xref: /openbmc/linux/drivers/media/pci/bt8xx/bttv-i2c.c (revision 457ba4ce)
1 /*
2 
3     bttv-i2c.c  --  all the i2c code is here
4 
5     bttv - Bt848 frame grabber driver
6 
7     Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
8 			   & Marcus Metzler (mocm@thp.uni-koeln.de)
9     (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
10 
11     (c) 2005 Mauro Carvalho Chehab <mchehab@infradead.org>
12 	- Multituner support and i2c address binding
13 
14     This program is free software; you can redistribute it and/or modify
15     it under the terms of the GNU General Public License as published by
16     the Free Software Foundation; either version 2 of the License, or
17     (at your option) any later version.
18 
19     This program is distributed in the hope that it will be useful,
20     but WITHOUT ANY WARRANTY; without even the implied warranty of
21     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22     GNU General Public License for more details.
23 
24     You should have received a copy of the GNU General Public License
25     along with this program; if not, write to the Free Software
26     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 
28 */
29 
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/delay.h>
35 
36 #include "bttvp.h"
37 #include <media/v4l2-common.h>
38 #include <linux/jiffies.h>
39 #include <asm/io.h>
40 
41 static int i2c_debug;
42 static int i2c_hw;
43 static int i2c_scan;
44 module_param(i2c_debug, int, 0644);
45 MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
46 module_param(i2c_hw,    int, 0444);
47 MODULE_PARM_DESC(i2c_hw,"force use of hardware i2c support, "
48 			"instead of software bitbang");
49 module_param(i2c_scan,  int, 0444);
50 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
51 
52 static unsigned int i2c_udelay = 5;
53 module_param(i2c_udelay, int, 0444);
54 MODULE_PARM_DESC(i2c_udelay,"soft i2c delay at insmod time, in usecs "
55 		"(should be 5 or higher). Lower value means higher bus speed.");
56 
57 /* ----------------------------------------------------------------------- */
58 /* I2C functions - bitbanging adapter (software i2c)                       */
59 
60 static void bttv_bit_setscl(void *data, int state)
61 {
62 	struct bttv *btv = (struct bttv*)data;
63 
64 	if (state)
65 		btv->i2c_state |= 0x02;
66 	else
67 		btv->i2c_state &= ~0x02;
68 	btwrite(btv->i2c_state, BT848_I2C);
69 	btread(BT848_I2C);
70 }
71 
72 static void bttv_bit_setsda(void *data, int state)
73 {
74 	struct bttv *btv = (struct bttv*)data;
75 
76 	if (state)
77 		btv->i2c_state |= 0x01;
78 	else
79 		btv->i2c_state &= ~0x01;
80 	btwrite(btv->i2c_state, BT848_I2C);
81 	btread(BT848_I2C);
82 }
83 
84 static int bttv_bit_getscl(void *data)
85 {
86 	struct bttv *btv = (struct bttv*)data;
87 	int state;
88 
89 	state = btread(BT848_I2C) & 0x02 ? 1 : 0;
90 	return state;
91 }
92 
93 static int bttv_bit_getsda(void *data)
94 {
95 	struct bttv *btv = (struct bttv*)data;
96 	int state;
97 
98 	state = btread(BT848_I2C) & 0x01;
99 	return state;
100 }
101 
102 static struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
103 	.setsda  = bttv_bit_setsda,
104 	.setscl  = bttv_bit_setscl,
105 	.getsda  = bttv_bit_getsda,
106 	.getscl  = bttv_bit_getscl,
107 	.udelay  = 16,
108 	.timeout = 200,
109 };
110 
111 /* ----------------------------------------------------------------------- */
112 /* I2C functions - hardware i2c                                            */
113 
114 static u32 functionality(struct i2c_adapter *adap)
115 {
116 	return I2C_FUNC_SMBUS_EMUL;
117 }
118 
119 static int
120 bttv_i2c_wait_done(struct bttv *btv)
121 {
122 	int rc = 0;
123 
124 	/* timeout */
125 	if (wait_event_interruptible_timeout(btv->i2c_queue,
126 	    btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
127 		rc = -EIO;
128 
129 	if (btv->i2c_done & BT848_INT_RACK)
130 		rc = 1;
131 	btv->i2c_done = 0;
132 	return rc;
133 }
134 
135 #define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
136 		BT848_I2C_SCL | BT848_I2C_SDA)
137 
138 static int
139 bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
140 {
141 	u32 xmit;
142 	int retval,cnt;
143 
144 	/* sanity checks */
145 	if (0 == msg->len)
146 		return -EINVAL;
147 
148 	/* start, address + first byte */
149 	xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
150 	if (msg->len > 1 || !last)
151 		xmit |= BT878_I2C_NOSTOP;
152 	btwrite(xmit, BT848_I2C);
153 	retval = bttv_i2c_wait_done(btv);
154 	if (retval < 0)
155 		goto err;
156 	if (retval == 0)
157 		goto eio;
158 	if (i2c_debug) {
159 		pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
160 	}
161 
162 	for (cnt = 1; cnt < msg->len; cnt++ ) {
163 		/* following bytes */
164 		xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
165 		if (cnt < msg->len-1 || !last)
166 			xmit |= BT878_I2C_NOSTOP;
167 		btwrite(xmit, BT848_I2C);
168 		retval = bttv_i2c_wait_done(btv);
169 		if (retval < 0)
170 			goto err;
171 		if (retval == 0)
172 			goto eio;
173 		if (i2c_debug)
174 			pr_cont(" %02x", msg->buf[cnt]);
175 	}
176 	if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
177 		pr_cont(">\n");
178 	return msg->len;
179 
180  eio:
181 	retval = -EIO;
182  err:
183 	if (i2c_debug)
184 		pr_cont(" ERR: %d\n",retval);
185 	return retval;
186 }
187 
188 static int
189 bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
190 {
191 	u32 xmit;
192 	u32 cnt;
193 	int retval;
194 
195 	for (cnt = 0; cnt < msg->len; cnt++) {
196 		xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
197 		if (cnt < msg->len-1)
198 			xmit |= BT848_I2C_W3B;
199 		if (cnt < msg->len-1 || !last)
200 			xmit |= BT878_I2C_NOSTOP;
201 		if (cnt)
202 			xmit |= BT878_I2C_NOSTART;
203 
204 		if (i2c_debug) {
205 			if (!(xmit & BT878_I2C_NOSTART))
206 				pr_cont(" <R %02x", (msg->addr << 1) +1);
207 		}
208 
209 		btwrite(xmit, BT848_I2C);
210 		retval = bttv_i2c_wait_done(btv);
211 		if (retval < 0)
212 			goto err;
213 		if (retval == 0)
214 			goto eio;
215 		msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
216 		if (i2c_debug) {
217 			pr_cont(" =%02x", msg->buf[cnt]);
218 		}
219 		if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
220 			pr_cont(" >\n");
221 	}
222 
223 
224 	return msg->len;
225 
226  eio:
227 	retval = -EIO;
228  err:
229 	if (i2c_debug)
230 		pr_cont(" ERR: %d\n",retval);
231 	return retval;
232 }
233 
234 static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
235 {
236 	struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
237 	struct bttv *btv = to_bttv(v4l2_dev);
238 	int retval = 0;
239 	int i;
240 
241 	if (i2c_debug)
242 		pr_debug("bt-i2c:");
243 
244 	btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
245 	for (i = 0 ; i < num; i++) {
246 		if (msgs[i].flags & I2C_M_RD) {
247 			/* read */
248 			retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
249 			if (retval < 0)
250 				goto err;
251 		} else {
252 			/* write */
253 			retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
254 			if (retval < 0)
255 				goto err;
256 		}
257 	}
258 	return num;
259 
260  err:
261 	return retval;
262 }
263 
264 static const struct i2c_algorithm bttv_algo = {
265 	.master_xfer   = bttv_i2c_xfer,
266 	.functionality = functionality,
267 };
268 
269 /* ----------------------------------------------------------------------- */
270 /* I2C functions - common stuff                                            */
271 
272 /* read I2C */
273 int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
274 {
275 	unsigned char buffer = 0;
276 
277 	if (0 != btv->i2c_rc)
278 		return -1;
279 	if (bttv_verbose && NULL != probe_for)
280 		pr_info("%d: i2c: checking for %s @ 0x%02x... ",
281 			btv->c.nr, probe_for, addr);
282 	btv->i2c_client.addr = addr >> 1;
283 	if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
284 		if (NULL != probe_for) {
285 			if (bttv_verbose)
286 				pr_cont("not found\n");
287 		} else
288 			pr_warn("%d: i2c read 0x%x: error\n",
289 				btv->c.nr, addr);
290 		return -1;
291 	}
292 	if (bttv_verbose && NULL != probe_for)
293 		pr_cont("found\n");
294 	return buffer;
295 }
296 
297 /* write I2C */
298 int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
299 		    unsigned char b2, int both)
300 {
301 	unsigned char buffer[2];
302 	int bytes = both ? 2 : 1;
303 
304 	if (0 != btv->i2c_rc)
305 		return -1;
306 	btv->i2c_client.addr = addr >> 1;
307 	buffer[0] = b1;
308 	buffer[1] = b2;
309 	if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
310 		return -1;
311 	return 0;
312 }
313 
314 /* read EEPROM content */
315 void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
316 {
317 	memset(eedata, 0, 256);
318 	if (0 != btv->i2c_rc)
319 		return;
320 	btv->i2c_client.addr = addr >> 1;
321 	tveeprom_read(&btv->i2c_client, eedata, 256);
322 }
323 
324 static char *i2c_devs[128] = {
325 	[ 0x1c >> 1 ] = "lgdt330x",
326 	[ 0x30 >> 1 ] = "IR (hauppauge)",
327 	[ 0x80 >> 1 ] = "msp34xx",
328 	[ 0x86 >> 1 ] = "tda9887",
329 	[ 0xa0 >> 1 ] = "eeprom",
330 	[ 0xc0 >> 1 ] = "tuner (analog)",
331 	[ 0xc2 >> 1 ] = "tuner (analog)",
332 };
333 
334 static void do_i2c_scan(char *name, struct i2c_client *c)
335 {
336 	unsigned char buf;
337 	int i,rc;
338 
339 	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
340 		c->addr = i;
341 		rc = i2c_master_recv(c,&buf,0);
342 		if (rc < 0)
343 			continue;
344 		pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
345 			name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
346 	}
347 }
348 
349 /* init + register i2c adapter */
350 int init_bttv_i2c(struct bttv *btv)
351 {
352 	strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
353 
354 	if (i2c_hw)
355 		btv->use_i2c_hw = 1;
356 	if (btv->use_i2c_hw) {
357 		/* bt878 */
358 		strlcpy(btv->c.i2c_adap.name, "bt878",
359 			sizeof(btv->c.i2c_adap.name));
360 		btv->c.i2c_adap.algo = &bttv_algo;
361 	} else {
362 		/* bt848 */
363 	/* Prevents usage of invalid delay values */
364 		if (i2c_udelay<5)
365 			i2c_udelay=5;
366 
367 		strlcpy(btv->c.i2c_adap.name, "bttv",
368 			sizeof(btv->c.i2c_adap.name));
369 		btv->i2c_algo = bttv_i2c_algo_bit_template;
370 		btv->i2c_algo.udelay = i2c_udelay;
371 		btv->i2c_algo.data = btv;
372 		btv->c.i2c_adap.algo_data = &btv->i2c_algo;
373 	}
374 	btv->c.i2c_adap.owner = THIS_MODULE;
375 
376 	btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
377 	snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
378 		 "bt%d #%d [%s]", btv->id, btv->c.nr,
379 		 btv->use_i2c_hw ? "hw" : "sw");
380 
381 	i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
382 	btv->i2c_client.adapter = &btv->c.i2c_adap;
383 
384 
385 	if (btv->use_i2c_hw) {
386 		btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
387 	} else {
388 		bttv_bit_setscl(btv,1);
389 		bttv_bit_setsda(btv,1);
390 		btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
391 	}
392 	if (0 == btv->i2c_rc && i2c_scan)
393 		do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
394 
395 	return btv->i2c_rc;
396 }
397 
398 int fini_bttv_i2c(struct bttv *btv)
399 {
400 	if (0 != btv->i2c_rc)
401 		return 0;
402 
403 	return i2c_del_adapter(&btv->c.i2c_adap);
404 }
405