summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/bridge/nxp-ptn3460.c
blob: 0851101a8c72430aace124f1e61d1702a7fff975 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
// SPDX-License-Identifier: GPL-2.0-only
/*
 * NXP PTN3460 DP/LVDS bridge driver
 *
 * Copyright (C) 2013 Google, Inc.
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#define PTN3460_EDID_ADDR			0x0
#define PTN3460_EDID_EMULATION_ADDR		0x84
#define PTN3460_EDID_ENABLE_EMULATION		0
#define PTN3460_EDID_EMULATION_SELECTION	1
#define PTN3460_EDID_SRAM_LOAD_ADDR		0x85

struct ptn3460_bridge {
	struct drm_connector connector;
	struct i2c_client *client;
	struct drm_bridge bridge;
	struct drm_bridge *panel_bridge;
	struct gpio_desc *gpio_pd_n;
	struct gpio_desc *gpio_rst_n;
	u32 edid_emulation;
	bool enabled;
};

static inline struct ptn3460_bridge *
		bridge_to_ptn3460(struct drm_bridge *bridge)
{
	return container_of(bridge, struct ptn3460_bridge, bridge);
}

static inline struct ptn3460_bridge *
		connector_to_ptn3460(struct drm_connector *connector)
{
	return container_of(connector, struct ptn3460_bridge, connector);
}

static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
		u8 *buf, int len)
{
	int ret;

	ret = i2c_master_send(ptn_bridge->client, &addr, 1);
	if (ret <= 0) {
		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
		return ret;
	}

	ret = i2c_master_recv(ptn_bridge->client, buf, len);
	if (ret <= 0) {
		DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
		return ret;
	}

	return 0;
}

static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
		char val)
{
	int ret;
	char buf[2];

	buf[0] = addr;
	buf[1] = val;

	ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
	if (ret <= 0) {
		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
		return ret;
	}

	return 0;
}

static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
{
	int ret;
	char val;

	/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
			ptn_bridge->edid_emulation);
	if (ret) {
		DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
		return ret;
	}

	/* Enable EDID emulation and select the desired EDID */
	val = 1 << PTN3460_EDID_ENABLE_EMULATION |
		ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;

	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
	if (ret) {
		DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
		return ret;
	}

	return 0;
}

static void ptn3460_pre_enable(struct drm_bridge *bridge)
{
	struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
	int ret;

	if (ptn_bridge->enabled)
		return;

	gpiod_set_value(ptn_bridge->gpio_pd_n, 1);

	gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
	usleep_range(10, 20);
	gpiod_set_value(ptn_bridge->gpio_rst_n, 1);

	/*
	 * There's a bug in the PTN chip where it falsely asserts hotplug before
	 * it is fully functional. We're forced to wait for the maximum start up
	 * time specified in the chip's datasheet to make sure we're really up.
	 */
	msleep(90);

	ret = ptn3460_select_edid(ptn_bridge);
	if (ret)
		DRM_ERROR("Select EDID failed ret=%d\n", ret);

	ptn_bridge->enabled = true;
}

static void ptn3460_disable(struct drm_bridge *bridge)
{
	struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);

	if (!ptn_bridge->enabled)
		return;

	ptn_bridge->enabled = false;

	gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
	gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
}


static struct edid *ptn3460_get_edid(struct drm_bridge *bridge,
				     struct drm_connector *connector)
{
	struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
	bool power_off;
	u8 *edid;
	int ret;

	power_off = !ptn_bridge->enabled;
	ptn3460_pre_enable(&ptn_bridge->bridge);

	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
	if (!edid) {
		DRM_ERROR("Failed to allocate EDID\n");
		goto out;
	}

	ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
				 EDID_LENGTH);
	if (ret) {
		kfree(edid);
		edid = NULL;
		goto out;
	}

out:
	if (power_off)
		ptn3460_disable(&ptn_bridge->bridge);

	return (struct edid *)edid;
}

static int ptn3460_connector_get_modes(struct drm_connector *connector)
{
	struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);
	struct edid *edid;
	int num_modes;

	edid = ptn3460_get_edid(&ptn_bridge->bridge, connector);
	drm_connector_update_edid_property(connector, edid);
	num_modes = drm_add_edid_modes(connector, edid);
	kfree(edid);

	return num_modes;
}

static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
	.get_modes = ptn3460_connector_get_modes,
};

static const struct drm_connector_funcs ptn3460_connector_funcs = {
	.fill_modes = drm_helper_probe_single_connector_modes,
	.destroy = drm_connector_cleanup,
	.reset = drm_atomic_helper_connector_reset,
	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int ptn3460_bridge_attach(struct drm_bridge *bridge,
				 enum drm_bridge_attach_flags flags)
{
	struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
	int ret;

	/* Let this driver create connector if requested */
	ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge,
				bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
	if (ret < 0)
		return ret;

	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
		return 0;

	if (!bridge->encoder) {
		DRM_ERROR("Parent encoder object not found");
		return -ENODEV;
	}

	ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
	ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
			&ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
	if (ret) {
		DRM_ERROR("Failed to initialize connector with drm\n");
		return ret;
	}
	drm_connector_helper_add(&ptn_bridge->connector,
					&ptn3460_connector_helper_funcs);
	drm_connector_register(&ptn_bridge->connector);
	drm_connector_attach_encoder(&ptn_bridge->connector,
							bridge->encoder);

	drm_helper_hpd_irq_event(ptn_bridge->connector.dev);

	return ret;
}

static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
	.pre_enable = ptn3460_pre_enable,
	.disable = ptn3460_disable,
	.attach = ptn3460_bridge_attach,
	.get_edid = ptn3460_get_edid,
};

static int ptn3460_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct ptn3460_bridge *ptn_bridge;
	struct drm_bridge *panel_bridge;
	int ret;

	ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
	if (!ptn_bridge) {
		return -ENOMEM;
	}

	panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
	if (IS_ERR(panel_bridge))
		return PTR_ERR(panel_bridge);

	ptn_bridge->panel_bridge = panel_bridge;
	ptn_bridge->client = client;

	ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
					       GPIOD_OUT_HIGH);
	if (IS_ERR(ptn_bridge->gpio_pd_n)) {
		ret = PTR_ERR(ptn_bridge->gpio_pd_n);
		dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
		return ret;
	}

	/*
	 * Request the reset pin low to avoid the bridge being
	 * initialized prematurely
	 */
	ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
						GPIOD_OUT_LOW);
	if (IS_ERR(ptn_bridge->gpio_rst_n)) {
		ret = PTR_ERR(ptn_bridge->gpio_rst_n);
		DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
		return ret;
	}

	ret = of_property_read_u32(dev->of_node, "edid-emulation",
			&ptn_bridge->edid_emulation);
	if (ret) {
		dev_err(dev, "Can't read EDID emulation value\n");
		return ret;
	}

	ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
	ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
	ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS;
	ptn_bridge->bridge.of_node = dev->of_node;
	drm_bridge_add(&ptn_bridge->bridge);

	i2c_set_clientdata(client, ptn_bridge);

	return 0;
}

static void ptn3460_remove(struct i2c_client *client)
{
	struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);

	drm_bridge_remove(&ptn_bridge->bridge);
}

static const struct i2c_device_id ptn3460_i2c_table[] = {
	{"ptn3460", 0},
	{},
};
MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);

static const struct of_device_id ptn3460_match[] = {
	{ .compatible = "nxp,ptn3460" },
	{},
};
MODULE_DEVICE_TABLE(of, ptn3460_match);

static struct i2c_driver ptn3460_driver = {
	.id_table	= ptn3460_i2c_table,
	.probe		= ptn3460_probe,
	.remove		= ptn3460_remove,
	.driver		= {
		.name	= "nxp,ptn3460",
		.of_match_table = ptn3460_match,
	},
};
module_i2c_driver(ptn3460_driver);

MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
MODULE_LICENSE("GPL v2");