[PATCH v12 5/9] drm/msm: Add MSM-specific DSC helper methods

[Jessica Zhang]

On 5/17/2023 4:01 PM, Marijn Suijten wrote:
> On 2023-05-17 15:27:18, Jessica Zhang wrote:
>> Introduce MSM-specific DSC helper methods, as some calculations are
>> common between DP and DSC.
>>
>> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/msm_dsc_helper.h | 38 ++++++++++++++++++++++++++++++++++++
>>   1 file changed, 38 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/msm_dsc_helper.h b/drivers/gpu/drm/msm/msm_dsc_helper.h
>> new file mode 100644
>> index 000000000000..c7d7ed026368
>> --- /dev/null
>> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h
>> @@ -0,0 +1,38 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved
>> + *
>> + * Helper methods for MSM-specific DSC calculations that are common between timing engine,
>> + * DSI, and DP.
>> + */
>> +
>> +#ifndef MSM_DSC_HELPER_H_
>> +#define MSM_DSC_HELPER_H_
>> +
>> +#include <linux/math.h>
>> +#include <drm/display/drm_dsc_helper.h>
>> +
>> +/**
>> + * msm_dsc_calculate_slices_per_intf() - get number of slices per interface
> 
> Oh no, we just went to get to match the function below, and now this is
> back at calculate.  My bad, I wasn't clear enough in previous review: I
> meant the ext after the -, so "get number of" -> "calculate number of".

Hi Marijn,

Got it.

> 
> Sorry!
> 
>> + * @dsc: Pointer to drm dsc config struct
>> + * @intf_width: interface width in pixels
>> + * Returns: Integer representing the number of slices for the given interface
>> + */
>> +static inline u32 msm_dsc_calculate_slices_per_intf(const struct drm_dsc_config *dsc, int intf_width)
> 
> u32... also for intf_width?

Acked.

Thanks,

Jessica Zhang

> 
> - Marijn
> 
>> +{
>> +	return DIV_ROUND_UP(intf_width, dsc->slice_width);
>> +}
>> +
>> +/**
>> + * msm_dsc_get_bytes_per_line() - calculate bytes per line
>> + * @dsc: Pointer to drm dsc config struct
>> + * Returns: Integer value representing bytes per line. DSI and DP need
>> + *          to perform further calculations to turn this into pclk_per_intf,
>> + *          such as dividing by different values depending on if widebus is enabled.
>> + */
>> +static inline u32 msm_dsc_get_bytes_per_line(const struct drm_dsc_config *dsc)
>> +{
>> +	return dsc->slice_count * dsc->slice_chunk_size;
>> +}
>> +
>> +#endif /* MSM_DSC_HELPER_H_ */
>>
>> -- 
>> 2.40.1
>>