treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / media / pci / saa7164 / saa7164-i2c.c
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 }