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
16static 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
55err:
56	return retval;
57}
58
59static u32 saa7164_functionality(struct i2c_adapter *adap)
60{
61	return I2C_FUNC_I2C;
62}
63
64static const struct i2c_algorithm saa7164_i2c_algo_template = {
65	.master_xfer	= i2c_xfer,
66	.functionality	= saa7164_functionality,
67};
68
69/* ----------------------------------------------------------------------- */
70
71static const struct i2c_adapter saa7164_i2c_adap_template = {
72	.name              = "saa7164",
73	.owner             = THIS_MODULE,
74	.algo              = &saa7164_i2c_algo_template,
75};
76
77static const struct i2c_client saa7164_i2c_client_template = {
78	.name	= "saa7164 internal",
79};
80
81int 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
108int saa7164_i2c_unregister(struct saa7164_i2c *bus)
109{
110	i2c_del_adapter(&bus->i2c_adap);
111	return 0;
112}
113