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(client: ptn_bridge->client, buf: &addr, count: 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(client: ptn_bridge->client, buf, count: 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(client: 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 | val: 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(desc: ptn_bridge->gpio_pd_n, value: 1); |
124 | |
125 | gpiod_set_value(desc: ptn_bridge->gpio_rst_n, value: 0); |
126 | usleep_range(min: 10, max: 20); |
127 | gpiod_set_value(desc: ptn_bridge->gpio_rst_n, value: 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(msecs: 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(desc: ptn_bridge->gpio_rst_n, value: 1); |
153 | gpiod_set_value(desc: ptn_bridge->gpio_pd_n, value: 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(bridge: &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, buf: edid, |
175 | EDID_LENGTH); |
176 | if (ret) { |
177 | kfree(objp: edid); |
178 | edid = NULL; |
179 | goto out; |
180 | } |
181 | |
182 | out: |
183 | if (power_off) |
184 | ptn3460_disable(bridge: &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(bridge: &ptn_bridge->bridge, connector); |
196 | drm_connector_update_edid_property(connector, edid); |
197 | num_modes = drm_add_edid_modes(connector, edid); |
198 | kfree(objp: 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(encoder: bridge->encoder, bridge: ptn_bridge->panel_bridge, |
223 | previous: bridge, flags: 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(dev: bridge->dev, connector: &ptn_bridge->connector, |
237 | funcs: &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(connector: &ptn_bridge->connector, |
243 | funcs: &ptn3460_connector_helper_funcs); |
244 | drm_connector_register(connector: &ptn_bridge->connector); |
245 | drm_connector_attach_encoder(connector: &ptn_bridge->connector, |
246 | encoder: bridge->encoder); |
247 | |
248 | drm_helper_hpd_irq_event(dev: 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 | { |
262 | struct device *dev = &client->dev; |
263 | struct ptn3460_bridge *ptn_bridge; |
264 | struct drm_bridge *panel_bridge; |
265 | int ret; |
266 | |
267 | ptn_bridge = devm_kzalloc(dev, size: sizeof(*ptn_bridge), GFP_KERNEL); |
268 | if (!ptn_bridge) { |
269 | return -ENOMEM; |
270 | } |
271 | |
272 | panel_bridge = devm_drm_of_get_bridge(dev, node: dev->of_node, port: 0, endpoint: 0); |
273 | if (IS_ERR(ptr: panel_bridge)) |
274 | return PTR_ERR(ptr: panel_bridge); |
275 | |
276 | ptn_bridge->panel_bridge = panel_bridge; |
277 | ptn_bridge->client = client; |
278 | |
279 | ptn_bridge->gpio_pd_n = devm_gpiod_get(dev: &client->dev, con_id: "powerdown" , |
280 | flags: GPIOD_OUT_HIGH); |
281 | if (IS_ERR(ptr: ptn_bridge->gpio_pd_n)) { |
282 | ret = PTR_ERR(ptr: ptn_bridge->gpio_pd_n); |
283 | dev_err(dev, "cannot get gpio_pd_n %d\n" , ret); |
284 | return ret; |
285 | } |
286 | |
287 | /* |
288 | * Request the reset pin low to avoid the bridge being |
289 | * initialized prematurely |
290 | */ |
291 | ptn_bridge->gpio_rst_n = devm_gpiod_get(dev: &client->dev, con_id: "reset" , |
292 | flags: GPIOD_OUT_LOW); |
293 | if (IS_ERR(ptr: ptn_bridge->gpio_rst_n)) { |
294 | ret = PTR_ERR(ptr: ptn_bridge->gpio_rst_n); |
295 | DRM_ERROR("cannot get gpio_rst_n %d\n" , ret); |
296 | return ret; |
297 | } |
298 | |
299 | ret = of_property_read_u32(np: dev->of_node, propname: "edid-emulation" , |
300 | out_value: &ptn_bridge->edid_emulation); |
301 | if (ret) { |
302 | dev_err(dev, "Can't read EDID emulation value\n" ); |
303 | return ret; |
304 | } |
305 | |
306 | ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; |
307 | ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; |
308 | ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; |
309 | ptn_bridge->bridge.of_node = dev->of_node; |
310 | drm_bridge_add(bridge: &ptn_bridge->bridge); |
311 | |
312 | i2c_set_clientdata(client, data: ptn_bridge); |
313 | |
314 | return 0; |
315 | } |
316 | |
317 | static void ptn3460_remove(struct i2c_client *client) |
318 | { |
319 | struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); |
320 | |
321 | drm_bridge_remove(bridge: &ptn_bridge->bridge); |
322 | } |
323 | |
324 | static const struct i2c_device_id ptn3460_i2c_table[] = { |
325 | {"ptn3460" , 0}, |
326 | {}, |
327 | }; |
328 | MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); |
329 | |
330 | static const struct of_device_id ptn3460_match[] = { |
331 | { .compatible = "nxp,ptn3460" }, |
332 | {}, |
333 | }; |
334 | MODULE_DEVICE_TABLE(of, ptn3460_match); |
335 | |
336 | static struct i2c_driver ptn3460_driver = { |
337 | .id_table = ptn3460_i2c_table, |
338 | .probe = ptn3460_probe, |
339 | .remove = ptn3460_remove, |
340 | .driver = { |
341 | .name = "nxp,ptn3460" , |
342 | .of_match_table = ptn3460_match, |
343 | }, |
344 | }; |
345 | module_i2c_driver(ptn3460_driver); |
346 | |
347 | MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>" ); |
348 | MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver" ); |
349 | MODULE_LICENSE("GPL v2" ); |
350 | |