diff options
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 52 |
1 files changed, 32 insertions, 20 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 8a5f5825bb7..7f0a0a62cf6 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -357,13 +357,29 @@ static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) return wrcount; } +static int acknak(struct i2c_adapter *i2c_adap, int is_ack) +{ + struct i2c_algo_bit_data *adap = i2c_adap->algo_data; + + /* assert: sda is high */ + if (is_ack) /* send ack */ + setsda(adap, 0); + udelay((adap->udelay + 1) / 2); + if (sclhi(adap) < 0) { /* timeout */ + dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); + return -ETIMEDOUT; + } + scllo(adap); + return 0; +} + static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) { int inval; int rdcount=0; /* counts bytes read */ - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; unsigned char *temp = msg->buf; int count = msg->len; + const unsigned flags = msg->flags; while (count > 0) { inval = i2c_inb(i2c_adap); @@ -377,28 +393,12 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) temp++; count--; - if (msg->flags & I2C_M_NO_RD_ACK) { - bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x\n", - inval); - continue; - } - - /* assert: sda is high */ - if (count) /* send ack */ - setsda(adap, 0); - udelay((adap->udelay + 1) / 2); - bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x %s\n", inval, - count ? "A" : "NA"); - if (sclhi(adap)<0) { /* timeout */ - dev_err(&i2c_adap->dev, "readbytes: timeout at ack\n"); - return -ETIMEDOUT; - }; - scllo(adap); - /* Some SMBus transactions require that we receive the transaction length as the first read byte. */ - if (rdcount == 1 && (msg->flags & I2C_M_RECV_LEN)) { + if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { + if (!(flags & I2C_M_NO_RD_ACK)) + acknak(i2c_adap, 0); dev_err(&i2c_adap->dev, "readbytes: invalid " "block length (%d)\n", inval); return -EREMOTEIO; @@ -409,6 +409,18 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) count += inval; msg->len += inval; } + + bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", + inval, + (flags & I2C_M_NO_RD_ACK) + ? "(no ack/nak)" + : (count ? "A" : "NA")); + + if (!(flags & I2C_M_NO_RD_ACK)) { + inval = acknak(i2c_adap, count); + if (inval < 0) + return inval; + } } return rdcount; } |