5572fbbbb5ae7b7411276b063b79666c0932730b
[linux-2.6.git] / drivers / media / video / cx23885 / cx23885-i2c.c
1 /*
2  *  Driver for the Conexant CX23885 PCIe bridge
3  *
4  *  Copyright (c) 2006 Steven Toth <stoth@hauppauge.com>
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 = 0;
33 module_param(i2c_debug, int, 0644);
34 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
35
36 static unsigned int i2c_scan = 0;
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...)      if (i2c_debug >= level) \
41         printk(KERN_DEBUG "%s: " fmt, dev->name , ## arg)
42
43 #define I2C_WAIT_DELAY 32
44 #define I2C_WAIT_RETRY 64
45
46 #define I2C_EXTEND  (1 << 3)
47 #define I2C_NOSTOP  (1 << 4)
48
49 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
50 {
51         struct cx23885_i2c *bus = i2c_adap->algo_data;
52         struct cx23885_dev *dev = bus->dev;
53         return cx_read(bus->reg_stat) & 0x01;
54 }
55
56 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
57 {
58         struct cx23885_i2c *bus = i2c_adap->algo_data;
59         struct cx23885_dev *dev = bus->dev;
60         return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
61 }
62
63 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
64 {
65         int count;
66
67         for (count = 0; count < I2C_WAIT_RETRY; count++) {
68                 if (!i2c_is_busy(i2c_adap))
69                         break;
70                 udelay(I2C_WAIT_DELAY);
71         }
72
73         if (I2C_WAIT_RETRY == count)
74                 return 0;
75
76         return 1;
77 }
78
79 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
80                          const struct i2c_msg *msg, int last)
81 {
82         struct cx23885_i2c *bus = i2c_adap->algo_data;
83         struct cx23885_dev *dev = bus->dev;
84         u32 wdata, addr, ctrl;
85         int retval, cnt;
86
87         dprintk(1, "%s()\n", __FUNCTION__);
88         /* Deal with i2c probe functions with zero payload */
89         if (msg->len == 0) {
90                 cx_write(bus->reg_addr, msg->addr << 25);
91                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
92                 if (!i2c_wait_done(i2c_adap))
93                         return -EIO;
94                 if (!i2c_slave_did_ack(i2c_adap))
95                         return -EIO;
96
97                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
98                 return 0;
99         }
100
101
102         /* dev, reg + first byte */
103         addr = (msg->addr << 25) | msg->buf[0];
104         wdata = msg->buf[0];
105         ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
106
107         if (msg->len > 1)
108                 ctrl |= I2C_NOSTOP | I2C_EXTEND;
109
110         cx_write(bus->reg_addr, addr);
111         cx_write(bus->reg_wdata, wdata);
112         cx_write(bus->reg_ctrl, ctrl);
113
114         retval = i2c_wait_done(i2c_adap);
115         if (retval < 0)
116                 goto err;
117         if (retval == 0)
118                 goto eio;
119         if (i2c_debug) {
120                 printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
121                 if (!(ctrl & I2C_NOSTOP))
122                         printk(" >\n");
123         }
124
125         for (cnt = 1; cnt < msg->len; cnt++ ) {
126                 /* following bytes */
127                 wdata = msg->buf[cnt];
128                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
129
130                 if (cnt < msg->len-1 || !last)
131                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
132
133                 cx_write(bus->reg_addr, addr);
134                 cx_write(bus->reg_wdata, wdata);
135                 cx_write(bus->reg_ctrl, ctrl);
136
137                 retval = i2c_wait_done(i2c_adap);
138                 if (retval < 0)
139                         goto err;
140                 if (retval == 0)
141                         goto eio;
142                 if (i2c_debug) {
143                         printk(" %02x", msg->buf[cnt]);
144                         if (!(ctrl & I2C_NOSTOP))
145                                 printk(" >\n");
146                 }
147         }
148         return msg->len;
149
150  eio:
151         retval = -EIO;
152  err:
153         printk(" ERR: %d\n", retval);
154         return retval;
155 }
156
157 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
158                          const struct i2c_msg *msg, int last)
159 {
160         struct cx23885_i2c *bus = i2c_adap->algo_data;
161         struct cx23885_dev *dev = bus->dev;
162         u32 ctrl, cnt;
163         int retval;
164
165         dprintk(1, "%s()\n", __FUNCTION__);
166
167         /* Deal with i2c probe functions with zero payload */
168         if (msg->len == 0) {
169                 cx_write(bus->reg_addr, msg->addr << 25);
170                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
171                 if (!i2c_wait_done(i2c_adap))
172                         return -EIO;
173                 if (!i2c_slave_did_ack(i2c_adap))
174                         return -EIO;
175
176
177                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
178                 return 0;
179         }
180
181         for(cnt = 0; cnt < msg->len; cnt++) {
182
183                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
184
185                 if (cnt < msg->len-1 || !last)
186                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
187
188                 cx_write(bus->reg_addr, msg->addr << 25);
189                 cx_write(bus->reg_ctrl, ctrl);
190
191                 retval = i2c_wait_done(i2c_adap);
192                 if (retval < 0)
193                         goto err;
194                 if (retval == 0)
195                         goto eio;
196                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
197                 if (i2c_debug) {
198                         if (!(ctrl & I2C_NOSTOP))
199                                 printk(" <R %02x", (msg->addr << 1) +1);
200                         printk(" =%02x", msg->buf[cnt]);
201                         if (!(ctrl & I2C_NOSTOP))
202                                 printk(" >\n");
203                 }
204         }
205         return msg->len;
206
207  eio:
208         retval = -EIO;
209  err:
210         printk(" ERR: %d\n", retval);
211         return retval;
212 }
213
214 static int i2c_xfer(struct i2c_adapter *i2c_adap,
215                     struct i2c_msg *msgs, int num)
216 {
217         struct cx23885_i2c *bus = i2c_adap->algo_data;
218         struct cx23885_dev *dev = bus->dev;
219         int i, retval = 0;
220
221         dprintk(1, "%s(num = %d)\n", __FUNCTION__, num);
222
223         for (i = 0 ; i < num; i++) {
224                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
225                         __FUNCTION__, num, msgs[i].addr, msgs[i].len);
226                 if (msgs[i].flags & I2C_M_RD) {
227                         /* read */
228                         retval = i2c_readbytes(i2c_adap, &msgs[i], i+1 == num);
229                         if (retval < 0)
230                                 goto err;
231                 } else {
232                         /* write */
233                         retval = i2c_sendbytes(i2c_adap, &msgs[i], i+1 == num);
234                         if (retval < 0)
235                                 goto err;
236                 }
237         }
238         return num;
239
240  err:
241         return retval;
242 }
243
244 static int attach_inform(struct i2c_client *client)
245 {
246         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
247
248         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
249                 client->driver->driver.name, client->addr, client->name);
250
251         if (!client->driver->command)
252                 return 0;
253
254         return 0;
255 }
256
257 static int detach_inform(struct i2c_client *client)
258 {
259         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
260
261         dprintk(1, "i2c detach [client=%s]\n", client->name);
262
263         return 0;
264 }
265
266 void cx23885_call_i2c_clients(struct cx23885_i2c *bus,
267                               unsigned int cmd, void *arg)
268 {
269         if (bus->i2c_rc != 0)
270                 return;
271
272         i2c_clients_command(&bus->i2c_adap, cmd, arg);
273 }
274
275 static int cx23885_algo_control(struct i2c_adapter *adap,
276                                 unsigned int cmd, unsigned long arg)
277 {
278         return 0;
279 }
280
281 static u32 cx23885_functionality(struct i2c_adapter *adap)
282 {
283         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
284 }
285
286 static struct i2c_algorithm cx23885_i2c_algo_template = {
287         .master_xfer    = i2c_xfer,
288         .algo_control   = cx23885_algo_control,
289         .functionality  = cx23885_functionality,
290 };
291
292 /* ----------------------------------------------------------------------- */
293
294 static struct i2c_adapter cx23885_i2c_adap_template = {
295         .name              = "cx23885",
296         .owner             = THIS_MODULE,
297         .id                = I2C_HW_B_CX23885,
298         .algo              = &cx23885_i2c_algo_template,
299         .client_register   = attach_inform,
300         .client_unregister = detach_inform,
301 };
302
303 static struct i2c_client cx23885_i2c_client_template = {
304         .name   = "cx23885 internal",
305 };
306
307 static char *i2c_devs[128] = {
308         [ 0x32 >> 1 ] = "cx24227",
309         [ 0x88 >> 1 ] = "cx25837",
310         [ 0x84 >> 1 ] = "tda8295",
311         [ 0xa0 >> 1 ] = "eeprom",
312         [ 0xc0 >> 1 ] = "mt2131/tda8275",
313         [ 0xc2 >> 1 ] = "mt2131/tda8275",
314 };
315
316 static void do_i2c_scan(char *name, struct i2c_client *c)
317 {
318         unsigned char buf;
319         int i, rc;
320
321         for (i = 0; i < 128; i++) {
322                 c->addr = i;
323                 rc = i2c_master_recv(c, &buf, 0);
324                 if (rc < 0)
325                         continue;
326                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
327                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
328         }
329 }
330
331 /* init + register i2c algo-bit adapter */
332 int cx23885_i2c_register(struct cx23885_i2c *bus)
333 {
334         struct cx23885_dev *dev = bus->dev;
335
336         dprintk(1, "%s(bus = %d)\n", __FUNCTION__, bus->nr);
337
338         memcpy(&bus->i2c_adap, &cx23885_i2c_adap_template,
339                sizeof(bus->i2c_adap));
340         memcpy(&bus->i2c_algo, &cx23885_i2c_algo_template,
341                sizeof(bus->i2c_algo));
342         memcpy(&bus->i2c_client, &cx23885_i2c_client_template,
343                sizeof(bus->i2c_client));
344
345         bus->i2c_adap.dev.parent = &dev->pci->dev;
346
347         strlcpy(bus->i2c_adap.name, bus->dev->name,
348                 sizeof(bus->i2c_adap.name));
349
350         bus->i2c_algo.data = bus;
351         bus->i2c_adap.algo_data = bus;
352         i2c_add_adapter(&bus->i2c_adap);
353
354         bus->i2c_client.adapter = &bus->i2c_adap;
355
356         if (0 == bus->i2c_rc) {
357                 printk("%s: i2c bus %d registered\n", dev->name, bus->nr);
358                 if (i2c_scan)
359                         do_i2c_scan(dev->name, &bus->i2c_client);
360         } else
361                 printk("%s: i2c bus %d register FAILED\n", dev->name, bus->nr);
362
363         return bus->i2c_rc;
364 }
365
366 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
367 {
368         i2c_del_adapter(&bus->i2c_adap);
369         return 0;
370 }
371
372 /* ----------------------------------------------------------------------- */
373
374 EXPORT_SYMBOL(cx23885_call_i2c_clients);
375
376 /*
377  * Local variables:
378  * c-basic-offset: 8
379  * End:
380  */