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