[PATCH 26/28] drm: Move drm_display_mode an related docs into kerneldoc

Daniel Vetter
2015-12-04T08:46:07Z

This was in the documentation for modeset helper hooks, where it is a
bit misplaced.

v2: Reindent the drm_mode_status enum, inspired by Ville.

Cc: ville.syrjala@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
Documentation/DocBook/gpu.tmpl | 192 -----------------------
drivers/gpu/drm/drm_modes.c | 3 +-
include/drm/drm_modes.h | 342 +++++++++++++++++++++++++++++++++++------
3 files changed, 297 insertions(+), 240 deletions(-)

diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index 5312f5a05798..86e5b12a49ba 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -1758,198 +1758,6 @@ void intel_crt_init(struct drm_device *dev)
<function>drm_add_edid_modes</function> manually in that case.


- When adding modes manually the driver creates each mode with a call to
- <function>drm_mode_create</function> and must fill the following fields.
-
-
- <synopsis>__u32 type;</synopsis>
-
- Mode type bitmask, a combination of
- <variablelist>
- <varlistentry>
- <term>DRM_MODE_TYPE_BUILTIN</term>
- not used?
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_CLOCK_C</term>
- not used?
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_CRTC_C</term>
- not used?
- </varlistentry>
- <varlistentry>
- <term>
- DRM_MODE_TYPE_PREFERRED - The preferred mode for the connector
- </term>
-
- not used?
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_DEFAULT</term>
- not used?
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_USERDEF</term>
- not used?
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_TYPE_DRIVER</term>
-
-
- The mode has been created by the driver (as opposed to
- to user-created modes).
-
-
- </varlistentry>
- </variablelist>
- Drivers must set the DRM_MODE_TYPE_DRIVER bit for all modes they
- create, and set the DRM_MODE_TYPE_PREFERRED bit for the preferred
- mode.
-
-
-
- <synopsis>__u32 clock;</synopsis>
- Pixel clock frequency in kHz unit
-
-
- <synopsis>__u16 hdisplay, hsync_start, hsync_end, htotal;
- __u16 vdisplay, vsync_start, vsync_end, vtotal;</synopsis>
- Horizontal and vertical timing information
- <screen>
- Active Front Sync Back
- Region Porch Porch
- <-----------------------><----------------><-------------><-------------->
-
- //////////////////////|
- ////////////////////// |
- ////////////////////// |.................. ................
- _______________
-
- <----- [hv]display ----->
- <------------- [hv]sync_start ------------>
- <--------------------- [hv]sync_end --------------------->
- <-------------------------------- [hv]total ----------------------------->
- </screen>
-
-
- <synopsis>__u16 hskew;
- __u16 vscan;</synopsis>
- Unknown
-
-
- <synopsis>__u32 flags;</synopsis>
-
- Mode flags, a combination of
- <variablelist>
- <varlistentry>
- <term>DRM_MODE_FLAG_PHSYNC</term>
-
- Horizontal sync is active high
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NHSYNC</term>
-
- Horizontal sync is active low
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PVSYNC</term>
-
- Vertical sync is active high
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NVSYNC</term>
-
- Vertical sync is active low
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_INTERLACE</term>
-
- Mode is interlaced
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_DBLSCAN</term>
-
- Mode uses doublescan
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_CSYNC</term>
-
- Mode uses composite sync
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PCSYNC</term>
-
- Composite sync is active high
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_NCSYNC</term>
-
- Composite sync is active low
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_HSKEW</term>
-
- hskew provided (not used?)
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_BCAST</term>
-
- not used?
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_PIXMUX</term>
-
- not used?
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_DBLCLK</term>
-
- not used?
-
- </varlistentry>
- <varlistentry>
- <term>DRM_MODE_FLAG_CLKDIV2</term>
-
- ?
-
- </varlistentry>
- </variablelist>
-
-
- Note that modes marked with the INTERLACE or DBLSCAN flags will be
- filtered out by
- <function>drm_helper_probe_single_connector_modes</function> if
- the connector's <structfield>interlace_allowed</structfield> or
- <structfield>doublescan_allowed</structfield> field is set to 0.
-
-
-
- <synopsis>char name[DRM_DISPLAY_MODE_LEN];</synopsis>
-
- Mode name. The driver must call
- <function>drm_mode_set_name</function> to fill the mode name from
- <structfield>hdisplay</structfield>,
- <structfield>vdisplay</structfield> and interlace flag after
- filling the corresponding fields.
-
-
-
-
-
The <structfield>vrefresh</structfield> value is computed by
<function>drm_helper_probe_single_connector_modes</function>.

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 5f79b9334a38..041138f5acc9 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -708,7 +708,8 @@ void drm_mode_set_name(struct drm_display_mode *mode)
}
EXPORT_SYMBOL(drm_mode_set_name);

-/** drm_mode_hsync - get the hsync of a mode
+/**
+ * drm_mode_hsync - get the hsync of a mode
* @mode: mode
*
* Returns:
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index f9115aee43f4..cd3c42256ab8 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -35,46 +35,91 @@
* structures).
*/

+/**
+ * enum drm_mode_status - hardware support status of a mode
+ * @MODE_OK: Mode OK
+ * @MODE_HSYNC: hsync out of range
+ * @MODE_VSYNC: vsync out of range
+ * @MODE_H_ILLEGAL: mode has illegal horizontal timings
+ * @MODE_V_ILLEGAL: mode has illegal horizontal timings
+ * @MODE_BAD_WIDTH: requires an unsupported linepitch
+ * @MODE_NOMODE: no mode with a matching name
+ * @MODE_NO_INTERLACE: interlaced mode not supported
+ * @MODE_NO_DBLESCAN: doublescan mode not supported
+ * @MODE_NO_VSCAN: multiscan mode not supported
+ * @MODE_MEM: insufficient video memory
+ * @MODE_VIRTUAL_X: mode width too large for specified virtual size
+ * @MODE_VIRTUAL_Y: mode height too large for specified virtual size
+ * @MODE_MEM_VIRT: insufficient video memory given virtual size
+ * @MODE_NOCLOCK: no fixed clock available
+ * @MODE_CLOCK_HIGH: clock required is too high
+ * @MODE_CLOCK_LOW: clock required is too low
+ * @MODE_CLOCK_RANGE: clock/mode isn't in a ClockRange
+ * @MODE_BAD_HVALUE: horizontal timing was out of range
+ * @MODE_BAD_VVALUE: vertical timing was out of range
+ * @MODE_BAD_VSCAN: VScan value out of range
+ * @MODE_HSYNC_NARROW: horizontal sync too narrow
+ * @MODE_HSYNC_WIDE: horizontal sync too wide
+ * @MODE_HBLANK_NARROW: horizontal blanking too narrow
+ * @MODE_HBLANK_WIDE: horizontal blanking too wide
+ * @MODE_VSYNC_NARROW: vertical sync too narrow
+ * @MODE_VSYNC_WIDE: vertical sync too wide
+ * @MODE_VBLANK_NARROW: vertical blanking too narrow
+ * @MODE_VBLANK_WIDE: vertical blanking too wide
+ * @MODE_PANEL: exceeds panel dimensions
+ * @MODE_INTERLACE_WIDTH: width too large for interlaced mode
+ * @MODE_ONE_WIDTH: only one width is supported
+ * @MODE_ONE_HEIGHT: only one height is supported
+ * @MODE_ONE_SIZE: only one resolution is supported
+ * @MODE_NO_REDUCED: monitor doesn't accept reduced blanking
+ * @MODE_NO_STEREO: stereo modes not supported
+ * @MODE_UNVERIFIED: mode needs to reverified
+ * @MODE_BAD: unspecified reason
+ * @MODE_ERROR: error condition
+ *
+ * This enum is used to filter out modes not supported by the driver/hardware
+ * combination.
+ */
enum drm_mode_status {
- MODE_OK = 0, /* Mode OK */
- MODE_HSYNC, /* hsync out of range */
- MODE_VSYNC, /* vsync out of range */
- MODE_H_ILLEGAL, /* mode has illegal horizontal timings */
- MODE_V_ILLEGAL, /* mode has illegal horizontal timings */
- MODE_BAD_WIDTH, /* requires an unsupported linepitch */
- MODE_NOMODE, /* no mode with a matching name */
- MODE_NO_INTERLACE, /* interlaced mode not supported */
- MODE_NO_DBLESCAN, /* doublescan mode not supported */
- MODE_NO_VSCAN, /* multiscan mode not supported */
- MODE_MEM, /* insufficient video memory */
- MODE_VIRTUAL_X, /* mode width too large for specified virtual size */
- MODE_VIRTUAL_Y, /* mode height too large for specified virtual size */
- MODE_MEM_VIRT, /* insufficient video memory given virtual size */
- MODE_NOCLOCK, /* no fixed clock available */
- MODE_CLOCK_HIGH, /* clock required is too high */
- MODE_CLOCK_LOW, /* clock required is too low */
- MODE_CLOCK_RANGE, /* clock/mode isn't in a ClockRange */
- MODE_BAD_HVALUE, /* horizontal timing was out of range */
- MODE_BAD_VVALUE, /* vertical timing was out of range */
- MODE_BAD_VSCAN, /* VScan value out of range */
- MODE_HSYNC_NARROW, /* horizontal sync too narrow */
- MODE_HSYNC_WIDE, /* horizontal sync too wide */
- MODE_HBLANK_NARROW, /* horizontal blanking too narrow */
- MODE_HBLANK_WIDE, /* horizontal blanking too wide */
- MODE_VSYNC_NARROW, /* vertical sync too narrow */
- MODE_VSYNC_WIDE, /* vertical sync too wide */
- MODE_VBLANK_NARROW, /* vertical blanking too narrow */
- MODE_VBLANK_WIDE, /* vertical blanking too wide */
- MODE_PANEL, /* exceeds panel dimensions */
- MODE_INTERLACE_WIDTH, /* width too large for interlaced mode */
- MODE_ONE_WIDTH, /* only one width is supported */
- MODE_ONE_HEIGHT, /* only one height is supported */
- MODE_ONE_SIZE, /* only one resolution is supported */
- MODE_NO_REDUCED, /* monitor doesn't accept reduced blanking */
- MODE_NO_STEREO, /* stereo modes not supported */
- MODE_UNVERIFIED = -3, /* mode needs to reverified */
- MODE_BAD = -2, /* unspecified reason */
- MODE_ERROR = -1 /* error condition */
+ MODE_OK = 0,
+ MODE_HSYNC,
+ MODE_VSYNC,
+ MODE_H_ILLEGAL,
+ MODE_V_ILLEGAL,
+ MODE_BAD_WIDTH,
+ MODE_NOMODE,
+ MODE_NO_INTERLACE,
+ MODE_NO_DBLESCAN,
+ MODE_NO_VSCAN,
+ MODE_MEM,
+ MODE_VIRTUAL_X,
+ MODE_VIRTUAL_Y,
+ MODE_MEM_VIRT,
+ MODE_NOCLOCK,
+ MODE_CLOCK_HIGH,
+ MODE_CLOCK_LOW,
+ MODE_CLOCK_RANGE,
+ MODE_BAD_HVALUE,
+ MODE_BAD_VVALUE,
+ MODE_BAD_VSCAN,
+ MODE_HSYNC_NARROW,
+ MODE_HSYNC_WIDE,
+ MODE_HBLANK_NARROW,
+ MODE_HBLANK_WIDE,
+ MODE_VSYNC_NARROW,
+ MODE_VSYNC_WIDE,
+ MODE_VBLANK_NARROW,
+ MODE_VBLANK_WIDE,
+ MODE_PANEL,
+ MODE_INTERLACE_WIDTH,
+ MODE_ONE_WIDTH,
+ MODE_ONE_HEIGHT,
+ MODE_ONE_SIZE,
+ MODE_NO_REDUCED,
+ MODE_NO_STEREO,
+ MODE_UNVERIFIED = -3,
+ MODE_BAD = -2,
+ MODE_ERROR = -1
};

#define DRM_MODE_TYPE_CLOCK_CRTC_C (DRM_MODE_TYPE_CLOCK_C | \
@@ -96,17 +141,124 @@ enum drm_mode_status {

#define DRM_MODE_FLAG_3D_MAX DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF

+/**
+ * struct drm_display_mode - DRM kernel-internal display mode structure
+ * @hdisplay: horizontal display size
+ * @hsync_start: horizontal sync start
+ * @hsync_end: horizontal sync end
+ * @htotal: horizontal total size
+ * @hskew: horizontal skew?!
+ * @vdisplay: vertical display size
+ * @vsync_start: vertical sync start
+ * @vsync_end: vertical sync end
+ * @vtotal: vertical total size
+ * @vscan: vertical scan?!
+ * @crtc_hdisplay: hardware modehorizontal display size
+ * @crtc_hsync_start: hardware modehorizontal sync start
+ * @crtc_hsync_end: hardware modehorizontal sync end
+ * @crtc_htotal: hardware modehorizontal total size
+ * @crtc_hskew: hardware modehorizontal skew?!
+ * @crtc_vdisplay: hardware modevertical display size
+ * @crtc_vsync_start: hardware modevertical sync start
+ * @crtc_vsync_end: hardware modevertical sync end
+ * @crtc_vtotal: hardware modevertical total size
+ * @crtc_vscan: hardware modevertical scan?!
+ *
+ * The horizontal an vertical timings are defined per the following diagram:
+ *
+ *
+ * Active Front Sync Back
+ * Region Porch Porch
+ * <-----------------------><----------------><-------------><-------------->
+ *
+ * //////////////////////|
+ * ////////////////////// |
+ * ////////////////////// |.................. ................
+ * _______________
+ *
+ * <----- [hv]display ----->
+ * <------------- [hv]sync_start ------------>
+ * <--------------------- [hv]sync_end --------------------->
+ * <-------------------------------- [hv]total ----------------------------->*
+ *
+ * This structure contains two copies of timings. First are the plain timings,
+ * which specify the logical mode, as it would be for a progressive 1:1 scanout
+ * at the refresh rate userspace can observe through vblank timestamps. Then
+ * there's the hardware timings, which are corrected for interlacing,
+ * double-clocking and similar things. They are provided as a convience, and can
+ * be appropriately computed using drm_mode_set_crtcinfo().
+ */
struct drm_display_mode {
- /* Header */
+ /**
+ * @head:
+ *
+ * struct list_head for mode lists.
+ */
struct list_head head;
+
+ /**
+ * @base:
+ *
+ * A display mode is a normal modeset object, possibly including public
+ * userspace id.
+ *
+ * FIXME:
+ *
+ * This can probably be removed since the entire concept of userspace
+ * managing modes explicitly hasn't ever landed in upstream kernel mode
+ * setting support.
+ */
struct drm_mode_object base;

+ /**
+ * @name:
+ *
+ * Human-readable name of the mode, filled out with drm_mode_set_name().
+ */
char name[DRM_DISPLAY_MODE_LEN];

+ /**
+ * @status:
+ *
+ * Status of the mode, used to filter out modes not supported by the
+ * hardware. See enum &drm_mode_status.
+ */
enum drm_mode_status status;
+
+ /**
+ * @type:
+ *
+ * A bitmask of flags, mostly about the source of a mode. Possible flags
+ * are:
+ *
+ * - DRM_MODE_TYPE_BUILTIN: Meant for hard-coded modes, effectively
+ * unused.
+ * - DRM_MODE_TYPE_PREFERRED: Preferred mode, usually the native
+ * resolution of an LCD panel. There should only be one preferred
+ * mode per connector at any given time.
+ * - DRM_MODE_TYPE_DRIVER: Mode created by the driver, which is all of
+ * them really. Drivers must set this bit for all modes they create
+ * and expose to userspace.
+ *
+ * Plus a big list of flags which shouldn't be used at all, but are
+ * still around since these flags are also used in the userspace ABI:
+ *
+ * - DRM_MODE_TYPE_DEFAULT: Again a leftover, use
+ * DRM_MODE_TYPE_PREFERRED instead.
+ * - DRM_MODE_TYPE_CLOCK_C and DRM_MODE_TYPE_CRTC_C: Define leftovers
+ * which are stuck around for hysterical raisins only. No one has an
+ * idea what they where meant for. Don't use.
+ * - DRM_MODE_TYPE_USERDEF: Mode defined by userspace, again a vestige
+ * from older kms designs where userspace had to first add a custom
+ * mode to the kernel's mode list before it could use it. Don't use.
+ */
unsigned int type;

- /* Proposed mode values */
+ /**
+ * @clock:
+ *
+ * Pixel clock in kHz.
+ */
int clock; /* in kHz */
int hdisplay;
int hsync_start;
@@ -118,14 +270,74 @@ struct drm_display_mode {
int vsync_end;
int vtotal;
int vscan;
+ /**
+ * @flags:
+ *
+ * Sync and timing flags:
+ *
+ * - DRM_MODE_FLAG_PHSYNC: horizontal sync is active high.
+ * - DRM_MODE_FLAG_NHSYNC: horizontal sync is active low.
+ * - DRM_MODE_FLAG_PVSYNC: vertical sync is active high.
+ * - DRM_MODE_FLAG_NVSYNC: vertical sync is active low.
+ * - DRM_MODE_FLAG_INTERLACE: mode is interlaced.
+ * - DRM_MODE_FLAG_DBLSCAN: mode uses doublescan.
+ * - DRM_MODE_FLAG_CSYNC: mode uses composite sync.
+ * - DRM_MODE_FLAG_PCSYNC: composite sync is active high.
+ * - DRM_MODE_FLAG_NCSYNC: composite sync is active low.
+ * - DRM_MODE_FLAG_HSKEW: hskew provided (not used?).
+ * - DRM_MODE_FLAG_BCAST: not used?
+ * - DRM_MODE_FLAG_PIXMUX: not used?
+ * - DRM_MODE_FLAG_DBLCLK: double-clocked mode.
+ * - DRM_MODE_FLAG_CLKDIV2: half-clocked mode.
+ *
+ * Additionally there's flags to specify how 3D modes are packed:
+ *
+ * - DRM_MODE_FLAG_3D_NONE: normal, non-3D mode.
+ * - DRM_MODE_FLAG_3D_FRAME_PACKING: 2 full frames for left and right.
+ * - DRM_MODE_FLAG_3D_FIELD_ALTERNATIVE: interleaved like fields.
+ * - DRM_MODE_FLAG_3D_LINE_ALTERNATIVE: interleaved lines.
+ * - DRM_MODE_FLAG_3D_SIDE_BY_SIDE_FULL: side-by-side full frames.
+ * - DRM_MODE_FLAG_3D_L_DEPTH: ?
+ * - DRM_MODE_FLAG_3D_L_DEPTH_GFX_GFX_DEPTH: ?
+ * - DRM_MODE_FLAG_3D_TOP_AND_BOTTOM: frame split into top and bottom
+ * parts.
+ * - DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF: frame split into left and
+ * right parts.
+ */
unsigned int flags;

- /* Addressable image size (may be 0 for projectors, etc.) */
+ /**
+ * @width_mm:
+ *
+ * Addressable size of the output in mm, projectors should set this to
+ * 0.
+ */
int width_mm;
+
+ /**
+ * @height_mm:
+ *
+ * Addressable size of the output in mm, projectors should set this to
+ * 0.
+ */
int height_mm;

- /* Actual mode we give to hw */
- int crtc_clock; /* in KHz */
+ /**
+ * @crtc_clock:
+ *
+ * Actual pixel or dot clock in the hardware. This differs from the
+ * logical @clock when e.g. using interlacing, double-clocking, stereo
+ * modes or other fancy stuff that changes the timings and signals
+ * actually sent over the wire.
+ *
+ * This is again in kHz.
+ *
+ * Note that with digital outputs like HDMI or DP there's usually a
+ * massive confusion between the dot clock and the signal clock at the
+ * bit encoding level. Especially when a 8b/10b encoding is used and the
+ * differences is exactly a factor of 10.
+ */
+ int crtc_clock;
int crtc_hdisplay;
int crtc_hblank_start;
int crtc_hblank_end;
@@ -140,12 +352,48 @@ struct drm_display_mode {
int crtc_vsync_end;
int crtc_vtotal;

- /* Driver private mode info */
+ /**
+ * @private:
+ *
+ * Pointer for driver private data. This can only be used for mode
+ * objects passed to drivers in modeset operations. It shouldn't be used
+ * by atomic drivers since they can store any additional data by
+ * subclassing state structures.
+ */
int *private;
+
+ /**
+ * @private_flags:
+ *
+ * Similar to @private, but just an integer.
+ */
int private_flags;

- int vrefresh; /* in Hz */
- int hsync; /* in kHz */
+ /**
+ * @vrefresh:
+ *
+ * Vertical refresh rate, for debug output in human readable form. Not
+ * used in a functional way.
+ *
+ * This value is in Hz.
+ */
+ int vrefresh;
+
+ /**
+ * @hsync:
+ *
+ * Horizontal refresh rate, for debug output in human readable form. Not
+ * used in a functional way.
+ *
+ * This value is in kHz.
+ */
+ int hsync;
+
+ /**
+ * @picture_aspect_ratio:
+ *
+ * Filed for setting the HDMI picture aspect ratio of a mode.
+ */
enum hdmi_picture_aspect picture_aspect_ratio;
};

--
2.5.1

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