X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=Documentation%2Fi2c%2Fsmbus-protocol;fp=Documentation%2Fi2c%2Fsmbus-protocol;h=7c19d1a2bea0a4936a20bfaad6972800c8bf4794;hb=b5527a7766f0505dc72efe3cefe5e9dea826f611;hp=9df47441f0e73063c39f39fe22acc1fb3a753416;hpb=6d376fcc28d98f7f8f652755ae4dca1ff7240563;p=karo-tx-linux.git

diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol
index 9df47441f0e7..7c19d1a2bea0 100644
--- a/Documentation/i2c/smbus-protocol
+++ b/Documentation/i2c/smbus-protocol
@@ -185,6 +185,22 @@ the protocol. All ARP communications use slave address 0x61 and
 require PEC checksums.
 
 
+SMBus Alert
+===========
+
+SMBus Alert was introduced in Revision 1.0 of the specification.
+
+The SMBus alert protocol allows several SMBus slave devices to share a
+single interrupt pin on the SMBus master, while still allowing the master
+to know which slave triggered the interrupt.
+
+This is implemented the following way in the Linux kernel:
+* I2C bus drivers which support SMBus alert should call
+  i2c_setup_smbus_alert() to setup SMBus alert support.
+* I2C drivers for devices which can trigger SMBus alerts should implement
+  the optional alert() callback.
+
+
 I2C Block Transactions
 ======================