On 03/11/2015 04:42 AM, Benjamin Herrenschmidt wrote:
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.
Quirk *also* return error to the user if any of the conditions mismatch with
what we have indicated through the quriks structure...
I think we can't land up here by-passing the check for quirks so above
checks
are duplicated here..
Neelesh.
- 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);
--
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