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
17static unsigned int i2c_debug;
18module_param(i2c_debug, int, 0644);
19MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
20
21static unsigned int i2c_scan;
22module_param(i2c_scan, int, 0444);
23MODULE_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
37static 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
44static 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
51static 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
67static 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
148static 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
209static 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
244static u32 cx23885_functionality(struct i2c_adapter *adap)
245{
246	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
247}
248
249static const struct i2c_algorithm cx23885_i2c_algo_template = {
250	.master_xfer	= i2c_xfer,
251	.functionality	= cx23885_functionality,
252};
253
254/* ----------------------------------------------------------------------- */
255
256static const struct i2c_adapter cx23885_i2c_adap_template = {
257	.name              = "cx23885",
258	.owner             = THIS_MODULE,
259	.algo              = &cx23885_i2c_algo_template,
260};
261
262static const struct i2c_client cx23885_i2c_client_template = {
263	.name	= "cx23885 internal",
264};
265
266static 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
283static 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 */
299int 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
347int cx23885_i2c_unregister(struct cx23885_i2c *bus)
348{
349	i2c_del_adapter(&bus->i2c_adap);
350	return 0;
351}
352
353void 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