1 // SPDX-License-Identifier: GPL-2.0-only
3 * NXP PTN3460 DP/LVDS bridge driver
5 * Copyright (C) 2013 Google, Inc.
8 #include <linux/delay.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/module.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>
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
28 struct ptn3460_bridge {
29 struct drm_connector connector;
30 struct i2c_client *client;
31 struct drm_bridge bridge;
33 struct drm_panel *panel;
34 struct gpio_desc *gpio_pd_n;
35 struct gpio_desc *gpio_rst_n;
40 static inline struct ptn3460_bridge *
41 bridge_to_ptn3460(struct drm_bridge *bridge)
43 return container_of(bridge, struct ptn3460_bridge, bridge);
46 static inline struct ptn3460_bridge *
47 connector_to_ptn3460(struct drm_connector *connector)
49 return container_of(connector, struct ptn3460_bridge, connector);
52 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
57 ret = i2c_master_send(ptn_bridge->client, &addr, 1);
59 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
63 ret = i2c_master_recv(ptn_bridge->client, buf, len);
65 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
72 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
81 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
83 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
90 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
95 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
96 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
97 ptn_bridge->edid_emulation);
99 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
103 /* Enable EDID emulation and select the desired EDID */
104 val = 1 << PTN3460_EDID_ENABLE_EMULATION |
105 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
107 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
109 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
116 static void ptn3460_pre_enable(struct drm_bridge *bridge)
118 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
121 if (ptn_bridge->enabled)
124 gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
126 gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
127 usleep_range(10, 20);
128 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
130 if (drm_panel_prepare(ptn_bridge->panel)) {
131 DRM_ERROR("failed to prepare panel\n");
136 * There's a bug in the PTN chip where it falsely asserts hotplug before
137 * it is fully functional. We're forced to wait for the maximum start up
138 * time specified in the chip's datasheet to make sure we're really up.
142 ret = ptn3460_select_edid(ptn_bridge);
144 DRM_ERROR("Select EDID failed ret=%d\n", ret);
146 ptn_bridge->enabled = true;
149 static void ptn3460_enable(struct drm_bridge *bridge)
151 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
153 if (drm_panel_enable(ptn_bridge->panel)) {
154 DRM_ERROR("failed to enable panel\n");
159 static void ptn3460_disable(struct drm_bridge *bridge)
161 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
163 if (!ptn_bridge->enabled)
166 ptn_bridge->enabled = false;
168 if (drm_panel_disable(ptn_bridge->panel)) {
169 DRM_ERROR("failed to disable panel\n");
173 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
174 gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
177 static void ptn3460_post_disable(struct drm_bridge *bridge)
179 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
181 if (drm_panel_unprepare(ptn_bridge->panel)) {
182 DRM_ERROR("failed to unprepare panel\n");
187 static int ptn3460_get_modes(struct drm_connector *connector)
189 struct ptn3460_bridge *ptn_bridge;
191 int ret, num_modes = 0;
194 ptn_bridge = connector_to_ptn3460(connector);
196 if (ptn_bridge->edid)
197 return drm_add_edid_modes(connector, ptn_bridge->edid);
199 power_off = !ptn_bridge->enabled;
200 ptn3460_pre_enable(&ptn_bridge->bridge);
202 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
204 DRM_ERROR("Failed to allocate EDID\n");
208 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
215 ptn_bridge->edid = (struct edid *)edid;
216 drm_connector_update_edid_property(connector, ptn_bridge->edid);
218 num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
222 ptn3460_disable(&ptn_bridge->bridge);
227 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
228 .get_modes = ptn3460_get_modes,
231 static const struct drm_connector_funcs ptn3460_connector_funcs = {
232 .fill_modes = drm_helper_probe_single_connector_modes,
233 .destroy = drm_connector_cleanup,
234 .reset = drm_atomic_helper_connector_reset,
235 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
236 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
239 static int ptn3460_bridge_attach(struct drm_bridge *bridge,
240 enum drm_bridge_attach_flags flags)
242 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
245 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
246 DRM_ERROR("Fix bridge driver to make connector optional!");
250 if (!bridge->encoder) {
251 DRM_ERROR("Parent encoder object not found");
255 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
256 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
257 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
259 DRM_ERROR("Failed to initialize connector with drm\n");
262 drm_connector_helper_add(&ptn_bridge->connector,
263 &ptn3460_connector_helper_funcs);
264 drm_connector_register(&ptn_bridge->connector);
265 drm_connector_attach_encoder(&ptn_bridge->connector,
268 if (ptn_bridge->panel)
269 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
271 drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
276 static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
277 .pre_enable = ptn3460_pre_enable,
278 .enable = ptn3460_enable,
279 .disable = ptn3460_disable,
280 .post_disable = ptn3460_post_disable,
281 .attach = ptn3460_bridge_attach,
284 static int ptn3460_probe(struct i2c_client *client,
285 const struct i2c_device_id *id)
287 struct device *dev = &client->dev;
288 struct ptn3460_bridge *ptn_bridge;
291 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
296 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ptn_bridge->panel, NULL);
300 ptn_bridge->client = client;
302 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
304 if (IS_ERR(ptn_bridge->gpio_pd_n)) {
305 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
306 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
311 * Request the reset pin low to avoid the bridge being
312 * initialized prematurely
314 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
316 if (IS_ERR(ptn_bridge->gpio_rst_n)) {
317 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
318 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
322 ret = of_property_read_u32(dev->of_node, "edid-emulation",
323 &ptn_bridge->edid_emulation);
325 dev_err(dev, "Can't read EDID emulation value\n");
329 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
330 ptn_bridge->bridge.of_node = dev->of_node;
331 drm_bridge_add(&ptn_bridge->bridge);
333 i2c_set_clientdata(client, ptn_bridge);
338 static int ptn3460_remove(struct i2c_client *client)
340 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
342 drm_bridge_remove(&ptn_bridge->bridge);
347 static const struct i2c_device_id ptn3460_i2c_table[] = {
351 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
353 static const struct of_device_id ptn3460_match[] = {
354 { .compatible = "nxp,ptn3460" },
357 MODULE_DEVICE_TABLE(of, ptn3460_match);
359 static struct i2c_driver ptn3460_driver = {
360 .id_table = ptn3460_i2c_table,
361 .probe = ptn3460_probe,
362 .remove = ptn3460_remove,
364 .name = "nxp,ptn3460",
365 .of_match_table = ptn3460_match,
368 module_i2c_driver(ptn3460_driver);
370 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
371 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
372 MODULE_LICENSE("GPL v2");