diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-bcm-iproc.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 9ffdffaf6141..30efb7913b2e 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -81,6 +81,7 @@ #define M_CMD_PROTOCOL_MASK 0xf #define M_CMD_PROTOCOL_BLK_WR 0x7 #define M_CMD_PROTOCOL_BLK_RD 0x8 +#define M_CMD_PROTOCOL_PROCESS 0xa #define M_CMD_PEC_SHIFT 8 #define M_CMD_RD_CNT_SHIFT 0 #define M_CMD_RD_CNT_MASK 0xff @@ -675,13 +676,20 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c, return 0; } -static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, - struct i2c_msg *msg) +/* + * If 'process_call' is true, then this is a multi-msg transfer that requires + * a repeated start between the messages. + * More specifically, it must be a write (reg) followed by a read (data). + * The i2c quirks are set to enforce this rule. + */ +static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c, + struct i2c_msg *msgs, bool process_call) { int i; u8 addr; u32 val, tmp, val_intr_en; unsigned int tx_bytes; + struct i2c_msg *msg = &msgs[0]; /* check if bus is busy */ if (!!(iproc_i2c_rd_reg(iproc_i2c, @@ -707,14 +715,29 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, val = msg->buf[i]; /* mark the last byte */ - if (i == msg->len - 1) - val |= BIT(M_TX_WR_STATUS_SHIFT); + if (!process_call && (i == msg->len - 1)) + val |= 1 << M_TX_WR_STATUS_SHIFT; iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); } iproc_i2c->tx_bytes = tx_bytes; } + /* Process the read message if this is process call */ + if (process_call) { + msg++; + iproc_i2c->msg = msg; /* point to second msg */ + + /* + * The last byte to be sent out should be a slave + * address with read operation + */ + addr = i2c_8bit_addr_from_msg(msg); + /* mark it the last byte out */ + val = addr | (1 << M_TX_WR_STATUS_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); + } + /* mark as incomplete before starting the transaction */ if (iproc_i2c->irq) reinit_completion(&iproc_i2c->done); @@ -733,7 +756,7 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, * underrun interrupt, which will be triggerred when the TX FIFO is * empty. When that happens we can then pump more data into the FIFO */ - if (!(msg->flags & I2C_M_RD) && + if (!process_call && !(msg->flags & I2C_M_RD) && msg->len > iproc_i2c->tx_bytes) val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT); @@ -743,6 +766,8 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, */ val = BIT(M_CMD_START_BUSY_SHIFT); if (msg->flags & I2C_M_RD) { + u32 protocol; + iproc_i2c->rx_bytes = 0; if (msg->len > M_RX_FIFO_MAX_THLD_VALUE) iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE; @@ -758,7 +783,10 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, /* enable the RX threshold interrupt */ val_intr_en |= BIT(IE_M_RX_THLD_SHIFT); - val |= (M_CMD_PROTOCOL_BLK_RD << M_CMD_PROTOCOL_SHIFT) | + protocol = process_call ? + M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD; + + val |= (protocol << M_CMD_PROTOCOL_SHIFT) | (msg->len << M_CMD_RD_CNT_SHIFT); } else { val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); @@ -774,17 +802,24 @@ static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg msgs[], int num) { struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter); - int ret, i; + bool process_call = false; + int ret; - /* go through all messages */ - for (i = 0; i < num; i++) { - ret = bcm_iproc_i2c_xfer_single_msg(iproc_i2c, &msgs[i]); - if (ret) { - dev_dbg(iproc_i2c->device, "xfer failed\n"); - return ret; + if (num == 2) { + /* Repeated start, use process call */ + process_call = true; + if (msgs[1].flags & I2C_M_NOSTART) { + dev_err(iproc_i2c->device, "Invalid repeated start\n"); + return -EOPNOTSUPP; } } + ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call); + if (ret) { + dev_dbg(iproc_i2c->device, "xfer failed\n"); + return ret; + } + return num; } @@ -809,6 +844,8 @@ static struct i2c_algorithm bcm_iproc_algo = { }; static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = { + .flags = I2C_AQ_COMB_WRITE_THEN_READ, + .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE, .max_read_len = M_RX_MAX_READ_LEN, }; |