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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-bit.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c52
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 8a5f5825bb72..7f0a0a62cf60 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;
}