Re: [PATCH 3/4] drm/modes: Add initializer macro DRM_MODE_INIT()

[Sam Ravnborg <sam@ravnborg.org>]

On Wed, Aug 10, 2022 at 01:20:52PM +0200, Thomas Zimmermann wrote:
> The macro DRM_MODE_INIT() initializes an instance of
> struct drm_display_mode with typical parameters. Convert simpledrm
> and also update the macro DRM_SIMPLE_MODE().
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

It is nice that the macros are now documented.

	Sam

> ---
>  drivers/gpu/drm/tiny/simpledrm.c | 23 ++++++++-------------
>  include/drm/drm_modes.h          | 35 +++++++++++++++++++++++++++-----
>  2 files changed, 39 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
> index 31d3bc6c5acf..cc509154b296 100644
> --- a/drivers/gpu/drm/tiny/simpledrm.c
> +++ b/drivers/gpu/drm/tiny/simpledrm.c
> @@ -30,16 +30,6 @@
>  #define DRIVER_MAJOR	1
>  #define DRIVER_MINOR	0
>  
> -/*
> - * Assume a monitor resolution of 96 dpi to
> - * get a somewhat reasonable screen size.
> - */
> -#define RES_MM(d)	\
> -	(((d) * 254ul) / (96ul * 10ul))
> -
> -#define SIMPLEDRM_MODE(hd, vd)	\
> -	DRM_SIMPLE_MODE(hd, vd, RES_MM(hd), RES_MM(vd))
> -
>  /*
>   * Helpers for simplefb
>   */
> @@ -641,10 +631,15 @@ static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
>  static struct drm_display_mode simpledrm_mode(unsigned int width,
>  					      unsigned int height)
>  {
> -	struct drm_display_mode mode = { SIMPLEDRM_MODE(width, height) };
> -
> -	mode.clock = mode.hdisplay * mode.vdisplay * 60 / 1000 /* kHz */;
> -	drm_mode_set_name(&mode);
> +	/*
> +	 * Assume a monitor resolution of 96 dpi to
> +	 * get a somewhat reasonable screen size.
> +	 */
> +	const struct drm_display_mode mode = {
> +		DRM_MODE_INIT(60, width, height,
> +			      DRM_MODE_RES_MM(width, 96ul),
> +			      DRM_MODE_RES_MM(height, 96ul))
> +	};
>  
>  	return mode;
>  }
> diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
> index a80ae9639e96..bb932806f029 100644
> --- a/include/drm/drm_modes.h
> +++ b/include/drm/drm_modes.h
> @@ -138,6 +138,35 @@ enum drm_mode_status {
>  	.vsync_start = (vss), .vsync_end = (vse), .vtotal = (vt), \
>  	.vscan = (vs), .flags = (f)
>  
> +/**
> + * DRM_MODE_RES_MM - Calculates the display size from resolution and DPI
> + * @res: The resolution in pixel
> + * @dpi: The number of dots per inch
> + */
> +#define DRM_MODE_RES_MM(res, dpi)	\
> +	(((res) * 254ul) / ((dpi) * 10ul))
> +
> +#define __DRM_MODE_INIT(pix, hd, vd, hd_mm, vd_mm) \
> +	.type = DRM_MODE_TYPE_DRIVER, .clock = (pix), \
> +	.hdisplay = (hd), .hsync_start = (hd), .hsync_end = (hd), \
> +	.htotal = (hd), .vdisplay = (vd), .vsync_start = (vd), \
> +	.vsync_end = (vd), .vtotal = (vd), .width_mm = (hd_mm), \
> +	.height_mm = (vd_mm)
> +
> +/**
> + * DRM_SIMPLE_MODE_INIT - Initialize display mode
> + * @hz: Vertical refresh rate in Hertz
> + * @hd: Horizontal resolution, width
> + * @vd: Vertical resolution, height
> + * @hd_mm: Display width in millimeters
> + * @vd_mm: Display height in millimeters
> + *
> + * This macro initializes a &drm_display_mode that contains information about
> + * refresh rate, resolution and physical size.
> + */
> +#define DRM_MODE_INIT(hz, hd, vd, hd_mm, vd_mm) \
> +	__DRM_MODE_INIT((hd) * (vd) * (hz) / 1000 /* kHz */, hd, vd, hd_mm, vd_mm)
> +
>  /**
>   * DRM_SIMPLE_MODE - Simple display mode
>   * @hd: Horizontal resolution, width
> @@ -149,11 +178,7 @@ enum drm_mode_status {
>   * resolution and physical size.
>   */
>  #define DRM_SIMPLE_MODE(hd, vd, hd_mm, vd_mm) \
> -	.type = DRM_MODE_TYPE_DRIVER, .clock = 1 /* pass validation */, \
> -	.hdisplay = (hd), .hsync_start = (hd), .hsync_end = (hd), \
> -	.htotal = (hd), .vdisplay = (vd), .vsync_start = (vd), \
> -	.vsync_end = (vd), .vtotal = (vd), .width_mm = (hd_mm), \
> -	.height_mm = (vd_mm)
> +	__DRM_MODE_INIT(1 /* pass validation */, hd, vd, hd_mm, vd_mm)
>  
>  #define CRTC_INTERLACE_HALVE_V	(1 << 0) /* halve V values for interlacing */
>  #define CRTC_STEREO_DOUBLE	(1 << 1) /* adjust timings for stereo modes */
> -- 
> 2.37.1