Commit | Line | Data |
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1da177e4 | 1 | /* ------------------------------------------------------------------------ * |
c6e8bb2c | 2 | * i2c-parport-light.c I2C bus over parallel port * |
1da177e4 | 3 | * ------------------------------------------------------------------------ * |
927ab2f8 | 4 | Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org> |
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. | |
21 | ||
22 | You should have received a copy of the GNU General Public License | |
23 | along with this program; if not, write to the Free Software | |
24 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
25 | * ------------------------------------------------------------------------ */ | |
26 | ||
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/module.h> | |
29 | #include <linux/init.h> | |
6d376fcc | 30 | #include <linux/delay.h> |
c6e8bb2c | 31 | #include <linux/platform_device.h> |
1da177e4 LT |
32 | #include <linux/ioport.h> |
33 | #include <linux/i2c.h> | |
34 | #include <linux/i2c-algo-bit.h> | |
927ab2f8 | 35 | #include <linux/i2c-smbus.h> |
21782180 | 36 | #include <linux/io.h> |
1da177e4 LT |
37 | #include "i2c-parport.h" |
38 | ||
39 | #define DEFAULT_BASE 0x378 | |
c6e8bb2c JD |
40 | #define DRVNAME "i2c-parport-light" |
41 | ||
42 | static struct platform_device *pdev; | |
1da177e4 LT |
43 | |
44 | static u16 base; | |
45 | module_param(base, ushort, 0); | |
46 | MODULE_PARM_DESC(base, "Base I/O address"); | |
47 | ||
927ab2f8 JD |
48 | static int irq; |
49 | module_param(irq, int, 0); | |
50 | MODULE_PARM_DESC(irq, "IRQ (optional)"); | |
51 | ||
1da177e4 LT |
52 | /* ----- Low-level parallel port access ----------------------------------- */ |
53 | ||
54 | static inline void port_write(unsigned char p, unsigned char d) | |
55 | { | |
56 | outb(d, base+p); | |
57 | } | |
58 | ||
59 | static inline unsigned char port_read(unsigned char p) | |
60 | { | |
61 | return inb(base+p); | |
62 | } | |
63 | ||
64 | /* ----- Unified line operation functions --------------------------------- */ | |
65 | ||
66 | static inline void line_set(int state, const struct lineop *op) | |
67 | { | |
68 | u8 oldval = port_read(op->port); | |
69 | ||
70 | /* Touch only the bit(s) needed */ | |
71 | if ((op->inverted && !state) || (!op->inverted && state)) | |
72 | port_write(op->port, oldval | op->val); | |
73 | else | |
74 | port_write(op->port, oldval & ~op->val); | |
75 | } | |
76 | ||
77 | static inline int line_get(const struct lineop *op) | |
78 | { | |
79 | u8 oldval = port_read(op->port); | |
80 | ||
81 | return ((op->inverted && (oldval & op->val) != op->val) | |
82 | || (!op->inverted && (oldval & op->val) == op->val)); | |
83 | } | |
84 | ||
85 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | |
86 | ||
87 | static void parport_setscl(void *data, int state) | |
88 | { | |
89 | line_set(state, &adapter_parm[type].setscl); | |
90 | } | |
91 | ||
92 | static void parport_setsda(void *data, int state) | |
93 | { | |
94 | line_set(state, &adapter_parm[type].setsda); | |
95 | } | |
96 | ||
97 | static int parport_getscl(void *data) | |
98 | { | |
99 | return line_get(&adapter_parm[type].getscl); | |
100 | } | |
101 | ||
102 | static int parport_getsda(void *data) | |
103 | { | |
104 | return line_get(&adapter_parm[type].getsda); | |
105 | } | |
106 | ||
107 | /* Encapsulate the functions above in the correct structure | |
108 | Note that getscl will be set to NULL by the attaching code for adapters | |
109 | that cannot read SCL back */ | |
110 | static struct i2c_algo_bit_data parport_algo_data = { | |
111 | .setsda = parport_setsda, | |
112 | .setscl = parport_setscl, | |
113 | .getsda = parport_getsda, | |
114 | .getscl = parport_getscl, | |
115 | .udelay = 50, | |
1da177e4 | 116 | .timeout = HZ, |
07da0372 | 117 | }; |
1da177e4 | 118 | |
c6e8bb2c | 119 | /* ----- Driver registration ---------------------------------------------- */ |
1da177e4 LT |
120 | |
121 | static struct i2c_adapter parport_adapter = { | |
122 | .owner = THIS_MODULE, | |
123 | .class = I2C_CLASS_HWMON, | |
1da177e4 LT |
124 | .algo_data = &parport_algo_data, |
125 | .name = "Parallel port adapter (light)", | |
126 | }; | |
127 | ||
927ab2f8 JD |
128 | /* SMBus alert support */ |
129 | static struct i2c_smbus_alert_setup alert_data = { | |
130 | .alert_edge_triggered = 1, | |
131 | }; | |
132 | static struct i2c_client *ara; | |
133 | static struct lineop parport_ctrl_irq = { | |
134 | .val = (1 << 4), | |
07da0372 | 135 | .port = PORT_CTRL, |
927ab2f8 JD |
136 | }; |
137 | ||
0b255e92 | 138 | static int i2c_parport_probe(struct platform_device *pdev) |
c6e8bb2c JD |
139 | { |
140 | int err; | |
c6e8bb2c JD |
141 | |
142 | /* Reset hardware to a sane state (SCL and SDA high) */ | |
143 | parport_setsda(NULL, 1); | |
144 | parport_setscl(NULL, 1); | |
145 | /* Other init if needed (power on...) */ | |
6d376fcc | 146 | if (adapter_parm[type].init.val) { |
c6e8bb2c | 147 | line_set(1, &adapter_parm[type].init); |
6d376fcc JD |
148 | /* Give powered devices some time to settle */ |
149 | msleep(100); | |
150 | } | |
c6e8bb2c JD |
151 | |
152 | parport_adapter.dev.parent = &pdev->dev; | |
153 | err = i2c_bit_add_bus(&parport_adapter); | |
927ab2f8 | 154 | if (err) { |
c6e8bb2c | 155 | dev_err(&pdev->dev, "Unable to register with I2C\n"); |
927ab2f8 JD |
156 | return err; |
157 | } | |
158 | ||
159 | /* Setup SMBus alert if supported */ | |
160 | if (adapter_parm[type].smbus_alert && irq) { | |
161 | alert_data.irq = irq; | |
162 | ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data); | |
163 | if (ara) | |
164 | line_set(1, &parport_ctrl_irq); | |
165 | else | |
166 | dev_warn(&pdev->dev, "Failed to register ARA client\n"); | |
167 | } | |
168 | ||
169 | return 0; | |
c6e8bb2c JD |
170 | } |
171 | ||
0b255e92 | 172 | static int i2c_parport_remove(struct platform_device *pdev) |
c6e8bb2c | 173 | { |
927ab2f8 JD |
174 | if (ara) { |
175 | line_set(0, &parport_ctrl_irq); | |
176 | i2c_unregister_device(ara); | |
177 | ara = NULL; | |
178 | } | |
c6e8bb2c JD |
179 | i2c_del_adapter(&parport_adapter); |
180 | ||
181 | /* Un-init if needed (power off...) */ | |
182 | if (adapter_parm[type].init.val) | |
183 | line_set(0, &adapter_parm[type].init); | |
184 | ||
c6e8bb2c JD |
185 | return 0; |
186 | } | |
187 | ||
188 | static struct platform_driver i2c_parport_driver = { | |
189 | .driver = { | |
190 | .owner = THIS_MODULE, | |
191 | .name = DRVNAME, | |
192 | }, | |
193 | .probe = i2c_parport_probe, | |
0b255e92 | 194 | .remove = i2c_parport_remove, |
c6e8bb2c JD |
195 | }; |
196 | ||
197 | static int __init i2c_parport_device_add(u16 address) | |
198 | { | |
c6e8bb2c JD |
199 | int err; |
200 | ||
201 | pdev = platform_device_alloc(DRVNAME, -1); | |
202 | if (!pdev) { | |
203 | err = -ENOMEM; | |
204 | printk(KERN_ERR DRVNAME ": Device allocation failed\n"); | |
205 | goto exit; | |
206 | } | |
207 | ||
c6e8bb2c JD |
208 | err = platform_device_add(pdev); |
209 | if (err) { | |
210 | printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n", | |
211 | err); | |
212 | goto exit_device_put; | |
213 | } | |
214 | ||
215 | return 0; | |
216 | ||
217 | exit_device_put: | |
218 | platform_device_put(pdev); | |
219 | exit: | |
220 | return err; | |
221 | } | |
1da177e4 LT |
222 | |
223 | static int __init i2c_parport_init(void) | |
224 | { | |
c6e8bb2c JD |
225 | int err; |
226 | ||
e97b81dd | 227 | if (type < 0) { |
c6e8bb2c | 228 | printk(KERN_ERR DRVNAME ": adapter type unspecified\n"); |
e97b81dd MH |
229 | return -ENODEV; |
230 | } | |
231 | ||
232 | if (type >= ARRAY_SIZE(adapter_parm)) { | |
c6e8bb2c | 233 | printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type); |
e97b81dd | 234 | return -ENODEV; |
1da177e4 | 235 | } |
7e3d7db5 | 236 | |
1da177e4 | 237 | if (base == 0) { |
c6e8bb2c | 238 | pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE); |
1da177e4 LT |
239 | base = DEFAULT_BASE; |
240 | } | |
241 | ||
9def2556 JD |
242 | if (!request_region(base, 3, DRVNAME)) |
243 | return -EBUSY; | |
244 | ||
927ab2f8 JD |
245 | if (irq != 0) |
246 | pr_info(DRVNAME ": using irq %d\n", irq); | |
247 | ||
07da0372 | 248 | if (!adapter_parm[type].getscl.val) |
1da177e4 LT |
249 | parport_algo_data.getscl = NULL; |
250 | ||
c6e8bb2c JD |
251 | /* Sets global pdev as a side effect */ |
252 | err = i2c_parport_device_add(base); | |
253 | if (err) | |
9def2556 | 254 | goto exit_release; |
1da177e4 | 255 | |
c6e8bb2c JD |
256 | err = platform_driver_register(&i2c_parport_driver); |
257 | if (err) | |
258 | goto exit_device; | |
7e3d7db5 | 259 | |
1da177e4 | 260 | return 0; |
c6e8bb2c JD |
261 | |
262 | exit_device: | |
263 | platform_device_unregister(pdev); | |
9def2556 JD |
264 | exit_release: |
265 | release_region(base, 3); | |
c6e8bb2c | 266 | return err; |
1da177e4 LT |
267 | } |
268 | ||
269 | static void __exit i2c_parport_exit(void) | |
270 | { | |
c6e8bb2c JD |
271 | platform_driver_unregister(&i2c_parport_driver); |
272 | platform_device_unregister(pdev); | |
9def2556 | 273 | release_region(base, 3); |
1da177e4 LT |
274 | } |
275 | ||
276 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | |
277 | MODULE_DESCRIPTION("I2C bus over parallel port (light)"); | |
278 | MODULE_LICENSE("GPL"); | |
279 | ||
280 | module_init(i2c_parport_init); | |
281 | module_exit(i2c_parport_exit); |