708f01ab47fabcc905b10648cae310ed9ffa71a7
[sfrench/cifs-2.6.git] / drivers / media / usb / au0828 / au0828-i2c.c
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
26 static inline int i2c_slave_did_write_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_WRITE_ACK ? 0 : 1;
31 }
32
33 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
34 {
35         struct au0828_dev *dev = i2c_adap->algo_data;
36         return au0828_read(dev, AU0828_I2C_STATUS_201) &
37                 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
38 }
39
40 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
41 {
42         int count;
43
44         for (count = 0; count < I2C_WAIT_RETRY; count++) {
45                 if (!i2c_slave_did_read_ack(i2c_adap))
46                         break;
47                 udelay(I2C_WAIT_DELAY);
48         }
49
50         if (I2C_WAIT_RETRY == count)
51                 return 0;
52
53         return 1;
54 }
55
56 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
57 {
58         struct au0828_dev *dev = i2c_adap->algo_data;
59         return au0828_read(dev, AU0828_I2C_STATUS_201) &
60                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
61 }
62
63 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
64 {
65         int count;
66
67         for (count = 0; count < I2C_WAIT_RETRY; count++) {
68                 if (!i2c_is_read_busy(i2c_adap))
69                         break;
70                 udelay(I2C_WAIT_DELAY);
71         }
72
73         if (I2C_WAIT_RETRY == count)
74                 return 0;
75
76         return 1;
77 }
78
79 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
80 {
81         struct au0828_dev *dev = i2c_adap->algo_data;
82         return au0828_read(dev, AU0828_I2C_STATUS_201) &
83                 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
84 }
85
86 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
87 {
88         int count;
89
90         for (count = 0; count < I2C_WAIT_RETRY; count++) {
91                 if (i2c_is_write_done(i2c_adap))
92                         break;
93                 udelay(I2C_WAIT_DELAY);
94         }
95
96         if (I2C_WAIT_RETRY == count)
97                 return 0;
98
99         return 1;
100 }
101
102 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
103 {
104         struct au0828_dev *dev = i2c_adap->algo_data;
105         return au0828_read(dev, AU0828_I2C_STATUS_201) &
106                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
107 }
108
109 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
110 {
111         int count;
112
113         for (count = 0; count < I2C_WAIT_RETRY; count++) {
114                 if (!i2c_is_busy(i2c_adap))
115                         break;
116                 udelay(I2C_WAIT_DELAY);
117         }
118
119         if (I2C_WAIT_RETRY == count)
120                 return 0;
121
122         return 1;
123 }
124
125 /* FIXME: Implement join handling correctly */
126 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
127         const struct i2c_msg *msg, int joined_rlen)
128 {
129         int i, strobe = 0;
130         struct au0828_dev *dev = i2c_adap->algo_data;
131         u8 i2c_speed = dev->board.i2c_clk_divider;
132
133         dprintk(4, "%s()\n", __func__);
134
135         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
136
137         if (((dev->board.tuner_type == TUNER_XC5000) ||
138              (dev->board.tuner_type == TUNER_XC5000C)) &&
139             (dev->board.tuner_addr == msg->addr)) {
140                 /*
141                  * Due to I2C clock stretch, we need to use a lower speed
142                  * on xc5000 for commands. However, firmware transfer can
143                  * speed up to 400 KHz.
144                  */
145                 if (msg->len == 64)
146                         i2c_speed = AU0828_I2C_CLK_250KHZ;
147                 else
148                         i2c_speed = AU0828_I2C_CLK_20KHZ;
149         }
150         /* Set the I2C clock */
151         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
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 */
216 static 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         u8 i2c_speed = dev->board.i2c_clk_divider;
221         int i;
222
223         dprintk(4, "%s()\n", __func__);
224
225         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
226
227         /*
228          * Due to xc5000c clock stretch, we cannot use full speed at
229          * readings from xc5000, as otherwise they'll fail.
230          */
231         if (((dev->board.tuner_type == TUNER_XC5000) ||
232              (dev->board.tuner_type == TUNER_XC5000C)) &&
233             (dev->board.tuner_addr == msg->addr))
234                 i2c_speed = AU0828_I2C_CLK_20KHZ;
235
236         /* Set the I2C clock */
237         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
238
239         /* Hardware needs 8 bit addresses */
240         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
241
242         dprintk(4, " RECV:\n");
243
244         /* Deal with i2c_scan */
245         if (msg->len == 0) {
246                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
247                              AU0828_I2C_TRIGGER_READ);
248
249                 if (i2c_wait_read_ack(i2c_adap))
250                         return -EIO;
251                 return 0;
252         }
253
254         for (i = 0; i < msg->len;) {
255
256                 i++;
257
258                 if (i < msg->len)
259                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
260                                      AU0828_I2C_TRIGGER_READ |
261                                      AU0828_I2C_TRIGGER_HOLD);
262                 else
263                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
264                                      AU0828_I2C_TRIGGER_READ);
265
266                 if (!i2c_wait_read_done(i2c_adap))
267                         return -EIO;
268
269                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
270                         0xff;
271
272                 dprintk(4, " %02x\n", msg->buf[i-1]);
273         }
274         if (!i2c_wait_done(i2c_adap))
275                 return -EIO;
276
277         dprintk(4, "\n");
278
279         return msg->len;
280 }
281
282 static int i2c_xfer(struct i2c_adapter *i2c_adap,
283                     struct i2c_msg *msgs, int num)
284 {
285         int i, retval = 0;
286
287         dprintk(4, "%s(num = %d)\n", __func__, num);
288
289         for (i = 0; i < num; i++) {
290                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
291                         __func__, num, msgs[i].addr, msgs[i].len);
292                 if (msgs[i].flags & I2C_M_RD) {
293                         /* read */
294                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
295                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
296                            msgs[i].addr == msgs[i + 1].addr) {
297                         /* write then read from same address */
298                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
299                                                msgs[i + 1].len);
300                         if (retval < 0)
301                                 goto err;
302                         i++;
303                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
304                 } else {
305                         /* write */
306                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
307                 }
308                 if (retval < 0)
309                         goto err;
310         }
311         return num;
312
313 err:
314         return retval;
315 }
316
317 static u32 au0828_functionality(struct i2c_adapter *adap)
318 {
319         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
320 }
321
322 static const struct i2c_algorithm au0828_i2c_algo_template = {
323         .master_xfer    = i2c_xfer,
324         .functionality  = au0828_functionality,
325 };
326
327 /* ----------------------------------------------------------------------- */
328
329 static const struct i2c_adapter au0828_i2c_adap_template = {
330         .name              = KBUILD_MODNAME,
331         .owner             = THIS_MODULE,
332         .algo              = &au0828_i2c_algo_template,
333 };
334
335 static const struct i2c_client au0828_i2c_client_template = {
336         .name   = "au0828 internal",
337 };
338
339 static char *i2c_devs[128] = {
340         [0x8e >> 1] = "au8522",
341         [0xa0 >> 1] = "eeprom",
342         [0xc2 >> 1] = "tuner/xc5000",
343 };
344
345 static void do_i2c_scan(char *name, struct i2c_client *c)
346 {
347         unsigned char buf;
348         int i, rc;
349
350         for (i = 0; i < 128; i++) {
351                 c->addr = i;
352                 rc = i2c_master_recv(c, &buf, 0);
353                 if (rc < 0)
354                         continue;
355                 pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
356                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
357         }
358 }
359
360 /* init + register i2c adapter */
361 int au0828_i2c_register(struct au0828_dev *dev)
362 {
363         dprintk(1, "%s()\n", __func__);
364
365         dev->i2c_adap = au0828_i2c_adap_template;
366         dev->i2c_algo = au0828_i2c_algo_template;
367         dev->i2c_client = au0828_i2c_client_template;
368
369         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
370
371         strscpy(dev->i2c_adap.name, KBUILD_MODNAME,
372                 sizeof(dev->i2c_adap.name));
373
374         dev->i2c_adap.algo = &dev->i2c_algo;
375         dev->i2c_adap.algo_data = dev;
376 #ifdef CONFIG_VIDEO_AU0828_V4L2
377         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
378 #else
379         i2c_set_adapdata(&dev->i2c_adap, dev);
380 #endif
381         i2c_add_adapter(&dev->i2c_adap);
382
383         dev->i2c_client.adapter = &dev->i2c_adap;
384
385         if (0 == dev->i2c_rc) {
386                 pr_info("i2c bus registered\n");
387                 if (i2c_scan)
388                         do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
389         } else
390                 pr_info("i2c bus register FAILED\n");
391
392         return dev->i2c_rc;
393 }
394
395 int au0828_i2c_unregister(struct au0828_dev *dev)
396 {
397         i2c_del_adapter(&dev->i2c_adap);
398         return 0;
399 }
400