1 /*
2  *  Driver for the Auvitek AU0828 USB bridge
3  *
4  *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #include "au0828.h"
23 
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/init.h>
27 #include <linux/delay.h>
28 #include <linux/io.h>
29 
30 #include "media/tuner.h"
31 #include <media/v4l2-common.h>
32 
33 static int i2c_scan;
34 module_param(i2c_scan, int, 0444);
35 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
36 
37 #define I2C_WAIT_DELAY 25
38 #define I2C_WAIT_RETRY 1000
39 
40 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
41 {
42 	struct au0828_dev *dev = i2c_adap->algo_data;
43 	return au0828_read(dev, AU0828_I2C_STATUS_201) &
44 		AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
45 }
46 
47 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
48 {
49 	struct au0828_dev *dev = i2c_adap->algo_data;
50 	return au0828_read(dev, AU0828_I2C_STATUS_201) &
51 		AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
52 }
53 
54 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
55 {
56 	int count;
57 
58 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
59 		if (!i2c_slave_did_read_ack(i2c_adap))
60 			break;
61 		udelay(I2C_WAIT_DELAY);
62 	}
63 
64 	if (I2C_WAIT_RETRY == count)
65 		return 0;
66 
67 	return 1;
68 }
69 
70 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
71 {
72 	struct au0828_dev *dev = i2c_adap->algo_data;
73 	return au0828_read(dev, AU0828_I2C_STATUS_201) &
74 		AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
75 }
76 
77 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
78 {
79 	int count;
80 
81 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
82 		if (!i2c_is_read_busy(i2c_adap))
83 			break;
84 		udelay(I2C_WAIT_DELAY);
85 	}
86 
87 	if (I2C_WAIT_RETRY == count)
88 		return 0;
89 
90 	return 1;
91 }
92 
93 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
94 {
95 	struct au0828_dev *dev = i2c_adap->algo_data;
96 	return au0828_read(dev, AU0828_I2C_STATUS_201) &
97 		AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
98 }
99 
100 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
101 {
102 	int count;
103 
104 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
105 		if (i2c_is_write_done(i2c_adap))
106 			break;
107 		udelay(I2C_WAIT_DELAY);
108 	}
109 
110 	if (I2C_WAIT_RETRY == count)
111 		return 0;
112 
113 	return 1;
114 }
115 
116 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
117 {
118 	struct au0828_dev *dev = i2c_adap->algo_data;
119 	return au0828_read(dev, AU0828_I2C_STATUS_201) &
120 		AU0828_I2C_STATUS_BUSY ? 1 : 0;
121 }
122 
123 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
124 {
125 	int count;
126 
127 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
128 		if (!i2c_is_busy(i2c_adap))
129 			break;
130 		udelay(I2C_WAIT_DELAY);
131 	}
132 
133 	if (I2C_WAIT_RETRY == count)
134 		return 0;
135 
136 	return 1;
137 }
138 
139 /* FIXME: Implement join handling correctly */
140 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
141 	const struct i2c_msg *msg, int joined_rlen)
142 {
143 	int i, strobe = 0;
144 	struct au0828_dev *dev = i2c_adap->algo_data;
145 	u8 i2c_speed = dev->board.i2c_clk_divider;
146 
147 	dprintk(4, "%s()\n", __func__);
148 
149 	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
150 
151 	if (((dev->board.tuner_type == TUNER_XC5000) ||
152 	     (dev->board.tuner_type == TUNER_XC5000C)) &&
153 	    (dev->board.tuner_addr == msg->addr)) {
154 		/*
155 		 * Due to I2C clock stretch, we need to use a lower speed
156 		 * on xc5000 for commands. However, firmware transfer can
157 		 * speed up to 400 KHz.
158 		 */
159 		if (msg->len == 64)
160 			i2c_speed = AU0828_I2C_CLK_250KHZ;
161 		else
162 			i2c_speed = AU0828_I2C_CLK_20KHZ;
163 	}
164 	/* Set the I2C clock */
165 	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
166 
167 	/* Hardware needs 8 bit addresses */
168 	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
169 
170 	dprintk(4, "SEND: %02x\n", msg->addr);
171 
172 	/* Deal with i2c_scan */
173 	if (msg->len == 0) {
174 		/* The analog tuner detection code makes use of the SMBUS_QUICK
175 		   message (which involves a zero length i2c write).  To avoid
176 		   checking the status register when we didn't strobe out any
177 		   actual bytes to the bus, just do a read check.  This is
178 		   consistent with how I saw i2c device checking done in the
179 		   USB trace of the Windows driver */
180 		au0828_write(dev, AU0828_I2C_TRIGGER_200,
181 			     AU0828_I2C_TRIGGER_READ);
182 
183 		if (!i2c_wait_done(i2c_adap))
184 			return -EIO;
185 
186 		if (i2c_wait_read_ack(i2c_adap))
187 			return -EIO;
188 
189 		return 0;
190 	}
191 
192 	for (i = 0; i < msg->len;) {
193 
194 		dprintk(4, " %02x\n", msg->buf[i]);
195 
196 		au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
197 
198 		strobe++;
199 		i++;
200 
201 		if ((strobe >= 4) || (i >= msg->len)) {
202 
203 			/* Strobe the byte into the bus */
204 			if (i < msg->len)
205 				au0828_write(dev, AU0828_I2C_TRIGGER_200,
206 					     AU0828_I2C_TRIGGER_WRITE |
207 					     AU0828_I2C_TRIGGER_HOLD);
208 			else
209 				au0828_write(dev, AU0828_I2C_TRIGGER_200,
210 					     AU0828_I2C_TRIGGER_WRITE);
211 
212 			/* Reset strobe trigger */
213 			strobe = 0;
214 
215 			if (!i2c_wait_write_done(i2c_adap))
216 				return -EIO;
217 
218 		}
219 
220 	}
221 	if (!i2c_wait_done(i2c_adap))
222 		return -EIO;
223 
224 	dprintk(4, "\n");
225 
226 	return msg->len;
227 }
228 
229 /* FIXME: Implement join handling correctly */
230 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
231 	const struct i2c_msg *msg, int joined)
232 {
233 	struct au0828_dev *dev = i2c_adap->algo_data;
234 	u8 i2c_speed = dev->board.i2c_clk_divider;
235 	int i;
236 
237 	dprintk(4, "%s()\n", __func__);
238 
239 	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
240 
241 	/*
242 	 * Due to xc5000c clock stretch, we cannot use full speed at
243 	 * readings from xc5000, as otherwise they'll fail.
244 	 */
245 	if (((dev->board.tuner_type == TUNER_XC5000) ||
246 	     (dev->board.tuner_type == TUNER_XC5000C)) &&
247 	    (dev->board.tuner_addr == msg->addr))
248 		i2c_speed = AU0828_I2C_CLK_20KHZ;
249 
250 	/* Set the I2C clock */
251 	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
252 
253 	/* Hardware needs 8 bit addresses */
254 	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
255 
256 	dprintk(4, " RECV:\n");
257 
258 	/* Deal with i2c_scan */
259 	if (msg->len == 0) {
260 		au0828_write(dev, AU0828_I2C_TRIGGER_200,
261 			     AU0828_I2C_TRIGGER_READ);
262 
263 		if (i2c_wait_read_ack(i2c_adap))
264 			return -EIO;
265 		return 0;
266 	}
267 
268 	for (i = 0; i < msg->len;) {
269 
270 		i++;
271 
272 		if (i < msg->len)
273 			au0828_write(dev, AU0828_I2C_TRIGGER_200,
274 				     AU0828_I2C_TRIGGER_READ |
275 				     AU0828_I2C_TRIGGER_HOLD);
276 		else
277 			au0828_write(dev, AU0828_I2C_TRIGGER_200,
278 				     AU0828_I2C_TRIGGER_READ);
279 
280 		if (!i2c_wait_read_done(i2c_adap))
281 			return -EIO;
282 
283 		msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
284 			0xff;
285 
286 		dprintk(4, " %02x\n", msg->buf[i-1]);
287 	}
288 	if (!i2c_wait_done(i2c_adap))
289 		return -EIO;
290 
291 	dprintk(4, "\n");
292 
293 	return msg->len;
294 }
295 
296 static int i2c_xfer(struct i2c_adapter *i2c_adap,
297 		    struct i2c_msg *msgs, int num)
298 {
299 	int i, retval = 0;
300 
301 	dprintk(4, "%s(num = %d)\n", __func__, num);
302 
303 	for (i = 0; i < num; i++) {
304 		dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
305 			__func__, num, msgs[i].addr, msgs[i].len);
306 		if (msgs[i].flags & I2C_M_RD) {
307 			/* read */
308 			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
309 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
310 			   msgs[i].addr == msgs[i + 1].addr) {
311 			/* write then read from same address */
312 			retval = i2c_sendbytes(i2c_adap, &msgs[i],
313 					       msgs[i + 1].len);
314 			if (retval < 0)
315 				goto err;
316 			i++;
317 			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
318 		} else {
319 			/* write */
320 			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
321 		}
322 		if (retval < 0)
323 			goto err;
324 	}
325 	return num;
326 
327 err:
328 	return retval;
329 }
330 
331 static u32 au0828_functionality(struct i2c_adapter *adap)
332 {
333 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
334 }
335 
336 static struct i2c_algorithm au0828_i2c_algo_template = {
337 	.master_xfer	= i2c_xfer,
338 	.functionality	= au0828_functionality,
339 };
340 
341 /* ----------------------------------------------------------------------- */
342 
343 static struct i2c_adapter au0828_i2c_adap_template = {
344 	.name              = KBUILD_MODNAME,
345 	.owner             = THIS_MODULE,
346 	.algo              = &au0828_i2c_algo_template,
347 };
348 
349 static struct i2c_client au0828_i2c_client_template = {
350 	.name	= "au0828 internal",
351 };
352 
353 static char *i2c_devs[128] = {
354 	[0x8e >> 1] = "au8522",
355 	[0xa0 >> 1] = "eeprom",
356 	[0xc2 >> 1] = "tuner/xc5000",
357 };
358 
359 static void do_i2c_scan(char *name, struct i2c_client *c)
360 {
361 	unsigned char buf;
362 	int i, rc;
363 
364 	for (i = 0; i < 128; i++) {
365 		c->addr = i;
366 		rc = i2c_master_recv(c, &buf, 0);
367 		if (rc < 0)
368 			continue;
369 		pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
370 		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
371 	}
372 }
373 
374 /* init + register i2c adapter */
375 int au0828_i2c_register(struct au0828_dev *dev)
376 {
377 	dprintk(1, "%s()\n", __func__);
378 
379 	dev->i2c_adap = au0828_i2c_adap_template;
380 	dev->i2c_algo = au0828_i2c_algo_template;
381 	dev->i2c_client = au0828_i2c_client_template;
382 
383 	dev->i2c_adap.dev.parent = &dev->usbdev->dev;
384 
385 	strlcpy(dev->i2c_adap.name, KBUILD_MODNAME,
386 		sizeof(dev->i2c_adap.name));
387 
388 	dev->i2c_adap.algo = &dev->i2c_algo;
389 	dev->i2c_adap.algo_data = dev;
390 #ifdef CONFIG_VIDEO_AU0828_V4L2
391 	i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
392 #else
393 	i2c_set_adapdata(&dev->i2c_adap, dev);
394 #endif
395 	i2c_add_adapter(&dev->i2c_adap);
396 
397 	dev->i2c_client.adapter = &dev->i2c_adap;
398 
399 	if (0 == dev->i2c_rc) {
400 		pr_info("i2c bus registered\n");
401 		if (i2c_scan)
402 			do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
403 	} else
404 		pr_info("i2c bus register FAILED\n");
405 
406 	return dev->i2c_rc;
407 }
408 
409 int au0828_i2c_unregister(struct au0828_dev *dev)
410 {
411 	i2c_del_adapter(&dev->i2c_adap);
412 	return 0;
413 }
414 
415