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/module.h>
9 #include <linux/of.h>
10 #include <linux/of_graph.h>
11 #include <linux/platform_device.h>
12 #include <linux/regulator/consumer.h>
13
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_bridge.h>
16 #include <drm/drm_of.h>
17 #include <drm/drm_panel.h>
18
19 struct lvds_codec {
20 struct device *dev;
21 struct drm_bridge bridge;
22 struct drm_bridge *panel_bridge;
23 struct drm_bridge_timings timings;
24 struct regulator *vcc;
25 struct gpio_desc *powerdown_gpio;
26 u32 connector_type;
27 unsigned int bus_format;
28 };
29
to_lvds_codec(struct drm_bridge * bridge)30 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
31 {
32 return container_of(bridge, struct lvds_codec, bridge);
33 }
34
lvds_codec_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)35 static int lvds_codec_attach(struct drm_bridge *bridge,
36 enum drm_bridge_attach_flags flags)
37 {
38 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
39
40 return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
41 bridge, flags);
42 }
43
lvds_codec_enable(struct drm_bridge * bridge)44 static void lvds_codec_enable(struct drm_bridge *bridge)
45 {
46 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
47 int ret;
48
49 ret = regulator_enable(lvds_codec->vcc);
50 if (ret) {
51 dev_err(lvds_codec->dev,
52 "Failed to enable regulator \"vcc\": %d\n", ret);
53 return;
54 }
55
56 if (lvds_codec->powerdown_gpio)
57 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
58 }
59
lvds_codec_disable(struct drm_bridge * bridge)60 static void lvds_codec_disable(struct drm_bridge *bridge)
61 {
62 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
63 int ret;
64
65 if (lvds_codec->powerdown_gpio)
66 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
67
68 ret = regulator_disable(lvds_codec->vcc);
69 if (ret)
70 dev_err(lvds_codec->dev,
71 "Failed to disable regulator \"vcc\": %d\n", ret);
72 }
73
74 static const struct drm_bridge_funcs funcs = {
75 .attach = lvds_codec_attach,
76 .enable = lvds_codec_enable,
77 .disable = lvds_codec_disable,
78 };
79
80 #define MAX_INPUT_SEL_FORMATS 1
81 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)82 lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
83 struct drm_bridge_state *bridge_state,
84 struct drm_crtc_state *crtc_state,
85 struct drm_connector_state *conn_state,
86 u32 output_fmt,
87 unsigned int *num_input_fmts)
88 {
89 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
90 u32 *input_fmts;
91
92 *num_input_fmts = 0;
93
94 input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
95 GFP_KERNEL);
96 if (!input_fmts)
97 return NULL;
98
99 input_fmts[0] = lvds_codec->bus_format;
100 *num_input_fmts = MAX_INPUT_SEL_FORMATS;
101
102 return input_fmts;
103 }
104
105 static const struct drm_bridge_funcs funcs_decoder = {
106 .attach = lvds_codec_attach,
107 .enable = lvds_codec_enable,
108 .disable = lvds_codec_disable,
109 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
110 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
111 .atomic_reset = drm_atomic_helper_bridge_reset,
112 .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
113 };
114
lvds_codec_probe(struct platform_device * pdev)115 static int lvds_codec_probe(struct platform_device *pdev)
116 {
117 struct device *dev = &pdev->dev;
118 struct device_node *panel_node;
119 struct device_node *bus_node;
120 struct drm_panel *panel;
121 struct lvds_codec *lvds_codec;
122 u32 val;
123 int ret;
124
125 lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
126 if (!lvds_codec)
127 return -ENOMEM;
128
129 lvds_codec->dev = &pdev->dev;
130 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
131
132 lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
133 if (IS_ERR(lvds_codec->vcc))
134 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
135 "Unable to get \"vcc\" supply\n");
136
137 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
138 GPIOD_OUT_HIGH);
139 if (IS_ERR(lvds_codec->powerdown_gpio))
140 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
141 "powerdown GPIO failure\n");
142
143 /* Locate the panel DT node. */
144 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
145 if (!panel_node) {
146 dev_dbg(dev, "panel DT node not found\n");
147 return -ENXIO;
148 }
149
150 panel = of_drm_find_panel(panel_node);
151 of_node_put(panel_node);
152 if (IS_ERR(panel)) {
153 dev_dbg(dev, "panel not found, deferring probe\n");
154 return PTR_ERR(panel);
155 }
156
157 lvds_codec->panel_bridge =
158 devm_drm_panel_bridge_add_typed(dev, panel,
159 lvds_codec->connector_type);
160 if (IS_ERR(lvds_codec->panel_bridge))
161 return PTR_ERR(lvds_codec->panel_bridge);
162
163 lvds_codec->bridge.funcs = &funcs;
164
165 /*
166 * Decoder input LVDS format is a property of the decoder chip or even
167 * its strapping. Handle data-mapping the same way lvds-panel does. In
168 * case data-mapping is not present, do nothing, since there are still
169 * legacy bindings which do not specify this property.
170 */
171 if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
172 bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
173 if (!bus_node) {
174 dev_dbg(dev, "bus DT node not found\n");
175 return -ENXIO;
176 }
177
178 ret = drm_of_lvds_get_data_mapping(bus_node);
179 of_node_put(bus_node);
180 if (ret == -ENODEV) {
181 dev_warn(dev, "missing 'data-mapping' DT property\n");
182 } else if (ret < 0) {
183 dev_err(dev, "invalid 'data-mapping' DT property\n");
184 return ret;
185 } else {
186 lvds_codec->bus_format = ret;
187 lvds_codec->bridge.funcs = &funcs_decoder;
188 }
189 }
190
191 /*
192 * Encoder might sample data on different clock edge than the display,
193 * for example OnSemi FIN3385 has a dedicated strapping pin to select
194 * the sampling edge.
195 */
196 if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
197 !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
198 lvds_codec->timings.input_bus_flags = val ?
199 DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
200 DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
201 }
202
203 /*
204 * The panel_bridge bridge is attached to the panel's of_node,
205 * but we need a bridge attached to our of_node for our user
206 * to look up.
207 */
208 lvds_codec->bridge.of_node = dev->of_node;
209 lvds_codec->bridge.timings = &lvds_codec->timings;
210 drm_bridge_add(&lvds_codec->bridge);
211
212 platform_set_drvdata(pdev, lvds_codec);
213
214 return 0;
215 }
216
lvds_codec_remove(struct platform_device * pdev)217 static void lvds_codec_remove(struct platform_device *pdev)
218 {
219 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
220
221 drm_bridge_remove(&lvds_codec->bridge);
222 }
223
224 static const struct of_device_id lvds_codec_match[] = {
225 {
226 .compatible = "lvds-decoder",
227 .data = (void *)DRM_MODE_CONNECTOR_DPI,
228 },
229 {
230 .compatible = "lvds-encoder",
231 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
232 },
233 {
234 .compatible = "thine,thc63lvdm83d",
235 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
236 },
237 {},
238 };
239 MODULE_DEVICE_TABLE(of, lvds_codec_match);
240
241 static struct platform_driver lvds_codec_driver = {
242 .probe = lvds_codec_probe,
243 .remove_new = lvds_codec_remove,
244 .driver = {
245 .name = "lvds-codec",
246 .of_match_table = lvds_codec_match,
247 },
248 };
249 module_platform_driver(lvds_codec_driver);
250
251 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
252 MODULE_DESCRIPTION("LVDS encoders and decoders");
253 MODULE_LICENSE("GPL");
254