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-rw-r--r--Documentation/i2c/chips/pcf857412
1 files changed, 5 insertions, 7 deletions
diff --git a/Documentation/i2c/chips/pcf8574 b/Documentation/i2c/chips/pcf8574
index 5c1ad1376b62..235815c075ff 100644
--- a/Documentation/i2c/chips/pcf8574
+++ b/Documentation/i2c/chips/pcf8574
@@ -4,13 +4,13 @@ Kernel driver pcf8574
4Supported chips: 4Supported chips:
5 * Philips PCF8574 5 * Philips PCF8574
6 Prefix: 'pcf8574' 6 Prefix: 'pcf8574'
7 Addresses scanned: I2C 0x20 - 0x27 7 Addresses scanned: none
8 Datasheet: Publicly available at the Philips Semiconductors website 8 Datasheet: Publicly available at the Philips Semiconductors website
9 http://www.semiconductors.philips.com/pip/PCF8574P.html 9 http://www.semiconductors.philips.com/pip/PCF8574P.html
10 10
11 * Philips PCF8574A 11 * Philips PCF8574A
12 Prefix: 'pcf8574a' 12 Prefix: 'pcf8574a'
13 Addresses scanned: I2C 0x38 - 0x3f 13 Addresses scanned: none
14 Datasheet: Publicly available at the Philips Semiconductors website 14 Datasheet: Publicly available at the Philips Semiconductors website
15 http://www.semiconductors.philips.com/pip/PCF8574P.html 15 http://www.semiconductors.philips.com/pip/PCF8574P.html
16 16
@@ -38,12 +38,10 @@ For more informations see the datasheet.
38Accessing PCF8574(A) via /sys interface 38Accessing PCF8574(A) via /sys interface
39------------------------------------- 39-------------------------------------
40 40
41! Be careful !
42The PCF8574(A) is plainly impossible to detect ! Stupid chip. 41The PCF8574(A) is plainly impossible to detect ! Stupid chip.
43So every chip with address in the interval [20..27] and [38..3f] are 42So, you have to pass the I2C bus and address of the installed PCF857A
44detected as PCF8574(A). If you have other chips in this address 43and PCF8574A devices explicitly to the driver at load time via the
45range, the workaround is to load this module after the one 44force=... parameter.
46for your others chips.
47 45
48On detection (i.e. insmod, modprobe et al.), directories are being 46On detection (i.e. insmod, modprobe et al.), directories are being
49created for each detected PCF8574(A): 47created for each detected PCF8574(A):