From 833bedb813689807385ae73175389c73a3f855c1 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 16 Jul 2008 19:30:06 +0200 Subject: i2c: Convert the pcf8574 driver to a new-style i2c driver The new-style pcf8574 driver implements the optional detect() callback to cover the use cases of the legacy driver. Warning: users will now have to use the force module parameter to get the driver to attach to their device. That's not a bad thing as these devices can't be detected anyway. Note that this doesn't change the fact that this driver is deprecated in favor of gpio/pcf857x. Signed-off-by: Jean Delvare --- Documentation/i2c/chips/pcf8574 | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'Documentation/i2c') 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 Supported chips: * Philips PCF8574 Prefix: 'pcf8574' - Addresses scanned: I2C 0x20 - 0x27 + Addresses scanned: none Datasheet: Publicly available at the Philips Semiconductors website http://www.semiconductors.philips.com/pip/PCF8574P.html * Philips PCF8574A Prefix: 'pcf8574a' - Addresses scanned: I2C 0x38 - 0x3f + Addresses scanned: none Datasheet: Publicly available at the Philips Semiconductors website http://www.semiconductors.philips.com/pip/PCF8574P.html @@ -38,12 +38,10 @@ For more informations see the datasheet. Accessing PCF8574(A) via /sys interface ------------------------------------- -! Be careful ! The PCF8574(A) is plainly impossible to detect ! Stupid chip. -So every chip with address in the interval [20..27] and [38..3f] are -detected as PCF8574(A). If you have other chips in this address -range, the workaround is to load this module after the one -for your others chips. +So, you have to pass the I2C bus and address of the installed PCF857A +and PCF8574A devices explicitly to the driver at load time via the +force=... parameter. On detection (i.e. insmod, modprobe et al.), directories are being created for each detected PCF8574(A): -- cgit v1.2.3 From 97addff6def3f8e228a634fa017589f45c69de5c Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 16 Jul 2008 19:30:06 +0200 Subject: i2c: Convert the pcf8575 driver to a new-style i2c driver The new-style pcf8575 driver implements the optional detect() callback to cover the use cases of the legacy driver. Warning: users will now have to use the force module parameter to get the driver to attach to their device. That's not a bad thing as these devices can't be detected anyway. Note that this doesn't change the fact that this driver is deprecated in favor of gpio/pcf857x. Signed-off-by: Jean Delvare --- Documentation/i2c/chips/pcf8575 | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'Documentation/i2c') diff --git a/Documentation/i2c/chips/pcf8575 b/Documentation/i2c/chips/pcf8575 index 25f5698a61cf..40b268eb276f 100644 --- a/Documentation/i2c/chips/pcf8575 +++ b/Documentation/i2c/chips/pcf8575 @@ -40,12 +40,9 @@ Detection --------- There is no method known to detect whether a chip on a given I2C address is -a PCF8575 or whether it is any other I2C device. So there are two alternatives -to let the driver find the installed PCF8575 devices: -- Load this driver after any other I2C driver for I2C devices with addresses - in the range 0x20 .. 0x27. -- Pass the I2C bus and address of the installed PCF8575 devices explicitly to - the driver at load time via the probe=... or force=... parameters. +a PCF8575 or whether it is any other I2C device, so you have to pass the I2C +bus and address of the installed PCF8575 devices explicitly to the driver at +load time via the force=... parameter. /sys interface -------------- -- cgit v1.2.3 From 3d63430a26b91fe3daee0dd933f899c225e66daa Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 16 Jul 2008 19:30:07 +0200 Subject: i2c: Convert the pca9539 driver to a new-style i2c driver The new-style pca9539 driver implements the optional detect() callback to cover the use cases of the legacy driver. Warning: users will now have to use the force module parameter to get the driver to attach to their device. That's not a bad thing as these devices can't be detected anyway. Note that this doesn't change the fact that this driver is deprecated in favor of gpio/pca953x. Signed-off-by: Jean Delvare --- Documentation/i2c/chips/pca9539 | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'Documentation/i2c') diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539 index 1d81c530c4a5..6aff890088b1 100644 --- a/Documentation/i2c/chips/pca9539 +++ b/Documentation/i2c/chips/pca9539 @@ -7,7 +7,7 @@ drivers/gpio/pca9539.c instead. Supported chips: * Philips PCA9539 Prefix: 'pca9539' - Addresses scanned: 0x74 - 0x77 + Addresses scanned: none Datasheet: http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf @@ -23,6 +23,14 @@ The input sense can also be inverted. The 16 lines are split between two bytes. +Detection +--------- + +The PCA9539 is difficult to detect and not commonly found in PC machines, +so you have to pass the I2C bus and address of the installed PCA9539 +devices explicitly to the driver at load time via the force=... parameter. + + Sysfs entries ------------- -- cgit v1.2.3 From bd8d421f7ca9f8da3d820d28379d796500f69529 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 16 Jul 2008 19:30:07 +0200 Subject: i2c: Convert the max6875 driver to a new-style i2c driver The new-style max6875 driver implements the optional detect() callback to cover the use cases of the legacy driver. I'm curious if anyone really needs this though, so it might be removed in the feature. Signed-off-by: Jean Delvare --- Documentation/i2c/chips/max6875 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/i2c') diff --git a/Documentation/i2c/chips/max6875 b/Documentation/i2c/chips/max6875 index a0cd8af2f408..10ca43cd1a72 100644 --- a/Documentation/i2c/chips/max6875 +++ b/Documentation/i2c/chips/max6875 @@ -49,7 +49,7 @@ $ modprobe max6875 force=0,0x50 The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple addresses. For example, for address 0x50, it also reserves 0x51. -The even-address instance is called 'max6875', the odd one is 'max6875 subclient'. +The even-address instance is called 'max6875', the odd one is 'dummy'. Programming the chip using i2c-dev -- cgit v1.2.3