1 /*
2  * ddbridge-i2c.c: Digital Devices bridge i2c driver
3  *
4  * Copyright (C) 2010-2017 Digital Devices GmbH
5  *                         Ralph Metzler <rjkm@metzlerbros.de>
6  *                         Marcus Metzler <mocm@metzlerbros.de>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 only, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/delay.h>
23 #include <linux/slab.h>
24 #include <linux/poll.h>
25 #include <linux/io.h>
26 #include <linux/pci.h>
27 #include <linux/pci_ids.h>
28 #include <linux/timer.h>
29 #include <linux/i2c.h>
30 #include <linux/swab.h>
31 #include <linux/vmalloc.h>
32 
33 #include "ddbridge.h"
34 #include "ddbridge-i2c.h"
35 #include "ddbridge-regs.h"
36 #include "ddbridge-io.h"
37 
38 /******************************************************************************/
39 
40 static int ddb_i2c_cmd(struct ddb_i2c *i2c, u32 adr, u32 cmd)
41 {
42 	struct ddb *dev = i2c->dev;
43 	unsigned long stat;
44 	u32 val;
45 
46 	ddbwritel(dev, (adr << 9) | cmd, i2c->regs + I2C_COMMAND);
47 	stat = wait_for_completion_timeout(&i2c->completion, HZ);
48 	val = ddbreadl(dev, i2c->regs + I2C_COMMAND);
49 	if (stat == 0) {
50 		dev_err(dev->dev, "I2C timeout, card %d, port %d, link %u\n",
51 			dev->nr, i2c->nr, i2c->link);
52 		{
53 			u32 istat = ddbreadl(dev, INTERRUPT_STATUS);
54 
55 			dev_err(dev->dev, "DDBridge IRS %08x\n", istat);
56 			if (i2c->link) {
57 				u32 listat = ddbreadl(dev,
58 					DDB_LINK_TAG(i2c->link) |
59 					INTERRUPT_STATUS);
60 
61 				dev_err(dev->dev, "DDBridge link %u IRS %08x\n",
62 					i2c->link, listat);
63 			}
64 			if (istat & 1) {
65 				ddbwritel(dev, istat & 1, INTERRUPT_ACK);
66 			} else {
67 				u32 mon = ddbreadl(dev,
68 					i2c->regs + I2C_MONITOR);
69 
70 				dev_err(dev->dev, "I2C cmd=%08x mon=%08x\n",
71 					val, mon);
72 			}
73 		}
74 		return -EIO;
75 	}
76 	if (val & 0x70000)
77 		return -EIO;
78 	return 0;
79 }
80 
81 static int ddb_i2c_master_xfer(struct i2c_adapter *adapter,
82 			       struct i2c_msg msg[], int num)
83 {
84 	struct ddb_i2c *i2c = (struct ddb_i2c *) i2c_get_adapdata(adapter);
85 	struct ddb *dev = i2c->dev;
86 	u8 addr = 0;
87 
88 	addr = msg[0].addr;
89 	if (msg[0].len > i2c->bsize)
90 		return -EIO;
91 	switch (num) {
92 	case 1:
93 		if (msg[0].flags & I2C_M_RD) {
94 			ddbwritel(dev, msg[0].len << 16,
95 				  i2c->regs + I2C_TASKLENGTH);
96 			if (ddb_i2c_cmd(i2c, addr, 3))
97 				break;
98 			ddbcpyfrom(dev, msg[0].buf,
99 				   i2c->rbuf, msg[0].len);
100 			return num;
101 		}
102 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
103 		ddbwritel(dev, msg[0].len, i2c->regs + I2C_TASKLENGTH);
104 		if (ddb_i2c_cmd(i2c, addr, 2))
105 			break;
106 		return num;
107 	case 2:
108 		if ((msg[0].flags & I2C_M_RD) == I2C_M_RD)
109 			break;
110 		if ((msg[1].flags & I2C_M_RD) != I2C_M_RD)
111 			break;
112 		if (msg[1].len > i2c->bsize)
113 			break;
114 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
115 		ddbwritel(dev, msg[0].len | (msg[1].len << 16),
116 			  i2c->regs + I2C_TASKLENGTH);
117 		if (ddb_i2c_cmd(i2c, addr, 1))
118 			break;
119 		ddbcpyfrom(dev, msg[1].buf,
120 			   i2c->rbuf,
121 			   msg[1].len);
122 		return num;
123 	default:
124 		break;
125 	}
126 	return -EIO;
127 }
128 
129 static u32 ddb_i2c_functionality(struct i2c_adapter *adap)
130 {
131 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
132 }
133 
134 static const struct i2c_algorithm ddb_i2c_algo = {
135 	.master_xfer   = ddb_i2c_master_xfer,
136 	.functionality = ddb_i2c_functionality,
137 };
138 
139 void ddb_i2c_release(struct ddb *dev)
140 {
141 	int i;
142 	struct ddb_i2c *i2c;
143 
144 	for (i = 0; i < dev->i2c_num; i++) {
145 		i2c = &dev->i2c[i];
146 		i2c_del_adapter(&i2c->adap);
147 	}
148 }
149 
150 static void i2c_handler(unsigned long priv)
151 {
152 	struct ddb_i2c *i2c = (struct ddb_i2c *) priv;
153 
154 	complete(&i2c->completion);
155 }
156 
157 static int ddb_i2c_add(struct ddb *dev, struct ddb_i2c *i2c,
158 		       const struct ddb_regmap *regmap, int link,
159 		       int i, int num)
160 {
161 	struct i2c_adapter *adap;
162 
163 	i2c->nr = i;
164 	i2c->dev = dev;
165 	i2c->link = link;
166 	i2c->bsize = regmap->i2c_buf->size;
167 	i2c->wbuf = DDB_LINK_TAG(link) |
168 		(regmap->i2c_buf->base + i2c->bsize * i);
169 	i2c->rbuf = i2c->wbuf; /* + i2c->bsize / 2 */
170 	i2c->regs = DDB_LINK_TAG(link) |
171 		(regmap->i2c->base + regmap->i2c->size * i);
172 	ddbwritel(dev, I2C_SPEED_100, i2c->regs + I2C_TIMING);
173 	ddbwritel(dev, ((i2c->rbuf & 0xffff) << 16) | (i2c->wbuf & 0xffff),
174 		i2c->regs + I2C_TASKADDRESS);
175 	init_completion(&i2c->completion);
176 
177 	adap = &i2c->adap;
178 	i2c_set_adapdata(adap, i2c);
179 #ifdef I2C_ADAP_CLASS_TV_DIGITAL
180 	adap->class = I2C_ADAP_CLASS_TV_DIGITAL|I2C_CLASS_TV_ANALOG;
181 #else
182 #ifdef I2C_CLASS_TV_ANALOG
183 	adap->class = I2C_CLASS_TV_ANALOG;
184 #endif
185 #endif
186 	snprintf(adap->name, I2C_NAME_SIZE, "ddbridge_%02x.%x.%x",
187 		dev->nr, i2c->link, i);
188 	adap->algo = &ddb_i2c_algo;
189 	adap->algo_data = (void *)i2c;
190 	adap->dev.parent = dev->dev;
191 	return i2c_add_adapter(adap);
192 }
193 
194 int ddb_i2c_init(struct ddb *dev)
195 {
196 	int stat = 0;
197 	u32 i, j, num = 0, l, base;
198 	struct ddb_i2c *i2c;
199 	struct i2c_adapter *adap;
200 	const struct ddb_regmap *regmap;
201 
202 	for (l = 0; l < DDB_MAX_LINK; l++) {
203 		if (!dev->link[l].info)
204 			continue;
205 		regmap = dev->link[l].info->regmap;
206 		if (!regmap || !regmap->i2c)
207 			continue;
208 		base = regmap->irq_base_i2c;
209 		for (i = 0; i < regmap->i2c->num; i++) {
210 			if (!(dev->link[l].info->i2c_mask & (1 << i)))
211 				continue;
212 			i2c = &dev->i2c[num];
213 			dev->handler_data[l][i + base] = (unsigned long) i2c;
214 			dev->handler[l][i + base] = i2c_handler;
215 			stat = ddb_i2c_add(dev, i2c, regmap, l, i, num);
216 			if (stat)
217 				break;
218 			num++;
219 		}
220 	}
221 	if (stat) {
222 		for (j = 0; j < num; j++) {
223 			i2c = &dev->i2c[j];
224 			adap = &i2c->adap;
225 			i2c_del_adapter(adap);
226 		}
227 	} else
228 		dev->i2c_num = num;
229 	return stat;
230 }
231