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