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
rzg2l_du_encoder_count_ports(struct device_node * node)25 static unsigned int rzg2l_du_encoder_count_ports(struct device_node *node)
26 {
27 struct device_node *ports;
28 struct device_node *port;
29 unsigned int num_ports = 0;
30
31 ports = of_get_child_by_name(node, "ports");
32 if (!ports)
33 ports = of_node_get(node);
34
35 for_each_child_of_node(ports, port) {
36 if (of_node_name_eq(port, "port"))
37 num_ports++;
38 }
39
40 of_node_put(ports);
41
42 return num_ports;
43 }
44
45 static const struct drm_encoder_funcs rzg2l_du_encoder_funcs = {
46 };
47
48 static enum drm_mode_status
rzg2l_du_encoder_mode_valid(struct drm_encoder * encoder,const struct drm_display_mode * mode)49 rzg2l_du_encoder_mode_valid(struct drm_encoder *encoder,
50 const struct drm_display_mode *mode)
51 {
52 struct rzg2l_du_encoder *renc = to_rzg2l_encoder(encoder);
53
54 if (renc->output == RZG2L_DU_OUTPUT_DPAD0 && mode->clock > 83500)
55 return MODE_CLOCK_HIGH;
56
57 return MODE_OK;
58 }
59
60 static const struct drm_encoder_helper_funcs rzg2l_du_encoder_helper_funcs = {
61 .mode_valid = rzg2l_du_encoder_mode_valid,
62 };
63
rzg2l_du_encoder_init(struct rzg2l_du_device * rcdu,enum rzg2l_du_output output,struct device_node * enc_node)64 int rzg2l_du_encoder_init(struct rzg2l_du_device *rcdu,
65 enum rzg2l_du_output output,
66 struct device_node *enc_node)
67 {
68 struct rzg2l_du_encoder *renc;
69 struct drm_connector *connector;
70 struct drm_bridge *bridge;
71 int ret;
72
73 /*
74 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
75 * DT node has a single port, assume that it describes a panel and
76 * create a panel bridge.
77 */
78 if (output == RZG2L_DU_OUTPUT_DPAD0 && rzg2l_du_encoder_count_ports(enc_node) == 1) {
79 struct drm_panel *panel = of_drm_find_panel(enc_node);
80
81 if (IS_ERR(panel))
82 return PTR_ERR(panel);
83
84 bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
85 DRM_MODE_CONNECTOR_DPI);
86 if (IS_ERR(bridge))
87 return PTR_ERR(bridge);
88 } else {
89 bridge = of_drm_find_bridge(enc_node);
90 if (!bridge)
91 return -EPROBE_DEFER;
92 }
93
94 dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
95 enc_node, rzg2l_du_output_name(output));
96
97 renc = drmm_encoder_alloc(&rcdu->ddev, struct rzg2l_du_encoder, base,
98 &rzg2l_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
99 NULL);
100 if (IS_ERR(renc))
101 return PTR_ERR(renc);
102
103 renc->output = output;
104 drm_encoder_helper_add(&renc->base, &rzg2l_du_encoder_helper_funcs);
105
106 /* Attach the bridge to the encoder. */
107 ret = drm_bridge_attach(&renc->base, bridge, NULL,
108 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
109 if (ret) {
110 dev_err(rcdu->dev,
111 "failed to attach bridge %pOF for output %s (%d)\n",
112 bridge->of_node, rzg2l_du_output_name(output), ret);
113 return ret;
114 }
115
116 /* Create the connector for the chain of bridges. */
117 connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
118 if (IS_ERR(connector)) {
119 dev_err(rcdu->dev,
120 "failed to created connector for output %s (%ld)\n",
121 rzg2l_du_output_name(output), PTR_ERR(connector));
122 return PTR_ERR(connector);
123 }
124
125 return drm_connector_attach_encoder(connector, &renc->base);
126 }
127