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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2004 Steven J. Hill
3 * Copyright (C) 2001,2002,2003 Broadcom Corporation
Jean Delvare51c37112006-08-13 23:33:16 +02004 * Copyright (C) 1995-2000 Simon G. Vogl
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20
Jean Delvare51c37112006-08-13 23:33:16 +020021#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/module.h>
Jean Delvare51c37112006-08-13 23:33:16 +020023#include <linux/init.h>
24#include <linux/i2c.h>
25#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <asm/sibyte/sb1250_regs.h>
27#include <asm/sibyte/sb1250_smbus.h>
28
Jean Delvare51c37112006-08-13 23:33:16 +020029
30struct i2c_algo_sibyte_data {
31 void *data; /* private data */
32 int bus; /* which bus */
33 void *reg_base; /* CSR base */
34};
35
36/* ----- global defines ----------------------------------------------- */
37#define SMB_CSR(a,r) ((long)(a->reg_base + r))
38
39/* ----- global variables --------------------------------------------- */
40
41/* module parameters:
42 */
43static int bit_scan; /* have a look at what's hanging 'round */
44module_param(bit_scan, int, 0);
45MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
46
47
48static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
49 unsigned short flags, char read_write,
50 u8 command, int size, union i2c_smbus_data * data)
51{
52 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
53 int data_bytes = 0;
54 int error;
55
56 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
57 ;
58
59 switch (size) {
60 case I2C_SMBUS_QUICK:
61 csr_out32((V_SMB_ADDR(addr) |
62 (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
63 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
64 break;
65 case I2C_SMBUS_BYTE:
66 if (read_write == I2C_SMBUS_READ) {
67 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
68 SMB_CSR(adap, R_SMB_START));
69 data_bytes = 1;
70 } else {
71 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
72 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
73 SMB_CSR(adap, R_SMB_START));
74 }
75 break;
76 case I2C_SMBUS_BYTE_DATA:
77 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
78 if (read_write == I2C_SMBUS_READ) {
79 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
80 SMB_CSR(adap, R_SMB_START));
81 data_bytes = 1;
82 } else {
83 csr_out32(V_SMB_LB(data->byte),
84 SMB_CSR(adap, R_SMB_DATA));
85 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
86 SMB_CSR(adap, R_SMB_START));
87 }
88 break;
89 case I2C_SMBUS_WORD_DATA:
90 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
91 if (read_write == I2C_SMBUS_READ) {
92 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
93 SMB_CSR(adap, R_SMB_START));
94 data_bytes = 2;
95 } else {
96 csr_out32(V_SMB_LB(data->word & 0xff),
97 SMB_CSR(adap, R_SMB_DATA));
98 csr_out32(V_SMB_MB(data->word >> 8),
99 SMB_CSR(adap, R_SMB_DATA));
100 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
101 SMB_CSR(adap, R_SMB_START));
102 }
103 break;
104 default:
105 return -1; /* XXXKW better error code? */
106 }
107
108 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
109 ;
110
111 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
112 if (error & M_SMB_ERROR) {
113 /* Clear error bit by writing a 1 */
114 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
115 return -1; /* XXXKW better error code? */
116 }
117
118 if (data_bytes == 1)
119 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
120 if (data_bytes == 2)
121 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
122
123 return 0;
124}
125
126static u32 bit_func(struct i2c_adapter *adap)
127{
128 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
129 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
130}
131
132
133/* -----exported algorithm data: ------------------------------------- */
134
Jean Delvare8f9082c2006-09-03 22:39:46 +0200135static const struct i2c_algorithm i2c_sibyte_algo = {
Jean Delvare51c37112006-08-13 23:33:16 +0200136 .smbus_xfer = smbus_xfer,
137 .functionality = bit_func,
138};
139
140/*
141 * registering functions to load algorithms at runtime
142 */
143int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
144{
145 int i;
146 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
147
148 /* register new adapter to i2c module... */
149 i2c_adap->algo = &i2c_sibyte_algo;
150
151 /* Set the frequency to 100 kHz */
152 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
153 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
154
155 /* scan bus */
156 if (bit_scan) {
157 union i2c_smbus_data data;
158 int rc;
159 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
160 i2c_adap->name);
161 for (i = 0x00; i < 0x7f; i++) {
162 /* XXXKW is this a realistic probe? */
163 rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
164 I2C_SMBUS_BYTE_DATA, &data);
165 if (!rc) {
166 printk("(%02x)",i);
167 } else
168 printk(".");
169 }
170 printk("\n");
171 }
172
173 return i2c_add_adapter(i2c_adap);
174}
175
176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177static struct i2c_algo_sibyte_data sibyte_board_data[2] = {
Ralf Baechlea242b442005-08-09 10:07:57 -0700178 { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) },
179 { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180};
181
182static struct i2c_adapter sibyte_board_adapter[2] = {
183 {
184 .owner = THIS_MODULE,
185 .id = I2C_HW_SIBYTE,
186 .class = I2C_CLASS_HWMON,
187 .algo = NULL,
188 .algo_data = &sibyte_board_data[0],
189 .name = "SiByte SMBus 0",
190 },
191 {
192 .owner = THIS_MODULE,
193 .id = I2C_HW_SIBYTE,
194 .class = I2C_CLASS_HWMON,
195 .algo = NULL,
196 .algo_data = &sibyte_board_data[1],
197 .name = "SiByte SMBus 1",
198 },
199};
200
201static int __init i2c_sibyte_init(void)
202{
203 printk("i2c-swarm.o: i2c SMBus adapter module for SiByte board\n");
204 if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0)
205 return -ENODEV;
206 if (i2c_sibyte_add_bus(&sibyte_board_adapter[1], K_SMB_FREQ_400KHZ) < 0)
207 return -ENODEV;
208 return 0;
209}
210
211static void __exit i2c_sibyte_exit(void)
212{
Jean Delvare51c37112006-08-13 23:33:16 +0200213 i2c_del_bus(&sibyte_board_adapter[0]);
214 i2c_del_bus(&sibyte_board_adapter[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
217module_init(i2c_sibyte_init);
218module_exit(i2c_sibyte_exit);
219
Jean Delvare643bd3f2006-08-13 23:34:05 +0200220MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
222MODULE_LICENSE("GPL");