Re: [RFC V2 04/12] i2c: opal: make use of the new infrastructure for quirks

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




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+renesas@xxxxxxxxxxxxxxxxxxxx>

Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
   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);


--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux