Loading...
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 <linux/module.h>
23#include <linux/moduleparam.h>
24#include <linux/init.h>
25#include <linux/delay.h>
26#include <linux/io.h>
27
28#include "au0828.h"
29
30#include <media/v4l2-common.h>
31
32static int i2c_scan;
33module_param(i2c_scan, int, 0444);
34MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
35
36#define I2C_WAIT_DELAY 512
37#define I2C_WAIT_RETRY 64
38
39static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
40{
41 struct au0828_dev *dev = i2c_adap->algo_data;
42 return au0828_read(dev, AU0828_I2C_STATUS_201) &
43 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
44}
45
46static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
47{
48 struct au0828_dev *dev = i2c_adap->algo_data;
49 return au0828_read(dev, AU0828_I2C_STATUS_201) &
50 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
51}
52
53static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
54{
55 int count;
56
57 for (count = 0; count < I2C_WAIT_RETRY; count++) {
58 if (!i2c_slave_did_read_ack(i2c_adap))
59 break;
60 udelay(I2C_WAIT_DELAY);
61 }
62
63 if (I2C_WAIT_RETRY == count)
64 return 0;
65
66 return 1;
67}
68
69static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
70{
71 struct au0828_dev *dev = i2c_adap->algo_data;
72 return au0828_read(dev, AU0828_I2C_STATUS_201) &
73 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
74}
75
76static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
77{
78 int count;
79
80 for (count = 0; count < I2C_WAIT_RETRY; count++) {
81 if (!i2c_is_read_busy(i2c_adap))
82 break;
83 udelay(I2C_WAIT_DELAY);
84 }
85
86 if (I2C_WAIT_RETRY == count)
87 return 0;
88
89 return 1;
90}
91
92static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
93{
94 struct au0828_dev *dev = i2c_adap->algo_data;
95 return au0828_read(dev, AU0828_I2C_STATUS_201) &
96 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
97}
98
99static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
100{
101 int count;
102
103 for (count = 0; count < I2C_WAIT_RETRY; count++) {
104 if (i2c_is_write_done(i2c_adap))
105 break;
106 udelay(I2C_WAIT_DELAY);
107 }
108
109 if (I2C_WAIT_RETRY == count)
110 return 0;
111
112 return 1;
113}
114
115static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
116{
117 struct au0828_dev *dev = i2c_adap->algo_data;
118 return au0828_read(dev, AU0828_I2C_STATUS_201) &
119 AU0828_I2C_STATUS_BUSY ? 1 : 0;
120}
121
122static int i2c_wait_done(struct i2c_adapter *i2c_adap)
123{
124 int count;
125
126 for (count = 0; count < I2C_WAIT_RETRY; count++) {
127 if (!i2c_is_busy(i2c_adap))
128 break;
129 udelay(I2C_WAIT_DELAY);
130 }
131
132 if (I2C_WAIT_RETRY == count)
133 return 0;
134
135 return 1;
136}
137
138/* FIXME: Implement join handling correctly */
139static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
140 const struct i2c_msg *msg, int joined_rlen)
141{
142 int i, strobe = 0;
143 struct au0828_dev *dev = i2c_adap->algo_data;
144
145 dprintk(4, "%s()\n", __func__);
146
147 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
148
149 /* Set the I2C clock */
150 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
151 dev->board.i2c_clk_divider);
152
153 /* Hardware needs 8 bit addresses */
154 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
155
156 dprintk(4, "SEND: %02x\n", msg->addr);
157
158 /* Deal with i2c_scan */
159 if (msg->len == 0) {
160 /* The analog tuner detection code makes use of the SMBUS_QUICK
161 message (which involves a zero length i2c write). To avoid
162 checking the status register when we didn't strobe out any
163 actual bytes to the bus, just do a read check. This is
164 consistent with how I saw i2c device checking done in the
165 USB trace of the Windows driver */
166 au0828_write(dev, AU0828_I2C_TRIGGER_200,
167 AU0828_I2C_TRIGGER_READ);
168
169 if (!i2c_wait_done(i2c_adap))
170 return -EIO;
171
172 if (i2c_wait_read_ack(i2c_adap))
173 return -EIO;
174
175 return 0;
176 }
177
178 for (i = 0; i < msg->len;) {
179
180 dprintk(4, " %02x\n", msg->buf[i]);
181
182 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
183
184 strobe++;
185 i++;
186
187 if ((strobe >= 4) || (i >= msg->len)) {
188
189 /* Strobe the byte into the bus */
190 if (i < msg->len)
191 au0828_write(dev, AU0828_I2C_TRIGGER_200,
192 AU0828_I2C_TRIGGER_WRITE |
193 AU0828_I2C_TRIGGER_HOLD);
194 else
195 au0828_write(dev, AU0828_I2C_TRIGGER_200,
196 AU0828_I2C_TRIGGER_WRITE);
197
198 /* Reset strobe trigger */
199 strobe = 0;
200
201 if (!i2c_wait_write_done(i2c_adap))
202 return -EIO;
203
204 }
205
206 }
207 if (!i2c_wait_done(i2c_adap))
208 return -EIO;
209
210 dprintk(4, "\n");
211
212 return msg->len;
213}
214
215/* FIXME: Implement join handling correctly */
216static int i2c_readbytes(struct i2c_adapter *i2c_adap,
217 const struct i2c_msg *msg, int joined)
218{
219 struct au0828_dev *dev = i2c_adap->algo_data;
220 int i;
221
222 dprintk(4, "%s()\n", __func__);
223
224 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
225
226 /* Set the I2C clock */
227 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
228 dev->board.i2c_clk_divider);
229
230 /* Hardware needs 8 bit addresses */
231 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
232
233 dprintk(4, " RECV:\n");
234
235 /* Deal with i2c_scan */
236 if (msg->len == 0) {
237 au0828_write(dev, AU0828_I2C_TRIGGER_200,
238 AU0828_I2C_TRIGGER_READ);
239
240 if (i2c_wait_read_ack(i2c_adap))
241 return -EIO;
242 return 0;
243 }
244
245 for (i = 0; i < msg->len;) {
246
247 i++;
248
249 if (i < msg->len)
250 au0828_write(dev, AU0828_I2C_TRIGGER_200,
251 AU0828_I2C_TRIGGER_READ |
252 AU0828_I2C_TRIGGER_HOLD);
253 else
254 au0828_write(dev, AU0828_I2C_TRIGGER_200,
255 AU0828_I2C_TRIGGER_READ);
256
257 if (!i2c_wait_read_done(i2c_adap))
258 return -EIO;
259
260 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
261 0xff;
262
263 dprintk(4, " %02x\n", msg->buf[i-1]);
264 }
265 if (!i2c_wait_done(i2c_adap))
266 return -EIO;
267
268 dprintk(4, "\n");
269
270 return msg->len;
271}
272
273static int i2c_xfer(struct i2c_adapter *i2c_adap,
274 struct i2c_msg *msgs, int num)
275{
276 int i, retval = 0;
277
278 dprintk(4, "%s(num = %d)\n", __func__, num);
279
280 for (i = 0; i < num; i++) {
281 dprintk(4, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
282 __func__, num, msgs[i].addr, msgs[i].len);
283 if (msgs[i].flags & I2C_M_RD) {
284 /* read */
285 retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
286 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
287 msgs[i].addr == msgs[i + 1].addr) {
288 /* write then read from same address */
289 retval = i2c_sendbytes(i2c_adap, &msgs[i],
290 msgs[i + 1].len);
291 if (retval < 0)
292 goto err;
293 i++;
294 retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
295 } else {
296 /* write */
297 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
298 }
299 if (retval < 0)
300 goto err;
301 }
302 return num;
303
304err:
305 return retval;
306}
307
308static u32 au0828_functionality(struct i2c_adapter *adap)
309{
310 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
311}
312
313static struct i2c_algorithm au0828_i2c_algo_template = {
314 .master_xfer = i2c_xfer,
315 .functionality = au0828_functionality,
316};
317
318/* ----------------------------------------------------------------------- */
319
320static struct i2c_adapter au0828_i2c_adap_template = {
321 .name = DRIVER_NAME,
322 .owner = THIS_MODULE,
323 .algo = &au0828_i2c_algo_template,
324};
325
326static struct i2c_client au0828_i2c_client_template = {
327 .name = "au0828 internal",
328};
329
330static char *i2c_devs[128] = {
331 [0x8e >> 1] = "au8522",
332 [0xa0 >> 1] = "eeprom",
333 [0xc2 >> 1] = "tuner/xc5000",
334};
335
336static void do_i2c_scan(char *name, struct i2c_client *c)
337{
338 unsigned char buf;
339 int i, rc;
340
341 for (i = 0; i < 128; i++) {
342 c->addr = i;
343 rc = i2c_master_recv(c, &buf, 0);
344 if (rc < 0)
345 continue;
346 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x [%s]\n",
347 name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
348 }
349}
350
351/* init + register i2c adapter */
352int au0828_i2c_register(struct au0828_dev *dev)
353{
354 dprintk(1, "%s()\n", __func__);
355
356 memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
357 sizeof(dev->i2c_adap));
358 memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
359 sizeof(dev->i2c_algo));
360 memcpy(&dev->i2c_client, &au0828_i2c_client_template,
361 sizeof(dev->i2c_client));
362
363 dev->i2c_adap.dev.parent = &dev->usbdev->dev;
364
365 strlcpy(dev->i2c_adap.name, DRIVER_NAME,
366 sizeof(dev->i2c_adap.name));
367
368 dev->i2c_adap.algo = &dev->i2c_algo;
369 dev->i2c_adap.algo_data = dev;
370 i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
371 i2c_add_adapter(&dev->i2c_adap);
372
373 dev->i2c_client.adapter = &dev->i2c_adap;
374
375 if (0 == dev->i2c_rc) {
376 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
377 if (i2c_scan)
378 do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
379 } else
380 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
381
382 return dev->i2c_rc;
383}
384
385int au0828_i2c_unregister(struct au0828_dev *dev)
386{
387 i2c_del_adapter(&dev->i2c_adap);
388 return 0;
389}
390