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(adap: 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(adap: &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(adap: &sibyte_board_adapter[0]); |
177 | i2c_del_adapter(adap: &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.)" ); |
184 | MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>" ); |
185 | MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards" ); |
186 | MODULE_LICENSE("GPL" ); |
187 | |