w1: add touch block command

Writes and returns sampled data back to userspace.

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 25 insertions, 1 deletions

diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 5139c25ca96..442bd8bbd4a 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -238,7 +238,6 @@ EXPORT_SYMBOL_GPL(w1_read_8);
  * @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)
 {
@@ -256,6 +255,31 @@ void w1_write_block(struct w1_master *dev, const u8 *buf, int len)
 EXPORT_SYMBOL_GPL(w1_write_block);
 
 /**
+ * Touches 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
+ */
+void w1_touch_block(struct w1_master *dev, u8 *buf, int len)
+{
+        int i, j;
+        u8 tmp;
+
+        for (i = 0; i < len; ++i) {
+                tmp = 0;
+                for (j = 0; j < 8; ++j) {
+                        if (j == 7)
+                                w1_pre_write(dev);
+                        tmp |= w1_touch_bit(dev, (buf[i] >> j) & 0x1) << j;
+                }
+
+                buf[i] = tmp;
+        }
+}
+EXPORT_SYMBOL_GPL(w1_touch_block);
+
+/**
  * Reads a series of bytes.
  *
  * @param dev     the master device