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

[Marijn Suijten]

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".

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?

- 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
>