1 /*
2  *  Driver for the NXP SAA7164 PCIe bridge
3  *
4  *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <linux/io.h>
27 
28 #include "saa7164.h"
29 
30 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
31 {
32 	struct saa7164_i2c *bus = i2c_adap->algo_data;
33 	struct saa7164_dev *dev = bus->dev;
34 	int i, retval = 0;
35 
36 	dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
37 
38 	for (i = 0 ; i < num; i++) {
39 		dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
40 			__func__, num, msgs[i].addr, msgs[i].len);
41 		if (msgs[i].flags & I2C_M_RD) {
42 			retval = saa7164_api_i2c_read(bus,
43 				msgs[i].addr,
44 				0 /* reglen */,
45 				NULL /* reg */, msgs[i].len, msgs[i].buf);
46 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
47 			   msgs[i].addr == msgs[i + 1].addr) {
48 			/* write then read from same address */
49 
50 			retval = saa7164_api_i2c_read(bus, msgs[i].addr,
51 				msgs[i].len, msgs[i].buf,
52 				msgs[i+1].len, msgs[i+1].buf
53 				);
54 
55 			i++;
56 
57 			if (retval < 0)
58 				goto err;
59 		} else {
60 			/* write */
61 			retval = saa7164_api_i2c_write(bus, msgs[i].addr,
62 				msgs[i].len, msgs[i].buf);
63 		}
64 		if (retval < 0)
65 			goto err;
66 	}
67 	return num;
68 
69 err:
70 	return retval;
71 }
72 
73 static u32 saa7164_functionality(struct i2c_adapter *adap)
74 {
75 	return I2C_FUNC_I2C;
76 }
77 
78 static struct i2c_algorithm saa7164_i2c_algo_template = {
79 	.master_xfer	= i2c_xfer,
80 	.functionality	= saa7164_functionality,
81 };
82 
83 /* ----------------------------------------------------------------------- */
84 
85 static struct i2c_adapter saa7164_i2c_adap_template = {
86 	.name              = "saa7164",
87 	.owner             = THIS_MODULE,
88 	.algo              = &saa7164_i2c_algo_template,
89 };
90 
91 static struct i2c_client saa7164_i2c_client_template = {
92 	.name	= "saa7164 internal",
93 };
94 
95 int saa7164_i2c_register(struct saa7164_i2c *bus)
96 {
97 	struct saa7164_dev *dev = bus->dev;
98 
99 	dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
100 
101 	bus->i2c_adap = saa7164_i2c_adap_template;
102 	bus->i2c_client = saa7164_i2c_client_template;
103 
104 	bus->i2c_adap.dev.parent = &dev->pci->dev;
105 
106 	strlcpy(bus->i2c_adap.name, bus->dev->name,
107 		sizeof(bus->i2c_adap.name));
108 
109 	bus->i2c_adap.algo_data = bus;
110 	i2c_set_adapdata(&bus->i2c_adap, bus);
111 	i2c_add_adapter(&bus->i2c_adap);
112 
113 	bus->i2c_client.adapter = &bus->i2c_adap;
114 
115 	if (0 != bus->i2c_rc)
116 		printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
117 			dev->name, bus->nr);
118 
119 	return bus->i2c_rc;
120 }
121 
122 int saa7164_i2c_unregister(struct saa7164_i2c *bus)
123 {
124 	i2c_del_adapter(&bus->i2c_adap);
125 	return 0;
126 }
127