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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2019 Renesas Electronics Corporation
4 * Copyright (C) 2016 Laurent Pinchart <[email protected]>
5 */
6
7#include <linux/gpio/consumer.h>
8#include <linux/media-bus-format.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/of_graph.h>
12#include <linux/platform_device.h>
13#include <linux/regulator/consumer.h>
14
15#include <drm/drm_atomic_helper.h>
16#include <drm/drm_bridge.h>
17#include <drm/drm_of.h>
18#include <drm/drm_panel.h>
19
20struct lvds_codec {
21 struct device *dev;
22 struct drm_bridge bridge;
23 struct drm_bridge *panel_bridge;
24 struct drm_bridge_timings timings;
25 struct regulator *vcc;
26 struct gpio_desc *powerdown_gpio;
27 u32 connector_type;
28 unsigned int bus_format;
29};
30
31static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
32{
33 return container_of(bridge, struct lvds_codec, bridge);
34}
35
36static int lvds_codec_attach(struct drm_bridge *bridge,
37 struct drm_encoder *encoder,
38 enum drm_bridge_attach_flags flags)
39{
40 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
41
42 return drm_bridge_attach(encoder, lvds_codec->panel_bridge,
43 bridge, flags);
44}
45
46static void lvds_codec_enable(struct drm_bridge *bridge,
47 struct drm_atomic_commit *commit)
48{
49 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
50 int ret;
51
52 ret = regulator_enable(lvds_codec->vcc);
53 if (ret) {
54 dev_err(lvds_codec->dev,
55 "Failed to enable regulator \"vcc\": %d\n", ret);
56 return;
57 }
58
59 if (lvds_codec->powerdown_gpio)
60 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
61}
62
63static void lvds_codec_disable(struct drm_bridge *bridge,
64 struct drm_atomic_commit *commit)
65{
66 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
67 int ret;
68
69 if (lvds_codec->powerdown_gpio)
70 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
71
72 ret = regulator_disable(lvds_codec->vcc);
73 if (ret)
74 dev_err(lvds_codec->dev,
75 "Failed to disable regulator \"vcc\": %d\n", ret);
76}
77
78#define MAX_INPUT_SEL_FORMATS 1
79static u32 *
80lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
81 struct drm_bridge_state *bridge_state,
82 struct drm_crtc_state *crtc_state,
83 struct drm_connector_state *conn_state,
84 u32 output_fmt,
85 unsigned int *num_input_fmts)
86{
87 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
88 u32 *input_fmts;
89
90 *num_input_fmts = 0;
91
92 input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
93 GFP_KERNEL);
94 if (!input_fmts)
95 return NULL;
96
97 input_fmts[0] = lvds_codec->bus_format;
98 *num_input_fmts = MAX_INPUT_SEL_FORMATS;
99
100 return input_fmts;
101}
102
103static const struct drm_bridge_funcs funcs = {
104 .attach = lvds_codec_attach,
105 .atomic_enable = lvds_codec_enable,
106 .atomic_disable = lvds_codec_disable,
107 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
108 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
109 .atomic_create_state = drm_atomic_helper_bridge_create_state,
110 .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
111};
112
113static int lvds_codec_probe(struct platform_device *pdev)
114{
115 struct device *dev = &pdev->dev;
116 struct device_node *panel_node;
117 struct device_node *bus_node;
118 struct drm_panel *panel;
119 struct lvds_codec *lvds_codec;
120 u32 val;
121 int ret;
122
123 lvds_codec = devm_drm_bridge_alloc(dev, struct lvds_codec, bridge,
124 &funcs);
125 if (IS_ERR(lvds_codec))
126 return PTR_ERR(lvds_codec);
127
128 lvds_codec->dev = &pdev->dev;
129 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
130
131 lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
132 if (IS_ERR(lvds_codec->vcc))
133 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
134 "Unable to get \"vcc\" supply\n");
135
136 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
137 GPIOD_OUT_HIGH);
138 if (IS_ERR(lvds_codec->powerdown_gpio))
139 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
140 "powerdown GPIO failure\n");
141
142 /* Locate the panel DT node. */
143 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
144 if (!panel_node) {
145 dev_dbg(dev, "panel DT node not found\n");
146 return -ENXIO;
147 }
148
149 panel = of_drm_find_panel(panel_node);
150 of_node_put(panel_node);
151 if (IS_ERR(panel)) {
152 dev_dbg(dev, "panel not found, deferring probe\n");
153 return PTR_ERR(panel);
154 }
155
156 lvds_codec->panel_bridge =
157 devm_drm_panel_bridge_add_typed(dev, panel,
158 lvds_codec->connector_type);
159 drm_panel_put(panel);
160 if (IS_ERR(lvds_codec->panel_bridge))
161 return PTR_ERR(lvds_codec->panel_bridge);
162
163 /*
164 * Decoder input LVDS format is a property of the decoder chip or even
165 * its strapping. Handle data-mapping the same way lvds-panel does. In
166 * case data-mapping is not present, do nothing, since there are still
167 * legacy bindings which do not specify this property.
168 */
169 if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
170 bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
171 if (!bus_node) {
172 dev_dbg(dev, "bus DT node not found\n");
173 return -ENXIO;
174 }
175
176 ret = drm_of_lvds_get_data_mapping(bus_node);
177 of_node_put(bus_node);
178 if (ret == -ENODEV) {
179 dev_warn(dev, "missing 'data-mapping' DT property\n");
180 } else if (ret < 0) {
181 dev_err(dev, "invalid 'data-mapping' DT property\n");
182 return ret;
183 } else {
184 lvds_codec->bus_format = ret;
185 }
186 } else {
187 lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
188 }
189
190 /*
191 * Encoder might sample data on different clock edge than the display,
192 * for example OnSemi FIN3385 has a dedicated strapping pin to select
193 * the sampling edge.
194 */
195 if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
196 !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
197 lvds_codec->timings.input_bus_flags = val ?
198 DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
199 DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
200 }
201
202 /*
203 * The panel_bridge bridge is attached to the panel's of_node,
204 * but we need a bridge attached to our of_node for our user
205 * to look up.
206 */
207 lvds_codec->bridge.of_node = dev->of_node;
208 lvds_codec->bridge.timings = &lvds_codec->timings;
209 drm_bridge_add(&lvds_codec->bridge);
210
211 platform_set_drvdata(pdev, lvds_codec);
212
213 return 0;
214}
215
216static void lvds_codec_remove(struct platform_device *pdev)
217{
218 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
219
220 drm_bridge_remove(&lvds_codec->bridge);
221}
222
223static const struct of_device_id lvds_codec_match[] = {
224 {
225 .compatible = "lvds-decoder",
226 .data = (void *)DRM_MODE_CONNECTOR_DPI,
227 },
228 {
229 .compatible = "lvds-encoder",
230 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
231 },
232 {
233 .compatible = "thine,thc63lvdm83d",
234 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
235 },
236 {},
237};
238MODULE_DEVICE_TABLE(of, lvds_codec_match);
239
240static struct platform_driver lvds_codec_driver = {
241 .probe = lvds_codec_probe,
242 .remove = lvds_codec_remove,
243 .driver = {
244 .name = "lvds-codec",
245 .of_match_table = lvds_codec_match,
246 },
247};
248module_platform_driver(lvds_codec_driver);
249
250MODULE_AUTHOR("Laurent Pinchart <[email protected]>");
251MODULE_DESCRIPTION("LVDS encoders and decoders");
252MODULE_LICENSE("GPL");