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 	val &= 0x70000;
77 	if (val == 0x20000)
78 		dev_err(dev->dev, "I2C bus error\n");
79 	if (val)
80 		return -EIO;
81 	return 0;
82 }
83 
84 static int ddb_i2c_master_xfer(struct i2c_adapter *adapter,
85 			       struct i2c_msg msg[], int num)
86 {
87 	struct ddb_i2c *i2c = (struct ddb_i2c *)i2c_get_adapdata(adapter);
88 	struct ddb *dev = i2c->dev;
89 	u8 addr = 0;
90 
91 	addr = msg[0].addr;
92 	if (msg[0].len > i2c->bsize)
93 		return -EIO;
94 	switch (num) {
95 	case 1:
96 		if (msg[0].flags & I2C_M_RD) {
97 			ddbwritel(dev, msg[0].len << 16,
98 				  i2c->regs + I2C_TASKLENGTH);
99 			if (ddb_i2c_cmd(i2c, addr, 3))
100 				break;
101 			ddbcpyfrom(dev, msg[0].buf,
102 				   i2c->rbuf, msg[0].len);
103 			return num;
104 		}
105 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
106 		ddbwritel(dev, msg[0].len, i2c->regs + I2C_TASKLENGTH);
107 		if (ddb_i2c_cmd(i2c, addr, 2))
108 			break;
109 		return num;
110 	case 2:
111 		if ((msg[0].flags & I2C_M_RD) == I2C_M_RD)
112 			break;
113 		if ((msg[1].flags & I2C_M_RD) != I2C_M_RD)
114 			break;
115 		if (msg[1].len > i2c->bsize)
116 			break;
117 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
118 		ddbwritel(dev, msg[0].len | (msg[1].len << 16),
119 			  i2c->regs + I2C_TASKLENGTH);
120 		if (ddb_i2c_cmd(i2c, addr, 1))
121 			break;
122 		ddbcpyfrom(dev, msg[1].buf,
123 			   i2c->rbuf,
124 			   msg[1].len);
125 		return num;
126 	default:
127 		break;
128 	}
129 	return -EIO;
130 }
131 
132 static u32 ddb_i2c_functionality(struct i2c_adapter *adap)
133 {
134 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
135 }
136 
137 static const struct i2c_algorithm ddb_i2c_algo = {
138 	.master_xfer   = ddb_i2c_master_xfer,
139 	.functionality = ddb_i2c_functionality,
140 };
141 
142 void ddb_i2c_release(struct ddb *dev)
143 {
144 	int i;
145 	struct ddb_i2c *i2c;
146 
147 	for (i = 0; i < dev->i2c_num; i++) {
148 		i2c = &dev->i2c[i];
149 		i2c_del_adapter(&i2c->adap);
150 	}
151 }
152 
153 static void i2c_handler(void *priv)
154 {
155 	struct ddb_i2c *i2c = (struct ddb_i2c *)priv;
156 
157 	complete(&i2c->completion);
158 }
159 
160 static int ddb_i2c_add(struct ddb *dev, struct ddb_i2c *i2c,
161 		       const struct ddb_regmap *regmap, int link,
162 		       int i, int num)
163 {
164 	struct i2c_adapter *adap;
165 
166 	i2c->nr = i;
167 	i2c->dev = dev;
168 	i2c->link = link;
169 	i2c->bsize = regmap->i2c_buf->size;
170 	i2c->wbuf = DDB_LINK_TAG(link) |
171 		(regmap->i2c_buf->base + i2c->bsize * i);
172 	i2c->rbuf = i2c->wbuf; /* + i2c->bsize / 2 */
173 	i2c->regs = DDB_LINK_TAG(link) |
174 		(regmap->i2c->base + regmap->i2c->size * i);
175 	ddbwritel(dev, I2C_SPEED_100, i2c->regs + I2C_TIMING);
176 	ddbwritel(dev, ((i2c->rbuf & 0xffff) << 16) | (i2c->wbuf & 0xffff),
177 		  i2c->regs + I2C_TASKADDRESS);
178 	init_completion(&i2c->completion);
179 
180 	adap = &i2c->adap;
181 	i2c_set_adapdata(adap, i2c);
182 #ifdef I2C_ADAP_CLASS_TV_DIGITAL
183 	adap->class = I2C_ADAP_CLASS_TV_DIGITAL | I2C_CLASS_TV_ANALOG;
184 #else
185 #ifdef I2C_CLASS_TV_ANALOG
186 	adap->class = I2C_CLASS_TV_ANALOG;
187 #endif
188 #endif
189 	snprintf(adap->name, I2C_NAME_SIZE, "ddbridge_%02x.%x.%x",
190 		 dev->nr, i2c->link, i);
191 	adap->algo = &ddb_i2c_algo;
192 	adap->algo_data = (void *)i2c;
193 	adap->dev.parent = dev->dev;
194 	return i2c_add_adapter(adap);
195 }
196 
197 int ddb_i2c_init(struct ddb *dev)
198 {
199 	int stat = 0;
200 	u32 i, j, num = 0, l, base;
201 	struct ddb_i2c *i2c;
202 	struct i2c_adapter *adap;
203 	const struct ddb_regmap *regmap;
204 
205 	for (l = 0; l < DDB_MAX_LINK; l++) {
206 		if (!dev->link[l].info)
207 			continue;
208 		regmap = dev->link[l].info->regmap;
209 		if (!regmap || !regmap->i2c)
210 			continue;
211 		base = regmap->irq_base_i2c;
212 		for (i = 0; i < regmap->i2c->num; i++) {
213 			if (!(dev->link[l].info->i2c_mask & (1 << i)))
214 				continue;
215 			i2c = &dev->i2c[num];
216 			ddb_irq_set(dev, l, i + base, i2c_handler, i2c);
217 			stat = ddb_i2c_add(dev, i2c, regmap, l, i, num);
218 			if (stat)
219 				break;
220 			num++;
221 		}
222 	}
223 	if (stat) {
224 		for (j = 0; j < num; j++) {
225 			i2c = &dev->i2c[j];
226 			adap = &i2c->adap;
227 			i2c_del_adapter(adap);
228 		}
229 	} else {
230 		dev->i2c_num = num;
231 	}
232 
233 	return stat;
234 }
235