2 * NXP PTN3460 DP/LVDS bridge driver
4 * Copyright (C) 2013 Google, Inc.
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.
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.
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>
22 #include <linux/of_gpio.h>
23 #include <linux/of_graph.h>
25 #include <drm/drm_panel.h>
28 #include "drm_crtc_helper.h"
29 #include "drm_atomic_helper.h"
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
39 struct ptn3460_bridge {
40 struct drm_connector connector;
41 struct i2c_client *client;
42 struct drm_bridge bridge;
44 struct drm_panel *panel;
45 struct gpio_desc *gpio_pd_n;
46 struct gpio_desc *gpio_rst_n;
51 static inline struct ptn3460_bridge *
52 bridge_to_ptn3460(struct drm_bridge *bridge)
54 return container_of(bridge, struct ptn3460_bridge, bridge);
57 static inline struct ptn3460_bridge *
58 connector_to_ptn3460(struct drm_connector *connector)
60 return container_of(connector, struct ptn3460_bridge, connector);
63 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
68 ret = i2c_master_send(ptn_bridge->client, &addr, 1);
70 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
74 ret = i2c_master_recv(ptn_bridge->client, buf, len);
76 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
83 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
92 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
94 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
101 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
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);
110 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
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;
118 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
120 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
127 static void ptn3460_pre_enable(struct drm_bridge *bridge)
129 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
132 if (ptn_bridge->enabled)
135 gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
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);
141 if (drm_panel_prepare(ptn_bridge->panel)) {
142 DRM_ERROR("failed to prepare panel\n");
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.
153 ret = ptn3460_select_edid(ptn_bridge);
155 DRM_ERROR("Select EDID failed ret=%d\n", ret);
157 ptn_bridge->enabled = true;
160 static void ptn3460_enable(struct drm_bridge *bridge)
162 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
164 if (drm_panel_enable(ptn_bridge->panel)) {
165 DRM_ERROR("failed to enable panel\n");
170 static void ptn3460_disable(struct drm_bridge *bridge)
172 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
174 if (!ptn_bridge->enabled)
177 ptn_bridge->enabled = false;
179 if (drm_panel_disable(ptn_bridge->panel)) {
180 DRM_ERROR("failed to disable panel\n");
184 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
185 gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
188 static void ptn3460_post_disable(struct drm_bridge *bridge)
190 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
192 if (drm_panel_unprepare(ptn_bridge->panel)) {
193 DRM_ERROR("failed to unprepare panel\n");
198 static int ptn3460_get_modes(struct drm_connector *connector)
200 struct ptn3460_bridge *ptn_bridge;
202 int ret, num_modes = 0;
205 ptn_bridge = connector_to_ptn3460(connector);
207 if (ptn_bridge->edid)
208 return drm_add_edid_modes(connector, ptn_bridge->edid);
210 power_off = !ptn_bridge->enabled;
211 ptn3460_pre_enable(&ptn_bridge->bridge);
213 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
215 DRM_ERROR("Failed to allocate EDID\n");
219 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
226 ptn_bridge->edid = (struct edid *)edid;
227 drm_mode_connector_update_edid_property(connector, ptn_bridge->edid);
229 num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
233 ptn3460_disable(&ptn_bridge->bridge);
238 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
239 .get_modes = ptn3460_get_modes,
242 static const struct drm_connector_funcs ptn3460_connector_funcs = {
243 .dpms = drm_atomic_helper_connector_dpms,
244 .fill_modes = drm_helper_probe_single_connector_modes,
245 .destroy = drm_connector_cleanup,
246 .reset = drm_atomic_helper_connector_reset,
247 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
248 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
251 static int ptn3460_bridge_attach(struct drm_bridge *bridge)
253 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
256 if (!bridge->encoder) {
257 DRM_ERROR("Parent encoder object not found");
261 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
262 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
263 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
265 DRM_ERROR("Failed to initialize connector with drm\n");
268 drm_connector_helper_add(&ptn_bridge->connector,
269 &ptn3460_connector_helper_funcs);
270 drm_connector_register(&ptn_bridge->connector);
271 drm_mode_connector_attach_encoder(&ptn_bridge->connector,
274 if (ptn_bridge->panel)
275 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
277 drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
282 static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
283 .pre_enable = ptn3460_pre_enable,
284 .enable = ptn3460_enable,
285 .disable = ptn3460_disable,
286 .post_disable = ptn3460_post_disable,
287 .attach = ptn3460_bridge_attach,
290 static int ptn3460_probe(struct i2c_client *client,
291 const struct i2c_device_id *id)
293 struct device *dev = &client->dev;
294 struct ptn3460_bridge *ptn_bridge;
295 struct device_node *endpoint, *panel_node;
298 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
303 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
305 panel_node = of_graph_get_remote_port_parent(endpoint);
307 ptn_bridge->panel = of_drm_find_panel(panel_node);
308 of_node_put(panel_node);
309 if (!ptn_bridge->panel)
310 return -EPROBE_DEFER;
314 ptn_bridge->client = client;
316 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
318 if (IS_ERR(ptn_bridge->gpio_pd_n)) {
319 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
320 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
325 * Request the reset pin low to avoid the bridge being
326 * initialized prematurely
328 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
330 if (IS_ERR(ptn_bridge->gpio_rst_n)) {
331 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
332 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
336 ret = of_property_read_u32(dev->of_node, "edid-emulation",
337 &ptn_bridge->edid_emulation);
339 dev_err(dev, "Can't read EDID emulation value\n");
343 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
344 ptn_bridge->bridge.of_node = dev->of_node;
345 ret = drm_bridge_add(&ptn_bridge->bridge);
347 DRM_ERROR("Failed to add bridge\n");
351 i2c_set_clientdata(client, ptn_bridge);
356 static int ptn3460_remove(struct i2c_client *client)
358 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
360 drm_bridge_remove(&ptn_bridge->bridge);
365 static const struct i2c_device_id ptn3460_i2c_table[] = {
369 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
371 static const struct of_device_id ptn3460_match[] = {
372 { .compatible = "nxp,ptn3460" },
375 MODULE_DEVICE_TABLE(of, ptn3460_match);
377 static struct i2c_driver ptn3460_driver = {
378 .id_table = ptn3460_i2c_table,
379 .probe = ptn3460_probe,
380 .remove = ptn3460_remove,
382 .name = "nxp,ptn3460",
383 .of_match_table = ptn3460_match,
386 module_i2c_driver(ptn3460_driver);
388 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
389 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
390 MODULE_LICENSE("GPL v2");