1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for the NXP SAA7164 PCIe bridge
4  *
5  *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/moduleparam.h>
10 #include <linux/init.h>
11 #include <linux/delay.h>
12 #include <linux/io.h>
13 
14 #include "saa7164.h"
15 
16 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
17 {
18 	struct saa7164_i2c *bus = i2c_adap->algo_data;
19 	struct saa7164_dev *dev = bus->dev;
20 	int i, retval = 0;
21 
22 	dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
23 
24 	for (i = 0 ; i < num; i++) {
25 		dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
26 			__func__, num, msgs[i].addr, msgs[i].len);
27 		if (msgs[i].flags & I2C_M_RD) {
28 			retval = saa7164_api_i2c_read(bus,
29 				msgs[i].addr,
30 				0 /* reglen */,
31 				NULL /* reg */, msgs[i].len, msgs[i].buf);
32 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
33 			   msgs[i].addr == msgs[i + 1].addr) {
34 			/* write then read from same address */
35 
36 			retval = saa7164_api_i2c_read(bus, msgs[i].addr,
37 				msgs[i].len, msgs[i].buf,
38 				msgs[i+1].len, msgs[i+1].buf
39 				);
40 
41 			i++;
42 
43 			if (retval < 0)
44 				goto err;
45 		} else {
46 			/* write */
47 			retval = saa7164_api_i2c_write(bus, msgs[i].addr,
48 				msgs[i].len, msgs[i].buf);
49 		}
50 		if (retval < 0)
51 			goto err;
52 	}
53 	return num;
54 
55 err:
56 	return retval;
57 }
58 
59 static u32 saa7164_functionality(struct i2c_adapter *adap)
60 {
61 	return I2C_FUNC_I2C;
62 }
63 
64 static const struct i2c_algorithm saa7164_i2c_algo_template = {
65 	.master_xfer	= i2c_xfer,
66 	.functionality	= saa7164_functionality,
67 };
68 
69 /* ----------------------------------------------------------------------- */
70 
71 static const struct i2c_adapter saa7164_i2c_adap_template = {
72 	.name              = "saa7164",
73 	.owner             = THIS_MODULE,
74 	.algo              = &saa7164_i2c_algo_template,
75 };
76 
77 static const struct i2c_client saa7164_i2c_client_template = {
78 	.name	= "saa7164 internal",
79 };
80 
81 int saa7164_i2c_register(struct saa7164_i2c *bus)
82 {
83 	struct saa7164_dev *dev = bus->dev;
84 
85 	dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
86 
87 	bus->i2c_adap = saa7164_i2c_adap_template;
88 	bus->i2c_client = saa7164_i2c_client_template;
89 
90 	bus->i2c_adap.dev.parent = &dev->pci->dev;
91 
92 	strscpy(bus->i2c_adap.name, bus->dev->name,
93 		sizeof(bus->i2c_adap.name));
94 
95 	bus->i2c_adap.algo_data = bus;
96 	i2c_set_adapdata(&bus->i2c_adap, bus);
97 	i2c_add_adapter(&bus->i2c_adap);
98 
99 	bus->i2c_client.adapter = &bus->i2c_adap;
100 
101 	if (0 != bus->i2c_rc)
102 		printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
103 			dev->name, bus->nr);
104 
105 	return bus->i2c_rc;
106 }
107 
108 int saa7164_i2c_unregister(struct saa7164_i2c *bus)
109 {
110 	i2c_del_adapter(&bus->i2c_adap);
111 	return 0;
112 }
113