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

From: Neelesh Gupta <[email-masked]>
Date: Fri, 13 Mar 2015 14:20:11 +0530

Hi Wolfram,

Based on your patch:
"[RFC V2 04/12] i2c: opal: make use of the new infrastructure for quirks"

From: Neelesh Gupta <[email-masked]>
Subject: [PATCH] i2c: opal: Update quirk flags to do write-then-anything

Support write-then-anything in the case of 2 i2c messages
for i2c transfer.

Signed-off-by: Neelesh Gupta<[email-masked]>
---
  drivers/i2c/busses/i2c-opal.c |   11 +++++------
  1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-opal.c b/drivers/i2c/busses/i2c-opal.c
index b2788ec..1ec7fc9 100644
--- a/drivers/i2c/busses/i2c-opal.c
+++ b/drivers/i2c/busses/i2c-opal.c
@@ -104,7 +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:
-		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++)
@@ -199,13 +200,11 @@ 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.
+/* For two messages, we basically support simple smbus transactions of a
+ * write-then-anything.
   */
  static struct i2c_adapter_quirks i2c_opal_quirks = {
-	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
+	.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
  	.max_comb_1st_msg_len = 4,
  };

On 02/25/2015 09:31 PM, Wolfram Sang wrote:
> From: Wolfram Sang <[email-masked]>
>
> Signed-off-by: Wolfram Sang <[email-masked]>
> ---
>   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);