1/*
2 * Copyright (C) ST-Ericsson SA 2010
3 *
4 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
5 * License terms: GNU General Public License (GPL), version 2
6 */
7
8#define pr_fmt(fmt)	"mop500-uib: " fmt
9
10#include <linux/kernel.h>
11#include <linux/init.h>
12#include <linux/i2c.h>
13
14#include <mach/hardware.h>
15#include "board-mop500.h"
16
17enum mop500_uib {
18	STUIB,
19	U8500UIB,
20};
21
22struct uib {
23	const char *name;
24	const char *option;
25	void (*init)(void);
26};
27
28static struct uib __initdata mop500_uibs[] = {
29	[STUIB] = {
30		.name	= "ST-UIB",
31		.option	= "stuib",
32		.init	= mop500_stuib_init,
33	},
34	[U8500UIB] = {
35		.name	= "U8500-UIB",
36		.option	= "u8500uib",
37		.init	= mop500_u8500uib_init,
38	},
39};
40
41static struct uib *mop500_uib;
42
43static int __init mop500_uib_setup(char *str)
44{
45	int i;
46
47	for (i = 0; i < ARRAY_SIZE(mop500_uibs); i++) {
48		struct uib *uib = &mop500_uibs[i];
49
50		if (!strcmp(str, uib->option)) {
51			mop500_uib = uib;
52			break;
53		}
54	}
55
56	if (i == ARRAY_SIZE(mop500_uibs))
57		pr_err("invalid uib= option (%s)\n", str);
58
59	return 1;
60}
61__setup("uib=", mop500_uib_setup);
62
63/*
64 * The UIBs are detected after the I2C host controllers are registered, so
65 * i2c_register_board_info() can't be used.
66 */
67void mop500_uib_i2c_add(int busnum, struct i2c_board_info *info,
68		unsigned n)
69{
70	struct i2c_adapter *adap;
71	struct i2c_client *client;
72	int i;
73
74	adap = i2c_get_adapter(busnum);
75	if (!adap) {
76		pr_err("failed to get adapter i2c%d\n", busnum);
77		return;
78	}
79
80	for (i = 0; i < n; i++) {
81		client = i2c_new_device(adap, &info[i]);
82		if (!client)
83			pr_err("failed to register %s to i2c%d\n",
84					info[i].type, busnum);
85	}
86
87	i2c_put_adapter(adap);
88}
89
90static void __init __mop500_uib_init(struct uib *uib, const char *why)
91{
92	pr_info("%s (%s)\n", uib->name, why);
93	uib->init();
94}
95
96/*
97 * Detect the UIB attached based on the presence or absence of i2c devices.
98 */
99static int __init mop500_uib_init(void)
100{
101	struct uib *uib = mop500_uib;
102	struct i2c_adapter *i2c0;
103	int ret;
104
105	if (!cpu_is_u8500())
106		return -ENODEV;
107
108	if (uib) {
109		__mop500_uib_init(uib, "from uib= boot argument");
110		return 0;
111	}
112
113	i2c0 = i2c_get_adapter(0);
114	if (!i2c0) {
115		__mop500_uib_init(&mop500_uibs[STUIB],
116				"fallback, could not get i2c0");
117		return -ENODEV;
118	}
119
120	/* U8500-UIB has the TC35893 at 0x44 on I2C0, the ST-UIB doesn't. */
121	ret = i2c_smbus_xfer(i2c0, 0x44, 0, I2C_SMBUS_WRITE, 0,
122			I2C_SMBUS_QUICK, NULL);
123	i2c_put_adapter(i2c0);
124
125	if (ret == 0)
126		uib = &mop500_uibs[U8500UIB];
127	else
128		uib = &mop500_uibs[STUIB];
129
130	__mop500_uib_init(uib, "detected");
131
132	return 0;
133}
134
135module_init(mop500_uib_init);
136