[PATCH RFC 33/46] imx-drm: imx-drm-core: provide helper function to parse possible crtcs

Russell King
2014-01-02T21:28:34Z

Provide a helper function to parse possible crtcs before the encoder
is registered. The crtc mask is derived from the position of the
CRTCs registered in the drm_device.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
drivers/staging/imx-drm/imx-drm-core.c | 66 ++++++++++++++++++++++++++++++++
drivers/staging/imx-drm/imx-drm.h | 2 +
2 files changed, 68 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
index b11568d6444b..1cfb8a18d905 100644
--- a/drivers/staging/imx-drm/imx-drm-core.c
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -657,6 +657,72 @@ int imx_drm_add_encoder(struct drm_encoder *encoder,
}
EXPORT_SYMBOL_GPL(imx_drm_add_encoder);

+/*
+ * Find the DRM CRTC possible mask for the device node cookie/id.
+ *
+ * The encoder possible masks are defined by their position in the
+ * mode_config crtc_list. This means that CRTCs must not be added
+ * or removed once the DRM device has been fully initialised.
+ */
+static uint32_t imx_drm_find_crtc_mask(struct imx_drm_device *imxdrm,
+ void *cookie, int id)
+{
+ unsigned i;
+
+ for (i = 0; i < MAX_CRTC; i++) {
+ struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[i];
+ if (imx_drm_crtc && imx_drm_crtc->cookie.id == id &&
+ imx_drm_crtc->cookie.cookie == cookie)
+ return drm_helper_crtc_possible_mask(imx_drm_crtc->crtc);
+ }
+
+ return 0;
+}
+
+int imx_drm_encoder_parse_of(struct drm_device *drm,
+ struct drm_encoder *encoder, struct device_node *np)
+{
+ struct imx_drm_device *imxdrm = drm->dev_private;
+ uint32_t crtc_mask = 0;
+ int i, ret = 0;
+
+ for (i = 0; !ret; i++) {
+ struct of_phandle_args args;
+ uint32_t mask;
+ int id;
+
+ ret = of_parse_phandle_with_args(np, "crtcs", "#crtc-cells", i,
+ &args);
+ if (ret == -ENOENT)
+ break;
+ if (ret < 0)
+ return ret;
+
+ id = args.args_count > 0 ? args.args[0] : 0;
+ mask = imx_drm_find_crtc_mask(imxdrm, args.np, id);
+ of_node_put(args.np);
+
+ /*
+ * If we failed to find the CRTC(s) which this encoder is
+ * supposed to be connected to, it's because the CRTC has
+ * not been registered yet. Defer probing, and hope that
+ * the required CRTC is added later.
+ */
+ if (mask == 0)
+ return -EPROBE_DEFER;
+
+ crtc_mask |= mask;
+ }
+
+ encoder->possible_crtcs = crtc_mask;
+
+ /* FIXME: this is the mask of outputs which can clone this output. */
+ encoder->possible_clones = ~0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(imx_drm_encoder_parse_of);
+
int imx_drm_encoder_add_possible_crtcs(
struct imx_drm_encoder *imx_drm_encoder,
struct device_node *np)
diff --git a/drivers/staging/imx-drm/imx-drm.h b/drivers/staging/imx-drm/imx-drm.h
index 78465239ed4c..49d4aaf33f97 100644
--- a/drivers/staging/imx-drm/imx-drm.h
+++ b/drivers/staging/imx-drm/imx-drm.h
@@ -64,6 +64,8 @@ struct device_node;
int imx_drm_encoder_get_mux_id(struct drm_encoder *encoder);
int imx_drm_encoder_add_possible_crtcs(struct imx_drm_encoder *imx_drm_encoder,
struct device_node *np);
+int imx_drm_encoder_parse_of(struct drm_device *drm,
+ struct drm_encoder *encoder, struct device_node *np);

int imx_drm_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode);
--
1.7.4.4