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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2005 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * Simtec Generic I2C Controller
7*/
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/io.h>
15
16#include <linux/i2c.h>
17#include <linux/i2c-algo-bit.h>
18
19struct simtec_i2c_data {
20 struct resource *ioarea;
21 void __iomem *reg;
22 struct i2c_adapter adap;
23 struct i2c_algo_bit_data bit;
24};
25
26#define CMD_SET_SDA (1<<2)
27#define CMD_SET_SCL (1<<3)
28
29#define STATE_SDA (1<<0)
30#define STATE_SCL (1<<1)
31
32/* i2c bit-bus functions */
33
34static void simtec_i2c_setsda(void *pw, int state)
35{
36 struct simtec_i2c_data *pd = pw;
37 writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);
38}
39
40static void simtec_i2c_setscl(void *pw, int state)
41{
42 struct simtec_i2c_data *pd = pw;
43 writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);
44}
45
46static int simtec_i2c_getsda(void *pw)
47{
48 struct simtec_i2c_data *pd = pw;
49 return readb(pd->reg) & STATE_SDA ? 1 : 0;
50}
51
52static int simtec_i2c_getscl(void *pw)
53{
54 struct simtec_i2c_data *pd = pw;
55 return readb(pd->reg) & STATE_SCL ? 1 : 0;
56}
57
58/* device registration */
59
60static int simtec_i2c_probe(struct platform_device *dev)
61{
62 struct simtec_i2c_data *pd;
63 struct resource *res;
64 int size;
65 int ret;
66
67 pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);
68 if (pd == NULL)
69 return -ENOMEM;
70
71 platform_set_drvdata(dev, pd);
72
73 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
74 if (res == NULL) {
75 dev_err(&dev->dev, "cannot find IO resource\n");
76 ret = -ENOENT;
77 goto err;
78 }
79
80 size = resource_size(res);
81
82 pd->ioarea = request_mem_region(res->start, size, dev->name);
83 if (pd->ioarea == NULL) {
84 dev_err(&dev->dev, "cannot request IO\n");
85 ret = -ENXIO;
86 goto err;
87 }
88
89 pd->reg = ioremap(res->start, size);
90 if (pd->reg == NULL) {
91 dev_err(&dev->dev, "cannot map IO\n");
92 ret = -ENXIO;
93 goto err_res;
94 }
95
96 /* setup the private data */
97
98 pd->adap.owner = THIS_MODULE;
99 pd->adap.algo_data = &pd->bit;
100 pd->adap.dev.parent = &dev->dev;
101
102 strscpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));
103
104 pd->bit.data = pd;
105 pd->bit.setsda = simtec_i2c_setsda;
106 pd->bit.setscl = simtec_i2c_setscl;
107 pd->bit.getsda = simtec_i2c_getsda;
108 pd->bit.getscl = simtec_i2c_getscl;
109 pd->bit.timeout = HZ;
110 pd->bit.udelay = 20;
111
112 ret = i2c_bit_add_bus(&pd->adap);
113 if (ret)
114 goto err_all;
115
116 return 0;
117
118 err_all:
119 iounmap(pd->reg);
120
121 err_res:
122 release_mem_region(pd->ioarea->start, size);
123
124 err:
125 kfree(pd);
126 return ret;
127}
128
129static int simtec_i2c_remove(struct platform_device *dev)
130{
131 struct simtec_i2c_data *pd = platform_get_drvdata(dev);
132
133 i2c_del_adapter(&pd->adap);
134
135 iounmap(pd->reg);
136 release_mem_region(pd->ioarea->start, resource_size(pd->ioarea));
137 kfree(pd);
138
139 return 0;
140}
141
142/* device driver */
143
144static struct platform_driver simtec_i2c_driver = {
145 .driver = {
146 .name = "simtec-i2c",
147 },
148 .probe = simtec_i2c_probe,
149 .remove = simtec_i2c_remove,
150};
151
152module_platform_driver(simtec_i2c_driver);
153
154MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
155MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
156MODULE_LICENSE("GPL");
157MODULE_ALIAS("platform:simtec-i2c");
1/*
2 * Copyright (C) 2005 Simtec Electronics
3 * Ben Dooks <ben@simtec.co.uk>
4 *
5 * Simtec Generic I2C Controller
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
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
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/delay.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26#include <linux/io.h>
27
28#include <linux/i2c.h>
29#include <linux/i2c-algo-bit.h>
30
31struct simtec_i2c_data {
32 struct resource *ioarea;
33 void __iomem *reg;
34 struct i2c_adapter adap;
35 struct i2c_algo_bit_data bit;
36};
37
38#define CMD_SET_SDA (1<<2)
39#define CMD_SET_SCL (1<<3)
40
41#define STATE_SDA (1<<0)
42#define STATE_SCL (1<<1)
43
44/* i2c bit-bus functions */
45
46static void simtec_i2c_setsda(void *pw, int state)
47{
48 struct simtec_i2c_data *pd = pw;
49 writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);
50}
51
52static void simtec_i2c_setscl(void *pw, int state)
53{
54 struct simtec_i2c_data *pd = pw;
55 writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);
56}
57
58static int simtec_i2c_getsda(void *pw)
59{
60 struct simtec_i2c_data *pd = pw;
61 return readb(pd->reg) & STATE_SDA ? 1 : 0;
62}
63
64static int simtec_i2c_getscl(void *pw)
65{
66 struct simtec_i2c_data *pd = pw;
67 return readb(pd->reg) & STATE_SCL ? 1 : 0;
68}
69
70/* device registration */
71
72static int simtec_i2c_probe(struct platform_device *dev)
73{
74 struct simtec_i2c_data *pd;
75 struct resource *res;
76 int size;
77 int ret;
78
79 pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);
80 if (pd == NULL) {
81 dev_err(&dev->dev, "cannot allocate private data\n");
82 return -ENOMEM;
83 }
84
85 platform_set_drvdata(dev, pd);
86
87 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
88 if (res == NULL) {
89 dev_err(&dev->dev, "cannot find IO resource\n");
90 ret = -ENOENT;
91 goto err;
92 }
93
94 size = resource_size(res);
95
96 pd->ioarea = request_mem_region(res->start, size, dev->name);
97 if (pd->ioarea == NULL) {
98 dev_err(&dev->dev, "cannot request IO\n");
99 ret = -ENXIO;
100 goto err;
101 }
102
103 pd->reg = ioremap(res->start, size);
104 if (pd->reg == NULL) {
105 dev_err(&dev->dev, "cannot map IO\n");
106 ret = -ENXIO;
107 goto err_res;
108 }
109
110 /* setup the private data */
111
112 pd->adap.owner = THIS_MODULE;
113 pd->adap.algo_data = &pd->bit;
114 pd->adap.dev.parent = &dev->dev;
115
116 strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));
117
118 pd->bit.data = pd;
119 pd->bit.setsda = simtec_i2c_setsda;
120 pd->bit.setscl = simtec_i2c_setscl;
121 pd->bit.getsda = simtec_i2c_getsda;
122 pd->bit.getscl = simtec_i2c_getscl;
123 pd->bit.timeout = HZ;
124 pd->bit.udelay = 20;
125
126 ret = i2c_bit_add_bus(&pd->adap);
127 if (ret)
128 goto err_all;
129
130 return 0;
131
132 err_all:
133 iounmap(pd->reg);
134
135 err_res:
136 release_resource(pd->ioarea);
137 kfree(pd->ioarea);
138
139 err:
140 kfree(pd);
141 return ret;
142}
143
144static int simtec_i2c_remove(struct platform_device *dev)
145{
146 struct simtec_i2c_data *pd = platform_get_drvdata(dev);
147
148 i2c_del_adapter(&pd->adap);
149
150 iounmap(pd->reg);
151 release_resource(pd->ioarea);
152 kfree(pd->ioarea);
153 kfree(pd);
154
155 return 0;
156}
157
158/* device driver */
159
160static struct platform_driver simtec_i2c_driver = {
161 .driver = {
162 .name = "simtec-i2c",
163 .owner = THIS_MODULE,
164 },
165 .probe = simtec_i2c_probe,
166 .remove = simtec_i2c_remove,
167};
168
169module_platform_driver(simtec_i2c_driver);
170
171MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
172MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
173MODULE_LICENSE("GPL");
174MODULE_ALIAS("platform:simtec-i2c");