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gerrit-public.fairphone.software / kernel / msm-5.4 / a45cfe2cd7450e56b4f44802b34faaf2a78a6cdb / . / drivers / i2c / algos / i2c-algo-sibyte.c
blob: f2785499237bf10135f571c0ebfddb9b9e4e5474 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/* ------------------------------------------------------------------------- */
2/* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters */
3/* ------------------------------------------------------------------------- */
4/* Copyright (C) 2001,2002,2003 Broadcom Corporation
5 Copyright (C) 1995-2000 Simon G. Vogl
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
20/* ------------------------------------------------------------------------- */
21
22/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
23 Frodo Looijaard <frodol@dds.nl>. */
24
25/* Ported for SiByte SOCs by Broadcom Corporation. */
26
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/init.h>
30
31#include <asm/io.h>
32#include <asm/sibyte/sb1250_regs.h>
33#include <asm/sibyte/sb1250_smbus.h>
34
35#include <linux/i2c.h>
36#include <linux/i2c-algo-sibyte.h>
37
38/* ----- global defines ----------------------------------------------- */
39#define SMB_CSR(a,r) ((long)(a->reg_base + r))
40
41/* ----- global variables --------------------------------------------- */
42
43/* module parameters:
44 */
45static int bit_scan=0; /* have a look at what's hanging 'round */
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) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
62 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
63 break;
64 case I2C_SMBUS_BYTE:
65 if (read_write == I2C_SMBUS_READ) {
66 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
67 SMB_CSR(adap, R_SMB_START));
68 data_bytes = 1;
69 } else {
70 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
71 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
72 SMB_CSR(adap, R_SMB_START));
73 }
74 break;
75 case I2C_SMBUS_BYTE_DATA:
76 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
77 if (read_write == I2C_SMBUS_READ) {
78 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
79 SMB_CSR(adap, R_SMB_START));
80 data_bytes = 1;
81 } else {
82 csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
83 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
84 SMB_CSR(adap, R_SMB_START));
85 }
86 break;
87 case I2C_SMBUS_WORD_DATA:
88 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
89 if (read_write == I2C_SMBUS_READ) {
90 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
91 SMB_CSR(adap, R_SMB_START));
92 data_bytes = 2;
93 } else {
94 csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
95 csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
96 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
97 SMB_CSR(adap, R_SMB_START));
98 }
99 break;
100 default:
101 return -1; /* XXXKW better error code? */
102 }
103
104 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
105 ;
106
107 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
108 if (error & M_SMB_ERROR) {
109 /* Clear error bit by writing a 1 */
110 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
111 return -1; /* XXXKW better error code? */
112 }
113
114 if (data_bytes == 1)
115 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
116 if (data_bytes == 2)
117 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
118
119 return 0;
120}
121
122static int algo_control(struct i2c_adapter *adapter,
123 unsigned int cmd, unsigned long arg)
124{
125 return 0;
126}
127
128static u32 bit_func(struct i2c_adapter *adap)
129{
130 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
131 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
132}
133
134
135/* -----exported algorithm data: ------------------------------------- */
136
137static struct i2c_algorithm i2c_sibyte_algo = {
138 .name = "SiByte algorithm",
139 .id = I2C_ALGO_SIBYTE,
140 .smbus_xfer = smbus_xfer,
141 .algo_control = algo_control, /* ioctl */
142 .functionality = bit_func,
143};
144
145/*
146 * registering functions to load algorithms at runtime
147 */
148int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
149{
150 int i;
151 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
152
153 /* register new adapter to i2c module... */
154
155 i2c_adap->id |= i2c_sibyte_algo.id;
156 i2c_adap->algo = &i2c_sibyte_algo;
157
158 /* Set the frequency to 100 kHz */
159 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
160 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
161
162 /* scan bus */
163 if (bit_scan) {
164 union i2c_smbus_data data;
165 int rc;
166 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
167 i2c_adap->name);
168 for (i = 0x00; i < 0x7f; i++) {
169 /* XXXKW is this a realistic probe? */
170 rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
171 I2C_SMBUS_BYTE_DATA, &data);
172 if (!rc) {
173 printk("(%02x)",i);
174 } else
175 printk(".");
176 }
177 printk("\n");
178 }
179
180 i2c_add_adapter(i2c_adap);
181
182 return 0;
183}
184
185
186int i2c_sibyte_del_bus(struct i2c_adapter *adap)
187{
188 int res;
189
190 if ((res = i2c_del_adapter(adap)) < 0)
191 return res;
192
193 return 0;
194}
195
196int __init i2c_algo_sibyte_init (void)
197{
198 printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n");
199 return 0;
200}
201
202
203EXPORT_SYMBOL(i2c_sibyte_add_bus);
204EXPORT_SYMBOL(i2c_sibyte_del_bus);
205
206#ifdef MODULE
207MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
208MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
209MODULE_PARM(bit_scan, "i");
210MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
211MODULE_LICENSE("GPL");
212
213int init_module(void)
214{
215 return i2c_algo_sibyte_init();
216}
217
218void cleanup_module(void)
219{
220}
221#endif