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
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, bridge: lvds_codec->panel_bridge,
43 previous: bridge, flags);
44}
45
46static void lvds_codec_enable(struct drm_bridge *bridge)
47{
48 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
49 int ret;
50
51 ret = regulator_enable(regulator: lvds_codec->vcc);
52 if (ret) {
53 dev_err(lvds_codec->dev,
54 "Failed to enable regulator \"vcc\": %d\n", ret);
55 return;
56 }
57
58 if (lvds_codec->powerdown_gpio)
59 gpiod_set_value_cansleep(desc: lvds_codec->powerdown_gpio, value: 0);
60}
61
62static void lvds_codec_disable(struct drm_bridge *bridge)
63{
64 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
65 int ret;
66
67 if (lvds_codec->powerdown_gpio)
68 gpiod_set_value_cansleep(desc: lvds_codec->powerdown_gpio, value: 1);
69
70 ret = regulator_disable(regulator: lvds_codec->vcc);
71 if (ret)
72 dev_err(lvds_codec->dev,
73 "Failed to disable regulator \"vcc\": %d\n", ret);
74}
75
76#define MAX_INPUT_SEL_FORMATS 1
77static u32 *
78lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
79 struct drm_bridge_state *bridge_state,
80 struct drm_crtc_state *crtc_state,
81 struct drm_connector_state *conn_state,
82 u32 output_fmt,
83 unsigned int *num_input_fmts)
84{
85 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
86 u32 *input_fmts;
87
88 *num_input_fmts = 0;
89
90 input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
91 GFP_KERNEL);
92 if (!input_fmts)
93 return NULL;
94
95 input_fmts[0] = lvds_codec->bus_format;
96 *num_input_fmts = MAX_INPUT_SEL_FORMATS;
97
98 return input_fmts;
99}
100
101static const struct drm_bridge_funcs funcs = {
102 .attach = lvds_codec_attach,
103 .enable = lvds_codec_enable,
104 .disable = lvds_codec_disable,
105 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
106 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
107 .atomic_reset = drm_atomic_helper_bridge_reset,
108 .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
109};
110
111static int lvds_codec_probe(struct platform_device *pdev)
112{
113 struct device *dev = &pdev->dev;
114 struct device_node *panel_node;
115 struct device_node *bus_node;
116 struct drm_panel *panel;
117 struct lvds_codec *lvds_codec;
118 u32 val;
119 int ret;
120
121 lvds_codec = devm_drm_bridge_alloc(dev, struct lvds_codec, bridge,
122 &funcs);
123 if (IS_ERR(ptr: lvds_codec))
124 return PTR_ERR(ptr: lvds_codec);
125
126 lvds_codec->dev = &pdev->dev;
127 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
128
129 lvds_codec->vcc = devm_regulator_get(dev: lvds_codec->dev, id: "power");
130 if (IS_ERR(ptr: lvds_codec->vcc))
131 return dev_err_probe(dev, err: PTR_ERR(ptr: lvds_codec->vcc),
132 fmt: "Unable to get \"vcc\" supply\n");
133
134 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, con_id: "powerdown",
135 flags: GPIOD_OUT_HIGH);
136 if (IS_ERR(ptr: lvds_codec->powerdown_gpio))
137 return dev_err_probe(dev, err: PTR_ERR(ptr: lvds_codec->powerdown_gpio),
138 fmt: "powerdown GPIO failure\n");
139
140 /* Locate the panel DT node. */
141 panel_node = of_graph_get_remote_node(node: dev->of_node, port: 1, endpoint: 0);
142 if (!panel_node) {
143 dev_dbg(dev, "panel DT node not found\n");
144 return -ENXIO;
145 }
146
147 panel = of_drm_find_panel(np: panel_node);
148 of_node_put(node: panel_node);
149 if (IS_ERR(ptr: panel)) {
150 dev_dbg(dev, "panel not found, deferring probe\n");
151 return PTR_ERR(ptr: panel);
152 }
153
154 lvds_codec->panel_bridge =
155 devm_drm_panel_bridge_add_typed(dev, panel,
156 connector_type: lvds_codec->connector_type);
157 if (IS_ERR(ptr: lvds_codec->panel_bridge))
158 return PTR_ERR(ptr: lvds_codec->panel_bridge);
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(parent: dev->of_node, port_reg: 0, reg: 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(port: bus_node);
174 of_node_put(node: 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(np: dev->of_node, propname: "pclk-sample", out_value: &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(bridge: &lvds_codec->bridge);
207
208 platform_set_drvdata(pdev, data: lvds_codec);
209
210 return 0;
211}
212
213static void lvds_codec_remove(struct platform_device *pdev)
214{
215 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
216
217 drm_bridge_remove(bridge: &lvds_codec->bridge);
218}
219
220static 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};
235MODULE_DEVICE_TABLE(of, lvds_codec_match);
236
237static struct platform_driver lvds_codec_driver = {
238 .probe = lvds_codec_probe,
239 .remove = lvds_codec_remove,
240 .driver = {
241 .name = "lvds-codec",
242 .of_match_table = lvds_codec_match,
243 },
244};
245module_platform_driver(lvds_codec_driver);
246
247MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
248MODULE_DESCRIPTION("LVDS encoders and decoders");
249MODULE_LICENSE("GPL");
250

source code of linux/drivers/gpu/drm/bridge/lvds-codec.c