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
19 static int i2c_scan;
20 module_param(i2c_scan, int, 0444);
21 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
22
23 #define I2C_WAIT_DELAY 25
24 #define I2C_WAIT_RETRY 1000
25
i2c_slave_did_read_ack(struct i2c_adapter * i2c_adap)26 static 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
i2c_wait_read_ack(struct i2c_adapter * i2c_adap)33 static 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
i2c_is_read_busy(struct i2c_adapter * i2c_adap)49 static 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
i2c_wait_read_done(struct i2c_adapter * i2c_adap)56 static 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
i2c_is_write_done(struct i2c_adapter * i2c_adap)72 static 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
i2c_wait_write_done(struct i2c_adapter * i2c_adap)79 static 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
i2c_is_busy(struct i2c_adapter * i2c_adap)95 static 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
i2c_wait_done(struct i2c_adapter * i2c_adap)102 static 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 */
i2c_sendbytes(struct i2c_adapter * i2c_adap,const struct i2c_msg * msg,int joined_rlen)119 static 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 */
i2c_readbytes(struct i2c_adapter * i2c_adap,const struct i2c_msg * msg,int joined)209 static 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
i2c_xfer(struct i2c_adapter * i2c_adap,struct i2c_msg * msgs,int num)275 static 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
306 err:
307 return retval;
308 }
309
au0828_functionality(struct i2c_adapter * adap)310 static u32 au0828_functionality(struct i2c_adapter *adap)
311 {
312 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
313 }
314
315 static const struct i2c_algorithm au0828_i2c_algo_template = {
316 .master_xfer = i2c_xfer,
317 .functionality = au0828_functionality,
318 };
319
320 /* ----------------------------------------------------------------------- */
321
322 static const struct i2c_adapter au0828_i2c_adap_template = {
323 .name = KBUILD_MODNAME,
324 .owner = THIS_MODULE,
325 .algo = &au0828_i2c_algo_template,
326 };
327
328 static const struct i2c_client au0828_i2c_client_template = {
329 .name = "au0828 internal",
330 };
331
332 static char *i2c_devs[128] = {
333 [0x8e >> 1] = "au8522",
334 [0xa0 >> 1] = "eeprom",
335 [0xc2 >> 1] = "tuner/xc5000",
336 };
337
do_i2c_scan(char * name,struct i2c_client * c)338 static 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 */
au0828_i2c_register(struct au0828_dev * dev)354 int 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
au0828_i2c_unregister(struct au0828_dev * dev)388 int au0828_i2c_unregister(struct au0828_dev *dev)
389 {
390 i2c_del_adapter(&dev->i2c_adap);
391 return 0;
392 }
393
394