[PATCH] w1: Added w1_reset_select_slave() - Resets the bus and then selects the slave by

[linux-2.6] / drivers / w1 / w1_io.c

diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 2173336b60a72898f9fe016351a0d0aee95f0ccf..e2a043354ddfa3040fdc10c17350efb4c8fc653d 100644 (file)
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -129,6 +129,47 @@ static 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.
  *
@@ -233,7 +274,30 @@ 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);
+}
+
+/**
+ * Resets the bus and then selects the slave by sending either a skip rom
+ * or a rom match.
+ * The w1 master lock must be held.
+ *
+ * @param sl   the slave to select
+ * @return     0=success, anything else=error
+ */
+int w1_reset_select_slave(struct w1_slave *sl)
+{
+       if (w1_reset_bus(sl->master))
+               return -1;
+
+       if (sl->master->slave_count == 1)
+               w1_write_8(sl->master, W1_SKIP_ROM);
+       else {
+               u8 match[9] = {W1_MATCH_ROM, };
+               memcpy(&match[1], (u8 *)&sl->reg_num, 8);
+               w1_write_block(sl->master, match, 9);
+       }
+       return 0;
 }
 
 EXPORT_SYMBOL(w1_touch_bit);
@@ -245,3 +309,4 @@ EXPORT_SYMBOL(w1_delay);
 EXPORT_SYMBOL(w1_read_block);
 EXPORT_SYMBOL(w1_write_block);
 EXPORT_SYMBOL(w1_search_devices);
+EXPORT_SYMBOL(w1_reset_select_slave);