xref: /linux/drivers/media/pci/cx23885/cx23885-i2c.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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 
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <asm/io.h>
23 
24 #include "cx23885.h"
25 
26 #include <media/v4l2-common.h>
27 
28 static unsigned int i2c_debug;
29 module_param(i2c_debug, int, 0644);
30 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
31 
32 static unsigned int i2c_scan;
33 module_param(i2c_scan, int, 0444);
34 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
35 
36 #define dprintk(level, fmt, arg...)\
37 	do { if (i2c_debug >= level)\
38 		printk(KERN_DEBUG "%s/0: " fmt, dev->name, ## arg);\
39 	} while (0)
40 
41 #define I2C_WAIT_DELAY 32
42 #define I2C_WAIT_RETRY 64
43 
44 #define I2C_EXTEND  (1 << 3)
45 #define I2C_NOSTOP  (1 << 4)
46 
47 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
48 {
49 	struct cx23885_i2c *bus = i2c_adap->algo_data;
50 	struct cx23885_dev *dev = bus->dev;
51 	return cx_read(bus->reg_stat) & 0x01;
52 }
53 
54 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
55 {
56 	struct cx23885_i2c *bus = i2c_adap->algo_data;
57 	struct cx23885_dev *dev = bus->dev;
58 	return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
59 }
60 
61 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
62 {
63 	int count;
64 
65 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
66 		if (!i2c_is_busy(i2c_adap))
67 			break;
68 		udelay(I2C_WAIT_DELAY);
69 	}
70 
71 	if (I2C_WAIT_RETRY == count)
72 		return 0;
73 
74 	return 1;
75 }
76 
77 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
78 			 const struct i2c_msg *msg, int joined_rlen)
79 {
80 	struct cx23885_i2c *bus = i2c_adap->algo_data;
81 	struct cx23885_dev *dev = bus->dev;
82 	u32 wdata, addr, ctrl;
83 	int retval, cnt;
84 
85 	if (joined_rlen)
86 		dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
87 			msg->len, joined_rlen);
88 	else
89 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
90 
91 	/* Deal with i2c probe functions with zero payload */
92 	if (msg->len == 0) {
93 		cx_write(bus->reg_addr, msg->addr << 25);
94 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
95 		if (!i2c_wait_done(i2c_adap))
96 			return -EIO;
97 		if (!i2c_slave_did_ack(i2c_adap))
98 			return -ENXIO;
99 
100 		dprintk(1, "%s() returns 0\n", __func__);
101 		return 0;
102 	}
103 
104 
105 	/* dev, reg + first byte */
106 	addr = (msg->addr << 25) | msg->buf[0];
107 	wdata = msg->buf[0];
108 	ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
109 
110 	if (msg->len > 1)
111 		ctrl |= I2C_NOSTOP | I2C_EXTEND;
112 	else if (joined_rlen)
113 		ctrl |= I2C_NOSTOP;
114 
115 	cx_write(bus->reg_addr, addr);
116 	cx_write(bus->reg_wdata, wdata);
117 	cx_write(bus->reg_ctrl, ctrl);
118 
119 	if (!i2c_wait_done(i2c_adap))
120 		goto eio;
121 	if (i2c_debug) {
122 		printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
123 		if (!(ctrl & I2C_NOSTOP))
124 			printk(" >\n");
125 	}
126 
127 	for (cnt = 1; cnt < msg->len; cnt++) {
128 		/* following bytes */
129 		wdata = msg->buf[cnt];
130 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
131 
132 		if (cnt < msg->len - 1)
133 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
134 		else if (joined_rlen)
135 			ctrl |= I2C_NOSTOP;
136 
137 		cx_write(bus->reg_addr, addr);
138 		cx_write(bus->reg_wdata, wdata);
139 		cx_write(bus->reg_ctrl, ctrl);
140 
141 		if (!i2c_wait_done(i2c_adap))
142 			goto eio;
143 		if (i2c_debug) {
144 			dprintk(1, " %02x", msg->buf[cnt]);
145 			if (!(ctrl & I2C_NOSTOP))
146 				dprintk(1, " >\n");
147 		}
148 	}
149 	return msg->len;
150 
151  eio:
152 	retval = -EIO;
153 	if (i2c_debug)
154 		printk(KERN_ERR " ERR: %d\n", retval);
155 	return retval;
156 }
157 
158 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
159 			 const struct i2c_msg *msg, int joined)
160 {
161 	struct cx23885_i2c *bus = i2c_adap->algo_data;
162 	struct cx23885_dev *dev = bus->dev;
163 	u32 ctrl, cnt;
164 	int retval;
165 
166 
167 	if (i2c_debug && !joined)
168 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
169 
170 	/* Deal with i2c probe functions with zero payload */
171 	if (msg->len == 0) {
172 		cx_write(bus->reg_addr, msg->addr << 25);
173 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
174 		if (!i2c_wait_done(i2c_adap))
175 			return -EIO;
176 		if (!i2c_slave_did_ack(i2c_adap))
177 			return -ENXIO;
178 
179 
180 		dprintk(1, "%s() returns 0\n", __func__);
181 		return 0;
182 	}
183 
184 	if (i2c_debug) {
185 		if (joined)
186 			dprintk(1, " R");
187 		else
188 			dprintk(1, " <R %02x", (msg->addr << 1) + 1);
189 	}
190 
191 	for (cnt = 0; cnt < msg->len; cnt++) {
192 
193 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
194 
195 		if (cnt < msg->len - 1)
196 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
197 
198 		cx_write(bus->reg_addr, msg->addr << 25);
199 		cx_write(bus->reg_ctrl, ctrl);
200 
201 		if (!i2c_wait_done(i2c_adap))
202 			goto eio;
203 		msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
204 		if (i2c_debug) {
205 			dprintk(1, " %02x", msg->buf[cnt]);
206 			if (!(ctrl & I2C_NOSTOP))
207 				dprintk(1, " >\n");
208 		}
209 	}
210 	return msg->len;
211 
212  eio:
213 	retval = -EIO;
214 	if (i2c_debug)
215 		printk(KERN_ERR " ERR: %d\n", retval);
216 	return retval;
217 }
218 
219 static int i2c_xfer(struct i2c_adapter *i2c_adap,
220 		    struct i2c_msg *msgs, int num)
221 {
222 	struct cx23885_i2c *bus = i2c_adap->algo_data;
223 	struct cx23885_dev *dev = bus->dev;
224 	int i, retval = 0;
225 
226 	dprintk(1, "%s(num = %d)\n", __func__, num);
227 
228 	for (i = 0 ; i < num; i++) {
229 		dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
230 			__func__, num, msgs[i].addr, msgs[i].len);
231 		if (msgs[i].flags & I2C_M_RD) {
232 			/* read */
233 			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
234 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
235 			   msgs[i].addr == msgs[i + 1].addr) {
236 			/* write then read from same address */
237 			retval = i2c_sendbytes(i2c_adap, &msgs[i],
238 					       msgs[i + 1].len);
239 			if (retval < 0)
240 				goto err;
241 			i++;
242 			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
243 		} else {
244 			/* write */
245 			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
246 		}
247 		if (retval < 0)
248 			goto err;
249 	}
250 	return num;
251 
252  err:
253 	return retval;
254 }
255 
256 static u32 cx23885_functionality(struct i2c_adapter *adap)
257 {
258 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
259 }
260 
261 static struct i2c_algorithm cx23885_i2c_algo_template = {
262 	.master_xfer	= i2c_xfer,
263 	.functionality	= cx23885_functionality,
264 };
265 
266 /* ----------------------------------------------------------------------- */
267 
268 static struct i2c_adapter cx23885_i2c_adap_template = {
269 	.name              = "cx23885",
270 	.owner             = THIS_MODULE,
271 	.algo              = &cx23885_i2c_algo_template,
272 };
273 
274 static struct i2c_client cx23885_i2c_client_template = {
275 	.name	= "cx23885 internal",
276 };
277 
278 static char *i2c_devs[128] = {
279 	[0x10 >> 1] = "tda10048",
280 	[0x12 >> 1] = "dib7000pc",
281 	[0x1c >> 1] = "lgdt3303",
282 	[0x86 >> 1] = "tda9887",
283 	[0x32 >> 1] = "cx24227",
284 	[0x88 >> 1] = "cx25837",
285 	[0x84 >> 1] = "tda8295",
286 	[0x98 >> 1] = "flatiron",
287 	[0xa0 >> 1] = "eeprom",
288 	[0xc0 >> 1] = "tuner/mt2131/tda8275",
289 	[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
290 	[0xc8 >> 1] = "tuner/xc3028L",
291 };
292 
293 static void do_i2c_scan(char *name, struct i2c_client *c)
294 {
295 	unsigned char buf;
296 	int i, rc;
297 
298 	for (i = 0; i < 128; i++) {
299 		c->addr = i;
300 		rc = i2c_master_recv(c, &buf, 0);
301 		if (rc < 0)
302 			continue;
303 		printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
304 		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
305 	}
306 }
307 
308 /* init + register i2c adapter */
309 int cx23885_i2c_register(struct cx23885_i2c *bus)
310 {
311 	struct cx23885_dev *dev = bus->dev;
312 
313 	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
314 
315 	bus->i2c_adap = cx23885_i2c_adap_template;
316 	bus->i2c_client = cx23885_i2c_client_template;
317 	bus->i2c_adap.dev.parent = &dev->pci->dev;
318 
319 	strlcpy(bus->i2c_adap.name, bus->dev->name,
320 		sizeof(bus->i2c_adap.name));
321 
322 	bus->i2c_adap.algo_data = bus;
323 	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
324 	i2c_add_adapter(&bus->i2c_adap);
325 
326 	bus->i2c_client.adapter = &bus->i2c_adap;
327 
328 	if (0 == bus->i2c_rc) {
329 		dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
330 		if (i2c_scan) {
331 			printk(KERN_INFO "%s: scan bus %d:\n",
332 					dev->name, bus->nr);
333 			do_i2c_scan(dev->name, &bus->i2c_client);
334 		}
335 	} else
336 		printk(KERN_WARNING "%s: i2c bus %d register FAILED\n",
337 			dev->name, bus->nr);
338 
339 	/* Instantiate the IR receiver device, if present */
340 	if (0 == bus->i2c_rc) {
341 		struct i2c_board_info info;
342 		const unsigned short addr_list[] = {
343 			0x6b, I2C_CLIENT_END
344 		};
345 
346 		memset(&info, 0, sizeof(struct i2c_board_info));
347 		strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
348 		/* Use quick read command for probe, some IR chips don't
349 		 * support writes */
350 		i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
351 				      i2c_probe_func_quick_read);
352 	}
353 
354 	return bus->i2c_rc;
355 }
356 
357 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
358 {
359 	i2c_del_adapter(&bus->i2c_adap);
360 	return 0;
361 }
362 
363 void cx23885_av_clk(struct cx23885_dev *dev, int enable)
364 {
365 	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
366 	char buffer[3];
367 	struct i2c_msg msg;
368 	dprintk(1, "%s(enabled = %d)\n", __func__, enable);
369 
370 	/* Register 0x144 */
371 	buffer[0] = 0x01;
372 	buffer[1] = 0x44;
373 	if (enable == 1)
374 		buffer[2] = 0x05;
375 	else
376 		buffer[2] = 0x00;
377 
378 	msg.addr = 0x44;
379 	msg.flags = I2C_M_TEN;
380 	msg.len = 3;
381 	msg.buf = buffer;
382 
383 	i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
384 }
385