1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ddbridge-i2c.c: Digital Devices bridge i2c driver
4  *
5  * Copyright (C) 2010-2017 Digital Devices GmbH
6  *                         Ralph Metzler <rjkm@metzlerbros.de>
7  *                         Marcus Metzler <mocm@metzlerbros.de>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/poll.h>
16 #include <linux/io.h>
17 #include <linux/pci.h>
18 #include <linux/pci_ids.h>
19 #include <linux/timer.h>
20 #include <linux/i2c.h>
21 #include <linux/swab.h>
22 #include <linux/vmalloc.h>
23 
24 #include "ddbridge.h"
25 #include "ddbridge-i2c.h"
26 #include "ddbridge-regs.h"
27 #include "ddbridge-io.h"
28 
29 /******************************************************************************/
30 
ddb_i2c_cmd(struct ddb_i2c * i2c,u32 adr,u32 cmd)31 static int ddb_i2c_cmd(struct ddb_i2c *i2c, u32 adr, u32 cmd)
32 {
33 	struct ddb *dev = i2c->dev;
34 	unsigned long stat;
35 	u32 val;
36 
37 	ddbwritel(dev, (adr << 9) | cmd, i2c->regs + I2C_COMMAND);
38 	stat = wait_for_completion_timeout(&i2c->completion, HZ);
39 	val = ddbreadl(dev, i2c->regs + I2C_COMMAND);
40 	if (stat == 0) {
41 		dev_err(dev->dev, "I2C timeout, card %d, port %d, link %u\n",
42 			dev->nr, i2c->nr, i2c->link);
43 		{
44 			u32 istat = ddbreadl(dev, INTERRUPT_STATUS);
45 
46 			dev_err(dev->dev, "DDBridge IRS %08x\n", istat);
47 			if (i2c->link) {
48 				u32 listat = ddbreadl(dev,
49 					DDB_LINK_TAG(i2c->link) |
50 					INTERRUPT_STATUS);
51 
52 				dev_err(dev->dev, "DDBridge link %u IRS %08x\n",
53 					i2c->link, listat);
54 			}
55 			if (istat & 1) {
56 				ddbwritel(dev, istat & 1, INTERRUPT_ACK);
57 			} else {
58 				u32 mon = ddbreadl(dev,
59 					i2c->regs + I2C_MONITOR);
60 
61 				dev_err(dev->dev, "I2C cmd=%08x mon=%08x\n",
62 					val, mon);
63 			}
64 		}
65 		return -EIO;
66 	}
67 	val &= 0x70000;
68 	if (val == 0x20000)
69 		dev_err(dev->dev, "I2C bus error\n");
70 	if (val)
71 		return -EIO;
72 	return 0;
73 }
74 
ddb_i2c_master_xfer(struct i2c_adapter * adapter,struct i2c_msg msg[],int num)75 static int ddb_i2c_master_xfer(struct i2c_adapter *adapter,
76 			       struct i2c_msg msg[], int num)
77 {
78 	struct ddb_i2c *i2c = (struct ddb_i2c *)i2c_get_adapdata(adapter);
79 	struct ddb *dev = i2c->dev;
80 	u8 addr = 0;
81 
82 	addr = msg[0].addr;
83 	if (msg[0].len > i2c->bsize)
84 		return -EIO;
85 	switch (num) {
86 	case 1:
87 		if (msg[0].flags & I2C_M_RD) {
88 			ddbwritel(dev, msg[0].len << 16,
89 				  i2c->regs + I2C_TASKLENGTH);
90 			if (ddb_i2c_cmd(i2c, addr, 3))
91 				break;
92 			ddbcpyfrom(dev, msg[0].buf,
93 				   i2c->rbuf, msg[0].len);
94 			return num;
95 		}
96 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
97 		ddbwritel(dev, msg[0].len, i2c->regs + I2C_TASKLENGTH);
98 		if (ddb_i2c_cmd(i2c, addr, 2))
99 			break;
100 		return num;
101 	case 2:
102 		if ((msg[0].flags & I2C_M_RD) == I2C_M_RD)
103 			break;
104 		if ((msg[1].flags & I2C_M_RD) != I2C_M_RD)
105 			break;
106 		if (msg[1].len > i2c->bsize)
107 			break;
108 		ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
109 		ddbwritel(dev, msg[0].len | (msg[1].len << 16),
110 			  i2c->regs + I2C_TASKLENGTH);
111 		if (ddb_i2c_cmd(i2c, addr, 1))
112 			break;
113 		ddbcpyfrom(dev, msg[1].buf,
114 			   i2c->rbuf,
115 			   msg[1].len);
116 		return num;
117 	default:
118 		break;
119 	}
120 	return -EIO;
121 }
122 
ddb_i2c_functionality(struct i2c_adapter * adap)123 static u32 ddb_i2c_functionality(struct i2c_adapter *adap)
124 {
125 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
126 }
127 
128 static const struct i2c_algorithm ddb_i2c_algo = {
129 	.master_xfer   = ddb_i2c_master_xfer,
130 	.functionality = ddb_i2c_functionality,
131 };
132 
ddb_i2c_release(struct ddb * dev)133 void ddb_i2c_release(struct ddb *dev)
134 {
135 	int i;
136 	struct ddb_i2c *i2c;
137 
138 	for (i = 0; i < dev->i2c_num; i++) {
139 		i2c = &dev->i2c[i];
140 		i2c_del_adapter(&i2c->adap);
141 	}
142 }
143 
i2c_handler(void * priv)144 static void i2c_handler(void *priv)
145 {
146 	struct ddb_i2c *i2c = (struct ddb_i2c *)priv;
147 
148 	complete(&i2c->completion);
149 }
150 
ddb_i2c_add(struct ddb * dev,struct ddb_i2c * i2c,const struct ddb_regmap * regmap,int link,int i,int num)151 static int ddb_i2c_add(struct ddb *dev, struct ddb_i2c *i2c,
152 		       const struct ddb_regmap *regmap, int link,
153 		       int i, int num)
154 {
155 	struct i2c_adapter *adap;
156 
157 	i2c->nr = i;
158 	i2c->dev = dev;
159 	i2c->link = link;
160 	i2c->bsize = regmap->i2c_buf->size;
161 	i2c->wbuf = DDB_LINK_TAG(link) |
162 		(regmap->i2c_buf->base + i2c->bsize * i);
163 	i2c->rbuf = i2c->wbuf; /* + i2c->bsize / 2 */
164 	i2c->regs = DDB_LINK_TAG(link) |
165 		(regmap->i2c->base + regmap->i2c->size * i);
166 	ddbwritel(dev, I2C_SPEED_100, i2c->regs + I2C_TIMING);
167 	ddbwritel(dev, ((i2c->rbuf & 0xffff) << 16) | (i2c->wbuf & 0xffff),
168 		  i2c->regs + I2C_TASKADDRESS);
169 	init_completion(&i2c->completion);
170 
171 	adap = &i2c->adap;
172 	i2c_set_adapdata(adap, i2c);
173 #ifdef I2C_ADAP_CLASS_TV_DIGITAL
174 	adap->class = I2C_ADAP_CLASS_TV_DIGITAL | I2C_CLASS_TV_ANALOG;
175 #else
176 #ifdef I2C_CLASS_TV_ANALOG
177 	adap->class = I2C_CLASS_TV_ANALOG;
178 #endif
179 #endif
180 	snprintf(adap->name, I2C_NAME_SIZE, "ddbridge_%02x.%x.%x",
181 		 dev->nr, i2c->link, i);
182 	adap->algo = &ddb_i2c_algo;
183 	adap->algo_data = (void *)i2c;
184 	adap->dev.parent = dev->dev;
185 	return i2c_add_adapter(adap);
186 }
187 
ddb_i2c_init(struct ddb * dev)188 int ddb_i2c_init(struct ddb *dev)
189 {
190 	int stat = 0;
191 	u32 i, j, num = 0, l, base;
192 	struct ddb_i2c *i2c;
193 	struct i2c_adapter *adap;
194 	const struct ddb_regmap *regmap;
195 
196 	for (l = 0; l < DDB_MAX_LINK; l++) {
197 		if (!dev->link[l].info)
198 			continue;
199 		regmap = dev->link[l].info->regmap;
200 		if (!regmap || !regmap->i2c)
201 			continue;
202 		base = regmap->irq_base_i2c;
203 		for (i = 0; i < regmap->i2c->num; i++) {
204 			if (!(dev->link[l].info->i2c_mask & (1 << i)))
205 				continue;
206 			i2c = &dev->i2c[num];
207 			ddb_irq_set(dev, l, i + base, i2c_handler, i2c);
208 			stat = ddb_i2c_add(dev, i2c, regmap, l, i, num);
209 			if (stat)
210 				break;
211 			num++;
212 		}
213 	}
214 	if (stat) {
215 		for (j = 0; j < num; j++) {
216 			i2c = &dev->i2c[j];
217 			adap = &i2c->adap;
218 			i2c_del_adapter(adap);
219 		}
220 	} else {
221 		dev->i2c_num = num;
222 	}
223 
224 	return stat;
225 }
226