Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/w1-2.6

Documentation/w1/w1.generic

@@ -1,19 +1,92 @@
-Any w1 device must be connected to w1 bus master device - for example
-ds9490 usb device or w1-over-GPIO or RS232 converter.
-Driver for w1 bus master must provide several functions(you can find
-them in struct w1_bus_master definition in w1.h) which then will be
-called by w1 core to send various commands over w1 bus(by default it is
-reset and search commands). When some device is found on the bus, w1 core
-checks if driver for it's family is loaded.
-If driver is loaded w1 core creates new w1_slave object and registers it
-in the system(creates some generic sysfs files(struct w1_family_ops in
-w1_family.h), notifies any registered listener and so on...).
-It is device driver's business to provide any communication method
-upstream.
-For example w1_therm driver(ds18?20 thermal sensor family driver)
-provides temperature reading function which is bound to ->rbin() method
-of the above w1_family_ops structure.
-w1_smem - driver for simple 64bit memory cell provides ID reading
-method.
+The 1-wire (w1) subsystem
+------------------------------------------------------------------
+The 1-wire bus is a simple master-slave bus that communicates via a single
+signal wire (plus ground, so two wires).
+
+Devices communicate on the bus by pulling the signal to ground via an open
+drain output and by sampling the logic level of the signal line.
+
+The w1 subsystem provides the framework for managing w1 masters and
+communication with slaves.
+
+All w1 slave devices must be connected to a w1 bus master device.
+
+Example w1 master devices:
+    DS9490 usb device
+    W1-over-GPIO
+    DS2482 (i2c to w1 bridge)
+    Emulated devices, such as a RS232 converter, parallel port adapter, etc
+
+
+What does the w1 subsystem do?
+------------------------------------------------------------------
+When a w1 master driver registers with the w1 subsystem, the following occurs:
+
+ - sysfs entries for that w1 master are created
+ - the w1 bus is periodically searched for new slave devices
+
+When a device is found on the bus, w1 core checks if driver for it's family is
+loaded. If so, the family driver is attached to the slave.
+If there is no driver for the family, a simple sysfs entry is created
+for the slave device.
+
+
+W1 device families
+------------------------------------------------------------------
+Slave devices are handled by a driver written for a family of w1 devices.
+
+A family driver populates a struct w1_family_ops (see w1_family.h) and
+registers with the w1 subsystem.
+
+Current family drivers:
+w1_therm - (ds18?20 thermal sensor family driver)
+    provides temperature reading function which is bound to ->rbin() method
+    of the above w1_family_ops structure.
+
+w1_smem - driver for simple 64bit memory cell provides ID reading method.
 
 You can call above methods by reading appropriate sysfs files.
+
+
+What does a w1 master driver need to implement?
+------------------------------------------------------------------
+
+The driver for w1 bus master must provide at minimum two functions.
+
+Emulated devices must provide the ability to set the output signal level
+(write_bit) and sample the signal level (read_bit).
+
+Devices that support the 1-wire natively must provide the ability to write and
+sample a bit (touch_bit) and reset the bus (reset_bus).
+
+Most hardware provides higher-level functions that offload w1 handling.
+See struct w1_bus_master definition in w1.h for details.
+
+
+w1 master sysfs interface
+------------------------------------------------------------------
+<xx-xxxxxxxxxxxxx> - a directory for a found device. The format is family-serial
+bus                - (standard) symlink to the w1 bus
+driver             - (standard) symlink to the w1 driver
+w1_master_attempts - the number of times a search was attempted
+w1_master_max_slave_count
+                   - the maximum slaves that may be attached to a master
+w1_master_name     - the name of the device (w1_bus_masterX)
+w1_master_search   - the number of searches left to do, -1=continual (default)
+w1_master_slave_count
+                   - the number of slaves found
+w1_master_slaves   - the names of the slaves, one per line
+w1_master_timeout  - the delay in seconds between searches
+
+If you have a w1 bus that never changes (you don't add or remove devices),
+you can set w1_master_search to a positive value to disable searches.
+
+
+w1 slave sysfs interface
+------------------------------------------------------------------
+bus                - (standard) symlink to the w1 bus
+driver             - (standard) symlink to the w1 driver
+name               - the device name, usually the same as the directory name
+w1_slave           - (optional) a binary file whose meaning depends on the
+                     family driver
+

drivers/w1/Kconfig

@@ -3,9 +3,9 @@ menu "Dallas's 1-wire bus"
 config W1
 	tristate "Dallas's 1-wire support"
 	---help---
-	  Dallas's 1-wire bus is usefull to connect slow 1-pin devices 
+	  Dallas's 1-wire bus is usefull to connect slow 1-pin devices
 	  such as iButtons and thermal sensors.
-	  
+
 	  If you want W1 support, you should say Y here.
 
 	  This W1 support can also be built as a module.  If so, the module
@@ -17,8 +17,8 @@ config W1_MATROX
 	help
 	  Say Y here if you want to communicate with your 1-wire devices
 	  using Matrox's G400 GPIO pins.
-	  
-	  This support is also available as a module.  If so, the module 
+
+	  This support is also available as a module.  If so, the module
 	  will be called matrox_w1.ko.
 
 config W1_DS9490
@@ -27,17 +27,17 @@ config W1_DS9490
 	help
 	  Say Y here if you want to have a driver for DS9490R UWB <-> W1 bridge.
 
-	  This support is also available as a module.  If so, the module 
+	  This support is also available as a module.  If so, the module
 	  will be called ds9490r.ko.
 
-config W1_DS9490_BRIDGE
+config W1_DS9490R_BRIDGE
 	tristate "DS9490R USB <-> W1 transport layer for 1-wire"
 	depends on W1_DS9490
 	help
 	  Say Y here if you want to communicate with your 1-wire devices
 	  using DS9490R USB bridge.
 
-	  This support is also available as a module.  If so, the module 
+	  This support is also available as a module.  If so, the module
 	  will be called ds_w1_bridge.ko.
 
 config W1_THERM
@@ -51,7 +51,7 @@ config W1_SMEM
 	tristate "Simple 64bit memory family implementation"
 	depends on W1
 	help
-	  Say Y here if you want to connect 1-wire 
+	  Say Y here if you want to connect 1-wire
 	  simple 64bit memory rom(ds2401/ds2411/ds1990*) to you wire.
 
 endmenu

drivers/w1/ds_w1_bridge.c

@@ -83,11 +83,11 @@ static u8 ds9490r_read_byte(unsigned long data)
 	return byte;
 }
 
-static void ds9490r_write_block(unsigned long data, u8 *buf, int len)
+static void ds9490r_write_block(unsigned long data, const u8 *buf, int len)
 {
 	struct ds_device *dev = (struct ds_device *)data;
 
-	ds_write_block(dev, buf, len);
+	ds_write_block(dev, (u8 *)buf, len);
 }
 
 static u8 ds9490r_read_block(unsigned long data, u8 *buf, int len)

drivers/w1/matrox_w1.c

@@ -1,8 +1,8 @@
 /*
- * 	matrox_w1.c
+ *	matrox_w1.c
  *
  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
- * 
+ *
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@ static struct pci_driver matrox_w1_pci_driver = {
 	.remove = __devexit_p(matrox_w1_remove),
 };
 
-/* 
+/*
  * Matrox G400 DDC registers.
  */
 
@@ -177,8 +177,8 @@ static int __devinit matrox_w1_probe(struct pci_dev *pdev, const struct pci_devi
 
 	dev->bus_master = (struct w1_bus_master *)(dev + 1);
 
-	/* 
-	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c 
+	/*
+	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
 	 */
 
 	dev->phys_addr = pci_resource_start(pdev, 1);