diff options
Diffstat (limited to 'drivers/w1/masters/ds2490.c')
| -rw-r--r-- | drivers/w1/masters/ds2490.c | 25 |
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; |