#define VKMS_LUT_SIZE 256
+/**
+ * struct vkms_frame_info - Structure to store the state of a frame
+ *
+ * @fb: backing drm framebuffer
+ * @src: source rectangle of this frame in the source framebuffer, stored in 16.16 fixed-point form
+ * @dst: destination rectangle in the crtc buffer, stored in whole pixel units
+ * @map: see @drm_shadow_plane_state.data
+ * @rotation: rotation applied to the source.
+ *
+ * @src and @dst should have the same size modulo the rotation.
+ */
struct vkms_frame_info {
struct drm_framebuffer *fb;
struct drm_rect src, dst;
};
/**
- * vkms_plane_state - Driver specific plane state
+ * struct vkms_plane_state - Driver specific plane state
* @base: base plane state
* @frame_info: data required for composing computation
+ * @pixel_read: function to read a pixel in this plane. The creator of a struct vkms_plane_state
+ * must ensure that this pointer is valid
*/
struct vkms_plane_state {
struct drm_shadow_plane_state base;
};
/**
- * vkms_crtc_state - Driver specific CRTC state
+ * struct vkms_crtc_state - Driver specific CRTC state
+ *
* @base: base CRTC state
* @composer_work: work struct to compose and add CRC entries
- * @n_frame_start: start frame number for computed CRC
- * @n_frame_end: end frame number for computed CRC
+ *
+ * @num_active_planes: Number of active planes
+ * @active_planes: List containing all the active planes (counted by
+ * @num_active_planes). They should be stored in z-order.
+ * @active_writeback: Current active writeback job
+ * @gamma_lut: Look up table for gamma used in this CRTC
+ * @crc_pending: Protected by @vkms_output.composer_lock, true when the frame CRC is not computed
+ * yet. Used by vblank to detect if the composer is too slow.
+ * @wb_pending: Protected by @vkms_output.composer_lock, true when a writeback frame is requested.
+ * @frame_start: Protected by @vkms_output.composer_lock, saves the frame number before the start
+ * of the composition process.
+ * @frame_end: Protected by @vkms_output.composer_lock, saves the last requested frame number.
+ * This is used to generate enough CRC entries when the composition worker is too slow.
*/
struct vkms_crtc_state {
struct drm_crtc_state base;
struct work_struct composer_work;
int num_active_planes;
- /* stack of active planes for crc computation, should be in z order */
struct vkms_plane_state **active_planes;
struct vkms_writeback_job *active_writeback;
struct vkms_color_lut gamma_lut;
- /* below four are protected by vkms_output.composer_lock */
bool crc_pending;
bool wb_pending;
u64 frame_start;
u64 frame_end;
};
+/**
+ * struct vkms_output - Internal representation of all output components in VKMS
+ *
+ * @crtc: Base CRTC in DRM
+ * @encoder: DRM encoder used for this output
+ * @connector: DRM connector used for this output
+ * @wb_connecter: DRM writeback connector used for this output
+ * @vblank_hrtimer: Timer used to trigger the vblank
+ * @period_ns: vblank period, in nanoseconds, used to configure @vblank_hrtimer and to compute
+ * vblank timestamps
+ * @composer_workq: Ordered workqueue for @composer_state.composer_work.
+ * @lock: Lock used to protect concurrent access to the composer
+ * @composer_enabled: Protected by @lock, true when the VKMS composer is active (crc needed or
+ * writeback)
+ * @composer_state: Protected by @lock, current state of this VKMS output
+ * @composer_lock: Lock used internally to protect @composer_state members
+ */
struct vkms_output {
struct drm_crtc crtc;
struct drm_encoder encoder;
struct drm_writeback_connector wb_connector;
struct hrtimer vblank_hrtimer;
ktime_t period_ns;
- /* ordered wq for composer_work */
struct workqueue_struct *composer_workq;
- /* protects concurrent access to composer */
spinlock_t lock;
- /* protected by @lock */
bool composer_enabled;
struct vkms_crtc_state *composer_state;
spinlock_t composer_lock;
};
-struct vkms_device;
-
+/**
+ * struct vkms_config - General configuration for VKMS driver
+ *
+ * @writeback: If true, a writeback buffer can be attached to the CRTC
+ * @cursor: If true, a cursor plane is created in the VKMS device
+ * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device
+ * @dev: Used to store the current VKMS device. Only set when the device is instantiated.
+ */
struct vkms_config {
bool writeback;
bool cursor;
bool overlay;
- /* only set when instantiated */
struct vkms_device *dev;
};
+/**
+ * struct vkms_device - Description of a VKMS device
+ *
+ * @drm - Base device in DRM
+ * @platform - Associated platform device
+ * @output - Configuration and sub-components of the VKMS device
+ * @config: Configuration used in this VKMS device
+ */
struct vkms_device {
struct drm_device drm;
struct platform_device *platform;
const struct vkms_config *config;
};
+/*
+ * The following helpers are used to convert a member of a struct into its parent.
+ */
+
#define drm_crtc_to_vkms_output(target) \
container_of(target, struct vkms_output, crtc)
#define to_vkms_plane_state(target)\
container_of(target, struct vkms_plane_state, base.base)
-/* CRTC */
+/**
+ * vkms_crtc_init() - Initialize a CRTC for VKMS
+ * @dev: DRM device associated with the VKMS buffer
+ * @crtc: uninitialized CRTC device
+ * @primary: primary plane to attach to the CRTC
+ * @cursor: plane to attach to the CRTC
+ */
int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
struct drm_plane *primary, struct drm_plane *cursor);
+/**
+ * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
+ *
+ * @vkmsdev: VKMS device to initialize
+ * @index: CRTC which can be attached to the planes. The caller must ensure that
+ * @index is positive and less or equals to 31.
+ */
int vkms_output_init(struct vkms_device *vkmsdev, int index);
+/**
+ * vkms_plane_init() - Initialize a plane
+ *
+ * @vkmsdev: VKMS device containing the plane
+ * @type: type of plane to initialize
+ * @index: CRTC which can be attached to the plane. The caller must ensure that
+ * @index is positive and less or equals to 31.
+ */
struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
enum drm_plane_type type, int index);
#include "vkms_formats.h"
+/**
+ * pixel_offset() - Get the offset of the pixel at coordinates x/y in the first plane
+ *
+ * @frame_info: Buffer metadata
+ * @x: The x coordinate of the wanted pixel in the buffer
+ * @y: The y coordinate of the wanted pixel in the buffer
+ *
+ * The caller must ensure that the framebuffer associated with this request uses a pixel format
+ * where block_h == block_w == 1.
+ * If this requirement is not fulfilled, the resulting offset can point to an other pixel or
+ * outside of the buffer.
+ */
static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y)
{
return frame_info->offset + (y * frame_info->pitch)
+ (x * frame_info->cpp);
}
-/*
- * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates
+/**
+ * packed_pixels_addr() - Get the pointer to the block containing the pixel at the given
+ * coordinates
*
* @frame_info: Buffer metadata
- * @x: The x(width) coordinate of the 2D buffer
- * @y: The y(Heigth) coordinate of the 2D buffer
+ * @x: The x (width) coordinate inside the plane
+ * @y: The y (height) coordinate inside the plane
*
* Takes the information stored in the frame_info, a pair of coordinates, and
* returns the address of the first color channel.
* This function assumes the channels are packed together, i.e. a color channel
* comes immediately after another in the memory. And therefore, this function
* doesn't work for YUV with chroma subsampling (e.g. YUV420 and NV21).
+ *
+ * The caller must ensure that the framebuffer associated with this request uses a pixel format
+ * where block_h == block_w == 1, otherwise the returned pointer can be outside the buffer.
*/
static void *packed_pixels_addr(const struct vkms_frame_info *frame_info,
int x, int y)
return x;
}
+/*
+ * The following functions take pixel data from the buffer and convert them to the format
+ * ARGB16161616 in @out_pixel.
+ *
+ * They are used in the vkms_compose_row() function to handle multiple formats.
+ */
+
static void ARGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{
/*
}
/*
- * The following functions take an line of argb_u16 pixels from the
- * src_buffer, convert them to a specific format, and store them in the
- * destination.
+ * The following functions take one &struct pixel_argb_u16 and convert it to a specific format.
+ * The result is stored in @dst_pixels.
*
- * They are used in the `compose_active_planes` to convert and store a line
- * from the src_buffer to the writeback buffer.
+ * They are used in vkms_writeback_row() to convert and store a pixel from the src_buffer to
+ * the writeback buffer.
*/
static void argb_u16_to_ARGB8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{
*pixels = cpu_to_le16(r << 11 | g << 5 | b);
}
+/**
+ * vkms_writeback_row() - Generic loop for all supported writeback format. It is executed just
+ * after the blending to write a line in the writeback buffer.
+ *
+ * @wb: Job where to insert the final image
+ * @src_buffer: Line to write
+ * @y: Row to write in the writeback buffer
+ */
void vkms_writeback_row(struct vkms_writeback_job *wb,
const struct line_buffer *src_buffer, int y)
{
wb->pixel_write(dst_pixels, &in_pixels[x]);
}
+/**
+ * get_pixel_conversion_function() - Retrieve the correct read_pixel function for a specific
+ * format. The returned pointer is NULL for unsupported pixel formats. The caller must ensure that
+ * the pointer is valid before using it in a vkms_plane_state.
+ *
+ * @format: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h])
+ */
void *get_pixel_conversion_function(u32 format)
{
switch (format) {
}
}
+/**
+ * get_pixel_write_function() - Retrieve the correct write_pixel function for a specific format.
+ * The returned pointer is NULL for unsupported pixel formats. The caller must ensure that the
+ * pointer is valid before using it in a vkms_writeback_job.
+ *
+ * @format: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h])
+ */
void *get_pixel_write_function(u32 format)
{
switch (format) {