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
33static int i2c_scan;
34module_param(i2c_scan, int, 0444);
35MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
36
37#define I2C_WAIT_DELAY 25
38#define I2C_WAIT_RETRY 1000
39
40static 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
47static 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
54static 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
70static 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
77static 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
93static 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
100static 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
116static 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
123static 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 */
140static 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 */
230static 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
296static 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
327err:
328	return retval;
329}
330
331static u32 au0828_functionality(struct i2c_adapter *adap)
332{
333	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
334}
335
336static struct i2c_algorithm au0828_i2c_algo_template = {
337	.master_xfer	= i2c_xfer,
338	.functionality	= au0828_functionality,
339};
340
341/* ----------------------------------------------------------------------- */
342
343static struct i2c_adapter au0828_i2c_adap_template = {
344	.name              = KBUILD_MODNAME,
345	.owner             = THIS_MODULE,
346	.algo              = &au0828_i2c_algo_template,
347};
348
349static struct i2c_client au0828_i2c_client_template = {
350	.name	= "au0828 internal",
351};
352
353static char *i2c_devs[128] = {
354	[0x8e >> 1] = "au8522",
355	[0xa0 >> 1] = "eeprom",
356	[0xc2 >> 1] = "tuner/xc5000",
357};
358
359static 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 */
375int 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
409int au0828_i2c_unregister(struct au0828_dev *dev)
410{
411	i2c_del_adapter(&dev->i2c_adap);
412	return 0;
413}
414
415