On 2018-06-04 21:00, Eddie James wrote: > Execute I2C transfers from the FSI-attached I2C master. Use polling > instead of interrupts as we have no hardware IRQ over FSI. > > Signed-off-by: Eddie James <[email protected]> > --- > drivers/i2c/busses/i2c-fsi.c | 195 > ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 193 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c > index 101b9c5..4e5964e 100644 > --- a/drivers/i2c/busses/i2c-fsi.c > +++ b/drivers/i2c/busses/i2c-fsi.c > @@ -150,6 +150,7 @@ struct fsi_i2c_port { > struct i2c_adapter adapter; > struct fsi_i2c_master *master; > u16 port; > + u16 xfrd; > }; > > static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, > @@ -225,6 +226,99 @@ static int fsi_i2c_set_port(struct fsi_i2c_port *port) > return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy); > } > > +static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg, > + bool stop) > +{ > + struct fsi_i2c_master *i2c = port->master; > + u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR; > + > + port->xfrd = 0; > + > + if (msg->flags & I2C_M_RD) > + cmd |= I2C_CMD_READ; > + > + if (stop || msg->flags & I2C_M_STOP) > + cmd |= I2C_CMD_WITH_STOP; > + > + cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr >> 1); > + cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len); > + > + return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd); > +} > + > +static int fsi_i2c_get_op_bytes(int op_bytes) > +{ > + /* fsi is limited to max 4 byte aligned ops */ > + if (op_bytes > 4) > + return 4; > + else if (op_bytes == 3) > + return 2; > + return op_bytes; > +} > + > +static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, > + u8 fifo_count) > +{ > + int write; > + int rc; > + struct fsi_i2c_master *i2c = port->master; > + int bytes_to_write = i2c->fifo_size - fifo_count; > + int bytes_remaining = msg->len - port->xfrd; > + > + bytes_to_write = min(bytes_to_write, bytes_remaining); > + > + while (bytes_to_write) { > + write = fsi_i2c_get_op_bytes(bytes_to_write); > + > + rc = fsi_device_write(i2c->fsi, I2C_FSI_FIFO, > + &msg->buf[port->xfrd], write); > + if (rc) > + return rc; > + > + port->xfrd += write; > + bytes_to_write -= write; > + } > + > + return 0; > +} > + > +static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, > + u8 fifo_count) > +{ > + int read; > + int rc; > + struct fsi_i2c_master *i2c = port->master; > + int bytes_to_read; > + int xfr_remaining = msg->len - port->xfrd; > + u32 dummy; > + > + bytes_to_read = min_t(int, fifo_count, xfr_remaining); > + > + while (bytes_to_read) { > + read = fsi_i2c_get_op_bytes(bytes_to_read); > + > + if (xfr_remaining) { > + rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, > + &msg->buf[port->xfrd], read); > + if (rc) > + return rc; > + > + port->xfrd += read; > + xfr_remaining -= read; > + } else { > + /* no more buffer but data in fifo, need to clear it */ > + rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, &dummy, > + read); > + if (rc) > + return rc; > + } > + > + bytes_to_read -= read; > + } > + > + return 0; > +} > + > static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c) > { > int i, rc; > @@ -388,17 +482,114 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, > u32 status) > return -ETIMEDOUT; > } > > +static int fsi_i2c_handle_status(struct fsi_i2c_port *port, > + struct i2c_msg *msg, u32 status) > +{ > + int rc; > + u8 fifo_count; > + > + if (status & I2C_STAT_ERR) { > + rc = fsi_i2c_abort(port, status); > + if (rc) > + return rc; > + > + if (status & I2C_STAT_INV_CMD) > + return -EINVAL; > + > + if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN | > + I2C_STAT_BE_ACCESS)) > + return -EPROTO; > + > + if (status & I2C_STAT_NACK) > + return -ENXIO; > + > + if (status & I2C_STAT_LOST_ARB) > + return -EAGAIN; > + > + if (status & I2C_STAT_STOP_ERR) > + return -EBADMSG; > + > + return -EIO; > + } > + > + if (status & I2C_STAT_DAT_REQ) { > + fifo_count = FIELD_GET(I2C_STAT_FIFO_COUNT, status); > + > + if (msg->flags & I2C_M_RD) > + return fsi_i2c_read_fifo(port, msg, fifo_count); > + > + return fsi_i2c_write_fifo(port, msg, fifo_count); > + } > + > + if (status & I2C_STAT_CMD_COMP) { > + if (port->xfrd < msg->len) > + return -ENODATA; > + > + return msg->len; > + } > + > + return 0; > +} > + > +static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, > + unsigned long timeout) > +{ > + u32 status = 0; > + int rc; > + unsigned long start = jiffies; > + > + do { > + rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT, > + &status); > + if (rc) > + return rc; > + > + if (status & I2C_STAT_ANY_RESP) { > + rc = fsi_i2c_handle_status(port, msg, status); > + if (rc < 0) > + return rc; > + > + /* cmd complete and all data xfrd */ > + if (rc == msg->len) > + return 0; > + > + /* need to xfr more data, but maybe don't need wait */ > + continue; > + } > + > + usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US); > + } while (time_after(start + timeout, jiffies)); > + > + return -ETIMEDOUT; > +} > + > static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, > int num) > { > - int rc; > + int i, rc; > + unsigned long start_time; > struct fsi_i2c_port *port = adap->algo_data; > + struct i2c_msg *msg; > > rc = fsi_i2c_set_port(port); > if (rc) > return rc; > > - return -EOPNOTSUPP; > + for (i = 0; i < num; i++) { > + msg = msgs + i; > + start_time = jiffies; > + > + rc = fsi_i2c_start(port, msg, i == num - 1); > + if (rc) > + return rc; > + > + rc = fsi_i2c_wait(port, msg, > + adap->timeout - (jiffies - start_time)); > + if (rc) > + return rc; > + } > + > + return 0;
Zero is not the return value of success for .master_xfer Hint, "num" is your friend... Cheers, Peter > } > > static u32 fsi_i2c_functionality(struct i2c_adapter *adap) >
