files changed, 11 insertions, 9 deletions
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
index ee9984f35868..f426c13c63a9 100644
--- a/Documentation/i2c/busses/i2c-i801
+++ b/Documentation/i2c/busses/i2c-i801
@@ -37,6 +37,8 @@ Supported adapters:
* Intel Cedar Fork (PCH)
* Intel Ice Lake (PCH)
* Intel Comet Lake (PCH)
+ * Intel Elkhart Lake (PCH)
+ * Intel Tiger Lake (PCH)
Datasheets: Publicly available at the Intel website
On Intel Patsburg and later chipsets, both the normal host SMBus controller
@@ -58,6 +60,7 @@ question doesn't work as intended for whatever reason. Bit values:
0x02 disable the block buffer
0x08 disable the I2C block read functionality
0x10 don't use interrupts
+ 0x20 disable SMBus Host Notify
Description
@@ -88,7 +91,7 @@ SMBus controller.
Process Call Support
--------------------
-Not supported.
+Block process call is supported on the 82801EB (ICH5) and later chips.
I2C Block Read Support
@@ -118,16 +121,15 @@ BIOS to enable it, it means it has been hidden by the BIOS code. Asus is
well known for first doing this on their P4B motherboard, and many other
boards after that. Some vendor machines are affected as well.
-The first thing to try is the "i2c_ec" ACPI driver. It could be that the
+The first thing to try is the "i2c-scmi" ACPI driver. It could be that the
SMBus was hidden on purpose because it'll be driven by ACPI. If the
-i2c_ec driver works for you, just forget about the i2c-i801 driver and
-don't try to unhide the ICH SMBus. Even if i2c_ec doesn't work, you
+i2c-scmi driver works for you, just forget about the i2c-i801 driver and
+don't try to unhide the ICH SMBus. Even if i2c-scmi doesn't work, you
better make sure that the SMBus isn't used by the ACPI code. Try loading
-the "fan" and "thermal" drivers, and check in /proc/acpi/fan and
-/proc/acpi/thermal_zone. If you find anything there, it's likely that
-the ACPI is accessing the SMBus and it's safer not to unhide it. Only
-once you are certain that ACPI isn't using the SMBus, you can attempt
-to unhide it.
+the "fan" and "thermal" drivers, and check in /sys/class/thermal. If you
+find a thermal zone with type "acpitz", it's likely that the ACPI is
+accessing the SMBus and it's safer not to unhide it. Only once you are
+certain that ACPI isn't using the SMBus, you can attempt to unhide it.
In order to unhide the SMBus, we need to change the value of a PCI
register before the kernel enumerates the PCI devices. This is done in