1/*
2 * Copyright (C) 2004 Steven J. Hill
3 * Copyright (C) 2001,2002,2003 Broadcom Corporation
4 * Copyright (C) 1995-2000 Simon G. Vogl
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (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 * GNU General Public License for more details.
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/i2c.h>
21#include <linux/io.h>
22#include <asm/sibyte/sb1250_regs.h>
23#include <asm/sibyte/sb1250_smbus.h>
24
25
26struct i2c_algo_sibyte_data {
27	void *data;		/* private data */
28	int   bus;		/* which bus */
29	void *reg_base;		/* CSR base */
30};
31
32/* ----- global defines ----------------------------------------------- */
33#define SMB_CSR(a,r) ((long)(a->reg_base + r))
34
35
36static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
37		      unsigned short flags, char read_write,
38		      u8 command, int size, union i2c_smbus_data * data)
39{
40	struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
41	int data_bytes = 0;
42	int error;
43
44	while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
45		;
46
47	switch (size) {
48	case I2C_SMBUS_QUICK:
49		csr_out32((V_SMB_ADDR(addr) |
50			   (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
51			   V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
52		break;
53	case I2C_SMBUS_BYTE:
54		if (read_write == I2C_SMBUS_READ) {
55			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
56				  SMB_CSR(adap, R_SMB_START));
57			data_bytes = 1;
58		} else {
59			csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
60			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
61				  SMB_CSR(adap, R_SMB_START));
62		}
63		break;
64	case I2C_SMBUS_BYTE_DATA:
65		csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
66		if (read_write == I2C_SMBUS_READ) {
67			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
68				  SMB_CSR(adap, R_SMB_START));
69			data_bytes = 1;
70		} else {
71			csr_out32(V_SMB_LB(data->byte),
72				  SMB_CSR(adap, R_SMB_DATA));
73			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
74				  SMB_CSR(adap, R_SMB_START));
75		}
76		break;
77	case I2C_SMBUS_WORD_DATA:
78		csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
79		if (read_write == I2C_SMBUS_READ) {
80			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
81				  SMB_CSR(adap, R_SMB_START));
82			data_bytes = 2;
83		} else {
84			csr_out32(V_SMB_LB(data->word & 0xff),
85				  SMB_CSR(adap, R_SMB_DATA));
86			csr_out32(V_SMB_MB(data->word >> 8),
87				  SMB_CSR(adap, R_SMB_DATA));
88			csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
89				  SMB_CSR(adap, R_SMB_START));
90		}
91		break;
92	default:
93		return -EOPNOTSUPP;
94	}
95
96	while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
97		;
98
99	error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
100	if (error & M_SMB_ERROR) {
101		/* Clear error bit by writing a 1 */
102		csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
103		return (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO;
104	}
105
106	if (data_bytes == 1)
107		data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
108	if (data_bytes == 2)
109		data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
110
111	return 0;
112}
113
114static u32 bit_func(struct i2c_adapter *adap)
115{
116	return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
117		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
118}
119
120
121/* -----exported algorithm data: -------------------------------------	*/
122
123static const struct i2c_algorithm i2c_sibyte_algo = {
124	.smbus_xfer	= smbus_xfer,
125	.functionality	= bit_func,
126};
127
128/*
129 * registering functions to load algorithms at runtime
130 */
131static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
132{
133	struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
134
135	/* Register new adapter to i2c module... */
136	i2c_adap->algo = &i2c_sibyte_algo;
137
138	/* Set the requested frequency. */
139	csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
140	csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
141
142	return i2c_add_numbered_adapter(i2c_adap);
143}
144
145
146static struct i2c_algo_sibyte_data sibyte_board_data[2] = {
147	{ NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) },
148	{ NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) }
149};
150
151static struct i2c_adapter sibyte_board_adapter[2] = {
152	{
153		.owner		= THIS_MODULE,
154		.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
155		.algo		= NULL,
156		.algo_data	= &sibyte_board_data[0],
157		.nr		= 0,
158		.name		= "SiByte SMBus 0",
159	},
160	{
161		.owner		= THIS_MODULE,
162		.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
163		.algo		= NULL,
164		.algo_data	= &sibyte_board_data[1],
165		.nr		= 1,
166		.name		= "SiByte SMBus 1",
167	},
168};
169
170static int __init i2c_sibyte_init(void)
171{
172	pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n");
173	if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0)
174		return -ENODEV;
175	if (i2c_sibyte_add_bus(&sibyte_board_adapter[1],
176			       K_SMB_FREQ_400KHZ) < 0) {
177		i2c_del_adapter(&sibyte_board_adapter[0]);
178		return -ENODEV;
179	}
180	return 0;
181}
182
183static void __exit i2c_sibyte_exit(void)
184{
185	i2c_del_adapter(&sibyte_board_adapter[0]);
186	i2c_del_adapter(&sibyte_board_adapter[1]);
187}
188
189module_init(i2c_sibyte_init);
190module_exit(i2c_sibyte_exit);
191
192MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
193MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
194MODULE_LICENSE("GPL");
195