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-rw-r--r--drivers/w1/masters/ds2490.c25
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 5f5b97e24700..e1cac0730cbb 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -98,6 +98,8 @@
#define ST_EPOF 0x80
/* Status transfer size, 16 bytes status, 16 byte result flags */
#define ST_SIZE 0x20
+/* 1-wire data i/o fifo size, 128 bytes */
+#define FIFO_SIZE 0x80
/* Result Register flags */
#define RR_DETECT 0xA5 /* New device detected */
@@ -614,14 +616,11 @@ static int ds_read_byte(struct ds_device *dev, u8 *byte)
return 0;
}
-static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
+static int read_block_chunk(struct ds_device *dev, u8 *buf, int len)
{
struct ds_status st;
int err;
- if (len > 64*1024)
- return -E2BIG;
-
memset(buf, 0xFF, len);
err = ds_send_data(dev, buf, len);
@@ -640,6 +639,24 @@ static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
return err;
}
+static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
+{
+ int err, to_read, rem = len;
+
+ if (len > 64 * 1024)
+ return -E2BIG;
+
+ do {
+ to_read = rem <= FIFO_SIZE ? rem : FIFO_SIZE;
+ err = read_block_chunk(dev, &buf[len - rem], to_read);
+ if (err < 0)
+ return err;
+ rem -= to_read;
+ } while (rem);
+
+ return err;
+}
+
static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
{
int err;