Re: [PATCH v2 3/5] i2c: img-scb: add handle for stop detected interrupt

[James Hogan <james.hogan-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>]

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On 14/08/15 16:50, Sifan Naeem wrote:
> Stop Detected interrupt is triggered when a Stop bit is detected on
> the bus, which indicates the end of the current transfer.
> 
> When the end of a transfer is indicated by the Stop Detected interrupt,
> drain the FIFO and signal completion for the transaction. But if the
> interrupt was triggered before all data is written to the fifo or with
> more data expected return error with transfer complete signal.
> 
> Halting the bus is no longer necessary after a stop bit is detected
> on the bus, as there cannot be a repeated start transfer when the stop
> bit has been issued, hence remove the transaction halt bit.

This patch looks okay, but does this paragraph still apply?

Cheers
James

> 
> Signed-off-by: Sifan Naeem <sifan.naeem-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-img-scb.c |   11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c
> index 75a44e794d75..17e13ff475bb 100644
> --- a/drivers/i2c/busses/i2c-img-scb.c
> +++ b/drivers/i2c/busses/i2c-img-scb.c
> @@ -152,6 +152,7 @@
>  #define INT_TRANSACTION_DONE		BIT(15)
>  #define INT_SLAVE_EVENT			BIT(16)
>  #define INT_TIMING			BIT(18)
> +#define INT_STOP_DETECTED		BIT(19)
>  
>  #define INT_FIFO_FULL_FILLING	(INT_FIFO_FULL  | INT_FIFO_FILLING)
>  
> @@ -175,7 +176,8 @@
>  					 INT_WRITE_ACK_ERR    | \
>  					 INT_FIFO_FULL        | \
>  					 INT_FIFO_FILLING     | \
> -					 INT_FIFO_EMPTY)
> +					 INT_FIFO_EMPTY       | \
> +					 INT_STOP_DETECTED)
>  
>  #define INT_ENABLE_MASK_WAITSTOP	(INT_SLAVE_EVENT      | \
>  					 INT_ADDR_ACK_ERR     | \
> @@ -873,6 +875,13 @@ static unsigned int img_i2c_auto(struct img_i2c *i2c,
>  
>  	mod_timer(&i2c->check_timer, jiffies + msecs_to_jiffies(1));
>  
> +	if (int_status & INT_STOP_DETECTED) {
> +		/* Drain remaining data in FIFO and complete transaction */
> +		if (i2c->msg.flags & I2C_M_RD)
> +			img_i2c_read_fifo(i2c);
> +		return ISR_COMPLETE(0);
> +	}
> +
>  	if (i2c->msg.flags & I2C_M_RD) {
>  		if (int_status & INT_FIFO_FULL_FILLING) {
>  			img_i2c_read_fifo(i2c);
> 


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