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