Re: [PATCH 53/55] media: rkisp1: Shift DMA buffer addresses on i.MX8MP

[Dafna Hirschfeld <dafna@fastmail.com>]

On 26.06.2022 14:38, Laurent Pinchart wrote:
>Hi Paul,
>
>Thank you for the patch.
>
>On Wed, Jun 15, 2022 at 04:11:25AM +0900, Paul Elder wrote:
>> On the ISP that is integrated in the i.MX8MP, the DMA base addresses are
>> encoded in 34-bit. Shift them to the left by 2 bits so that they can be
>
>I think you meant right, not left.
>
>> contained in 32 bits.
>
>The important part here is that this is how the address is encoded in
>the hardware. I suppose it's obvious, otherwise it woudln't work at all,
>but maybe it could be explained more explicitly ?
>
>On the ISP that is integrated in the i.MX8MP, DMA addresses have been
>extended to 34 bits, with the 32 MSBs stored in the DMA address
>registers and the 2 LSBs set to 0. Shift the buffer addresses right by 2
>on that platform.

If the 32 MSB are all stored in the in the dma address then why do we
need to shift?
>
>> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
>
>Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
>> ---
>>  .../platform/rockchip/rkisp1/rkisp1-capture.c | 19 +++++++++++--------
>>  .../platform/rockchip/rkisp1/rkisp1-common.h  |  1 +
>>  .../platform/rockchip/rkisp1/rkisp1-dev.c     |  3 ++-
>>  3 files changed, 14 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
>> index 35cec263c563..234b1f8488cb 100644
>> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
>> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
>> @@ -624,6 +624,9 @@ static void rkisp1_dummy_buf_destroy(struct rkisp1_capture *cap)
>>
>>  static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
>>  {
>> +	u8 shift = cap->rkisp1->info->features & RKISP1_FEATURE_DMA_34BIT ?
>> +		   2 : 0;
>> +
>>  	cap->buf.curr = cap->buf.next;
>>  	cap->buf.next = NULL;
>>
>> @@ -636,7 +639,7 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
>>  		buff_addr = cap->buf.next->buff_addr;
>>
>>  		rkisp1_write(cap->rkisp1, cap->config->mi.y_base_ad_init,
>> -			     buff_addr[RKISP1_PLANE_Y]);
>> +			     buff_addr[RKISP1_PLANE_Y] >> shift);
>>  		/*
>>  		 * In order to support grey format we capture
>>  		 * YUV422 planar format from the camera and
>> @@ -645,17 +648,17 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
>>  		if (cap->pix.cfg->fourcc == V4L2_PIX_FMT_GREY) {
>>  			rkisp1_write(cap->rkisp1,
>>  				     cap->config->mi.cb_base_ad_init,
>> -				     cap->buf.dummy.dma_addr);
>> +				     cap->buf.dummy.dma_addr >> shift);
>>  			rkisp1_write(cap->rkisp1,
>>  				     cap->config->mi.cr_base_ad_init,
>> -				     cap->buf.dummy.dma_addr);
>> +				     cap->buf.dummy.dma_addr >> shift);
>>  		} else {
>>  			rkisp1_write(cap->rkisp1,
>>  				     cap->config->mi.cb_base_ad_init,
>> -				     buff_addr[RKISP1_PLANE_CB]);
>> +				     buff_addr[RKISP1_PLANE_CB] >> shift);
>>  			rkisp1_write(cap->rkisp1,
>>  				     cap->config->mi.cr_base_ad_init,
>> -				     buff_addr[RKISP1_PLANE_CR]);
>> +				     buff_addr[RKISP1_PLANE_CR] >> shift);
>>  		}
>>  	} else {
>>  		/*
>> @@ -663,11 +666,11 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
>>  		 * throw data if there is no available buffer.
>>  		 */
>>  		rkisp1_write(cap->rkisp1, cap->config->mi.y_base_ad_init,
>> -			     cap->buf.dummy.dma_addr);
>> +			     cap->buf.dummy.dma_addr >> shift);
>>  		rkisp1_write(cap->rkisp1, cap->config->mi.cb_base_ad_init,
>> -			     cap->buf.dummy.dma_addr);
>> +			     cap->buf.dummy.dma_addr >> shift);
>>  		rkisp1_write(cap->rkisp1, cap->config->mi.cr_base_ad_init,
>> -			     cap->buf.dummy.dma_addr);
>> +			     cap->buf.dummy.dma_addr >> shift);
>>  	}
>>
>>  	/* Set plane offsets */
>> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> index 96657e55a5b0..0b834579d08c 100644
>> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> @@ -113,6 +113,7 @@ enum rkisp1_feature {
>>  	RKISP1_FEATURE_DUAL_CROP = BIT(1),
>>  	RKISP1_FEATURE_RSZ_CROP = BIT(2),
>>  	RKISP1_FEATURE_MAIN_STRIDE = BIT(3),
>> +	RKISP1_FEATURE_DMA_34BIT = BIT(4),

doc this field

thanks,
Dafna

>>  };
>>
>>  /*
>> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> index d68a805e8b6b..4c77aa2bc50a 100644
>> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> @@ -506,7 +506,8 @@ static const struct rkisp1_info imx8mp_isp_info = {
>>  	.isr_size = ARRAY_SIZE(imx8mp_isp_isrs),
>>  	.isp_ver = IMX8MP_V10,
>>  	.features = RKISP1_FEATURE_RSZ_CROP
>> -		  | RKISP1_FEATURE_MAIN_STRIDE,
>> +		  | RKISP1_FEATURE_MAIN_STRIDE
>> +		  | RKISP1_FEATURE_DMA_34BIT,
>>  };
>>
>>  static const struct of_device_id rkisp1_of_match[] = {
>
>-- 
>Regards,
>
>Laurent Pinchart

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