Commit | Line | Data |
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1da177e4 | 1 | /* ------------------------------------------------------------------------ * |
c6e8bb2c | 2 | * i2c-parport-light.c I2C bus over parallel port * |
1da177e4 | 3 | * ------------------------------------------------------------------------ * |
7c81c60f | 4 | Copyright (C) 2003-2010 Jean Delvare <jdelvare@suse.de> |
07da0372 | 5 | |
1da177e4 LT |
6 | Based on older i2c-velleman.c driver |
7 | Copyright (C) 1995-2000 Simon G. Vogl | |
8 | With some changes from: | |
9 | Frodo Looijaard <frodol@dds.nl> | |
96de0e25 | 10 | Kyösti Mälkki <kmalkki@cc.hut.fi> |
07da0372 | 11 | |
1da177e4 LT |
12 | This program is free software; you can redistribute it and/or modify |
13 | it under the terms of the GNU General Public License as published by | |
14 | the Free Software Foundation; either version 2 of the License, or | |
15 | (at your option) any later version. | |
16 | ||
17 | This program is distributed in the hope that it will be useful, | |
18 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | GNU General Public License for more details. | |
1da177e4 LT |
21 | * ------------------------------------------------------------------------ */ |
22 | ||
1da177e4 LT |
23 | #include <linux/kernel.h> |
24 | #include <linux/module.h> | |
25 | #include <linux/init.h> | |
6d376fcc | 26 | #include <linux/delay.h> |
c6e8bb2c | 27 | #include <linux/platform_device.h> |
1da177e4 LT |
28 | #include <linux/ioport.h> |
29 | #include <linux/i2c.h> | |
30 | #include <linux/i2c-algo-bit.h> | |
927ab2f8 | 31 | #include <linux/i2c-smbus.h> |
21782180 | 32 | #include <linux/io.h> |
1da177e4 LT |
33 | #include "i2c-parport.h" |
34 | ||
35 | #define DEFAULT_BASE 0x378 | |
c6e8bb2c JD |
36 | #define DRVNAME "i2c-parport-light" |
37 | ||
38 | static struct platform_device *pdev; | |
1da177e4 LT |
39 | |
40 | static u16 base; | |
41 | module_param(base, ushort, 0); | |
42 | MODULE_PARM_DESC(base, "Base I/O address"); | |
43 | ||
927ab2f8 JD |
44 | static int irq; |
45 | module_param(irq, int, 0); | |
46 | MODULE_PARM_DESC(irq, "IRQ (optional)"); | |
47 | ||
1da177e4 LT |
48 | /* ----- Low-level parallel port access ----------------------------------- */ |
49 | ||
50 | static inline void port_write(unsigned char p, unsigned char d) | |
51 | { | |
52 | outb(d, base+p); | |
53 | } | |
54 | ||
55 | static inline unsigned char port_read(unsigned char p) | |
56 | { | |
57 | return inb(base+p); | |
58 | } | |
59 | ||
60 | /* ----- Unified line operation functions --------------------------------- */ | |
61 | ||
62 | static inline void line_set(int state, const struct lineop *op) | |
63 | { | |
64 | u8 oldval = port_read(op->port); | |
65 | ||
66 | /* Touch only the bit(s) needed */ | |
67 | if ((op->inverted && !state) || (!op->inverted && state)) | |
68 | port_write(op->port, oldval | op->val); | |
69 | else | |
70 | port_write(op->port, oldval & ~op->val); | |
71 | } | |
72 | ||
73 | static inline int line_get(const struct lineop *op) | |
74 | { | |
75 | u8 oldval = port_read(op->port); | |
76 | ||
77 | return ((op->inverted && (oldval & op->val) != op->val) | |
78 | || (!op->inverted && (oldval & op->val) == op->val)); | |
79 | } | |
80 | ||
81 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | |
82 | ||
83 | static void parport_setscl(void *data, int state) | |
84 | { | |
85 | line_set(state, &adapter_parm[type].setscl); | |
86 | } | |
87 | ||
88 | static void parport_setsda(void *data, int state) | |
89 | { | |
90 | line_set(state, &adapter_parm[type].setsda); | |
91 | } | |
92 | ||
93 | static int parport_getscl(void *data) | |
94 | { | |
95 | return line_get(&adapter_parm[type].getscl); | |
96 | } | |
97 | ||
98 | static int parport_getsda(void *data) | |
99 | { | |
100 | return line_get(&adapter_parm[type].getsda); | |
101 | } | |
102 | ||
103 | /* Encapsulate the functions above in the correct structure | |
104 | Note that getscl will be set to NULL by the attaching code for adapters | |
105 | that cannot read SCL back */ | |
106 | static struct i2c_algo_bit_data parport_algo_data = { | |
107 | .setsda = parport_setsda, | |
108 | .setscl = parport_setscl, | |
109 | .getsda = parport_getsda, | |
110 | .getscl = parport_getscl, | |
111 | .udelay = 50, | |
1da177e4 | 112 | .timeout = HZ, |
07da0372 | 113 | }; |
1da177e4 | 114 | |
c6e8bb2c | 115 | /* ----- Driver registration ---------------------------------------------- */ |
1da177e4 LT |
116 | |
117 | static struct i2c_adapter parport_adapter = { | |
118 | .owner = THIS_MODULE, | |
119 | .class = I2C_CLASS_HWMON, | |
1da177e4 LT |
120 | .algo_data = &parport_algo_data, |
121 | .name = "Parallel port adapter (light)", | |
122 | }; | |
123 | ||
927ab2f8 JD |
124 | /* SMBus alert support */ |
125 | static struct i2c_smbus_alert_setup alert_data = { | |
126 | .alert_edge_triggered = 1, | |
127 | }; | |
128 | static struct i2c_client *ara; | |
129 | static struct lineop parport_ctrl_irq = { | |
130 | .val = (1 << 4), | |
07da0372 | 131 | .port = PORT_CTRL, |
927ab2f8 JD |
132 | }; |
133 | ||
0b255e92 | 134 | static int i2c_parport_probe(struct platform_device *pdev) |
c6e8bb2c JD |
135 | { |
136 | int err; | |
c6e8bb2c JD |
137 | |
138 | /* Reset hardware to a sane state (SCL and SDA high) */ | |
139 | parport_setsda(NULL, 1); | |
140 | parport_setscl(NULL, 1); | |
141 | /* Other init if needed (power on...) */ | |
6d376fcc | 142 | if (adapter_parm[type].init.val) { |
c6e8bb2c | 143 | line_set(1, &adapter_parm[type].init); |
6d376fcc JD |
144 | /* Give powered devices some time to settle */ |
145 | msleep(100); | |
146 | } | |
c6e8bb2c JD |
147 | |
148 | parport_adapter.dev.parent = &pdev->dev; | |
149 | err = i2c_bit_add_bus(&parport_adapter); | |
927ab2f8 | 150 | if (err) { |
c6e8bb2c | 151 | dev_err(&pdev->dev, "Unable to register with I2C\n"); |
927ab2f8 JD |
152 | return err; |
153 | } | |
154 | ||
155 | /* Setup SMBus alert if supported */ | |
156 | if (adapter_parm[type].smbus_alert && irq) { | |
157 | alert_data.irq = irq; | |
158 | ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data); | |
159 | if (ara) | |
160 | line_set(1, &parport_ctrl_irq); | |
161 | else | |
162 | dev_warn(&pdev->dev, "Failed to register ARA client\n"); | |
163 | } | |
164 | ||
165 | return 0; | |
c6e8bb2c JD |
166 | } |
167 | ||
0b255e92 | 168 | static int i2c_parport_remove(struct platform_device *pdev) |
c6e8bb2c | 169 | { |
927ab2f8 JD |
170 | if (ara) { |
171 | line_set(0, &parport_ctrl_irq); | |
172 | i2c_unregister_device(ara); | |
173 | ara = NULL; | |
174 | } | |
c6e8bb2c JD |
175 | i2c_del_adapter(&parport_adapter); |
176 | ||
177 | /* Un-init if needed (power off...) */ | |
178 | if (adapter_parm[type].init.val) | |
179 | line_set(0, &adapter_parm[type].init); | |
180 | ||
c6e8bb2c JD |
181 | return 0; |
182 | } | |
183 | ||
184 | static struct platform_driver i2c_parport_driver = { | |
185 | .driver = { | |
c6e8bb2c JD |
186 | .name = DRVNAME, |
187 | }, | |
188 | .probe = i2c_parport_probe, | |
0b255e92 | 189 | .remove = i2c_parport_remove, |
c6e8bb2c JD |
190 | }; |
191 | ||
192 | static int __init i2c_parport_device_add(u16 address) | |
193 | { | |
c6e8bb2c JD |
194 | int err; |
195 | ||
196 | pdev = platform_device_alloc(DRVNAME, -1); | |
197 | if (!pdev) { | |
198 | err = -ENOMEM; | |
199 | printk(KERN_ERR DRVNAME ": Device allocation failed\n"); | |
200 | goto exit; | |
201 | } | |
202 | ||
c6e8bb2c JD |
203 | err = platform_device_add(pdev); |
204 | if (err) { | |
205 | printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n", | |
206 | err); | |
207 | goto exit_device_put; | |
208 | } | |
209 | ||
210 | return 0; | |
211 | ||
212 | exit_device_put: | |
213 | platform_device_put(pdev); | |
214 | exit: | |
215 | return err; | |
216 | } | |
1da177e4 LT |
217 | |
218 | static int __init i2c_parport_init(void) | |
219 | { | |
c6e8bb2c JD |
220 | int err; |
221 | ||
e97b81dd | 222 | if (type < 0) { |
c6e8bb2c | 223 | printk(KERN_ERR DRVNAME ": adapter type unspecified\n"); |
e97b81dd MH |
224 | return -ENODEV; |
225 | } | |
226 | ||
227 | if (type >= ARRAY_SIZE(adapter_parm)) { | |
c6e8bb2c | 228 | printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type); |
e97b81dd | 229 | return -ENODEV; |
1da177e4 | 230 | } |
7e3d7db5 | 231 | |
1da177e4 | 232 | if (base == 0) { |
c6e8bb2c | 233 | pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE); |
1da177e4 LT |
234 | base = DEFAULT_BASE; |
235 | } | |
236 | ||
9def2556 JD |
237 | if (!request_region(base, 3, DRVNAME)) |
238 | return -EBUSY; | |
239 | ||
927ab2f8 JD |
240 | if (irq != 0) |
241 | pr_info(DRVNAME ": using irq %d\n", irq); | |
242 | ||
07da0372 | 243 | if (!adapter_parm[type].getscl.val) |
1da177e4 LT |
244 | parport_algo_data.getscl = NULL; |
245 | ||
c6e8bb2c JD |
246 | /* Sets global pdev as a side effect */ |
247 | err = i2c_parport_device_add(base); | |
248 | if (err) | |
9def2556 | 249 | goto exit_release; |
1da177e4 | 250 | |
c6e8bb2c JD |
251 | err = platform_driver_register(&i2c_parport_driver); |
252 | if (err) | |
253 | goto exit_device; | |
7e3d7db5 | 254 | |
1da177e4 | 255 | return 0; |
c6e8bb2c JD |
256 | |
257 | exit_device: | |
258 | platform_device_unregister(pdev); | |
9def2556 JD |
259 | exit_release: |
260 | release_region(base, 3); | |
c6e8bb2c | 261 | return err; |
1da177e4 LT |
262 | } |
263 | ||
264 | static void __exit i2c_parport_exit(void) | |
265 | { | |
c6e8bb2c JD |
266 | platform_driver_unregister(&i2c_parport_driver); |
267 | platform_device_unregister(pdev); | |
9def2556 | 268 | release_region(base, 3); |
1da177e4 LT |
269 | } |
270 | ||
7c81c60f | 271 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
1da177e4 LT |
272 | MODULE_DESCRIPTION("I2C bus over parallel port (light)"); |
273 | MODULE_LICENSE("GPL"); | |
274 | ||
275 | module_init(i2c_parport_init); | |
276 | module_exit(i2c_parport_exit); |