summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/bridge/cadence/cdns-mhdp-cec.c
blob: 029ad761606a9c4aa33a1bb318bff94a0ff9dc43 (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
/*
 * Copyright 2019 NXP
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <drm/bridge/cdns-mhdp.h>

#define CEC_NAME	"cdns-mhdp-cec"

#define REG_ADDR_OFF 4

/* regsiter define */
#define TX_MSG_HEADER 0x33800
#define TX_MSG_LENGTH 0x33840
#define TX_MSG_CMD 0x33844
#define RX_MSG_CMD 0x33850
#define RX_CLEAR_BUF 0x33854
#define LOGICAL_ADDRESS_LA0 0x33858

#define CLK_DIV_MSB 0x3386c
#define CLK_DIV_LSB 0x33870
#define RX_MSG_DATA1 0x33900
#define RX_MSG_LENGTH 0x33940
#define RX_MSG_STATUS 0x33944
#define NUM_OF_MSG_RX_BUF 0x33948
#define TX_MSG_STATUS 0x3394c
#define DB_L_TIMER 0x33980

/**
 * CEC Transceiver operation.
 */
enum {
	CEC_TX_STOP,
	CEC_TX_TRANSMIT,
	CEC_TX_ABORT,
	CEC_TX_ABORT_AND_TRANSMIT
};

/**
 * CEC Transceiver status.
 */
enum {
	CEC_STS_IDLE,
	CEC_STS_BUSY,
	CEC_STS_SUCCESS,
	CEC_STS_ERROR
};

/**
 * CEC Receiver operation.
 */
enum {
	CEC_RX_STOP,
	CEC_RX_READ,
	CEC_RX_DISABLE,
	CEC_RX_ABORT_AND_CLR_FIFO
};
/**
 * Maximum number of Messages in the RX Buffers.
 */
#define CEC_MAX_RX_MSGS 2

static u32 mhdp_cec_read(struct cdns_mhdp_cec *cec, u32 offset)
{
	struct cdns_mhdp_device *mhdp =
			container_of(cec, struct cdns_mhdp_device, hdmi.cec);
	return cdns_mhdp_bus_read(mhdp, offset);
}

static void mhdp_cec_write(struct cdns_mhdp_cec *cec, u32 offset, u32 val)
{
	struct cdns_mhdp_device *mhdp =
			container_of(cec, struct cdns_mhdp_device, hdmi.cec);
	cdns_mhdp_bus_write(val, mhdp, offset);
}

static void mhdp_cec_clear_rx_buffer(struct cdns_mhdp_cec *cec)
{
	mhdp_cec_write(cec, RX_CLEAR_BUF, 1);
	mhdp_cec_write(cec, RX_CLEAR_BUF, 0);
}

static void mhdp_cec_set_divider(struct cdns_mhdp_cec *cec)
{
	struct cdns_mhdp_device *mhdp =
			container_of(cec, struct cdns_mhdp_device, hdmi.cec);
	u32 clk_div;

	/* Set clock divider */
	clk_div = cdns_mhdp_get_fw_clk(mhdp) * 10;

	mhdp_cec_write(cec, CLK_DIV_MSB,
			  (clk_div >> 8) & 0xFF);
	mhdp_cec_write(cec, CLK_DIV_LSB, clk_div & 0xFF);
}

static u32 mhdp_cec_read_message(struct cdns_mhdp_cec *cec)
{
	struct cec_msg *msg = &cec->msg;
	int len;
	int i;

	mhdp_cec_write(cec, RX_MSG_CMD, CEC_RX_READ);

	len = mhdp_cec_read(cec, RX_MSG_LENGTH);
	msg->len = len + 1;
	dev_dbg(cec->dev, "RX MSG len =%d\n", len);

	/* Read RX MSG bytes */
	for (i = 0; i < msg->len; ++i) {
		msg->msg[i] = (u8) mhdp_cec_read(cec, RX_MSG_DATA1 + (i * REG_ADDR_OFF));
		dev_dbg(cec->dev, "RX MSG[%d]=0x%x\n", i, msg->msg[i]);
	}

	mhdp_cec_write(cec, RX_MSG_CMD, CEC_RX_STOP);

	return true;
}

static u32 mhdp_cec_write_message(struct cdns_mhdp_cec *cec, struct cec_msg *msg)
{
	u8 i;

	mhdp_cec_write(cec, TX_MSG_CMD, CEC_TX_STOP);

	if (msg->len > CEC_MAX_MSG_SIZE) {
		dev_err(cec->dev, "Invalid MSG size!\n");
		return -EINVAL;
	}

	for (i = 0; i < msg->len; ++i)
		printk("msg[%d]=0x%x\n",i, msg->msg[i]);

	/* Write Message to register */
	for (i = 0; i < msg->len; ++i) {
		mhdp_cec_write(cec, TX_MSG_HEADER + (i * REG_ADDR_OFF),
			  msg->msg[i]);
	}
	/* Write Message Length (payload + opcode) */
	mhdp_cec_write(cec, TX_MSG_LENGTH, msg->len - 1);

	mhdp_cec_write(cec, TX_MSG_CMD, CEC_TX_TRANSMIT);

	return true;
}

static int mhdp_cec_set_logical_addr(struct cdns_mhdp_cec *cec, u32 la)
{
	u8 la_reg;
	u8 i;

	if (la == CEC_LOG_ADDR_INVALID)
		/* invalid all LA address */
		for (i = 0; i < CEC_MAX_LOG_ADDRS; i++) {
			mhdp_cec_write(cec, LOGICAL_ADDRESS_LA0 + (i * REG_ADDR_OFF), 0);
			return 0;
		}

	/* In fact cdns mhdp cec could support max 5 La address */
	for (i = 0; i < CEC_MAX_LOG_ADDRS; i++) {
		la_reg = mhdp_cec_read(cec, LOGICAL_ADDRESS_LA0 + (i * REG_ADDR_OFF));
		/* Check LA already used */
		if (la_reg & 0x10)
			continue;

		if ((la_reg & 0xF) == la) {
			dev_warn(cec->dev, "Warning. LA already in use.\n");
			return 0;
		}

		la = (la & 0xF) | (1 << 4);

		mhdp_cec_write(cec, LOGICAL_ADDRESS_LA0 + (i * REG_ADDR_OFF), la);
		return 0;
	}

	dev_warn(cec->dev, "All LA in use\n");

	return -ENXIO;
}

static int mhdp_cec_poll_worker(void *_cec)
{
	struct cdns_mhdp_cec *cec = (struct cdns_mhdp_cec *)_cec;
	int num_rx_msgs, i;
	int sts;

	set_freezable();

	for (;;) {
		if (kthread_freezable_should_stop(NULL))
			break;

		/* Check TX State */
		sts = mhdp_cec_read(cec, TX_MSG_STATUS);
		switch (sts) {
		case CEC_STS_SUCCESS:
			cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0,
					  0);
			mhdp_cec_write(cec, TX_MSG_CMD, CEC_TX_STOP);
			break;
		case CEC_STS_ERROR:
			mhdp_cec_write(cec, TX_MSG_CMD, CEC_TX_STOP);
			cec_transmit_done(cec->adap,
					  CEC_TX_STATUS_MAX_RETRIES |
					  CEC_TX_STATUS_NACK, 0, 1, 0, 0);
			break;
		case CEC_STS_BUSY:
		default:
			break;
		}

		/* Check RX State */
		sts = mhdp_cec_read(cec, RX_MSG_STATUS);
		num_rx_msgs = mhdp_cec_read(cec, NUM_OF_MSG_RX_BUF);
		switch (sts) {
		case CEC_STS_SUCCESS:
			if (num_rx_msgs == 0xf)
				num_rx_msgs = CEC_MAX_RX_MSGS;

			if (num_rx_msgs > CEC_MAX_RX_MSGS) {
				dev_err(cec->dev, "Error rx msg num %d\n",
					num_rx_msgs);
				mhdp_cec_clear_rx_buffer(cec);
				break;
			}

			/* Rx FIFO Depth 2 RX MSG */
			for (i = 0; i < num_rx_msgs; i++) {
				mhdp_cec_read_message(cec);
				cec->msg.rx_status = CEC_RX_STATUS_OK;
				cec_received_msg(cec->adap, &cec->msg);
			}
			break;
		default:
			break;
		}

		if (!kthread_should_stop())
			schedule_timeout_idle(20);
	}

	return 0;
}

static int mhdp_cec_adap_enable(struct cec_adapter *adap, bool enable)
{
	struct cdns_mhdp_cec *cec = cec_get_drvdata(adap);

	if (enable) {
		mhdp_cec_write(cec, DB_L_TIMER, 0x10);
		mhdp_cec_set_divider(cec);
	} else
		mhdp_cec_set_divider(cec);

	return 0;
}

static int mhdp_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
{
	struct cdns_mhdp_cec *cec = cec_get_drvdata(adap);

	return mhdp_cec_set_logical_addr(cec, addr);
}

static int mhdp_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
				 u32 signal_free_time, struct cec_msg *msg)
{
	struct cdns_mhdp_cec *cec = cec_get_drvdata(adap);

	mhdp_cec_write_message(cec, msg);

	return 0;
}

static const struct cec_adap_ops cdns_mhdp_cec_adap_ops = {
	.adap_enable = mhdp_cec_adap_enable,
	.adap_log_addr = mhdp_cec_adap_log_addr,
	.adap_transmit = mhdp_cec_adap_transmit,
};

int cdns_mhdp_register_cec_driver(struct device *dev)
{
	struct cdns_mhdp_device *mhdp = dev_get_drvdata(dev);
	struct cdns_mhdp_cec *cec = &mhdp->hdmi.cec;
	int ret;

	cec->adap = cec_allocate_adapter(&cdns_mhdp_cec_adap_ops, cec,
					 CEC_NAME,
					 CEC_CAP_PHYS_ADDR | CEC_CAP_LOG_ADDRS |
					 CEC_CAP_TRANSMIT | CEC_CAP_PASSTHROUGH
					 | CEC_CAP_RC, CEC_MAX_LOG_ADDRS);
	ret = PTR_ERR_OR_ZERO(cec->adap);
	if (ret)
		return ret;
	ret = cec_register_adapter(cec->adap, dev);
	if (ret) {
		cec_delete_adapter(cec->adap);
		return ret;
	}

	cec->dev = dev;

	cec->cec_worker = kthread_create(mhdp_cec_poll_worker, cec, "cdns-mhdp-cec");
	if (IS_ERR(cec->cec_worker))
		dev_err(cec->dev, "failed  create hdp cec thread\n");

	wake_up_process(cec->cec_worker);

	dev_dbg(dev, "CEC successfuly probed\n");
	return 0;
}

int cdns_mhdp_unregister_cec_driver(struct device *dev)
{
	struct cdns_mhdp_device *mhdp = dev_get_drvdata(dev);
	struct cdns_mhdp_cec *cec = &mhdp->hdmi.cec;

	if (cec->cec_worker) {
		kthread_stop(cec->cec_worker);
		cec->cec_worker = NULL;
	}
	cec_unregister_adapter(cec->adap);
	return 0;
}

MODULE_AUTHOR("Sandor.Yu@NXP.com");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("NXP CDNS MHDP HDMI CEC driver");