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
41static int i2c_debug;
42static int i2c_hw;
43static int i2c_scan;
44module_param(i2c_debug, int, 0644);
45MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
46module_param(i2c_hw,    int, 0444);
47MODULE_PARM_DESC(i2c_hw,"force use of hardware i2c support, "
48			"instead of software bitbang");
49module_param(i2c_scan,  int, 0444);
50MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
51
52static unsigned int i2c_udelay = 5;
53module_param(i2c_udelay, int, 0444);
54MODULE_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
60static 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
72static 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
84static 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
93static 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
102static struct i2c_algo_bit_data __devinitdata 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
114static u32 functionality(struct i2c_adapter *adap)
115{
116	return I2C_FUNC_SMBUS_EMUL;
117}
118
119static int
120bttv_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
138static int
139bttv_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 (!(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
188static int
189bttv_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
234static 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
264static 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 */
273int 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 */
298int 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 */
315void __devinit 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
324static 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
334static 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 */
350int __devinit 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		memcpy(&btv->i2c_algo, &bttv_i2c_algo_bit_template,
370		       sizeof(bttv_i2c_algo_bit_template));
371		btv->i2c_algo.udelay = i2c_udelay;
372		btv->i2c_algo.data = btv;
373		btv->c.i2c_adap.algo_data = &btv->i2c_algo;
374	}
375	btv->c.i2c_adap.owner = THIS_MODULE;
376
377	btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
378	snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
379		 "bt%d #%d [%s]", btv->id, btv->c.nr,
380		 btv->use_i2c_hw ? "hw" : "sw");
381
382	i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
383	btv->i2c_client.adapter = &btv->c.i2c_adap;
384
385
386	if (btv->use_i2c_hw) {
387		btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
388	} else {
389		bttv_bit_setscl(btv,1);
390		bttv_bit_setsda(btv,1);
391		btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
392	}
393	if (0 == btv->i2c_rc && i2c_scan)
394		do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
395
396	return btv->i2c_rc;
397}
398