Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015-2016 Free Electrons
4 * Copyright (C) 2015-2016 NextThing Co
5 *
6 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 */
8
9#include <linux/gpio/consumer.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/of_graph.h>
13#include <linux/platform_device.h>
14#include <linux/regulator/consumer.h>
15
16#include <drm/drm_atomic_helper.h>
17#include <drm/drm_bridge.h>
18#include <drm/drm_crtc.h>
19#include <drm/drm_edid.h>
20#include <drm/drm_print.h>
21#include <drm/drm_probe_helper.h>
22
23struct simple_bridge_info {
24 const struct drm_bridge_timings *timings;
25 unsigned int connector_type;
26};
27
28struct simple_bridge {
29 struct drm_bridge bridge;
30 struct drm_connector connector;
31
32 const struct simple_bridge_info *info;
33
34 struct regulator *vdd;
35 struct gpio_desc *enable;
36};
37
38static inline struct simple_bridge *
39drm_bridge_to_simple_bridge(struct drm_bridge *bridge)
40{
41 return container_of(bridge, struct simple_bridge, bridge);
42}
43
44static inline struct simple_bridge *
45drm_connector_to_simple_bridge(struct drm_connector *connector)
46{
47 return container_of(connector, struct simple_bridge, connector);
48}
49
50static int simple_bridge_get_modes(struct drm_connector *connector)
51{
52 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
53 const struct drm_edid *drm_edid;
54 int ret;
55
56 if (sbridge->bridge.next_bridge->ops & DRM_BRIDGE_OP_EDID) {
57 drm_edid = drm_bridge_edid_read(sbridge->bridge.next_bridge, connector);
58 if (!drm_edid)
59 DRM_INFO("EDID read failed. Fallback to standard modes\n");
60 } else {
61 drm_edid = NULL;
62 }
63
64 drm_edid_connector_update(connector, drm_edid);
65
66 if (!drm_edid) {
67 /*
68 * In case we cannot retrieve the EDIDs (missing or broken DDC
69 * bus from the next bridge), fallback on the XGA standards and
70 * prefer a mode pretty much anyone can handle.
71 */
72 ret = drm_add_modes_noedid(connector, 1920, 1200);
73 drm_set_preferred_mode(connector, 1024, 768);
74 return ret;
75 }
76
77 ret = drm_edid_connector_add_modes(connector);
78 drm_edid_free(drm_edid);
79
80 return ret;
81}
82
83static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = {
84 .get_modes = simple_bridge_get_modes,
85};
86
87static enum drm_connector_status
88simple_bridge_connector_detect(struct drm_connector *connector, bool force)
89{
90 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
91
92 return drm_bridge_detect(sbridge->bridge.next_bridge, connector);
93}
94
95static const struct drm_connector_funcs simple_bridge_con_funcs = {
96 .detect = simple_bridge_connector_detect,
97 .fill_modes = drm_helper_probe_single_connector_modes,
98 .destroy = drm_connector_cleanup,
99 .reset = drm_atomic_helper_connector_reset,
100 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
101 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
102};
103
104static int simple_bridge_attach(struct drm_bridge *bridge,
105 struct drm_encoder *encoder,
106 enum drm_bridge_attach_flags flags)
107{
108 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
109 int ret;
110
111 ret = drm_bridge_attach(encoder, sbridge->bridge.next_bridge, bridge,
112 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
113 if (ret < 0)
114 return ret;
115
116 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
117 return 0;
118
119 drm_connector_helper_add(&sbridge->connector,
120 &simple_bridge_con_helper_funcs);
121 ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector,
122 &simple_bridge_con_funcs,
123 sbridge->info->connector_type,
124 sbridge->bridge.next_bridge->ddc);
125 if (ret) {
126 DRM_ERROR("Failed to initialize connector\n");
127 return ret;
128 }
129
130 drm_connector_attach_encoder(&sbridge->connector, encoder);
131
132 return 0;
133}
134
135static void simple_bridge_enable(struct drm_bridge *bridge)
136{
137 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
138 int ret;
139
140 if (sbridge->vdd) {
141 ret = regulator_enable(sbridge->vdd);
142 if (ret)
143 DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
144 }
145
146 gpiod_set_value_cansleep(sbridge->enable, 1);
147}
148
149static void simple_bridge_disable(struct drm_bridge *bridge)
150{
151 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
152
153 gpiod_set_value_cansleep(sbridge->enable, 0);
154
155 if (sbridge->vdd)
156 regulator_disable(sbridge->vdd);
157}
158
159static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {
160 .attach = simple_bridge_attach,
161 .enable = simple_bridge_enable,
162 .disable = simple_bridge_disable,
163};
164
165static int simple_bridge_probe(struct platform_device *pdev)
166{
167 struct simple_bridge *sbridge;
168 struct device_node *remote;
169
170 sbridge = devm_drm_bridge_alloc(&pdev->dev, struct simple_bridge,
171 bridge, &simple_bridge_bridge_funcs);
172 if (IS_ERR(sbridge))
173 return PTR_ERR(sbridge);
174
175 sbridge->info = of_device_get_match_data(&pdev->dev);
176
177 /* Get the next bridge in the pipeline. */
178 remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
179 if (!remote)
180 return -EINVAL;
181
182 sbridge->bridge.next_bridge = of_drm_find_and_get_bridge(remote);
183 of_node_put(remote);
184
185 if (!sbridge->bridge.next_bridge) {
186 dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
187 return -EPROBE_DEFER;
188 }
189
190 /* Get the regulator and GPIO resources. */
191 sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
192 if (IS_ERR(sbridge->vdd)) {
193 int ret = PTR_ERR(sbridge->vdd);
194 if (ret == -EPROBE_DEFER)
195 return -EPROBE_DEFER;
196 sbridge->vdd = NULL;
197 dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
198 }
199
200 sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable",
201 GPIOD_OUT_LOW);
202 if (IS_ERR(sbridge->enable))
203 return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->enable),
204 "Unable to retrieve enable GPIO\n");
205
206 /* Register the bridge. */
207 sbridge->bridge.of_node = pdev->dev.of_node;
208 sbridge->bridge.timings = sbridge->info->timings;
209
210 return devm_drm_bridge_add(&pdev->dev, &sbridge->bridge);
211}
212
213/*
214 * We assume the ADV7123 DAC is the "default" for historical reasons
215 * Information taken from the ADV7123 datasheet, revision D.
216 * NOTE: the ADV7123EP seems to have other timings and need a new timings
217 * set if used.
218 */
219static const struct drm_bridge_timings default_bridge_timings = {
220 /* Timing specifications, datasheet page 7 */
221 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
222 .setup_time_ps = 500,
223 .hold_time_ps = 1500,
224};
225
226/*
227 * Information taken from the THS8134, THS8134A, THS8134B datasheet named
228 * "SLVS205D", dated May 1990, revised March 2000.
229 */
230static const struct drm_bridge_timings ti_ths8134_bridge_timings = {
231 /* From timing diagram, datasheet page 9 */
232 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
233 /* From datasheet, page 12 */
234 .setup_time_ps = 3000,
235 /* I guess this means latched input */
236 .hold_time_ps = 0,
237};
238
239/*
240 * Information taken from the THS8135 datasheet named "SLAS343B", dated
241 * May 2001, revised April 2013.
242 */
243static const struct drm_bridge_timings ti_ths8135_bridge_timings = {
244 /* From timing diagram, datasheet page 14 */
245 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
246 /* From datasheet, page 16 */
247 .setup_time_ps = 2000,
248 .hold_time_ps = 500,
249};
250
251static const struct of_device_id simple_bridge_match[] = {
252 {
253 .compatible = "dumb-vga-dac",
254 .data = &(const struct simple_bridge_info) {
255 .connector_type = DRM_MODE_CONNECTOR_VGA,
256 },
257 }, {
258 .compatible = "adi,adv7123",
259 .data = &(const struct simple_bridge_info) {
260 .timings = &default_bridge_timings,
261 .connector_type = DRM_MODE_CONNECTOR_VGA,
262 },
263 }, {
264 .compatible = "algoltek,ag6311",
265 .data = &(const struct simple_bridge_info) {
266 .connector_type = DRM_MODE_CONNECTOR_HDMIA,
267 },
268 }, {
269 .compatible = "asl-tek,cs5263",
270 .data = &(const struct simple_bridge_info) {
271 .connector_type = DRM_MODE_CONNECTOR_HDMIA,
272 },
273 }, {
274 .compatible = "parade,ps185hdm",
275 .data = &(const struct simple_bridge_info) {
276 .connector_type = DRM_MODE_CONNECTOR_HDMIA,
277 },
278 }, {
279 .compatible = "radxa,ra620",
280 .data = &(const struct simple_bridge_info) {
281 .connector_type = DRM_MODE_CONNECTOR_HDMIA,
282 },
283 }, {
284 .compatible = "realtek,rtd2171",
285 .data = &(const struct simple_bridge_info) {
286 .connector_type = DRM_MODE_CONNECTOR_HDMIA,
287 },
288 }, {
289 .compatible = "ti,opa362",
290 .data = &(const struct simple_bridge_info) {
291 .connector_type = DRM_MODE_CONNECTOR_Composite,
292 },
293 }, {
294 .compatible = "ti,ths8135",
295 .data = &(const struct simple_bridge_info) {
296 .timings = &ti_ths8135_bridge_timings,
297 .connector_type = DRM_MODE_CONNECTOR_VGA,
298 },
299 }, {
300 .compatible = "ti,ths8134",
301 .data = &(const struct simple_bridge_info) {
302 .timings = &ti_ths8134_bridge_timings,
303 .connector_type = DRM_MODE_CONNECTOR_VGA,
304 },
305 },
306 {},
307};
308MODULE_DEVICE_TABLE(of, simple_bridge_match);
309
310static struct platform_driver simple_bridge_driver = {
311 .probe = simple_bridge_probe,
312 .driver = {
313 .name = "simple-bridge",
314 .of_match_table = simple_bridge_match,
315 },
316};
317module_platform_driver(simple_bridge_driver);
318
319MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
320MODULE_DESCRIPTION("Simple DRM bridge driver");
321MODULE_LICENSE("GPL");