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 
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/io.h>
23 
24 #include "saa7164.h"
25 
26 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
27 {
28 	struct saa7164_i2c *bus = i2c_adap->algo_data;
29 	struct saa7164_dev *dev = bus->dev;
30 	int i, retval = 0;
31 
32 	dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
33 
34 	for (i = 0 ; i < num; i++) {
35 		dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
36 			__func__, num, msgs[i].addr, msgs[i].len);
37 		if (msgs[i].flags & I2C_M_RD) {
38 			retval = saa7164_api_i2c_read(bus,
39 				msgs[i].addr,
40 				0 /* reglen */,
41 				NULL /* reg */, msgs[i].len, msgs[i].buf);
42 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
43 			   msgs[i].addr == msgs[i + 1].addr) {
44 			/* write then read from same address */
45 
46 			retval = saa7164_api_i2c_read(bus, msgs[i].addr,
47 				msgs[i].len, msgs[i].buf,
48 				msgs[i+1].len, msgs[i+1].buf
49 				);
50 
51 			i++;
52 
53 			if (retval < 0)
54 				goto err;
55 		} else {
56 			/* write */
57 			retval = saa7164_api_i2c_write(bus, msgs[i].addr,
58 				msgs[i].len, msgs[i].buf);
59 		}
60 		if (retval < 0)
61 			goto err;
62 	}
63 	return num;
64 
65 err:
66 	return retval;
67 }
68 
69 static u32 saa7164_functionality(struct i2c_adapter *adap)
70 {
71 	return I2C_FUNC_I2C;
72 }
73 
74 static const struct i2c_algorithm saa7164_i2c_algo_template = {
75 	.master_xfer	= i2c_xfer,
76 	.functionality	= saa7164_functionality,
77 };
78 
79 /* ----------------------------------------------------------------------- */
80 
81 static const struct i2c_adapter saa7164_i2c_adap_template = {
82 	.name              = "saa7164",
83 	.owner             = THIS_MODULE,
84 	.algo              = &saa7164_i2c_algo_template,
85 };
86 
87 static const struct i2c_client saa7164_i2c_client_template = {
88 	.name	= "saa7164 internal",
89 };
90 
91 int saa7164_i2c_register(struct saa7164_i2c *bus)
92 {
93 	struct saa7164_dev *dev = bus->dev;
94 
95 	dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
96 
97 	bus->i2c_adap = saa7164_i2c_adap_template;
98 	bus->i2c_client = saa7164_i2c_client_template;
99 
100 	bus->i2c_adap.dev.parent = &dev->pci->dev;
101 
102 	strscpy(bus->i2c_adap.name, bus->dev->name,
103 		sizeof(bus->i2c_adap.name));
104 
105 	bus->i2c_adap.algo_data = bus;
106 	i2c_set_adapdata(&bus->i2c_adap, bus);
107 	i2c_add_adapter(&bus->i2c_adap);
108 
109 	bus->i2c_client.adapter = &bus->i2c_adap;
110 
111 	if (0 != bus->i2c_rc)
112 		printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
113 			dev->name, bus->nr);
114 
115 	return bus->i2c_rc;
116 }
117 
118 int saa7164_i2c_unregister(struct saa7164_i2c *bus)
119 {
120 	i2c_del_adapter(&bus->i2c_adap);
121 	return 0;
122 }
123