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1 | // SPDX-License-Identifier: GPL-2.0-only | |
2 | /* | |
3 | * NXP PTN3460 DP/LVDS bridge driver | |
4 | * | |
5 | * Copyright (C) 2013 Google, Inc. | |
6 | */ | |
7 | ||
8 | #include <linux/delay.h> | |
9 | #include <linux/gpio/consumer.h> | |
10 | #include <linux/i2c.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/of.h> | |
13 | #include <drm/drm_atomic_helper.h> | |
14 | #include <drm/drm_bridge.h> | |
15 | #include <drm/drm_crtc.h> | |
16 | #include <drm/drm_edid.h> | |
17 | #include <drm/drm_of.h> | |
18 | #include <drm/drm_panel.h> | |
19 | #include <drm/drm_print.h> | |
20 | #include <drm/drm_probe_helper.h> | |
21 | ||
22 | #define PTN3460_EDID_ADDR 0x0 | |
23 | #define PTN3460_EDID_EMULATION_ADDR 0x84 | |
24 | #define PTN3460_EDID_ENABLE_EMULATION 0 | |
25 | #define PTN3460_EDID_EMULATION_SELECTION 1 | |
26 | #define PTN3460_EDID_SRAM_LOAD_ADDR 0x85 | |
27 | ||
28 | struct ptn3460_bridge { | |
29 | struct drm_connector connector; | |
30 | struct i2c_client *client; | |
31 | struct drm_bridge bridge; | |
32 | struct drm_bridge *panel_bridge; | |
33 | struct gpio_desc *gpio_pd_n; | |
34 | struct gpio_desc *gpio_rst_n; | |
35 | u32 edid_emulation; | |
36 | bool enabled; | |
37 | }; | |
38 | ||
39 | static inline struct ptn3460_bridge * | |
40 | bridge_to_ptn3460(struct drm_bridge *bridge) | |
41 | { | |
42 | return container_of(bridge, struct ptn3460_bridge, bridge); | |
43 | } | |
44 | ||
45 | static inline struct ptn3460_bridge * | |
46 | connector_to_ptn3460(struct drm_connector *connector) | |
47 | { | |
48 | return container_of(connector, struct ptn3460_bridge, connector); | |
49 | } | |
50 | ||
51 | static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, | |
52 | u8 *buf, int len) | |
53 | { | |
54 | int ret; | |
55 | ||
56 | ret = i2c_master_send(ptn_bridge->client, &addr, 1); | |
57 | if (ret <= 0) { | |
58 | DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); | |
59 | return ret; | |
60 | } | |
61 | ||
62 | ret = i2c_master_recv(ptn_bridge->client, buf, len); | |
63 | if (ret <= 0) { | |
64 | DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); | |
65 | return ret; | |
66 | } | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, | |
72 | char val) | |
73 | { | |
74 | int ret; | |
75 | char buf[2]; | |
76 | ||
77 | buf[0] = addr; | |
78 | buf[1] = val; | |
79 | ||
80 | ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); | |
81 | if (ret <= 0) { | |
82 | DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); | |
83 | return ret; | |
84 | } | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge) | |
90 | { | |
91 | int ret; | |
92 | char val; | |
93 | ||
94 | /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */ | |
95 | ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR, | |
96 | ptn_bridge->edid_emulation); | |
97 | if (ret) { | |
98 | DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret); | |
99 | return ret; | |
100 | } | |
101 | ||
102 | /* Enable EDID emulation and select the desired EDID */ | |
103 | val = 1 << PTN3460_EDID_ENABLE_EMULATION | | |
104 | ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION; | |
105 | ||
106 | ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val); | |
107 | if (ret) { | |
108 | DRM_ERROR("Failed to write EDID value, ret=%d\n", ret); | |
109 | return ret; | |
110 | } | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static void ptn3460_pre_enable(struct drm_bridge *bridge) | |
116 | { | |
117 | struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); | |
118 | int ret; | |
119 | ||
120 | if (ptn_bridge->enabled) | |
121 | return; | |
122 | ||
123 | gpiod_set_value(ptn_bridge->gpio_pd_n, 1); | |
124 | ||
125 | gpiod_set_value(ptn_bridge->gpio_rst_n, 0); | |
126 | usleep_range(10, 20); | |
127 | gpiod_set_value(ptn_bridge->gpio_rst_n, 1); | |
128 | ||
129 | /* | |
130 | * There's a bug in the PTN chip where it falsely asserts hotplug before | |
131 | * it is fully functional. We're forced to wait for the maximum start up | |
132 | * time specified in the chip's datasheet to make sure we're really up. | |
133 | */ | |
134 | msleep(90); | |
135 | ||
136 | ret = ptn3460_select_edid(ptn_bridge); | |
137 | if (ret) | |
138 | DRM_ERROR("Select EDID failed ret=%d\n", ret); | |
139 | ||
140 | ptn_bridge->enabled = true; | |
141 | } | |
142 | ||
143 | static void ptn3460_disable(struct drm_bridge *bridge) | |
144 | { | |
145 | struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); | |
146 | ||
147 | if (!ptn_bridge->enabled) | |
148 | return; | |
149 | ||
150 | ptn_bridge->enabled = false; | |
151 | ||
152 | gpiod_set_value(ptn_bridge->gpio_rst_n, 1); | |
153 | gpiod_set_value(ptn_bridge->gpio_pd_n, 0); | |
154 | } | |
155 | ||
156 | ||
157 | static struct edid *ptn3460_get_edid(struct drm_bridge *bridge, | |
158 | struct drm_connector *connector) | |
159 | { | |
160 | struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); | |
161 | bool power_off; | |
162 | u8 *edid; | |
163 | int ret; | |
164 | ||
165 | power_off = !ptn_bridge->enabled; | |
166 | ptn3460_pre_enable(&ptn_bridge->bridge); | |
167 | ||
168 | edid = kmalloc(EDID_LENGTH, GFP_KERNEL); | |
169 | if (!edid) { | |
170 | DRM_ERROR("Failed to allocate EDID\n"); | |
171 | goto out; | |
172 | } | |
173 | ||
174 | ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, | |
175 | EDID_LENGTH); | |
176 | if (ret) { | |
177 | kfree(edid); | |
178 | edid = NULL; | |
179 | goto out; | |
180 | } | |
181 | ||
182 | out: | |
183 | if (power_off) | |
184 | ptn3460_disable(&ptn_bridge->bridge); | |
185 | ||
186 | return (struct edid *)edid; | |
187 | } | |
188 | ||
189 | static int ptn3460_connector_get_modes(struct drm_connector *connector) | |
190 | { | |
191 | struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); | |
192 | struct edid *edid; | |
193 | int num_modes; | |
194 | ||
195 | edid = ptn3460_get_edid(&ptn_bridge->bridge, connector); | |
196 | drm_connector_update_edid_property(connector, edid); | |
197 | num_modes = drm_add_edid_modes(connector, edid); | |
198 | kfree(edid); | |
199 | ||
200 | return num_modes; | |
201 | } | |
202 | ||
203 | static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { | |
204 | .get_modes = ptn3460_connector_get_modes, | |
205 | }; | |
206 | ||
207 | static const struct drm_connector_funcs ptn3460_connector_funcs = { | |
208 | .fill_modes = drm_helper_probe_single_connector_modes, | |
209 | .destroy = drm_connector_cleanup, | |
210 | .reset = drm_atomic_helper_connector_reset, | |
211 | .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, | |
212 | .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, | |
213 | }; | |
214 | ||
215 | static int ptn3460_bridge_attach(struct drm_bridge *bridge, | |
216 | enum drm_bridge_attach_flags flags) | |
217 | { | |
218 | struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); | |
219 | int ret; | |
220 | ||
221 | /* Let this driver create connector if requested */ | |
222 | ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge, | |
223 | bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR); | |
224 | if (ret < 0) | |
225 | return ret; | |
226 | ||
227 | if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) | |
228 | return 0; | |
229 | ||
230 | if (!bridge->encoder) { | |
231 | DRM_ERROR("Parent encoder object not found"); | |
232 | return -ENODEV; | |
233 | } | |
234 | ||
235 | ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; | |
236 | ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, | |
237 | &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); | |
238 | if (ret) { | |
239 | DRM_ERROR("Failed to initialize connector with drm\n"); | |
240 | return ret; | |
241 | } | |
242 | drm_connector_helper_add(&ptn_bridge->connector, | |
243 | &ptn3460_connector_helper_funcs); | |
244 | drm_connector_register(&ptn_bridge->connector); | |
245 | drm_connector_attach_encoder(&ptn_bridge->connector, | |
246 | bridge->encoder); | |
247 | ||
248 | drm_helper_hpd_irq_event(ptn_bridge->connector.dev); | |
249 | ||
250 | return ret; | |
251 | } | |
252 | ||
253 | static const struct drm_bridge_funcs ptn3460_bridge_funcs = { | |
254 | .pre_enable = ptn3460_pre_enable, | |
255 | .disable = ptn3460_disable, | |
256 | .attach = ptn3460_bridge_attach, | |
257 | .get_edid = ptn3460_get_edid, | |
258 | }; | |
259 | ||
260 | static int ptn3460_probe(struct i2c_client *client, | |
261 | const struct i2c_device_id *id) | |
262 | { | |
263 | struct device *dev = &client->dev; | |
264 | struct ptn3460_bridge *ptn_bridge; | |
265 | struct drm_bridge *panel_bridge; | |
266 | struct drm_panel *panel; | |
267 | int ret; | |
268 | ||
269 | ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); | |
270 | if (!ptn_bridge) { | |
271 | return -ENOMEM; | |
272 | } | |
273 | ||
274 | ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &panel, NULL); | |
275 | if (ret) | |
276 | return ret; | |
277 | ||
278 | panel_bridge = devm_drm_panel_bridge_add(dev, panel); | |
279 | if (IS_ERR(panel_bridge)) | |
280 | return PTR_ERR(panel_bridge); | |
281 | ||
282 | ptn_bridge->panel_bridge = panel_bridge; | |
283 | ptn_bridge->client = client; | |
284 | ||
285 | ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", | |
286 | GPIOD_OUT_HIGH); | |
287 | if (IS_ERR(ptn_bridge->gpio_pd_n)) { | |
288 | ret = PTR_ERR(ptn_bridge->gpio_pd_n); | |
289 | dev_err(dev, "cannot get gpio_pd_n %d\n", ret); | |
290 | return ret; | |
291 | } | |
292 | ||
293 | /* | |
294 | * Request the reset pin low to avoid the bridge being | |
295 | * initialized prematurely | |
296 | */ | |
297 | ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", | |
298 | GPIOD_OUT_LOW); | |
299 | if (IS_ERR(ptn_bridge->gpio_rst_n)) { | |
300 | ret = PTR_ERR(ptn_bridge->gpio_rst_n); | |
301 | DRM_ERROR("cannot get gpio_rst_n %d\n", ret); | |
302 | return ret; | |
303 | } | |
304 | ||
305 | ret = of_property_read_u32(dev->of_node, "edid-emulation", | |
306 | &ptn_bridge->edid_emulation); | |
307 | if (ret) { | |
308 | dev_err(dev, "Can't read EDID emulation value\n"); | |
309 | return ret; | |
310 | } | |
311 | ||
312 | ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; | |
313 | ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; | |
314 | ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; | |
315 | ptn_bridge->bridge.of_node = dev->of_node; | |
316 | drm_bridge_add(&ptn_bridge->bridge); | |
317 | ||
318 | i2c_set_clientdata(client, ptn_bridge); | |
319 | ||
320 | return 0; | |
321 | } | |
322 | ||
323 | static int ptn3460_remove(struct i2c_client *client) | |
324 | { | |
325 | struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); | |
326 | ||
327 | drm_bridge_remove(&ptn_bridge->bridge); | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
332 | static const struct i2c_device_id ptn3460_i2c_table[] = { | |
333 | {"ptn3460", 0}, | |
334 | {}, | |
335 | }; | |
336 | MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); | |
337 | ||
338 | static const struct of_device_id ptn3460_match[] = { | |
339 | { .compatible = "nxp,ptn3460" }, | |
340 | {}, | |
341 | }; | |
342 | MODULE_DEVICE_TABLE(of, ptn3460_match); | |
343 | ||
344 | static struct i2c_driver ptn3460_driver = { | |
345 | .id_table = ptn3460_i2c_table, | |
346 | .probe = ptn3460_probe, | |
347 | .remove = ptn3460_remove, | |
348 | .driver = { | |
349 | .name = "nxp,ptn3460", | |
350 | .of_match_table = ptn3460_match, | |
351 | }, | |
352 | }; | |
353 | module_i2c_driver(ptn3460_driver); | |
354 | ||
355 | MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); | |
356 | MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); | |
357 | MODULE_LICENSE("GPL v2"); |