diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 63 |
1 files changed, 49 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index a8ebb84e23f9..206caacd30d7 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target, } static int mpc_read(struct mpc_i2c *i2c, int target, - u8 *data, int length, int restart) + u8 *data, int length, int restart, bool recv_len) { unsigned timeout = i2c->adap.timeout; int i, result; @@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target, return result; if (length) { - if (length == 1) + if (length == 1 && !recv_len) writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); else writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA); @@ -479,17 +479,46 @@ static int mpc_read(struct mpc_i2c *i2c, int target, } for (i = 0; i < length; i++) { + u8 byte; + result = i2c_wait(i2c, timeout, 0); if (result < 0) return result; - /* Generate txack on next to last byte */ - if (i == length - 2) - writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); - /* Do not generate stop on last byte */ - if (i == length - 1) - writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX); - data[i] = readb(i2c->base + MPC_I2C_DR); + /* + * For block reads, we have to know the total length (1st byte) + * before we can determine if we are done. + */ + if (i || !recv_len) { + /* Generate txack on next to last byte */ + if (i == length - 2) + writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA + | CCR_TXAK); + /* Do not generate stop on last byte */ + if (i == length - 1) + writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA + | CCR_MTX); + } + + byte = readb(i2c->base + MPC_I2C_DR); + + /* + * Adjust length if first received byte is length. + * The length is 1 length byte plus actually data length + */ + if (i == 0 && recv_len) { + if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX) + return -EPROTO; + length += byte; + /* + * For block reads, generate txack here if data length + * is 1 byte (total length is 2 bytes). + */ + if (length == 2) + writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA + | CCR_TXAK); + } + data[i] = byte; } return length; @@ -532,12 +561,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) "Doing %s %d bytes to 0x%02x - %d of %d messages\n", pmsg->flags & I2C_M_RD ? "read" : "write", pmsg->len, pmsg->addr, i + 1, num); - if (pmsg->flags & I2C_M_RD) - ret = - mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); - else + if (pmsg->flags & I2C_M_RD) { + bool recv_len = pmsg->flags & I2C_M_RECV_LEN; + + ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i, + recv_len); + if (recv_len && ret > 0) + pmsg->len = ret; + } else { ret = mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); + } } mpc_i2c_stop(i2c); return (ret < 0) ? ret : num; @@ -545,7 +579,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) static u32 mpc_functionality(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL + | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL; } static const struct i2c_algorithm mpc_algo = { |