From: Luca Ceresoli Date: Wed, 29 Jan 2020 15:19:27 +0000 (+0100) Subject: docs: i2c: summary: extend introduction X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=096c22f88ea09dab449f039863a46cb504b9b3ec;p=linux.git docs: i2c: summary: extend introduction - state the "official" name (I²C, not I2C, according to the spec) at the beginning but keep using the more practical I2C elsewhere - mention some known different names - add link to the specification document Signed-off-by: Luca Ceresoli Reviewed-by: Jean Delvare Signed-off-by: Wolfram Sang --- diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst index 3a24eac173756..dbab737d50753 100644 --- a/Documentation/i2c/summary.rst +++ b/Documentation/i2c/summary.rst @@ -2,12 +2,18 @@ I2C and SMBus ============= -I2C (pronounce: I squared C) is a protocol developed by Philips. It is a -slow two-wire protocol (variable speed, up to 400 kHz), with a high speed -extension (3.4 MHz). It provides an inexpensive bus for connecting many -types of devices with infrequent or low bandwidth communications needs. -I2C is widely used with embedded systems. Some systems use variants that -don't meet branding requirements, and so are not advertised as being I2C. +I²C (pronounce: I squared C and written I2C in the kernel documentation) is +a protocol developed by Philips. It is a slow two-wire protocol (variable +speed, up to 400 kHz), with a high speed extension (3.4 MHz). It provides +an inexpensive bus for connecting many types of devices with infrequent or +low bandwidth communications needs. I2C is widely used with embedded +systems. Some systems use variants that don't meet branding requirements, +and so are not advertised as being I2C but come under different names, +e.g. TWI (Two Wire Interface), IIC. + +The official I2C specification is the `"I2C-bus specification and user +manual" (UM10204) `_ +published by NXP Semiconductors. SMBus (System Management Bus) is based on the I2C protocol, and is mostly a subset of I2C protocols and signaling. Many I2C devices will work on an