| Message ID | 1528138850-18259-6-git-send-email-eajames@linux.vnet.ibm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: Add FSI-attached I2C master algorithm | expand |
On Mon, Jun 4, 2018 at 10:00 PM, Eddie James <eajames@linux.vnet.ibm.com> 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 <eajames@linux.vnet.ibm.com> > --- > 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); Did you consider to unify READ + ADDR as ADDR_8BIT? > + 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) Since you dropped one of 'else', another also is not needed. > + 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; > + } Just to be sure, if by some reason write == 0 in the loop for a while, would it become infinite loop? > + > + 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; > + } Ditto for read == 0. > + > + 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; > } > > static u32 fsi_i2c_functionality(struct i2c_adapter *adap) > -- > 1.8.3.1 >
On 06/04/2018 02:14 PM, Andy Shevchenko wrote: > On Mon, Jun 4, 2018 at 10:00 PM, Eddie James <eajames@linux.vnet.ibm.com> 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 <eajames@linux.vnet.ibm.com> >> --- >> 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); > Did you consider to unify READ + ADDR as ADDR_8BIT? Yes, however the result from the i2c_8bit_addr_from_msg function is not equivalent. This hardware expects the 8-bit address to be concatenated with the read/not write bit. Also the function returns a u8, which won't work for addresses with bit 7 set, since it left-shifts by one. > >> + 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) > Since you dropped one of 'else', another also is not needed. True. > >> + 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; >> + } > Just to be sure, if by some reason write == 0 in the loop for a while, > would it become infinite loop? It's not possible that write == 0. Same for read below. Thanks, Eddie > >> + >> + 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; >> + } > Ditto for read == 0. > >> + >> + 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; >> } >> >> static u32 fsi_i2c_functionality(struct i2c_adapter *adap) >> -- >> 1.8.3.1 >> > >
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 <eajames@linux.vnet.ibm.com> > --- > 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) >
On 06/04/2018 02:45 PM, Peter Rosin wrote: > 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 <eajames@linux.vnet.ibm.com> >> --- >> 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 Good catch, I'll fix that. Thanks, Eddie > >> } >> >> static u32 fsi_i2c_functionality(struct i2c_adapter *adap) >>
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; } static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
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 <eajames@linux.vnet.ibm.com> --- drivers/i2c/busses/i2c-fsi.c | 195 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 193 insertions(+), 2 deletions(-)