xref: /openbmc/linux/drivers/media/pci/bt8xx/bttv-i2c.c (revision 4f6cce39)
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, instead of software bitbang");
48 module_param(i2c_scan,  int, 0444);
49 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
50 
51 static unsigned int i2c_udelay = 5;
52 module_param(i2c_udelay, int, 0444);
53 MODULE_PARM_DESC(i2c_udelay, "soft i2c delay at insmod time, in usecs (should be 5 or higher). Lower value means higher bus speed.");
54 
55 /* ----------------------------------------------------------------------- */
56 /* I2C functions - bitbanging adapter (software i2c)                       */
57 
58 static void bttv_bit_setscl(void *data, int state)
59 {
60 	struct bttv *btv = (struct bttv*)data;
61 
62 	if (state)
63 		btv->i2c_state |= 0x02;
64 	else
65 		btv->i2c_state &= ~0x02;
66 	btwrite(btv->i2c_state, BT848_I2C);
67 	btread(BT848_I2C);
68 }
69 
70 static void bttv_bit_setsda(void *data, int state)
71 {
72 	struct bttv *btv = (struct bttv*)data;
73 
74 	if (state)
75 		btv->i2c_state |= 0x01;
76 	else
77 		btv->i2c_state &= ~0x01;
78 	btwrite(btv->i2c_state, BT848_I2C);
79 	btread(BT848_I2C);
80 }
81 
82 static int bttv_bit_getscl(void *data)
83 {
84 	struct bttv *btv = (struct bttv*)data;
85 	int state;
86 
87 	state = btread(BT848_I2C) & 0x02 ? 1 : 0;
88 	return state;
89 }
90 
91 static int bttv_bit_getsda(void *data)
92 {
93 	struct bttv *btv = (struct bttv*)data;
94 	int state;
95 
96 	state = btread(BT848_I2C) & 0x01;
97 	return state;
98 }
99 
100 static struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
101 	.setsda  = bttv_bit_setsda,
102 	.setscl  = bttv_bit_setscl,
103 	.getsda  = bttv_bit_getsda,
104 	.getscl  = bttv_bit_getscl,
105 	.udelay  = 16,
106 	.timeout = 200,
107 };
108 
109 /* ----------------------------------------------------------------------- */
110 /* I2C functions - hardware i2c                                            */
111 
112 static u32 functionality(struct i2c_adapter *adap)
113 {
114 	return I2C_FUNC_SMBUS_EMUL;
115 }
116 
117 static int
118 bttv_i2c_wait_done(struct bttv *btv)
119 {
120 	int rc = 0;
121 
122 	/* timeout */
123 	if (wait_event_interruptible_timeout(btv->i2c_queue,
124 	    btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
125 		rc = -EIO;
126 
127 	if (btv->i2c_done & BT848_INT_RACK)
128 		rc = 1;
129 	btv->i2c_done = 0;
130 	return rc;
131 }
132 
133 #define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
134 		BT848_I2C_SCL | BT848_I2C_SDA)
135 
136 static int
137 bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
138 {
139 	u32 xmit;
140 	int retval,cnt;
141 
142 	/* sanity checks */
143 	if (0 == msg->len)
144 		return -EINVAL;
145 
146 	/* start, address + first byte */
147 	xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
148 	if (msg->len > 1 || !last)
149 		xmit |= BT878_I2C_NOSTOP;
150 	btwrite(xmit, BT848_I2C);
151 	retval = bttv_i2c_wait_done(btv);
152 	if (retval < 0)
153 		goto err;
154 	if (retval == 0)
155 		goto eio;
156 	if (i2c_debug) {
157 		pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
158 	}
159 
160 	for (cnt = 1; cnt < msg->len; cnt++ ) {
161 		/* following bytes */
162 		xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
163 		if (cnt < msg->len-1 || !last)
164 			xmit |= BT878_I2C_NOSTOP;
165 		btwrite(xmit, BT848_I2C);
166 		retval = bttv_i2c_wait_done(btv);
167 		if (retval < 0)
168 			goto err;
169 		if (retval == 0)
170 			goto eio;
171 		if (i2c_debug)
172 			pr_cont(" %02x", msg->buf[cnt]);
173 	}
174 	if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
175 		pr_cont(">\n");
176 	return msg->len;
177 
178  eio:
179 	retval = -EIO;
180  err:
181 	if (i2c_debug)
182 		pr_cont(" ERR: %d\n",retval);
183 	return retval;
184 }
185 
186 static int
187 bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
188 {
189 	u32 xmit;
190 	u32 cnt;
191 	int retval;
192 
193 	for (cnt = 0; cnt < msg->len; cnt++) {
194 		xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
195 		if (cnt < msg->len-1)
196 			xmit |= BT848_I2C_W3B;
197 		if (cnt < msg->len-1 || !last)
198 			xmit |= BT878_I2C_NOSTOP;
199 		if (cnt)
200 			xmit |= BT878_I2C_NOSTART;
201 
202 		if (i2c_debug) {
203 			if (!(xmit & BT878_I2C_NOSTART))
204 				pr_cont(" <R %02x", (msg->addr << 1) +1);
205 		}
206 
207 		btwrite(xmit, BT848_I2C);
208 		retval = bttv_i2c_wait_done(btv);
209 		if (retval < 0)
210 			goto err;
211 		if (retval == 0)
212 			goto eio;
213 		msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
214 		if (i2c_debug) {
215 			pr_cont(" =%02x", msg->buf[cnt]);
216 		}
217 		if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
218 			pr_cont(" >\n");
219 	}
220 
221 
222 	return msg->len;
223 
224  eio:
225 	retval = -EIO;
226  err:
227 	if (i2c_debug)
228 		pr_cont(" ERR: %d\n",retval);
229 	return retval;
230 }
231 
232 static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
233 {
234 	struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
235 	struct bttv *btv = to_bttv(v4l2_dev);
236 	int retval = 0;
237 	int i;
238 
239 	if (i2c_debug)
240 		pr_debug("bt-i2c:");
241 
242 	btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
243 	for (i = 0 ; i < num; i++) {
244 		if (msgs[i].flags & I2C_M_RD) {
245 			/* read */
246 			retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
247 			if (retval < 0)
248 				goto err;
249 		} else {
250 			/* write */
251 			retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
252 			if (retval < 0)
253 				goto err;
254 		}
255 	}
256 	return num;
257 
258  err:
259 	return retval;
260 }
261 
262 static const struct i2c_algorithm bttv_algo = {
263 	.master_xfer   = bttv_i2c_xfer,
264 	.functionality = functionality,
265 };
266 
267 /* ----------------------------------------------------------------------- */
268 /* I2C functions - common stuff                                            */
269 
270 /* read I2C */
271 int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
272 {
273 	unsigned char buffer = 0;
274 
275 	if (0 != btv->i2c_rc)
276 		return -1;
277 	if (bttv_verbose && NULL != probe_for)
278 		pr_info("%d: i2c: checking for %s @ 0x%02x... ",
279 			btv->c.nr, probe_for, addr);
280 	btv->i2c_client.addr = addr >> 1;
281 	if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
282 		if (NULL != probe_for) {
283 			if (bttv_verbose)
284 				pr_cont("not found\n");
285 		} else
286 			pr_warn("%d: i2c read 0x%x: error\n",
287 				btv->c.nr, addr);
288 		return -1;
289 	}
290 	if (bttv_verbose && NULL != probe_for)
291 		pr_cont("found\n");
292 	return buffer;
293 }
294 
295 /* write I2C */
296 int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
297 		    unsigned char b2, int both)
298 {
299 	unsigned char buffer[2];
300 	int bytes = both ? 2 : 1;
301 
302 	if (0 != btv->i2c_rc)
303 		return -1;
304 	btv->i2c_client.addr = addr >> 1;
305 	buffer[0] = b1;
306 	buffer[1] = b2;
307 	if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
308 		return -1;
309 	return 0;
310 }
311 
312 /* read EEPROM content */
313 void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
314 {
315 	memset(eedata, 0, 256);
316 	if (0 != btv->i2c_rc)
317 		return;
318 	btv->i2c_client.addr = addr >> 1;
319 	tveeprom_read(&btv->i2c_client, eedata, 256);
320 }
321 
322 static char *i2c_devs[128] = {
323 	[ 0x1c >> 1 ] = "lgdt330x",
324 	[ 0x30 >> 1 ] = "IR (hauppauge)",
325 	[ 0x80 >> 1 ] = "msp34xx",
326 	[ 0x86 >> 1 ] = "tda9887",
327 	[ 0xa0 >> 1 ] = "eeprom",
328 	[ 0xc0 >> 1 ] = "tuner (analog)",
329 	[ 0xc2 >> 1 ] = "tuner (analog)",
330 };
331 
332 static void do_i2c_scan(char *name, struct i2c_client *c)
333 {
334 	unsigned char buf;
335 	int i,rc;
336 
337 	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
338 		c->addr = i;
339 		rc = i2c_master_recv(c,&buf,0);
340 		if (rc < 0)
341 			continue;
342 		pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
343 			name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
344 	}
345 }
346 
347 /* init + register i2c adapter */
348 int init_bttv_i2c(struct bttv *btv)
349 {
350 	strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
351 
352 	if (i2c_hw)
353 		btv->use_i2c_hw = 1;
354 	if (btv->use_i2c_hw) {
355 		/* bt878 */
356 		strlcpy(btv->c.i2c_adap.name, "bt878",
357 			sizeof(btv->c.i2c_adap.name));
358 		btv->c.i2c_adap.algo = &bttv_algo;
359 	} else {
360 		/* bt848 */
361 	/* Prevents usage of invalid delay values */
362 		if (i2c_udelay<5)
363 			i2c_udelay=5;
364 
365 		strlcpy(btv->c.i2c_adap.name, "bttv",
366 			sizeof(btv->c.i2c_adap.name));
367 		btv->i2c_algo = bttv_i2c_algo_bit_template;
368 		btv->i2c_algo.udelay = i2c_udelay;
369 		btv->i2c_algo.data = btv;
370 		btv->c.i2c_adap.algo_data = &btv->i2c_algo;
371 	}
372 	btv->c.i2c_adap.owner = THIS_MODULE;
373 
374 	btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
375 	snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
376 		 "bt%d #%d [%s]", btv->id, btv->c.nr,
377 		 btv->use_i2c_hw ? "hw" : "sw");
378 
379 	i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
380 	btv->i2c_client.adapter = &btv->c.i2c_adap;
381 
382 
383 	if (btv->use_i2c_hw) {
384 		btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
385 	} else {
386 		bttv_bit_setscl(btv,1);
387 		bttv_bit_setsda(btv,1);
388 		btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
389 	}
390 	if (0 == btv->i2c_rc && i2c_scan)
391 		do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
392 
393 	return btv->i2c_rc;
394 }
395 
396 int fini_bttv_i2c(struct bttv *btv)
397 {
398 	if (btv->i2c_rc == 0)
399 		i2c_del_adapter(&btv->c.i2c_adap);
400 
401 	return 0;
402 }
403