1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Driver for the Auvitek AU0828 USB bridge
4 *
5 *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
6 */
7
8#include "au0828.h"
9
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/init.h>
13#include <linux/delay.h>
14#include <linux/io.h>
15
16#include "media/tuner.h"
17#include <media/v4l2-common.h>
18
19static int i2c_scan;
20module_param(i2c_scan, int, 0444);
21MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
22
23#define I2C_WAIT_DELAY 25
24#define I2C_WAIT_RETRY 1000
25
26static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
27{
28	struct au0828_dev *dev = i2c_adap->algo_data;
29	return au0828_read(dev, AU0828_I2C_STATUS_201) &
30		AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
31}
32
33static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
34{
35	int count;
36
37	for (count = 0; count < I2C_WAIT_RETRY; count++) {
38		if (!i2c_slave_did_read_ack(i2c_adap))
39			break;
40		udelay(I2C_WAIT_DELAY);
41	}
42
43	if (I2C_WAIT_RETRY == count)
44		return 0;
45
46	return 1;
47}
48
49static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
50{
51	struct au0828_dev *dev = i2c_adap->algo_data;
52	return au0828_read(dev, AU0828_I2C_STATUS_201) &
53		AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
54}
55
56static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
57{
58	int count;
59
60	for (count = 0; count < I2C_WAIT_RETRY; count++) {
61		if (!i2c_is_read_busy(i2c_adap))
62			break;
63		udelay(I2C_WAIT_DELAY);
64	}
65
66	if (I2C_WAIT_RETRY == count)
67		return 0;
68
69	return 1;
70}
71
72static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
73{
74	struct au0828_dev *dev = i2c_adap->algo_data;
75	return au0828_read(dev, AU0828_I2C_STATUS_201) &
76		AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
77}
78
79static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
80{
81	int count;
82
83	for (count = 0; count < I2C_WAIT_RETRY; count++) {
84		if (i2c_is_write_done(i2c_adap))
85			break;
86		udelay(I2C_WAIT_DELAY);
87	}
88
89	if (I2C_WAIT_RETRY == count)
90		return 0;
91
92	return 1;
93}
94
95static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
96{
97	struct au0828_dev *dev = i2c_adap->algo_data;
98	return au0828_read(dev, AU0828_I2C_STATUS_201) &
99		AU0828_I2C_STATUS_BUSY ? 1 : 0;
100}
101
102static int i2c_wait_done(struct i2c_adapter *i2c_adap)
103{
104	int count;
105
106	for (count = 0; count < I2C_WAIT_RETRY; count++) {
107		if (!i2c_is_busy(i2c_adap))
108			break;
109		udelay(I2C_WAIT_DELAY);
110	}
111
112	if (I2C_WAIT_RETRY == count)
113		return 0;
114
115	return 1;
116}
117
118/* FIXME: Implement join handling correctly */
119static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
120	const struct i2c_msg *msg, int joined_rlen)
121{
122	int i, strobe = 0;
123	struct au0828_dev *dev = i2c_adap->algo_data;
124	u8 i2c_speed = dev->board.i2c_clk_divider;
125
126	dprintk(4, "%s()\n", __func__);
127
128	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
129
130	if (((dev->board.tuner_type == TUNER_XC5000) ||
131	     (dev->board.tuner_type == TUNER_XC5000C)) &&
132	    (dev->board.tuner_addr == msg->addr)) {
133		/*
134		 * Due to I2C clock stretch, we need to use a lower speed
135		 * on xc5000 for commands. However, firmware transfer can
136		 * speed up to 400 KHz.
137		 */
138		if (msg->len == 64)
139			i2c_speed = AU0828_I2C_CLK_250KHZ;
140		else
141			i2c_speed = AU0828_I2C_CLK_20KHZ;
142	}
143	/* Set the I2C clock */
144	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
145
146	/* Hardware needs 8 bit addresses */
147	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
148
149	dprintk(4, "SEND: %02x\n", msg->addr);
150
151	/* Deal with i2c_scan */
152	if (msg->len == 0) {
153		/* The analog tuner detection code makes use of the SMBUS_QUICK
154		   message (which involves a zero length i2c write).  To avoid
155		   checking the status register when we didn't strobe out any
156		   actual bytes to the bus, just do a read check.  This is
157		   consistent with how I saw i2c device checking done in the
158		   USB trace of the Windows driver */
159		au0828_write(dev, AU0828_I2C_TRIGGER_200,
160			     AU0828_I2C_TRIGGER_READ);
161
162		if (!i2c_wait_done(i2c_adap))
163			return -EIO;
164
165		if (i2c_wait_read_ack(i2c_adap))
166			return -EIO;
167
168		return 0;
169	}
170
171	for (i = 0; i < msg->len;) {
172
173		dprintk(4, " %02x\n", msg->buf[i]);
174
175		au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
176
177		strobe++;
178		i++;
179
180		if ((strobe >= 4) || (i >= msg->len)) {
181
182			/* Strobe the byte into the bus */
183			if (i < msg->len)
184				au0828_write(dev, AU0828_I2C_TRIGGER_200,
185					     AU0828_I2C_TRIGGER_WRITE |
186					     AU0828_I2C_TRIGGER_HOLD);
187			else
188				au0828_write(dev, AU0828_I2C_TRIGGER_200,
189					     AU0828_I2C_TRIGGER_WRITE);
190
191			/* Reset strobe trigger */
192			strobe = 0;
193
194			if (!i2c_wait_write_done(i2c_adap))
195				return -EIO;
196
197		}
198
199	}
200	if (!i2c_wait_done(i2c_adap))
201		return -EIO;
202
203	dprintk(4, "\n");
204
205	return msg->len;
206}
207
208/* FIXME: Implement join handling correctly */
209static int i2c_readbytes(struct i2c_adapter *i2c_adap,
210	const struct i2c_msg *msg, int joined)
211{
212	struct au0828_dev *dev = i2c_adap->algo_data;
213	u8 i2c_speed = dev->board.i2c_clk_divider;
214	int i;
215
216	dprintk(4, "%s()\n", __func__);
217
218	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
219
220	/*
221	 * Due to xc5000c clock stretch, we cannot use full speed at
222	 * readings from xc5000, as otherwise they'll fail.
223	 */
224	if (((dev->board.tuner_type == TUNER_XC5000) ||
225	     (dev->board.tuner_type == TUNER_XC5000C)) &&
226	    (dev->board.tuner_addr == msg->addr))
227		i2c_speed = AU0828_I2C_CLK_20KHZ;
228
229	/* Set the I2C clock */
230	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
231
232	/* Hardware needs 8 bit addresses */
233	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
234
235	dprintk(4, " RECV:\n");
236
237	/* Deal with i2c_scan */
238	if (msg->len == 0) {
239		au0828_write(dev, AU0828_I2C_TRIGGER_200,
240			     AU0828_I2C_TRIGGER_READ);
241
242		if (i2c_wait_read_ack(i2c_adap))
243			return -EIO;
244		return 0;
245	}
246
247	for (i = 0; i < msg->len;) {
248
249		i++;
250
251		if (i < msg->len)
252			au0828_write(dev, AU0828_I2C_TRIGGER_200,
253				     AU0828_I2C_TRIGGER_READ |
254				     AU0828_I2C_TRIGGER_HOLD);
255		else
256			au0828_write(dev, AU0828_I2C_TRIGGER_200,
257				     AU0828_I2C_TRIGGER_READ);
258
259		if (!i2c_wait_read_done(i2c_adap))
260			return -EIO;
261
262		msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
263			0xff;
264
265		dprintk(4, " %02x\n", msg->buf[i-1]);
266	}
267	if (!i2c_wait_done(i2c_adap))
268		return -EIO;
269
270	dprintk(4, "\n");
271
272	return msg->len;
273}
274
275static int i2c_xfer(struct i2c_adapter *i2c_adap,
276		    struct i2c_msg *msgs, int num)
277{
278	int i, retval = 0;
279
280	dprintk(4, "%s(num = %d)\n", __func__, num);
281
282	for (i = 0; i < num; i++) {
283		dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
284			__func__, num, msgs[i].addr, msgs[i].len);
285		if (msgs[i].flags & I2C_M_RD) {
286			/* read */
287			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
288		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
289			   msgs[i].addr == msgs[i + 1].addr) {
290			/* write then read from same address */
291			retval = i2c_sendbytes(i2c_adap, &msgs[i],
292					       msgs[i + 1].len);
293			if (retval < 0)
294				goto err;
295			i++;
296			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
297		} else {
298			/* write */
299			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
300		}
301		if (retval < 0)
302			goto err;
303	}
304	return num;
305
306err:
307	return retval;
308}
309
310static u32 au0828_functionality(struct i2c_adapter *adap)
311{
312	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
313}
314
315static const struct i2c_algorithm au0828_i2c_algo_template = {
316	.master_xfer	= i2c_xfer,
317	.functionality	= au0828_functionality,
318};
319
320/* ----------------------------------------------------------------------- */
321
322static const struct i2c_adapter au0828_i2c_adap_template = {
323	.name              = KBUILD_MODNAME,
324	.owner             = THIS_MODULE,
325	.algo              = &au0828_i2c_algo_template,
326};
327
328static const struct i2c_client au0828_i2c_client_template = {
329	.name	= "au0828 internal",
330};
331
332static char *i2c_devs[128] = {
333	[0x8e >> 1] = "au8522",
334	[0xa0 >> 1] = "eeprom",
335	[0xc2 >> 1] = "tuner/xc5000",
336};
337
338static void do_i2c_scan(char *name, struct i2c_client *c)
339{
340	unsigned char buf;
341	int i, rc;
342
343	for (i = 0; i < 128; i++) {
344		c->addr = i;
345		rc = i2c_master_recv(c, &buf, 0);
346		if (rc < 0)
347			continue;
348		pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
349		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
350	}
351}
352
353/* init + register i2c adapter */
354int au0828_i2c_register(struct au0828_dev *dev)
355{
356	dprintk(1, "%s()\n", __func__);
357
358	dev->i2c_adap = au0828_i2c_adap_template;
359	dev->i2c_algo = au0828_i2c_algo_template;
360	dev->i2c_client = au0828_i2c_client_template;
361
362	dev->i2c_adap.dev.parent = &dev->usbdev->dev;
363
364	strscpy(dev->i2c_adap.name, KBUILD_MODNAME,
365		sizeof(dev->i2c_adap.name));
366
367	dev->i2c_adap.algo = &dev->i2c_algo;
368	dev->i2c_adap.algo_data = dev;
369#ifdef CONFIG_VIDEO_AU0828_V4L2
370	i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
371#else
372	i2c_set_adapdata(&dev->i2c_adap, dev);
373#endif
374	i2c_add_adapter(&dev->i2c_adap);
375
376	dev->i2c_client.adapter = &dev->i2c_adap;
377
378	if (0 == dev->i2c_rc) {
379		pr_info("i2c bus registered\n");
380		if (i2c_scan)
381			do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
382	} else
383		pr_info("i2c bus register FAILED\n");
384
385	return dev->i2c_rc;
386}
387
388int au0828_i2c_unregister(struct au0828_dev *dev)
389{
390	i2c_del_adapter(&dev->i2c_adap);
391	return 0;
392}
393
394