drm/simple-kms: Add drm_simple_encoder_{init,create}()

This patch makes the internal encoder implementation of the simple
KMS helpers available to drivers.

These simple-encoder helpers initialize an encoder with an empty
implementation. This covers the requirements of most of the existing
DRM drivers. A call to drm_simple_encoder_create() allocates and
initializes an encoder instance, a call to drm_simple_encoder_init()
initializes a pre-allocated instance.

v3:
	* remove drm_simple_encoder_create(); not required yet
	* provide more precise documentation
v2:
	* move simple encoder to KMS helpers
	* remove name argument; simplifies implementation
	* don't allocate with devm_ interfaces; unsafe with DRM

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228081828.18463-2-tzimmermann@suse.de
This commit is contained in:
Thomas Zimmermann 2020-02-28 09:18:25 +01:00
parent 4a1d0dbc83
commit 63170ac6f2
2 changed files with 35 additions and 3 deletions

View File

@ -26,12 +26,41 @@
* entity. Some flexibility for code reuse is provided through a separately
* allocated &drm_connector object and supporting optional &drm_bridge
* encoder drivers.
*
* Many drivers require only a very simple encoder that fulfills the minimum
* requirements of the display pipeline and does not add additional
* functionality. The function drm_simple_encoder_init() provides an
* implementation of such an encoder.
*/
static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = {
.destroy = drm_encoder_cleanup,
};
/**
* drm_simple_encoder_init - Initialize a preallocated encoder
* @dev: drm device
* @funcs: callbacks for this encoder
* @encoder_type: user visible type of the encoder
*
* Initialises a preallocated encoder that has no further functionality.
* Settings for possible CRTC and clones are left to their initial values.
* The encoder will be cleaned up automatically as part of the mode-setting
* cleanup.
*
* Returns:
* Zero on success, error code on failure.
*/
int drm_simple_encoder_init(struct drm_device *dev,
struct drm_encoder *encoder,
int encoder_type)
{
return drm_encoder_init(dev, encoder,
&drm_simple_encoder_funcs_cleanup,
encoder_type, NULL);
}
EXPORT_SYMBOL(drm_simple_encoder_init);
static enum drm_mode_status
drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
@ -288,8 +317,7 @@ int drm_simple_display_pipe_init(struct drm_device *dev,
return ret;
encoder->possible_crtcs = drm_crtc_mask(crtc);
ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
DRM_MODE_ENCODER_NONE, NULL);
ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
if (ret || !connector)
return ret;

View File

@ -181,4 +181,8 @@ int drm_simple_display_pipe_init(struct drm_device *dev,
const uint64_t *format_modifiers,
struct drm_connector *connector);
int drm_simple_encoder_init(struct drm_device *dev,
struct drm_encoder *encoder,
int encoder_type);
#endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */