On Wed, Feb 25, 2015 at 05:01:54PM +0100, Wolfram Sang wrote:
> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Hi Ludovic,

if you have a few minutes, could you please test this series? I'd like to
include it in 4.1. and because at91 is using the quirk infrastructure in
a more complex way, it is a really good test candidate.

Thanks,

   Wolfram

> ---
>  drivers/i2c/busses/i2c-at91.c | 32 +++++++++++---------------------
>  1 file changed, 11 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
> index 636fd2efad8850..b3a70e8fc653c5 100644
> --- a/drivers/i2c/busses/i2c-at91.c
> +++ b/drivers/i2c/busses/i2c-at91.c
> @@ -487,30 +487,10 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
>  	if (ret < 0)
>  		goto out;
>  
> -	/*
> -	 * The hardware can handle at most two messages concatenated by a
> -	 * repeated start via it's internal address feature.
> -	 */
> -	if (num > 2) {
> -		dev_err(dev->dev,
> -			"cannot handle more than two concatenated messages.\n");
> -		ret = 0;
> -		goto out;
> -	} else if (num == 2) {
> +	if (num == 2) {
>  		int internal_address = 0;
>  		int i;
>  
> -		if (msg->flags & I2C_M_RD) {
> -			dev_err(dev->dev, "first transfer must be write.\n");
> -			ret = -EINVAL;
> -			goto out;
> -		}
> -		if (msg->len > 3) {
> -			dev_err(dev->dev, "first message size must be <= 3.\n");
> -			ret = -EINVAL;
> -			goto out;
> -		}
> -
>  		/* 1st msg is put into the internal address, start with 2nd */
>  		m_start = &msg[1];
>  		for (i = 0; i < msg->len; ++i) {
> @@ -540,6 +520,15 @@ out:
>  	return ret;
>  }
>  
> +/*
> + * The hardware can handle at most two messages concatenated by a
> + * repeated start via it's internal address feature.
> + */
> +static struct i2c_adapter_quirks at91_twi_quirks = {
> +	.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
> +	.max_comb_1st_msg_len = 3,
> +};
> +
>  static u32 at91_twi_func(struct i2c_adapter *adapter)
>  {
>  	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
> @@ -777,6 +766,7 @@ static int at91_twi_probe(struct platform_device *pdev)
>  	dev->adapter.owner = THIS_MODULE;
>  	dev->adapter.class = I2C_CLASS_DEPRECATED;
>  	dev->adapter.algo = &at91_twi_algorithm;
> +	dev->adapter.quirks = &at91_twi_quirks;
>  	dev->adapter.dev.parent = dev->dev;
>  	dev->adapter.nr = pdev->id;
>  	dev->adapter.timeout = AT91_I2C_TIMEOUT;
> -- 
> 2.1.4
>