1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * RZ/G2L Display Unit Encoder
4  *
5  * Copyright (C) 2023 Renesas Electronics Corporation
6  *
7  * Based on rcar_du_encoder.c
8  */
9 
10 #include <linux/export.h>
11 #include <linux/of.h>
12 
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_bridge.h>
15 #include <drm/drm_bridge_connector.h>
16 #include <drm/drm_panel.h>
17 
18 #include "rzg2l_du_drv.h"
19 #include "rzg2l_du_encoder.h"
20 
21 /* -----------------------------------------------------------------------------
22  * Encoder
23  */
24 
25 static const struct drm_encoder_funcs rzg2l_du_encoder_funcs = {
26 };
27 
28 static enum drm_mode_status
rzg2l_du_encoder_mode_valid(struct drm_encoder * encoder,const struct drm_display_mode * mode)29 rzg2l_du_encoder_mode_valid(struct drm_encoder *encoder,
30 			    const struct drm_display_mode *mode)
31 {
32 	struct rzg2l_du_encoder *renc = to_rzg2l_encoder(encoder);
33 
34 	if (renc->output == RZG2L_DU_OUTPUT_DPAD0 && mode->clock > 83500)
35 		return MODE_CLOCK_HIGH;
36 
37 	return MODE_OK;
38 }
39 
40 static const struct drm_encoder_helper_funcs rzg2l_du_encoder_helper_funcs = {
41 	.mode_valid = rzg2l_du_encoder_mode_valid,
42 };
43 
rzg2l_du_encoder_init(struct rzg2l_du_device * rcdu,enum rzg2l_du_output output,struct device_node * enc_node)44 int rzg2l_du_encoder_init(struct rzg2l_du_device  *rcdu,
45 			  enum rzg2l_du_output output,
46 			  struct device_node *enc_node)
47 {
48 	struct rzg2l_du_encoder *renc;
49 	struct drm_connector *connector;
50 	struct drm_bridge *bridge;
51 	int ret;
52 
53 	/* Locate the DRM bridge from the DT node. */
54 	bridge = of_drm_find_bridge(enc_node);
55 	if (!bridge)
56 		return -EPROBE_DEFER;
57 
58 	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
59 		enc_node, rzg2l_du_output_name(output));
60 
61 	renc = drmm_encoder_alloc(&rcdu->ddev, struct rzg2l_du_encoder, base,
62 				  &rzg2l_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
63 				  NULL);
64 	if (IS_ERR(renc))
65 		return PTR_ERR(renc);
66 
67 	renc->output = output;
68 	drm_encoder_helper_add(&renc->base, &rzg2l_du_encoder_helper_funcs);
69 
70 	/* Attach the bridge to the encoder. */
71 	ret = drm_bridge_attach(&renc->base, bridge, NULL,
72 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
73 	if (ret) {
74 		dev_err(rcdu->dev,
75 			"failed to attach bridge %pOF for output %s (%d)\n",
76 			bridge->of_node, rzg2l_du_output_name(output), ret);
77 		return ret;
78 	}
79 
80 	/* Create the connector for the chain of bridges. */
81 	connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
82 	if (IS_ERR(connector)) {
83 		dev_err(rcdu->dev,
84 			"failed to created connector for output %s (%ld)\n",
85 			rzg2l_du_output_name(output), PTR_ERR(connector));
86 		return PTR_ERR(connector);
87 	}
88 
89 	return drm_connector_attach_encoder(connector, &renc->base);
90 }
91