1 files changed, 105 insertions, 12 deletions

diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 02796b5a39f6..00f032220173 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -1,8 +1,8 @@
 /*
- *      w1_io.c
+ *      w1_io.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
@@ -55,15 +55,29 @@ void w1_delay(unsigned long tm)
         udelay(tm * w1_delay_parm);
 }
 
+static void w1_write_bit(struct w1_master *dev, int bit);
+static u8 w1_read_bit(struct w1_master *dev);
+
+/**
+ * Generates a write-0 or write-1 cycle and samples the level.
+ */
 u8 w1_touch_bit(struct w1_master *dev, int bit)
 {
         if (dev->bus_master->touch_bit)
                 return dev->bus_master->touch_bit(dev->bus_master->data, bit);
-        else
+        else if (bit)
                 return w1_read_bit(dev);
+        else {
+                w1_write_bit(dev, 0);
+                return(0);
+        }
 }
 
-void w1_write_bit(struct w1_master *dev, int bit)
+/**
+ * Generates a write-0 or write-1 cycle.
+ * Only call if dev->bus_master->touch_bit is NULL
+ */
+static void w1_write_bit(struct w1_master *dev, int bit)
 {
         if (bit) {
                 dev->bus_master->write_bit(dev->bus_master->data, 0);
@@ -78,6 +92,12 @@ void w1_write_bit(struct w1_master *dev, int bit)
         }
 }
 
+/**
+ * Writes 8 bits.
+ *
+ * @param dev     the master device
+ * @param byte    the byte to write
+ */
 void w1_write_8(struct w1_master *dev, u8 byte)
 {
         int i;
@@ -86,10 +106,15 @@ void w1_write_8(struct w1_master *dev, u8 byte)
                 dev->bus_master->write_byte(dev->bus_master->data, byte);
         else
                 for (i = 0; i < 8; ++i)
-                        w1_write_bit(dev, (byte >> i) & 0x1);
+                        w1_touch_bit(dev, (byte >> i) & 0x1);
 }
 
-u8 w1_read_bit(struct w1_master *dev)
+
+/**
+ * Generates a write-1 cycle and samples the level.
+ * Only call if dev->bus_master->touch_bit is NULL
+ */
+static u8 w1_read_bit(struct w1_master *dev)
 {
         int result;
 
@@ -104,6 +129,53 @@ u8 w1_read_bit(struct w1_master *dev)
         return result & 0x1;
 }
 
+/**
+ * Does a triplet - used for searching ROM addresses.
+ * Return bits:
+ *  bit 0 = id_bit
+ *  bit 1 = comp_bit
+ *  bit 2 = dir_taken
+ * If both bits 0 & 1 are set, the search should be restarted.
+ *
+ * @param dev     the master device
+ * @param bdir    the bit to write if both id_bit and comp_bit are 0
+ * @return        bit fields - see above
+ */
+u8 w1_triplet(struct w1_master *dev, int bdir)
+{
+        if ( dev->bus_master->triplet )
+                return(dev->bus_master->triplet(dev->bus_master->data, bdir));
+        else {
+                u8 id_bit   = w1_touch_bit(dev, 1);
+                u8 comp_bit = w1_touch_bit(dev, 1);
+                u8 retval;
+
+                if ( id_bit && comp_bit )
+                        return(0x03);  /* error */
+
+                if ( !id_bit && !comp_bit ) {
+                        /* Both bits are valid, take the direction given */
+                        retval = bdir ? 0x04 : 0;
+                } else {
+                        /* Only one bit is valid, take that direction */
+                        bdir = id_bit;
+                        retval = id_bit ? 0x05 : 0x02;
+                }
+
+                if ( dev->bus_master->touch_bit )
+                        w1_touch_bit(dev, bdir);
+                else
+                        w1_write_bit(dev, bdir);
+                return(retval);
+        }
+}
+
+/**
+ * Reads 8 bits.
+ *
+ * @param dev     the master device
+ * @return        the byte read
+ */
 u8 w1_read_8(struct w1_master * dev)
 {
         int i;
@@ -113,12 +185,20 @@ u8 w1_read_8(struct w1_master * dev)
                 res = dev->bus_master->read_byte(dev->bus_master->data);
         else
                 for (i = 0; i < 8; ++i)
-                        res |= (w1_read_bit(dev) << i);
+                        res |= (w1_touch_bit(dev,1) << i);
 
         return res;
 }
 
-void w1_write_block(struct w1_master *dev, u8 *buf, int len)
+/**
+ * Writes a series of bytes.
+ *
+ * @param dev     the master device
+ * @param buf     pointer to the data to write
+ * @param len     the number of bytes to write
+ * @return        the byte read
+ */
+void w1_write_block(struct w1_master *dev, const u8 *buf, int len)
 {
         int i;
 
@@ -129,6 +209,14 @@ void w1_write_block(struct w1_master *dev, u8 *buf, int len)
                         w1_write_8(dev, buf[i]);
 }
 
+/**
+ * Reads a series of bytes.
+ *
+ * @param dev     the master device
+ * @param buf     pointer to the buffer to fill
+ * @param len     the number of bytes to read
+ * @return        the number of bytes read
+ */
 u8 w1_read_block(struct w1_master *dev, u8 *buf, int len)
 {
         int i;
@@ -145,9 +233,15 @@ u8 w1_read_block(struct w1_master *dev, u8 *buf, int len)
         return ret;
 }
 
+/**
+ * Issues a reset bus sequence.
+ *
+ * @param  dev The bus master pointer
+ * @return     0=Device present, 1=No device present or error
+ */
 int w1_reset_bus(struct w1_master *dev)
 {
-        int result = 0;
+        int result;
 
         if (dev->bus_master->reset_bus)
                 result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
@@ -180,12 +274,11 @@ void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb)
         if (dev->bus_master->search)
                 dev->bus_master->search(dev->bus_master->data, cb);
         else
-                w1_search(dev);
+                w1_search(dev, cb);
 }
 
-EXPORT_SYMBOL(w1_write_bit);
+EXPORT_SYMBOL(w1_touch_bit);
 EXPORT_SYMBOL(w1_write_8);
-EXPORT_SYMBOL(w1_read_bit);
 EXPORT_SYMBOL(w1_read_8);
 EXPORT_SYMBOL(w1_reset_bus);
 EXPORT_SYMBOL(w1_calc_crc8);