1 /*
2 * NXP PTN3460 DP/LVDS bridge driver
3 *
4 * Copyright (C) 2013 Google, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #include <linux/delay.h>
17 #include <linux/gpio.h>
18 #include <linux/gpio/consumer.h>
19 #include <linux/i2c.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/of_gpio.h>
23 #include <linux/of_graph.h>
24
25 #include <drm/drm_panel.h>
26
27 #include "bridge/ptn3460.h"
28
29 #include "drm_crtc.h"
30 #include "drm_crtc_helper.h"
31 #include "drm_edid.h"
32 #include "drmP.h"
33
34 #define PTN3460_EDID_ADDR 0x0
35 #define PTN3460_EDID_EMULATION_ADDR 0x84
36 #define PTN3460_EDID_ENABLE_EMULATION 0
37 #define PTN3460_EDID_EMULATION_SELECTION 1
38 #define PTN3460_EDID_SRAM_LOAD_ADDR 0x85
39
40 struct ptn3460_bridge {
41 struct drm_connector connector;
42 struct i2c_client *client;
43 struct drm_bridge bridge;
44 struct edid *edid;
45 struct drm_panel *panel;
46 struct gpio_desc *gpio_pd_n;
47 struct gpio_desc *gpio_rst_n;
48 u32 edid_emulation;
49 bool enabled;
50 };
51
52 static inline struct ptn3460_bridge *
bridge_to_ptn3460(struct drm_bridge * bridge)53 bridge_to_ptn3460(struct drm_bridge *bridge)
54 {
55 return container_of(bridge, struct ptn3460_bridge, bridge);
56 }
57
58 static inline struct ptn3460_bridge *
connector_to_ptn3460(struct drm_connector * connector)59 connector_to_ptn3460(struct drm_connector *connector)
60 {
61 return container_of(connector, struct ptn3460_bridge, connector);
62 }
63
ptn3460_read_bytes(struct ptn3460_bridge * ptn_bridge,char addr,u8 * buf,int len)64 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
65 u8 *buf, int len)
66 {
67 int ret;
68
69 ret = i2c_master_send(ptn_bridge->client, &addr, 1);
70 if (ret <= 0) {
71 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
72 return ret;
73 }
74
75 ret = i2c_master_recv(ptn_bridge->client, buf, len);
76 if (ret <= 0) {
77 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
78 return ret;
79 }
80
81 return 0;
82 }
83
ptn3460_write_byte(struct ptn3460_bridge * ptn_bridge,char addr,char val)84 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
85 char val)
86 {
87 int ret;
88 char buf[2];
89
90 buf[0] = addr;
91 buf[1] = val;
92
93 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
94 if (ret <= 0) {
95 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
96 return ret;
97 }
98
99 return 0;
100 }
101
ptn3460_select_edid(struct ptn3460_bridge * ptn_bridge)102 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
103 {
104 int ret;
105 char val;
106
107 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
108 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
109 ptn_bridge->edid_emulation);
110 if (ret) {
111 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
112 return ret;
113 }
114
115 /* Enable EDID emulation and select the desired EDID */
116 val = 1 << PTN3460_EDID_ENABLE_EMULATION |
117 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
118
119 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
120 if (ret) {
121 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
122 return ret;
123 }
124
125 return 0;
126 }
127
ptn3460_pre_enable(struct drm_bridge * bridge)128 static void ptn3460_pre_enable(struct drm_bridge *bridge)
129 {
130 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
131 int ret;
132
133 if (ptn_bridge->enabled)
134 return;
135
136 gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
137
138 gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
139 usleep_range(10, 20);
140 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
141
142 if (drm_panel_prepare(ptn_bridge->panel)) {
143 DRM_ERROR("failed to prepare panel\n");
144 return;
145 }
146
147 /*
148 * There's a bug in the PTN chip where it falsely asserts hotplug before
149 * it is fully functional. We're forced to wait for the maximum start up
150 * time specified in the chip's datasheet to make sure we're really up.
151 */
152 msleep(90);
153
154 ret = ptn3460_select_edid(ptn_bridge);
155 if (ret)
156 DRM_ERROR("Select EDID failed ret=%d\n", ret);
157
158 ptn_bridge->enabled = true;
159 }
160
ptn3460_enable(struct drm_bridge * bridge)161 static void ptn3460_enable(struct drm_bridge *bridge)
162 {
163 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
164
165 if (drm_panel_enable(ptn_bridge->panel)) {
166 DRM_ERROR("failed to enable panel\n");
167 return;
168 }
169 }
170
ptn3460_disable(struct drm_bridge * bridge)171 static void ptn3460_disable(struct drm_bridge *bridge)
172 {
173 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
174
175 if (!ptn_bridge->enabled)
176 return;
177
178 ptn_bridge->enabled = false;
179
180 if (drm_panel_disable(ptn_bridge->panel)) {
181 DRM_ERROR("failed to disable panel\n");
182 return;
183 }
184
185 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
186 gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
187 }
188
ptn3460_post_disable(struct drm_bridge * bridge)189 static void ptn3460_post_disable(struct drm_bridge *bridge)
190 {
191 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
192
193 if (drm_panel_unprepare(ptn_bridge->panel)) {
194 DRM_ERROR("failed to unprepare panel\n");
195 return;
196 }
197 }
198
ptn3460_get_modes(struct drm_connector * connector)199 static int ptn3460_get_modes(struct drm_connector *connector)
200 {
201 struct ptn3460_bridge *ptn_bridge;
202 u8 *edid;
203 int ret, num_modes = 0;
204 bool power_off;
205
206 ptn_bridge = connector_to_ptn3460(connector);
207
208 if (ptn_bridge->edid)
209 return drm_add_edid_modes(connector, ptn_bridge->edid);
210
211 power_off = !ptn_bridge->enabled;
212 ptn3460_pre_enable(&ptn_bridge->bridge);
213
214 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
215 if (!edid) {
216 DRM_ERROR("Failed to allocate EDID\n");
217 return 0;
218 }
219
220 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
221 EDID_LENGTH);
222 if (ret) {
223 kfree(edid);
224 goto out;
225 }
226
227 ptn_bridge->edid = (struct edid *)edid;
228 drm_mode_connector_update_edid_property(connector, ptn_bridge->edid);
229
230 num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
231
232 out:
233 if (power_off)
234 ptn3460_disable(&ptn_bridge->bridge);
235
236 return num_modes;
237 }
238
ptn3460_best_encoder(struct drm_connector * connector)239 static struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
240 {
241 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);
242
243 return ptn_bridge->bridge.encoder;
244 }
245
246 static struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
247 .get_modes = ptn3460_get_modes,
248 .best_encoder = ptn3460_best_encoder,
249 };
250
ptn3460_detect(struct drm_connector * connector,bool force)251 static enum drm_connector_status ptn3460_detect(struct drm_connector *connector,
252 bool force)
253 {
254 return connector_status_connected;
255 }
256
ptn3460_connector_destroy(struct drm_connector * connector)257 static void ptn3460_connector_destroy(struct drm_connector *connector)
258 {
259 drm_connector_cleanup(connector);
260 }
261
262 static struct drm_connector_funcs ptn3460_connector_funcs = {
263 .dpms = drm_helper_connector_dpms,
264 .fill_modes = drm_helper_probe_single_connector_modes,
265 .detect = ptn3460_detect,
266 .destroy = ptn3460_connector_destroy,
267 };
268
ptn3460_bridge_attach(struct drm_bridge * bridge)269 static int ptn3460_bridge_attach(struct drm_bridge *bridge)
270 {
271 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
272 int ret;
273
274 if (!bridge->encoder) {
275 DRM_ERROR("Parent encoder object not found");
276 return -ENODEV;
277 }
278
279 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
280 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
281 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
282 if (ret) {
283 DRM_ERROR("Failed to initialize connector with drm\n");
284 return ret;
285 }
286 drm_connector_helper_add(&ptn_bridge->connector,
287 &ptn3460_connector_helper_funcs);
288 drm_connector_register(&ptn_bridge->connector);
289 drm_mode_connector_attach_encoder(&ptn_bridge->connector,
290 bridge->encoder);
291
292 if (ptn_bridge->panel)
293 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
294
295 drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
296
297 return ret;
298 }
299
300 static struct drm_bridge_funcs ptn3460_bridge_funcs = {
301 .pre_enable = ptn3460_pre_enable,
302 .enable = ptn3460_enable,
303 .disable = ptn3460_disable,
304 .post_disable = ptn3460_post_disable,
305 .attach = ptn3460_bridge_attach,
306 };
307
ptn3460_probe(struct i2c_client * client,const struct i2c_device_id * id)308 static int ptn3460_probe(struct i2c_client *client,
309 const struct i2c_device_id *id)
310 {
311 struct device *dev = &client->dev;
312 struct ptn3460_bridge *ptn_bridge;
313 struct device_node *endpoint, *panel_node;
314 int ret;
315
316 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
317 if (!ptn_bridge) {
318 return -ENOMEM;
319 }
320
321 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
322 if (endpoint) {
323 panel_node = of_graph_get_remote_port_parent(endpoint);
324 if (panel_node) {
325 ptn_bridge->panel = of_drm_find_panel(panel_node);
326 of_node_put(panel_node);
327 if (!ptn_bridge->panel)
328 return -EPROBE_DEFER;
329 }
330 }
331
332 ptn_bridge->client = client;
333
334 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown");
335 if (IS_ERR(ptn_bridge->gpio_pd_n)) {
336 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
337 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
338 return ret;
339 }
340
341 ret = gpiod_direction_output(ptn_bridge->gpio_pd_n, 1);
342 if (ret) {
343 DRM_ERROR("cannot configure gpio_pd_n\n");
344 return ret;
345 }
346
347 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset");
348 if (IS_ERR(ptn_bridge->gpio_rst_n)) {
349 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
350 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
351 return ret;
352 }
353 /*
354 * Request the reset pin low to avoid the bridge being
355 * initialized prematurely
356 */
357 ret = gpiod_direction_output(ptn_bridge->gpio_rst_n, 0);
358 if (ret) {
359 DRM_ERROR("cannot configure gpio_rst_n\n");
360 return ret;
361 }
362
363 ret = of_property_read_u32(dev->of_node, "edid-emulation",
364 &ptn_bridge->edid_emulation);
365 if (ret) {
366 dev_err(dev, "Can't read EDID emulation value\n");
367 return ret;
368 }
369
370 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
371 ptn_bridge->bridge.of_node = dev->of_node;
372 ret = drm_bridge_add(&ptn_bridge->bridge);
373 if (ret) {
374 DRM_ERROR("Failed to add bridge\n");
375 return ret;
376 }
377
378 i2c_set_clientdata(client, ptn_bridge);
379
380 return 0;
381 }
382
ptn3460_remove(struct i2c_client * client)383 static int ptn3460_remove(struct i2c_client *client)
384 {
385 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
386
387 drm_bridge_remove(&ptn_bridge->bridge);
388
389 return 0;
390 }
391
392 static const struct i2c_device_id ptn3460_i2c_table[] = {
393 {"nxp,ptn3460", 0},
394 {},
395 };
396 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
397
398 static const struct of_device_id ptn3460_match[] = {
399 { .compatible = "nxp,ptn3460" },
400 {},
401 };
402 MODULE_DEVICE_TABLE(of, ptn3460_match);
403
404 static struct i2c_driver ptn3460_driver = {
405 .id_table = ptn3460_i2c_table,
406 .probe = ptn3460_probe,
407 .remove = ptn3460_remove,
408 .driver = {
409 .name = "nxp,ptn3460",
410 .owner = THIS_MODULE,
411 .of_match_table = ptn3460_match,
412 },
413 };
414 module_i2c_driver(ptn3460_driver);
415
416 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
417 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
418 MODULE_LICENSE("GPL v2");
419