xref: /linux/drivers/media/pci/cx23885/cx23885-i2c.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  *  Driver for the Conexant CX23885 PCIe bridge
3  *
4  *  Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <asm/io.h>
27 
28 #include "cx23885.h"
29 
30 #include <media/v4l2-common.h>
31 
32 static unsigned int i2c_debug;
33 module_param(i2c_debug, int, 0644);
34 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
35 
36 static unsigned int i2c_scan;
37 module_param(i2c_scan, int, 0444);
38 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
39 
40 #define dprintk(level, fmt, arg...)\
41 	do { if (i2c_debug >= level)\
42 		printk(KERN_DEBUG "%s/0: " fmt, dev->name, ## arg);\
43 	} while (0)
44 
45 #define I2C_WAIT_DELAY 32
46 #define I2C_WAIT_RETRY 64
47 
48 #define I2C_EXTEND  (1 << 3)
49 #define I2C_NOSTOP  (1 << 4)
50 
51 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
52 {
53 	struct cx23885_i2c *bus = i2c_adap->algo_data;
54 	struct cx23885_dev *dev = bus->dev;
55 	return cx_read(bus->reg_stat) & 0x01;
56 }
57 
58 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
59 {
60 	struct cx23885_i2c *bus = i2c_adap->algo_data;
61 	struct cx23885_dev *dev = bus->dev;
62 	return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
63 }
64 
65 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
66 {
67 	int count;
68 
69 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
70 		if (!i2c_is_busy(i2c_adap))
71 			break;
72 		udelay(I2C_WAIT_DELAY);
73 	}
74 
75 	if (I2C_WAIT_RETRY == count)
76 		return 0;
77 
78 	return 1;
79 }
80 
81 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
82 			 const struct i2c_msg *msg, int joined_rlen)
83 {
84 	struct cx23885_i2c *bus = i2c_adap->algo_data;
85 	struct cx23885_dev *dev = bus->dev;
86 	u32 wdata, addr, ctrl;
87 	int retval, cnt;
88 
89 	if (joined_rlen)
90 		dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
91 			msg->len, joined_rlen);
92 	else
93 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
94 
95 	/* Deal with i2c probe functions with zero payload */
96 	if (msg->len == 0) {
97 		cx_write(bus->reg_addr, msg->addr << 25);
98 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
99 		if (!i2c_wait_done(i2c_adap))
100 			return -EIO;
101 		if (!i2c_slave_did_ack(i2c_adap))
102 			return -ENXIO;
103 
104 		dprintk(1, "%s() returns 0\n", __func__);
105 		return 0;
106 	}
107 
108 
109 	/* dev, reg + first byte */
110 	addr = (msg->addr << 25) | msg->buf[0];
111 	wdata = msg->buf[0];
112 	ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
113 
114 	if (msg->len > 1)
115 		ctrl |= I2C_NOSTOP | I2C_EXTEND;
116 	else if (joined_rlen)
117 		ctrl |= I2C_NOSTOP;
118 
119 	cx_write(bus->reg_addr, addr);
120 	cx_write(bus->reg_wdata, wdata);
121 	cx_write(bus->reg_ctrl, ctrl);
122 
123 	if (!i2c_wait_done(i2c_adap))
124 		goto eio;
125 	if (i2c_debug) {
126 		printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
127 		if (!(ctrl & I2C_NOSTOP))
128 			printk(" >\n");
129 	}
130 
131 	for (cnt = 1; cnt < msg->len; cnt++) {
132 		/* following bytes */
133 		wdata = msg->buf[cnt];
134 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
135 
136 		if (cnt < msg->len - 1)
137 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
138 		else if (joined_rlen)
139 			ctrl |= I2C_NOSTOP;
140 
141 		cx_write(bus->reg_addr, addr);
142 		cx_write(bus->reg_wdata, wdata);
143 		cx_write(bus->reg_ctrl, ctrl);
144 
145 		if (!i2c_wait_done(i2c_adap))
146 			goto eio;
147 		if (i2c_debug) {
148 			dprintk(1, " %02x", msg->buf[cnt]);
149 			if (!(ctrl & I2C_NOSTOP))
150 				dprintk(1, " >\n");
151 		}
152 	}
153 	return msg->len;
154 
155  eio:
156 	retval = -EIO;
157 	if (i2c_debug)
158 		printk(KERN_ERR " ERR: %d\n", retval);
159 	return retval;
160 }
161 
162 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
163 			 const struct i2c_msg *msg, int joined)
164 {
165 	struct cx23885_i2c *bus = i2c_adap->algo_data;
166 	struct cx23885_dev *dev = bus->dev;
167 	u32 ctrl, cnt;
168 	int retval;
169 
170 
171 	if (i2c_debug && !joined)
172 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
173 
174 	/* Deal with i2c probe functions with zero payload */
175 	if (msg->len == 0) {
176 		cx_write(bus->reg_addr, msg->addr << 25);
177 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
178 		if (!i2c_wait_done(i2c_adap))
179 			return -EIO;
180 		if (!i2c_slave_did_ack(i2c_adap))
181 			return -ENXIO;
182 
183 
184 		dprintk(1, "%s() returns 0\n", __func__);
185 		return 0;
186 	}
187 
188 	if (i2c_debug) {
189 		if (joined)
190 			dprintk(1, " R");
191 		else
192 			dprintk(1, " <R %02x", (msg->addr << 1) + 1);
193 	}
194 
195 	for (cnt = 0; cnt < msg->len; cnt++) {
196 
197 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
198 
199 		if (cnt < msg->len - 1)
200 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
201 
202 		cx_write(bus->reg_addr, msg->addr << 25);
203 		cx_write(bus->reg_ctrl, ctrl);
204 
205 		if (!i2c_wait_done(i2c_adap))
206 			goto eio;
207 		msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
208 		if (i2c_debug) {
209 			dprintk(1, " %02x", msg->buf[cnt]);
210 			if (!(ctrl & I2C_NOSTOP))
211 				dprintk(1, " >\n");
212 		}
213 	}
214 	return msg->len;
215 
216  eio:
217 	retval = -EIO;
218 	if (i2c_debug)
219 		printk(KERN_ERR " ERR: %d\n", retval);
220 	return retval;
221 }
222 
223 static int i2c_xfer(struct i2c_adapter *i2c_adap,
224 		    struct i2c_msg *msgs, int num)
225 {
226 	struct cx23885_i2c *bus = i2c_adap->algo_data;
227 	struct cx23885_dev *dev = bus->dev;
228 	int i, retval = 0;
229 
230 	dprintk(1, "%s(num = %d)\n", __func__, num);
231 
232 	for (i = 0 ; i < num; i++) {
233 		dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
234 			__func__, num, msgs[i].addr, msgs[i].len);
235 		if (msgs[i].flags & I2C_M_RD) {
236 			/* read */
237 			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
238 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
239 			   msgs[i].addr == msgs[i + 1].addr) {
240 			/* write then read from same address */
241 			retval = i2c_sendbytes(i2c_adap, &msgs[i],
242 					       msgs[i + 1].len);
243 			if (retval < 0)
244 				goto err;
245 			i++;
246 			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
247 		} else {
248 			/* write */
249 			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
250 		}
251 		if (retval < 0)
252 			goto err;
253 	}
254 	return num;
255 
256  err:
257 	return retval;
258 }
259 
260 static u32 cx23885_functionality(struct i2c_adapter *adap)
261 {
262 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
263 }
264 
265 static struct i2c_algorithm cx23885_i2c_algo_template = {
266 	.master_xfer	= i2c_xfer,
267 	.functionality	= cx23885_functionality,
268 };
269 
270 /* ----------------------------------------------------------------------- */
271 
272 static struct i2c_adapter cx23885_i2c_adap_template = {
273 	.name              = "cx23885",
274 	.owner             = THIS_MODULE,
275 	.algo              = &cx23885_i2c_algo_template,
276 };
277 
278 static struct i2c_client cx23885_i2c_client_template = {
279 	.name	= "cx23885 internal",
280 };
281 
282 static char *i2c_devs[128] = {
283 	[0x10 >> 1] = "tda10048",
284 	[0x12 >> 1] = "dib7000pc",
285 	[0x1c >> 1] = "lgdt3303",
286 	[0x86 >> 1] = "tda9887",
287 	[0x32 >> 1] = "cx24227",
288 	[0x88 >> 1] = "cx25837",
289 	[0x84 >> 1] = "tda8295",
290 	[0x98 >> 1] = "flatiron",
291 	[0xa0 >> 1] = "eeprom",
292 	[0xc0 >> 1] = "tuner/mt2131/tda8275",
293 	[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
294 	[0xc8 >> 1] = "tuner/xc3028L",
295 };
296 
297 static void do_i2c_scan(char *name, struct i2c_client *c)
298 {
299 	unsigned char buf;
300 	int i, rc;
301 
302 	for (i = 0; i < 128; i++) {
303 		c->addr = i;
304 		rc = i2c_master_recv(c, &buf, 0);
305 		if (rc < 0)
306 			continue;
307 		printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
308 		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
309 	}
310 }
311 
312 /* init + register i2c adapter */
313 int cx23885_i2c_register(struct cx23885_i2c *bus)
314 {
315 	struct cx23885_dev *dev = bus->dev;
316 
317 	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
318 
319 	bus->i2c_adap = cx23885_i2c_adap_template;
320 	bus->i2c_client = cx23885_i2c_client_template;
321 	bus->i2c_adap.dev.parent = &dev->pci->dev;
322 
323 	strlcpy(bus->i2c_adap.name, bus->dev->name,
324 		sizeof(bus->i2c_adap.name));
325 
326 	bus->i2c_adap.algo_data = bus;
327 	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
328 	i2c_add_adapter(&bus->i2c_adap);
329 
330 	bus->i2c_client.adapter = &bus->i2c_adap;
331 
332 	if (0 == bus->i2c_rc) {
333 		dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
334 		if (i2c_scan) {
335 			printk(KERN_INFO "%s: scan bus %d:\n",
336 					dev->name, bus->nr);
337 			do_i2c_scan(dev->name, &bus->i2c_client);
338 		}
339 	} else
340 		printk(KERN_WARNING "%s: i2c bus %d register FAILED\n",
341 			dev->name, bus->nr);
342 
343 	/* Instantiate the IR receiver device, if present */
344 	if (0 == bus->i2c_rc) {
345 		struct i2c_board_info info;
346 		const unsigned short addr_list[] = {
347 			0x6b, I2C_CLIENT_END
348 		};
349 
350 		memset(&info, 0, sizeof(struct i2c_board_info));
351 		strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
352 		/* Use quick read command for probe, some IR chips don't
353 		 * support writes */
354 		i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
355 				      i2c_probe_func_quick_read);
356 	}
357 
358 	return bus->i2c_rc;
359 }
360 
361 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
362 {
363 	i2c_del_adapter(&bus->i2c_adap);
364 	return 0;
365 }
366 
367 void cx23885_av_clk(struct cx23885_dev *dev, int enable)
368 {
369 	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
370 	char buffer[3];
371 	struct i2c_msg msg;
372 	dprintk(1, "%s(enabled = %d)\n", __func__, enable);
373 
374 	/* Register 0x144 */
375 	buffer[0] = 0x01;
376 	buffer[1] = 0x44;
377 	if (enable == 1)
378 		buffer[2] = 0x05;
379 	else
380 		buffer[2] = 0x00;
381 
382 	msg.addr = 0x44;
383 	msg.flags = I2C_M_TEN;
384 	msg.len = 3;
385 	msg.buf = buffer;
386 
387 	i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
388 }
389 
390 /* ----------------------------------------------------------------------- */
391 
392 /*
393  * Local variables:
394  * c-basic-offset: 8
395  * End:
396  */
397