Commit | Line | Data |
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1da177e4 LT |
1 | /* ------------------------------------------------------------------------ * |
2 | * i2c-parport.c I2C bus over parallel port * | |
3 | * ------------------------------------------------------------------------ * | |
56acc7a3 | 4 | Copyright (C) 2003-2011 Jean Delvare <khali@linux-fr.org> |
07da0372 | 5 | |
1da177e4 LT |
6 | Based on older i2c-philips-par.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> |
1da177e4 LT |
31 | #include <linux/parport.h> |
32 | #include <linux/i2c.h> | |
33 | #include <linux/i2c-algo-bit.h> | |
35859254 | 34 | #include <linux/i2c-smbus.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
56acc7a3 JD |
36 | #include <linux/list.h> |
37 | #include <linux/mutex.h> | |
1da177e4 LT |
38 | #include "i2c-parport.h" |
39 | ||
40 | /* ----- Device list ------------------------------------------------------ */ | |
41 | ||
42 | struct i2c_par { | |
43 | struct pardevice *pdev; | |
44 | struct i2c_adapter adapter; | |
45 | struct i2c_algo_bit_data algo_data; | |
35859254 JD |
46 | struct i2c_smbus_alert_setup alert_data; |
47 | struct i2c_client *ara; | |
56acc7a3 | 48 | struct list_head node; |
1da177e4 LT |
49 | }; |
50 | ||
56acc7a3 JD |
51 | static LIST_HEAD(adapter_list); |
52 | static DEFINE_MUTEX(adapter_list_lock); | |
1da177e4 LT |
53 | |
54 | /* ----- Low-level parallel port access ----------------------------------- */ | |
55 | ||
56 | static void port_write_data(struct parport *p, unsigned char d) | |
57 | { | |
58 | parport_write_data(p, d); | |
59 | } | |
60 | ||
61 | static void port_write_control(struct parport *p, unsigned char d) | |
62 | { | |
63 | parport_write_control(p, d); | |
64 | } | |
65 | ||
66 | static unsigned char port_read_data(struct parport *p) | |
67 | { | |
68 | return parport_read_data(p); | |
69 | } | |
70 | ||
71 | static unsigned char port_read_status(struct parport *p) | |
72 | { | |
73 | return parport_read_status(p); | |
74 | } | |
75 | ||
76 | static unsigned char port_read_control(struct parport *p) | |
77 | { | |
78 | return parport_read_control(p); | |
79 | } | |
80 | ||
07da0372 | 81 | static void (* const port_write[])(struct parport *, unsigned char) = { |
1da177e4 LT |
82 | port_write_data, |
83 | NULL, | |
84 | port_write_control, | |
85 | }; | |
86 | ||
07da0372 | 87 | static unsigned char (* const port_read[])(struct parport *) = { |
1da177e4 LT |
88 | port_read_data, |
89 | port_read_status, | |
90 | port_read_control, | |
91 | }; | |
92 | ||
93 | /* ----- Unified line operation functions --------------------------------- */ | |
94 | ||
95 | static inline void line_set(struct parport *data, int state, | |
96 | const struct lineop *op) | |
97 | { | |
98 | u8 oldval = port_read[op->port](data); | |
99 | ||
100 | /* Touch only the bit(s) needed */ | |
101 | if ((op->inverted && !state) || (!op->inverted && state)) | |
102 | port_write[op->port](data, oldval | op->val); | |
103 | else | |
104 | port_write[op->port](data, oldval & ~op->val); | |
105 | } | |
106 | ||
107 | static inline int line_get(struct parport *data, | |
108 | const struct lineop *op) | |
109 | { | |
110 | u8 oldval = port_read[op->port](data); | |
111 | ||
112 | return ((op->inverted && (oldval & op->val) != op->val) | |
113 | || (!op->inverted && (oldval & op->val) == op->val)); | |
114 | } | |
115 | ||
116 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | |
117 | ||
118 | static void parport_setscl(void *data, int state) | |
119 | { | |
120 | line_set((struct parport *) data, state, &adapter_parm[type].setscl); | |
121 | } | |
122 | ||
123 | static void parport_setsda(void *data, int state) | |
124 | { | |
125 | line_set((struct parport *) data, state, &adapter_parm[type].setsda); | |
126 | } | |
127 | ||
128 | static int parport_getscl(void *data) | |
129 | { | |
130 | return line_get((struct parport *) data, &adapter_parm[type].getscl); | |
131 | } | |
132 | ||
133 | static int parport_getsda(void *data) | |
134 | { | |
135 | return line_get((struct parport *) data, &adapter_parm[type].getsda); | |
136 | } | |
137 | ||
138 | /* Encapsulate the functions above in the correct structure. | |
139 | Note that this is only a template, from which the real structures are | |
140 | copied. The attaching code will set getscl to NULL for adapters that | |
614e24be | 141 | cannot read SCL back, and will also make the data field point to |
1da177e4 | 142 | the parallel port structure. */ |
bfdcad90 | 143 | static const struct i2c_algo_bit_data parport_algo_data = { |
1da177e4 LT |
144 | .setsda = parport_setsda, |
145 | .setscl = parport_setscl, | |
146 | .getsda = parport_getsda, | |
147 | .getscl = parport_getscl, | |
3af07bd2 | 148 | .udelay = 10, /* ~50 kbps */ |
1da177e4 | 149 | .timeout = HZ, |
07da0372 | 150 | }; |
1da177e4 LT |
151 | |
152 | /* ----- I2c and parallel port call-back functions and structures --------- */ | |
153 | ||
35859254 JD |
154 | void i2c_parport_irq(void *data) |
155 | { | |
156 | struct i2c_par *adapter = data; | |
157 | struct i2c_client *ara = adapter->ara; | |
158 | ||
159 | if (ara) { | |
160 | dev_dbg(&ara->dev, "SMBus alert received\n"); | |
161 | i2c_handle_smbus_alert(ara); | |
162 | } else | |
163 | dev_dbg(&adapter->adapter.dev, | |
164 | "SMBus alert received but no ARA client!\n"); | |
165 | } | |
166 | ||
07da0372 | 167 | static void i2c_parport_attach(struct parport *port) |
1da177e4 LT |
168 | { |
169 | struct i2c_par *adapter; | |
07da0372 | 170 | |
5263ebb5 | 171 | adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL); |
1da177e4 | 172 | if (adapter == NULL) { |
5263ebb5 | 173 | printk(KERN_ERR "i2c-parport: Failed to kzalloc\n"); |
1da177e4 LT |
174 | return; |
175 | } | |
1da177e4 LT |
176 | |
177 | pr_debug("i2c-parport: attaching to %s\n", port->name); | |
35859254 | 178 | parport_disable_irq(port); |
1da177e4 | 179 | adapter->pdev = parport_register_device(port, "i2c-parport", |
35859254 | 180 | NULL, NULL, i2c_parport_irq, PARPORT_FLAG_EXCL, adapter); |
1da177e4 LT |
181 | if (!adapter->pdev) { |
182 | printk(KERN_ERR "i2c-parport: Unable to register with parport\n"); | |
07da0372 | 183 | goto err_free; |
1da177e4 LT |
184 | } |
185 | ||
186 | /* Fill the rest of the structure */ | |
cacf2269 JD |
187 | adapter->adapter.owner = THIS_MODULE; |
188 | adapter->adapter.class = I2C_CLASS_HWMON; | |
cacf2269 JD |
189 | strlcpy(adapter->adapter.name, "Parallel port adapter", |
190 | sizeof(adapter->adapter.name)); | |
1da177e4 | 191 | adapter->algo_data = parport_algo_data; |
3af07bd2 JD |
192 | /* Slow down if we can't sense SCL */ |
193 | if (!adapter_parm[type].getscl.val) { | |
1da177e4 | 194 | adapter->algo_data.getscl = NULL; |
3af07bd2 JD |
195 | adapter->algo_data.udelay = 50; /* ~10 kbps */ |
196 | } | |
1da177e4 LT |
197 | adapter->algo_data.data = port; |
198 | adapter->adapter.algo_data = &adapter->algo_data; | |
da675296 | 199 | adapter->adapter.dev.parent = port->physport->dev; |
1da177e4 LT |
200 | |
201 | if (parport_claim_or_block(adapter->pdev) < 0) { | |
202 | printk(KERN_ERR "i2c-parport: Could not claim parallel port\n"); | |
07da0372 | 203 | goto err_unregister; |
1da177e4 LT |
204 | } |
205 | ||
206 | /* Reset hardware to a sane state (SCL and SDA high) */ | |
207 | parport_setsda(port, 1); | |
208 | parport_setscl(port, 1); | |
209 | /* Other init if needed (power on...) */ | |
6d376fcc | 210 | if (adapter_parm[type].init.val) { |
1da177e4 | 211 | line_set(port, 1, &adapter_parm[type].init); |
6d376fcc JD |
212 | /* Give powered devices some time to settle */ |
213 | msleep(100); | |
214 | } | |
1da177e4 | 215 | |
1da177e4 LT |
216 | if (i2c_bit_add_bus(&adapter->adapter) < 0) { |
217 | printk(KERN_ERR "i2c-parport: Unable to register with I2C\n"); | |
07da0372 | 218 | goto err_unregister; |
1da177e4 LT |
219 | } |
220 | ||
35859254 JD |
221 | /* Setup SMBus alert if supported */ |
222 | if (adapter_parm[type].smbus_alert) { | |
223 | adapter->alert_data.alert_edge_triggered = 1; | |
224 | adapter->ara = i2c_setup_smbus_alert(&adapter->adapter, | |
225 | &adapter->alert_data); | |
226 | if (adapter->ara) | |
227 | parport_enable_irq(port); | |
228 | else | |
229 | printk(KERN_WARNING "i2c-parport: Failed to register " | |
230 | "ARA client\n"); | |
231 | } | |
232 | ||
1da177e4 | 233 | /* Add the new adapter to the list */ |
56acc7a3 JD |
234 | mutex_lock(&adapter_list_lock); |
235 | list_add_tail(&adapter->node, &adapter_list); | |
236 | mutex_unlock(&adapter_list_lock); | |
07da0372 | 237 | return; |
1da177e4 | 238 | |
07da0372 | 239 | err_unregister: |
7b964f73 | 240 | parport_release(adapter->pdev); |
1da177e4 | 241 | parport_unregister_device(adapter->pdev); |
07da0372 | 242 | err_free: |
1da177e4 LT |
243 | kfree(adapter); |
244 | } | |
245 | ||
07da0372 | 246 | static void i2c_parport_detach(struct parport *port) |
1da177e4 | 247 | { |
56acc7a3 | 248 | struct i2c_par *adapter, *_n; |
1da177e4 LT |
249 | |
250 | /* Walk the list */ | |
56acc7a3 JD |
251 | mutex_lock(&adapter_list_lock); |
252 | list_for_each_entry_safe(adapter, _n, &adapter_list, node) { | |
1da177e4 | 253 | if (adapter->pdev->port == port) { |
35859254 JD |
254 | if (adapter->ara) { |
255 | parport_disable_irq(port); | |
256 | i2c_unregister_device(adapter->ara); | |
257 | } | |
3af07bd2 JD |
258 | i2c_del_adapter(&adapter->adapter); |
259 | ||
1da177e4 LT |
260 | /* Un-init if needed (power off...) */ |
261 | if (adapter_parm[type].init.val) | |
262 | line_set(port, 0, &adapter_parm[type].init); | |
07da0372 | 263 | |
7b964f73 | 264 | parport_release(adapter->pdev); |
1da177e4 | 265 | parport_unregister_device(adapter->pdev); |
56acc7a3 | 266 | list_del(&adapter->node); |
1da177e4 | 267 | kfree(adapter); |
1da177e4 LT |
268 | } |
269 | } | |
56acc7a3 | 270 | mutex_unlock(&adapter_list_lock); |
1da177e4 LT |
271 | } |
272 | ||
6c129be8 | 273 | static struct parport_driver i2c_parport_driver = { |
1da177e4 LT |
274 | .name = "i2c-parport", |
275 | .attach = i2c_parport_attach, | |
276 | .detach = i2c_parport_detach, | |
277 | }; | |
278 | ||
279 | /* ----- Module loading, unloading and information ------------------------ */ | |
280 | ||
281 | static int __init i2c_parport_init(void) | |
282 | { | |
e97b81dd MH |
283 | if (type < 0) { |
284 | printk(KERN_WARNING "i2c-parport: adapter type unspecified\n"); | |
285 | return -ENODEV; | |
286 | } | |
287 | ||
288 | if (type >= ARRAY_SIZE(adapter_parm)) { | |
1da177e4 | 289 | printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type); |
e97b81dd | 290 | return -ENODEV; |
1da177e4 | 291 | } |
7e3d7db5 | 292 | |
6c129be8 | 293 | return parport_register_driver(&i2c_parport_driver); |
1da177e4 LT |
294 | } |
295 | ||
296 | static void __exit i2c_parport_exit(void) | |
297 | { | |
6c129be8 | 298 | parport_unregister_driver(&i2c_parport_driver); |
1da177e4 LT |
299 | } |
300 | ||
301 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | |
302 | MODULE_DESCRIPTION("I2C bus over parallel port"); | |
303 | MODULE_LICENSE("GPL"); | |
304 | ||
305 | module_init(i2c_parport_init); | |
306 | module_exit(i2c_parport_exit); |