treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / i2c / busses / i2c-sibyte.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2004 Steven J. Hill
4  * Copyright (C) 2001,2002,2003 Broadcom Corporation
5  * Copyright (C) 1995-2000 Simon G. Vogl
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/i2c.h>
12 #include <linux/io.h>
13 #include <asm/sibyte/sb1250_regs.h>
14 #include <asm/sibyte/sb1250_smbus.h>
15
16
17 struct i2c_algo_sibyte_data {
18         void *data;             /* private data */
19         int   bus;              /* which bus */
20         void *reg_base;         /* CSR base */
21 };
22
23 /* ----- global defines ----------------------------------------------- */
24 #define SMB_CSR(a,r) ((long)(a->reg_base + r))
25
26
27 static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
28                       unsigned short flags, char read_write,
29                       u8 command, int size, union i2c_smbus_data * data)
30 {
31         struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
32         int data_bytes = 0;
33         int error;
34
35         while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
36                 ;
37
38         switch (size) {
39         case I2C_SMBUS_QUICK:
40                 csr_out32((V_SMB_ADDR(addr) |
41                            (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
42                            V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
43                 break;
44         case I2C_SMBUS_BYTE:
45                 if (read_write == I2C_SMBUS_READ) {
46                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
47                                   SMB_CSR(adap, R_SMB_START));
48                         data_bytes = 1;
49                 } else {
50                         csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
51                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
52                                   SMB_CSR(adap, R_SMB_START));
53                 }
54                 break;
55         case I2C_SMBUS_BYTE_DATA:
56                 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
57                 if (read_write == I2C_SMBUS_READ) {
58                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
59                                   SMB_CSR(adap, R_SMB_START));
60                         data_bytes = 1;
61                 } else {
62                         csr_out32(V_SMB_LB(data->byte),
63                                   SMB_CSR(adap, R_SMB_DATA));
64                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
65                                   SMB_CSR(adap, R_SMB_START));
66                 }
67                 break;
68         case I2C_SMBUS_WORD_DATA:
69                 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
70                 if (read_write == I2C_SMBUS_READ) {
71                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
72                                   SMB_CSR(adap, R_SMB_START));
73                         data_bytes = 2;
74                 } else {
75                         csr_out32(V_SMB_LB(data->word & 0xff),
76                                   SMB_CSR(adap, R_SMB_DATA));
77                         csr_out32(V_SMB_MB(data->word >> 8),
78                                   SMB_CSR(adap, R_SMB_DATA));
79                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
80                                   SMB_CSR(adap, R_SMB_START));
81                 }
82                 break;
83         default:
84                 return -EOPNOTSUPP;
85         }
86
87         while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
88                 ;
89
90         error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
91         if (error & M_SMB_ERROR) {
92                 /* Clear error bit by writing a 1 */
93                 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
94                 return (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO;
95         }
96
97         if (data_bytes == 1)
98                 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
99         if (data_bytes == 2)
100                 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
101
102         return 0;
103 }
104
105 static u32 bit_func(struct i2c_adapter *adap)
106 {
107         return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
108                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
109 }
110
111
112 /* -----exported algorithm data: -------------------------------------  */
113
114 static const struct i2c_algorithm i2c_sibyte_algo = {
115         .smbus_xfer     = smbus_xfer,
116         .functionality  = bit_func,
117 };
118
119 /*
120  * registering functions to load algorithms at runtime
121  */
122 static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
123 {
124         struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
125
126         /* Register new adapter to i2c module... */
127         i2c_adap->algo = &i2c_sibyte_algo;
128
129         /* Set the requested frequency. */
130         csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
131         csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
132
133         return i2c_add_numbered_adapter(i2c_adap);
134 }
135
136
137 static struct i2c_algo_sibyte_data sibyte_board_data[2] = {
138         { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) },
139         { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) }
140 };
141
142 static struct i2c_adapter sibyte_board_adapter[2] = {
143         {
144                 .owner          = THIS_MODULE,
145                 .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
146                 .algo           = NULL,
147                 .algo_data      = &sibyte_board_data[0],
148                 .nr             = 0,
149                 .name           = "SiByte SMBus 0",
150         },
151         {
152                 .owner          = THIS_MODULE,
153                 .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
154                 .algo           = NULL,
155                 .algo_data      = &sibyte_board_data[1],
156                 .nr             = 1,
157                 .name           = "SiByte SMBus 1",
158         },
159 };
160
161 static int __init i2c_sibyte_init(void)
162 {
163         pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n");
164         if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0)
165                 return -ENODEV;
166         if (i2c_sibyte_add_bus(&sibyte_board_adapter[1],
167                                K_SMB_FREQ_400KHZ) < 0) {
168                 i2c_del_adapter(&sibyte_board_adapter[0]);
169                 return -ENODEV;
170         }
171         return 0;
172 }
173
174 static void __exit i2c_sibyte_exit(void)
175 {
176         i2c_del_adapter(&sibyte_board_adapter[0]);
177         i2c_del_adapter(&sibyte_board_adapter[1]);
178 }
179
180 module_init(i2c_sibyte_init);
181 module_exit(i2c_sibyte_exit);
182
183 MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
184 MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
185 MODULE_LICENSE("GPL");