On Tue, 2015-03-10 at 22:43 +0530, Neelesh Gupta wrote: > I tested the i2c opal driver after updating the patch as below. > Basically I think we can also support write-then-{read/write} > for the number of messages = 2. > Ben, any issues if we support both write plus read/write in the > opal driver ?
Nope, in fact it's a good idea, I found myself having to expoes such an interface to some userspace tool of ours. However... > diff --git a/drivers/i2c/busses/i2c-opal.c b/drivers/i2c/busses/i2c-opal.c > index 16f90b1..85412ba 100644 > --- a/drivers/i2c/busses/i2c-opal.c > +++ b/drivers/i2c/busses/i2c-opal.c > @@ -104,18 +104,8 @@ static int i2c_opal_master_xfer(struct i2c_adapter > *adap, struct i2c_msg *msgs, > req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf)); > break; > case 2: > - /* For two messages, we basically support only simple > - * smbus transactions of a write plus a read. We might > - * want to allow also two writes but we'd have to bounce > - * the data into a single buffer. > - */ > - if ((msgs[0].flags & I2C_M_RD) || !(msgs[1].flags & I2C_M_RD)) > - return -EOPNOTSUPP; Don't we still want to enforce that the first message is a write ? Somebody may not be looking at the quirks... > - if (msgs[0].len > 4) > - return -EOPNOTSUPP; And that the len is supported... > - if (msgs[0].addr != msgs[1].addr) > - return -EOPNOTSUPP; Same... Ie, the quirk indicates to the callers what we support, but we should still check that we aren't called with something that doesn't match. > - req.type = OPAL_I2C_SM_READ; > + req.type = (msgs[1].flags & I2C_M_RD) ? > + OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; > req.addr = cpu_to_be16(msgs[0].addr); > req.subaddr_sz = msgs[0].len; > for (i = 0; i < msgs[0].len; i++) > @@ -210,6 +200,11 @@ static const struct i2c_algorithm i2c_opal_algo = { > .functionality = i2c_opal_func, > }; > > +static struct i2c_adapter_quirks i2c_opal_quirks = { > + .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR, > + .max_comb_1st_msg_len = 4, > +}; > + > static int i2c_opal_probe(struct platform_device *pdev) > { > struct i2c_adapter *adapter; > @@ -232,6 +227,7 @@ static int i2c_opal_probe(struct platform_device *pdev) > > adapter->algo = &i2c_opal_algo; > adapter->algo_data = (void *)(unsigned long)opal_id; > + adapter->quirks = &i2c_opal_quirks; > adapter->dev.parent = &pdev->dev; > adapter->dev.of_node = of_node_get(pdev->dev.of_node); > pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL); > > > > On 02/25/2015 09:31 PM, Wolfram Sang wrote: > > From: Wolfram Sang <wsa+rene...@sang-engineering.com> > > > > Signed-off-by: Wolfram Sang <wsa+rene...@sang-engineering.com> > > --- > > drivers/i2c/busses/i2c-opal.c | 22 +++++++++++----------- > > 1 file changed, 11 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-opal.c b/drivers/i2c/busses/i2c-opal.c > > index 16f90b1a750894..b2788ecad5b3cb 100644 > > --- a/drivers/i2c/busses/i2c-opal.c > > +++ b/drivers/i2c/busses/i2c-opal.c > > @@ -104,17 +104,6 @@ static int i2c_opal_master_xfer(struct i2c_adapter > > *adap, struct i2c_msg *msgs, > > req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf)); > > break; > > case 2: > > - /* For two messages, we basically support only simple > > - * smbus transactions of a write plus a read. We might > > - * want to allow also two writes but we'd have to bounce > > - * the data into a single buffer. > > - */ > > - if ((msgs[0].flags & I2C_M_RD) || !(msgs[1].flags & I2C_M_RD)) > > - return -EOPNOTSUPP; > > - if (msgs[0].len > 4) > > - return -EOPNOTSUPP; > > - if (msgs[0].addr != msgs[1].addr) > > - return -EOPNOTSUPP; > > req.type = OPAL_I2C_SM_READ; > > req.addr = cpu_to_be16(msgs[0].addr); > > req.subaddr_sz = msgs[0].len; > > @@ -210,6 +199,16 @@ static const struct i2c_algorithm i2c_opal_algo = { > > .functionality = i2c_opal_func, > > }; > > > > +/* For two messages, we basically support only simple > > + * smbus transactions of a write plus a read. We might > > + * want to allow also two writes but we'd have to bounce > > + * the data into a single buffer. > > + */ > > +static struct i2c_adapter_quirks i2c_opal_quirks = { > > + .flags = I2C_AQ_COMB_WRITE_THEN_READ, > > + .max_comb_1st_msg_len = 4, > > +}; > > + > > static int i2c_opal_probe(struct platform_device *pdev) > > { > > struct i2c_adapter *adapter; > > @@ -232,6 +231,7 @@ static int i2c_opal_probe(struct platform_device *pdev) > > > > adapter->algo = &i2c_opal_algo; > > adapter->algo_data = (void *)(unsigned long)opal_id; > > + adapter->quirks = &i2c_opal_quirks; > > adapter->dev.parent = &pdev->dev; > > adapter->dev.of_node = of_node_get(pdev->dev.of_node); > > pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL); _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev