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