1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for the Conexant CX23885 PCIe bridge
4  *
5  *  Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
6  */
7 
8 #include "cx23885.h"
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/delay.h>
13 #include <asm/io.h>
14 
15 #include <media/v4l2-common.h>
16 
17 static unsigned int i2c_debug;
18 module_param(i2c_debug, int, 0644);
19 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
20 
21 static unsigned int i2c_scan;
22 module_param(i2c_scan, int, 0444);
23 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
24 
25 #define dprintk(level, fmt, arg...)\
26 	do { if (i2c_debug >= level)\
27 		printk(KERN_DEBUG pr_fmt("%s: i2c:" fmt), \
28 			__func__, ##arg); \
29 	} while (0)
30 
31 #define I2C_WAIT_DELAY 32
32 #define I2C_WAIT_RETRY 64
33 
34 #define I2C_EXTEND  (1 << 3)
35 #define I2C_NOSTOP  (1 << 4)
36 
37 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
38 {
39 	struct cx23885_i2c *bus = i2c_adap->algo_data;
40 	struct cx23885_dev *dev = bus->dev;
41 	return cx_read(bus->reg_stat) & 0x01;
42 }
43 
44 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
45 {
46 	struct cx23885_i2c *bus = i2c_adap->algo_data;
47 	struct cx23885_dev *dev = bus->dev;
48 	return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
49 }
50 
51 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
52 {
53 	int count;
54 
55 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
56 		if (!i2c_is_busy(i2c_adap))
57 			break;
58 		udelay(I2C_WAIT_DELAY);
59 	}
60 
61 	if (I2C_WAIT_RETRY == count)
62 		return 0;
63 
64 	return 1;
65 }
66 
67 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
68 			 const struct i2c_msg *msg, int joined_rlen)
69 {
70 	struct cx23885_i2c *bus = i2c_adap->algo_data;
71 	struct cx23885_dev *dev = bus->dev;
72 	u32 wdata, addr, ctrl;
73 	int retval, cnt;
74 
75 	if (joined_rlen)
76 		dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
77 			msg->len, joined_rlen);
78 	else
79 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
80 
81 	/* Deal with i2c probe functions with zero payload */
82 	if (msg->len == 0) {
83 		cx_write(bus->reg_addr, msg->addr << 25);
84 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
85 		if (!i2c_wait_done(i2c_adap))
86 			return -EIO;
87 		if (!i2c_slave_did_ack(i2c_adap))
88 			return -ENXIO;
89 
90 		dprintk(1, "%s() returns 0\n", __func__);
91 		return 0;
92 	}
93 
94 
95 	/* dev, reg + first byte */
96 	addr = (msg->addr << 25) | msg->buf[0];
97 	wdata = msg->buf[0];
98 	ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
99 
100 	if (msg->len > 1)
101 		ctrl |= I2C_NOSTOP | I2C_EXTEND;
102 	else if (joined_rlen)
103 		ctrl |= I2C_NOSTOP;
104 
105 	cx_write(bus->reg_addr, addr);
106 	cx_write(bus->reg_wdata, wdata);
107 	cx_write(bus->reg_ctrl, ctrl);
108 
109 	if (!i2c_wait_done(i2c_adap))
110 		goto eio;
111 	if (i2c_debug) {
112 		printk(KERN_DEBUG " <W %02x %02x", msg->addr << 1, msg->buf[0]);
113 		if (!(ctrl & I2C_NOSTOP))
114 			pr_cont(" >\n");
115 	}
116 
117 	for (cnt = 1; cnt < msg->len; cnt++) {
118 		/* following bytes */
119 		wdata = msg->buf[cnt];
120 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
121 
122 		if (cnt < msg->len - 1)
123 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
124 		else if (joined_rlen)
125 			ctrl |= I2C_NOSTOP;
126 
127 		cx_write(bus->reg_addr, addr);
128 		cx_write(bus->reg_wdata, wdata);
129 		cx_write(bus->reg_ctrl, ctrl);
130 
131 		if (!i2c_wait_done(i2c_adap))
132 			goto eio;
133 		if (i2c_debug) {
134 			pr_cont(" %02x", msg->buf[cnt]);
135 			if (!(ctrl & I2C_NOSTOP))
136 				pr_cont(" >\n");
137 		}
138 	}
139 	return msg->len;
140 
141  eio:
142 	retval = -EIO;
143 	if (i2c_debug)
144 		pr_err(" ERR: %d\n", retval);
145 	return retval;
146 }
147 
148 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
149 			 const struct i2c_msg *msg, int joined)
150 {
151 	struct cx23885_i2c *bus = i2c_adap->algo_data;
152 	struct cx23885_dev *dev = bus->dev;
153 	u32 ctrl, cnt;
154 	int retval;
155 
156 
157 	if (i2c_debug && !joined)
158 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
159 
160 	/* Deal with i2c probe functions with zero payload */
161 	if (msg->len == 0) {
162 		cx_write(bus->reg_addr, msg->addr << 25);
163 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
164 		if (!i2c_wait_done(i2c_adap))
165 			return -EIO;
166 		if (!i2c_slave_did_ack(i2c_adap))
167 			return -ENXIO;
168 
169 
170 		dprintk(1, "%s() returns 0\n", __func__);
171 		return 0;
172 	}
173 
174 	if (i2c_debug) {
175 		if (joined)
176 			dprintk(1, " R");
177 		else
178 			dprintk(1, " <R %02x", (msg->addr << 1) + 1);
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)
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 		if (!i2c_wait_done(i2c_adap))
192 			goto eio;
193 		msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
194 		if (i2c_debug) {
195 			dprintk(1, " %02x", msg->buf[cnt]);
196 			if (!(ctrl & I2C_NOSTOP))
197 				dprintk(1, " >\n");
198 		}
199 	}
200 	return msg->len;
201 
202  eio:
203 	retval = -EIO;
204 	if (i2c_debug)
205 		pr_err(" ERR: %d\n", retval);
206 	return retval;
207 }
208 
209 static int i2c_xfer(struct i2c_adapter *i2c_adap,
210 		    struct i2c_msg *msgs, int num)
211 {
212 	int i, retval = 0;
213 
214 	dprintk(1, "%s(num = %d)\n", __func__, num);
215 
216 	for (i = 0 ; i < num; i++) {
217 		dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
218 			__func__, num, msgs[i].addr, msgs[i].len);
219 		if (msgs[i].flags & I2C_M_RD) {
220 			/* read */
221 			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
222 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
223 			   msgs[i].addr == msgs[i + 1].addr) {
224 			/* write then read from same address */
225 			retval = i2c_sendbytes(i2c_adap, &msgs[i],
226 					       msgs[i + 1].len);
227 			if (retval < 0)
228 				goto err;
229 			i++;
230 			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
231 		} else {
232 			/* write */
233 			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
234 		}
235 		if (retval < 0)
236 			goto err;
237 	}
238 	return num;
239 
240  err:
241 	return retval;
242 }
243 
244 static u32 cx23885_functionality(struct i2c_adapter *adap)
245 {
246 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
247 }
248 
249 static const struct i2c_algorithm cx23885_i2c_algo_template = {
250 	.master_xfer	= i2c_xfer,
251 	.functionality	= cx23885_functionality,
252 };
253 
254 /* ----------------------------------------------------------------------- */
255 
256 static const struct i2c_adapter cx23885_i2c_adap_template = {
257 	.name              = "cx23885",
258 	.owner             = THIS_MODULE,
259 	.algo              = &cx23885_i2c_algo_template,
260 };
261 
262 static const struct i2c_client cx23885_i2c_client_template = {
263 	.name	= "cx23885 internal",
264 };
265 
266 static char *i2c_devs[128] = {
267 	[0x10 >> 1] = "tda10048",
268 	[0x12 >> 1] = "dib7000pc",
269 	[0x1c >> 1] = "lgdt3303",
270 	[0x80 >> 1] = "cs3308",
271 	[0x82 >> 1] = "cs3308",
272 	[0x86 >> 1] = "tda9887",
273 	[0x32 >> 1] = "cx24227",
274 	[0x88 >> 1] = "cx25837",
275 	[0x84 >> 1] = "tda8295",
276 	[0x98 >> 1] = "flatiron",
277 	[0xa0 >> 1] = "eeprom",
278 	[0xc0 >> 1] = "tuner/mt2131/tda8275",
279 	[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
280 	[0xc8 >> 1] = "tuner/xc3028L",
281 };
282 
283 static void do_i2c_scan(char *name, struct i2c_client *c)
284 {
285 	unsigned char buf;
286 	int i, rc;
287 
288 	for (i = 0; i < 128; i++) {
289 		c->addr = i;
290 		rc = i2c_master_recv(c, &buf, 0);
291 		if (rc < 0)
292 			continue;
293 		pr_info("%s: i2c scan: found device @ 0x%04x  [%s]\n",
294 		       name, i, i2c_devs[i] ? i2c_devs[i] : "???");
295 	}
296 }
297 
298 /* init + register i2c adapter */
299 int cx23885_i2c_register(struct cx23885_i2c *bus)
300 {
301 	struct cx23885_dev *dev = bus->dev;
302 
303 	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
304 
305 	bus->i2c_adap = cx23885_i2c_adap_template;
306 	bus->i2c_client = cx23885_i2c_client_template;
307 	bus->i2c_adap.dev.parent = &dev->pci->dev;
308 
309 	strscpy(bus->i2c_adap.name, bus->dev->name,
310 		sizeof(bus->i2c_adap.name));
311 
312 	bus->i2c_adap.algo_data = bus;
313 	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
314 	i2c_add_adapter(&bus->i2c_adap);
315 
316 	bus->i2c_client.adapter = &bus->i2c_adap;
317 
318 	if (0 == bus->i2c_rc) {
319 		dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
320 		if (i2c_scan) {
321 			pr_info("%s: scan bus %d:\n",
322 					dev->name, bus->nr);
323 			do_i2c_scan(dev->name, &bus->i2c_client);
324 		}
325 	} else
326 		pr_warn("%s: i2c bus %d register FAILED\n",
327 			dev->name, bus->nr);
328 
329 	/* Instantiate the IR receiver device, if present */
330 	if (0 == bus->i2c_rc) {
331 		struct i2c_board_info info;
332 		static const unsigned short addr_list[] = {
333 			0x6b, I2C_CLIENT_END
334 		};
335 
336 		memset(&info, 0, sizeof(struct i2c_board_info));
337 		strscpy(info.type, "ir_video", I2C_NAME_SIZE);
338 		/* Use quick read command for probe, some IR chips don't
339 		 * support writes */
340 		i2c_new_scanned_device(&bus->i2c_adap, &info, addr_list,
341 				       i2c_probe_func_quick_read);
342 	}
343 
344 	return bus->i2c_rc;
345 }
346 
347 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
348 {
349 	i2c_del_adapter(&bus->i2c_adap);
350 	return 0;
351 }
352 
353 void cx23885_av_clk(struct cx23885_dev *dev, int enable)
354 {
355 	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
356 	char buffer[3];
357 	struct i2c_msg msg;
358 	dprintk(1, "%s(enabled = %d)\n", __func__, enable);
359 
360 	/* Register 0x144 */
361 	buffer[0] = 0x01;
362 	buffer[1] = 0x44;
363 	if (enable == 1)
364 		buffer[2] = 0x05;
365 	else
366 		buffer[2] = 0x00;
367 
368 	msg.addr = 0x44;
369 	msg.flags = I2C_M_TEN;
370 	msg.len = 3;
371 	msg.buf = buffer;
372 
373 	i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
374 }
375