1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3
4 bttv-i2c.c -- all the i2c code is here
5
6 bttv - Bt848 frame grabber driver
7
8 Copyright (C) 1996,97,98 Ralph Metzler (rjkm@thp.uni-koeln.de)
9 & Marcus Metzler (mocm@thp.uni-koeln.de)
10 (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
11
12 (c) 2005 Mauro Carvalho Chehab <mchehab@kernel.org>
13 - Multituner support and i2c address binding
14
15
16 */
17
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23
24 #include "bttvp.h"
25 #include <media/v4l2-common.h>
26 #include <linux/jiffies.h>
27 #include <asm/io.h>
28
29 static int i2c_debug;
30 static int i2c_hw;
31 static int i2c_scan;
32 module_param(i2c_debug, int, 0644);
33 MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
34 module_param(i2c_hw, int, 0444);
35 MODULE_PARM_DESC(i2c_hw, "force use of hardware i2c support, instead of software bitbang");
36 module_param(i2c_scan, int, 0444);
37 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
38
39 static unsigned int i2c_udelay = 5;
40 module_param(i2c_udelay, int, 0444);
41 MODULE_PARM_DESC(i2c_udelay, "soft i2c delay at insmod time, in usecs (should be 5 or higher). Lower value means higher bus speed.");
42
43 /* ----------------------------------------------------------------------- */
44 /* I2C functions - bitbanging adapter (software i2c) */
45
bttv_bit_setscl(void * data,int state)46 static void bttv_bit_setscl(void *data, int state)
47 {
48 struct bttv *btv = (struct bttv*)data;
49
50 if (state)
51 btv->i2c_state |= 0x02;
52 else
53 btv->i2c_state &= ~0x02;
54 btwrite(btv->i2c_state, BT848_I2C);
55 btread(BT848_I2C);
56 }
57
bttv_bit_setsda(void * data,int state)58 static void bttv_bit_setsda(void *data, int state)
59 {
60 struct bttv *btv = (struct bttv*)data;
61
62 if (state)
63 btv->i2c_state |= 0x01;
64 else
65 btv->i2c_state &= ~0x01;
66 btwrite(btv->i2c_state, BT848_I2C);
67 btread(BT848_I2C);
68 }
69
bttv_bit_getscl(void * data)70 static int bttv_bit_getscl(void *data)
71 {
72 struct bttv *btv = (struct bttv*)data;
73 int state;
74
75 state = btread(BT848_I2C) & 0x02 ? 1 : 0;
76 return state;
77 }
78
bttv_bit_getsda(void * data)79 static int bttv_bit_getsda(void *data)
80 {
81 struct bttv *btv = (struct bttv*)data;
82 int state;
83
84 state = btread(BT848_I2C) & 0x01;
85 return state;
86 }
87
88 static const struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
89 .setsda = bttv_bit_setsda,
90 .setscl = bttv_bit_setscl,
91 .getsda = bttv_bit_getsda,
92 .getscl = bttv_bit_getscl,
93 .udelay = 16,
94 .timeout = 200,
95 };
96
97 /* ----------------------------------------------------------------------- */
98 /* I2C functions - hardware i2c */
99
functionality(struct i2c_adapter * adap)100 static u32 functionality(struct i2c_adapter *adap)
101 {
102 return I2C_FUNC_SMBUS_EMUL;
103 }
104
105 static int
bttv_i2c_wait_done(struct bttv * btv)106 bttv_i2c_wait_done(struct bttv *btv)
107 {
108 int rc = 0;
109
110 /* timeout */
111 if (wait_event_interruptible_timeout(btv->i2c_queue,
112 btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
113 rc = -EIO;
114
115 if (btv->i2c_done & BT848_INT_RACK)
116 rc = 1;
117 btv->i2c_done = 0;
118 return rc;
119 }
120
121 #define I2C_HW (BT878_I2C_MODE | BT848_I2C_SYNC |\
122 BT848_I2C_SCL | BT848_I2C_SDA)
123
124 static int
bttv_i2c_sendbytes(struct bttv * btv,const struct i2c_msg * msg,int last)125 bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
126 {
127 u32 xmit;
128 int retval,cnt;
129
130 /* sanity checks */
131 if (0 == msg->len)
132 return -EINVAL;
133
134 /* start, address + first byte */
135 xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
136 if (msg->len > 1 || !last)
137 xmit |= BT878_I2C_NOSTOP;
138 btwrite(xmit, BT848_I2C);
139 retval = bttv_i2c_wait_done(btv);
140 if (retval < 0)
141 goto err;
142 if (retval == 0)
143 goto eio;
144 if (i2c_debug) {
145 pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
146 }
147
148 for (cnt = 1; cnt < msg->len; cnt++ ) {
149 /* following bytes */
150 xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
151 if (cnt < msg->len-1 || !last)
152 xmit |= BT878_I2C_NOSTOP;
153 btwrite(xmit, BT848_I2C);
154 retval = bttv_i2c_wait_done(btv);
155 if (retval < 0)
156 goto err;
157 if (retval == 0)
158 goto eio;
159 if (i2c_debug)
160 pr_cont(" %02x", msg->buf[cnt]);
161 }
162 if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
163 pr_cont(">\n");
164 return msg->len;
165
166 eio:
167 retval = -EIO;
168 err:
169 if (i2c_debug)
170 pr_cont(" ERR: %d\n",retval);
171 return retval;
172 }
173
174 static int
bttv_i2c_readbytes(struct bttv * btv,const struct i2c_msg * msg,int last)175 bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
176 {
177 u32 xmit;
178 u32 cnt;
179 int retval;
180
181 for (cnt = 0; cnt < msg->len; cnt++) {
182 xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
183 if (cnt < msg->len-1)
184 xmit |= BT848_I2C_W3B;
185 if (cnt < msg->len-1 || !last)
186 xmit |= BT878_I2C_NOSTOP;
187 if (cnt)
188 xmit |= BT878_I2C_NOSTART;
189
190 if (i2c_debug) {
191 if (!(xmit & BT878_I2C_NOSTART))
192 pr_cont(" <R %02x", (msg->addr << 1) +1);
193 }
194
195 btwrite(xmit, BT848_I2C);
196 retval = bttv_i2c_wait_done(btv);
197 if (retval < 0)
198 goto err;
199 if (retval == 0)
200 goto eio;
201 msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
202 if (i2c_debug) {
203 pr_cont(" =%02x", msg->buf[cnt]);
204 }
205 if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
206 pr_cont(" >\n");
207 }
208
209
210 return msg->len;
211
212 eio:
213 retval = -EIO;
214 err:
215 if (i2c_debug)
216 pr_cont(" ERR: %d\n",retval);
217 return retval;
218 }
219
bttv_i2c_xfer(struct i2c_adapter * i2c_adap,struct i2c_msg * msgs,int num)220 static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
221 {
222 struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
223 struct bttv *btv = to_bttv(v4l2_dev);
224 int retval = 0;
225 int i;
226
227 if (i2c_debug)
228 pr_debug("bt-i2c:");
229
230 btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
231 for (i = 0 ; i < num; i++) {
232 if (msgs[i].flags & I2C_M_RD) {
233 /* read */
234 retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
235 if (retval < 0)
236 goto err;
237 } else {
238 /* write */
239 retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
240 if (retval < 0)
241 goto err;
242 }
243 }
244 return num;
245
246 err:
247 return retval;
248 }
249
250 static const struct i2c_algorithm bttv_algo = {
251 .master_xfer = bttv_i2c_xfer,
252 .functionality = functionality,
253 };
254
255 /* ----------------------------------------------------------------------- */
256 /* I2C functions - common stuff */
257
258 /* read I2C */
bttv_I2CRead(struct bttv * btv,unsigned char addr,char * probe_for)259 int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
260 {
261 unsigned char buffer = 0;
262
263 if (0 != btv->i2c_rc)
264 return -1;
265 if (bttv_verbose && NULL != probe_for)
266 pr_info("%d: i2c: checking for %s @ 0x%02x... ",
267 btv->c.nr, probe_for, addr);
268 btv->i2c_client.addr = addr >> 1;
269 if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
270 if (NULL != probe_for) {
271 if (bttv_verbose)
272 pr_cont("not found\n");
273 } else
274 pr_warn("%d: i2c read 0x%x: error\n",
275 btv->c.nr, addr);
276 return -1;
277 }
278 if (bttv_verbose && NULL != probe_for)
279 pr_cont("found\n");
280 return buffer;
281 }
282
283 /* write I2C */
bttv_I2CWrite(struct bttv * btv,unsigned char addr,unsigned char b1,unsigned char b2,int both)284 int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
285 unsigned char b2, int both)
286 {
287 unsigned char buffer[2];
288 int bytes = both ? 2 : 1;
289
290 if (0 != btv->i2c_rc)
291 return -1;
292 btv->i2c_client.addr = addr >> 1;
293 buffer[0] = b1;
294 buffer[1] = b2;
295 if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
296 return -1;
297 return 0;
298 }
299
300 /* read EEPROM content */
bttv_readee(struct bttv * btv,unsigned char * eedata,int addr)301 void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
302 {
303 memset(eedata, 0, 256);
304 if (0 != btv->i2c_rc)
305 return;
306 btv->i2c_client.addr = addr >> 1;
307 tveeprom_read(&btv->i2c_client, eedata, 256);
308 }
309
310 static char *i2c_devs[128] = {
311 [ 0x1c >> 1 ] = "lgdt330x",
312 [ 0x30 >> 1 ] = "IR (hauppauge)",
313 [ 0x80 >> 1 ] = "msp34xx",
314 [ 0x86 >> 1 ] = "tda9887",
315 [ 0xa0 >> 1 ] = "eeprom",
316 [ 0xc0 >> 1 ] = "tuner (analog)",
317 [ 0xc2 >> 1 ] = "tuner (analog)",
318 };
319
do_i2c_scan(char * name,struct i2c_client * c)320 static void do_i2c_scan(char *name, struct i2c_client *c)
321 {
322 unsigned char buf;
323 int i,rc;
324
325 for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
326 c->addr = i;
327 rc = i2c_master_recv(c,&buf,0);
328 if (rc < 0)
329 continue;
330 pr_info("%s: i2c scan: found device @ 0x%x [%s]\n",
331 name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
332 }
333 }
334
335 /* init + register i2c adapter */
init_bttv_i2c(struct bttv * btv)336 int init_bttv_i2c(struct bttv *btv)
337 {
338 strscpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
339
340 if (i2c_hw)
341 btv->use_i2c_hw = 1;
342 if (btv->use_i2c_hw) {
343 /* bt878 */
344 strscpy(btv->c.i2c_adap.name, "bt878",
345 sizeof(btv->c.i2c_adap.name));
346 btv->c.i2c_adap.algo = &bttv_algo;
347 } else {
348 /* bt848 */
349 /* Prevents usage of invalid delay values */
350 if (i2c_udelay<5)
351 i2c_udelay=5;
352
353 strscpy(btv->c.i2c_adap.name, "bttv",
354 sizeof(btv->c.i2c_adap.name));
355 btv->i2c_algo = bttv_i2c_algo_bit_template;
356 btv->i2c_algo.udelay = i2c_udelay;
357 btv->i2c_algo.data = btv;
358 btv->c.i2c_adap.algo_data = &btv->i2c_algo;
359 }
360 btv->c.i2c_adap.owner = THIS_MODULE;
361
362 btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
363 snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
364 "bt%d #%d [%s]", btv->id, btv->c.nr,
365 btv->use_i2c_hw ? "hw" : "sw");
366
367 i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
368 btv->i2c_client.adapter = &btv->c.i2c_adap;
369
370
371 if (btv->use_i2c_hw) {
372 btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
373 } else {
374 bttv_bit_setscl(btv,1);
375 bttv_bit_setsda(btv,1);
376 btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
377 }
378 if (0 == btv->i2c_rc && i2c_scan)
379 do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
380
381 return btv->i2c_rc;
382 }
383
fini_bttv_i2c(struct bttv * btv)384 int fini_bttv_i2c(struct bttv *btv)
385 {
386 if (btv->i2c_rc == 0)
387 i2c_del_adapter(&btv->c.i2c_adap);
388
389 return 0;
390 }
391