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Commit | Line | Data |
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1da177e4 LT |
1 | /* ------------------------------------------------------------------------ * |
2 | * i2c-parport.c I2C bus over parallel port * | |
3 | * ------------------------------------------------------------------------ * | |
7c81c60f | 4 | Copyright (C) 2003-2011 Jean Delvare <jdelvare@suse.de> |
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. | |
1da177e4 LT |
21 | * ------------------------------------------------------------------------ */ |
22 | ||
20226118 SM |
23 | #define pr_fmt(fmt) "i2c-parport: " fmt |
24 | ||
1da177e4 LT |
25 | #include <linux/kernel.h> |
26 | #include <linux/module.h> | |
27 | #include <linux/init.h> | |
6d376fcc | 28 | #include <linux/delay.h> |
1da177e4 LT |
29 | #include <linux/parport.h> |
30 | #include <linux/i2c.h> | |
31 | #include <linux/i2c-algo-bit.h> | |
35859254 | 32 | #include <linux/i2c-smbus.h> |
5a0e3ad6 | 33 | #include <linux/slab.h> |
56acc7a3 JD |
34 | #include <linux/list.h> |
35 | #include <linux/mutex.h> | |
1da177e4 LT |
36 | #include "i2c-parport.h" |
37 | ||
38 | /* ----- Device list ------------------------------------------------------ */ | |
39 | ||
40 | struct i2c_par { | |
41 | struct pardevice *pdev; | |
42 | struct i2c_adapter adapter; | |
43 | struct i2c_algo_bit_data algo_data; | |
35859254 JD |
44 | struct i2c_smbus_alert_setup alert_data; |
45 | struct i2c_client *ara; | |
56acc7a3 | 46 | struct list_head node; |
1da177e4 LT |
47 | }; |
48 | ||
56acc7a3 JD |
49 | static LIST_HEAD(adapter_list); |
50 | static DEFINE_MUTEX(adapter_list_lock); | |
19a4fb21 SM |
51 | #define MAX_DEVICE 4 |
52 | static int parport[MAX_DEVICE] = {0, -1, -1, -1}; | |
53 | ||
1da177e4 LT |
54 | |
55 | /* ----- Low-level parallel port access ----------------------------------- */ | |
56 | ||
57 | static void port_write_data(struct parport *p, unsigned char d) | |
58 | { | |
59 | parport_write_data(p, d); | |
60 | } | |
61 | ||
62 | static void port_write_control(struct parport *p, unsigned char d) | |
63 | { | |
64 | parport_write_control(p, d); | |
65 | } | |
66 | ||
67 | static unsigned char port_read_data(struct parport *p) | |
68 | { | |
69 | return parport_read_data(p); | |
70 | } | |
71 | ||
72 | static unsigned char port_read_status(struct parport *p) | |
73 | { | |
74 | return parport_read_status(p); | |
75 | } | |
76 | ||
77 | static unsigned char port_read_control(struct parport *p) | |
78 | { | |
79 | return parport_read_control(p); | |
80 | } | |
81 | ||
07da0372 | 82 | static void (* const port_write[])(struct parport *, unsigned char) = { |
1da177e4 LT |
83 | port_write_data, |
84 | NULL, | |
85 | port_write_control, | |
86 | }; | |
87 | ||
07da0372 | 88 | static unsigned char (* const port_read[])(struct parport *) = { |
1da177e4 LT |
89 | port_read_data, |
90 | port_read_status, | |
91 | port_read_control, | |
92 | }; | |
93 | ||
94 | /* ----- Unified line operation functions --------------------------------- */ | |
95 | ||
96 | static inline void line_set(struct parport *data, int state, | |
97 | const struct lineop *op) | |
98 | { | |
99 | u8 oldval = port_read[op->port](data); | |
100 | ||
101 | /* Touch only the bit(s) needed */ | |
102 | if ((op->inverted && !state) || (!op->inverted && state)) | |
103 | port_write[op->port](data, oldval | op->val); | |
104 | else | |
105 | port_write[op->port](data, oldval & ~op->val); | |
106 | } | |
107 | ||
108 | static inline int line_get(struct parport *data, | |
109 | const struct lineop *op) | |
110 | { | |
111 | u8 oldval = port_read[op->port](data); | |
112 | ||
113 | return ((op->inverted && (oldval & op->val) != op->val) | |
114 | || (!op->inverted && (oldval & op->val) == op->val)); | |
115 | } | |
116 | ||
117 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | |
118 | ||
119 | static void parport_setscl(void *data, int state) | |
120 | { | |
121 | line_set((struct parport *) data, state, &adapter_parm[type].setscl); | |
122 | } | |
123 | ||
124 | static void parport_setsda(void *data, int state) | |
125 | { | |
126 | line_set((struct parport *) data, state, &adapter_parm[type].setsda); | |
127 | } | |
128 | ||
129 | static int parport_getscl(void *data) | |
130 | { | |
131 | return line_get((struct parport *) data, &adapter_parm[type].getscl); | |
132 | } | |
133 | ||
134 | static int parport_getsda(void *data) | |
135 | { | |
136 | return line_get((struct parport *) data, &adapter_parm[type].getsda); | |
137 | } | |
138 | ||
139 | /* Encapsulate the functions above in the correct structure. | |
140 | Note that this is only a template, from which the real structures are | |
141 | copied. The attaching code will set getscl to NULL for adapters that | |
614e24be | 142 | cannot read SCL back, and will also make the data field point to |
1da177e4 | 143 | the parallel port structure. */ |
bfdcad90 | 144 | static const struct i2c_algo_bit_data parport_algo_data = { |
1da177e4 LT |
145 | .setsda = parport_setsda, |
146 | .setscl = parport_setscl, | |
147 | .getsda = parport_getsda, | |
148 | .getscl = parport_getscl, | |
3af07bd2 | 149 | .udelay = 10, /* ~50 kbps */ |
1da177e4 | 150 | .timeout = HZ, |
07da0372 | 151 | }; |
1da177e4 LT |
152 | |
153 | /* ----- I2c and parallel port call-back functions and structures --------- */ | |
154 | ||
7fe442a1 | 155 | static void i2c_parport_irq(void *data) |
35859254 JD |
156 | { |
157 | struct i2c_par *adapter = data; | |
158 | struct i2c_client *ara = adapter->ara; | |
159 | ||
160 | if (ara) { | |
161 | dev_dbg(&ara->dev, "SMBus alert received\n"); | |
162 | i2c_handle_smbus_alert(ara); | |
163 | } else | |
164 | dev_dbg(&adapter->adapter.dev, | |
165 | "SMBus alert received but no ARA client!\n"); | |
166 | } | |
167 | ||
07da0372 | 168 | static void i2c_parport_attach(struct parport *port) |
1da177e4 LT |
169 | { |
170 | struct i2c_par *adapter; | |
19a4fb21 SM |
171 | int i; |
172 | struct pardev_cb i2c_parport_cb; | |
173 | ||
174 | for (i = 0; i < MAX_DEVICE; i++) { | |
175 | if (parport[i] == -1) | |
176 | continue; | |
177 | if (port->number == parport[i]) | |
178 | break; | |
179 | } | |
180 | if (i == MAX_DEVICE) { | |
20226118 | 181 | pr_debug("Not using parport%d.\n", port->number); |
19a4fb21 SM |
182 | return; |
183 | } | |
07da0372 | 184 | |
5263ebb5 | 185 | adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL); |
20226118 | 186 | if (!adapter) |
1da177e4 | 187 | return; |
8891f41a SM |
188 | memset(&i2c_parport_cb, 0, sizeof(i2c_parport_cb)); |
189 | i2c_parport_cb.flags = PARPORT_FLAG_EXCL; | |
190 | i2c_parport_cb.irq_func = i2c_parport_irq; | |
191 | i2c_parport_cb.private = adapter; | |
1da177e4 | 192 | |
20226118 | 193 | pr_debug("attaching to %s\n", port->name); |
35859254 | 194 | parport_disable_irq(port); |
8891f41a SM |
195 | adapter->pdev = parport_register_dev_model(port, "i2c-parport", |
196 | &i2c_parport_cb, i); | |
1da177e4 | 197 | if (!adapter->pdev) { |
20226118 | 198 | pr_err("Unable to register with parport\n"); |
07da0372 | 199 | goto err_free; |
1da177e4 LT |
200 | } |
201 | ||
202 | /* Fill the rest of the structure */ | |
cacf2269 JD |
203 | adapter->adapter.owner = THIS_MODULE; |
204 | adapter->adapter.class = I2C_CLASS_HWMON; | |
cacf2269 JD |
205 | strlcpy(adapter->adapter.name, "Parallel port adapter", |
206 | sizeof(adapter->adapter.name)); | |
1da177e4 | 207 | adapter->algo_data = parport_algo_data; |
3af07bd2 JD |
208 | /* Slow down if we can't sense SCL */ |
209 | if (!adapter_parm[type].getscl.val) { | |
1da177e4 | 210 | adapter->algo_data.getscl = NULL; |
3af07bd2 JD |
211 | adapter->algo_data.udelay = 50; /* ~10 kbps */ |
212 | } | |
1da177e4 LT |
213 | adapter->algo_data.data = port; |
214 | adapter->adapter.algo_data = &adapter->algo_data; | |
da675296 | 215 | adapter->adapter.dev.parent = port->physport->dev; |
1da177e4 LT |
216 | |
217 | if (parport_claim_or_block(adapter->pdev) < 0) { | |
c5f3d544 SM |
218 | dev_err(&adapter->pdev->dev, |
219 | "Could not claim parallel port\n"); | |
07da0372 | 220 | goto err_unregister; |
1da177e4 LT |
221 | } |
222 | ||
223 | /* Reset hardware to a sane state (SCL and SDA high) */ | |
224 | parport_setsda(port, 1); | |
225 | parport_setscl(port, 1); | |
226 | /* Other init if needed (power on...) */ | |
6d376fcc | 227 | if (adapter_parm[type].init.val) { |
1da177e4 | 228 | line_set(port, 1, &adapter_parm[type].init); |
6d376fcc JD |
229 | /* Give powered devices some time to settle */ |
230 | msleep(100); | |
231 | } | |
1da177e4 | 232 | |
1da177e4 | 233 | if (i2c_bit_add_bus(&adapter->adapter) < 0) { |
c5f3d544 | 234 | dev_err(&adapter->pdev->dev, "Unable to register with I2C\n"); |
07da0372 | 235 | goto err_unregister; |
1da177e4 LT |
236 | } |
237 | ||
35859254 JD |
238 | /* Setup SMBus alert if supported */ |
239 | if (adapter_parm[type].smbus_alert) { | |
240 | adapter->alert_data.alert_edge_triggered = 1; | |
241 | adapter->ara = i2c_setup_smbus_alert(&adapter->adapter, | |
242 | &adapter->alert_data); | |
243 | if (adapter->ara) | |
244 | parport_enable_irq(port); | |
245 | else | |
c5f3d544 SM |
246 | dev_warn(&adapter->pdev->dev, |
247 | "Failed to register ARA client\n"); | |
35859254 JD |
248 | } |
249 | ||
1da177e4 | 250 | /* Add the new adapter to the list */ |
56acc7a3 JD |
251 | mutex_lock(&adapter_list_lock); |
252 | list_add_tail(&adapter->node, &adapter_list); | |
253 | mutex_unlock(&adapter_list_lock); | |
07da0372 | 254 | return; |
1da177e4 | 255 | |
07da0372 | 256 | err_unregister: |
7b964f73 | 257 | parport_release(adapter->pdev); |
1da177e4 | 258 | parport_unregister_device(adapter->pdev); |
07da0372 | 259 | err_free: |
1da177e4 LT |
260 | kfree(adapter); |
261 | } | |
262 | ||
07da0372 | 263 | static void i2c_parport_detach(struct parport *port) |
1da177e4 | 264 | { |
56acc7a3 | 265 | struct i2c_par *adapter, *_n; |
1da177e4 LT |
266 | |
267 | /* Walk the list */ | |
56acc7a3 JD |
268 | mutex_lock(&adapter_list_lock); |
269 | list_for_each_entry_safe(adapter, _n, &adapter_list, node) { | |
1da177e4 | 270 | if (adapter->pdev->port == port) { |
35859254 JD |
271 | if (adapter->ara) { |
272 | parport_disable_irq(port); | |
273 | i2c_unregister_device(adapter->ara); | |
274 | } | |
3af07bd2 JD |
275 | i2c_del_adapter(&adapter->adapter); |
276 | ||
1da177e4 LT |
277 | /* Un-init if needed (power off...) */ |
278 | if (adapter_parm[type].init.val) | |
279 | line_set(port, 0, &adapter_parm[type].init); | |
07da0372 | 280 | |
7b964f73 | 281 | parport_release(adapter->pdev); |
1da177e4 | 282 | parport_unregister_device(adapter->pdev); |
56acc7a3 | 283 | list_del(&adapter->node); |
1da177e4 | 284 | kfree(adapter); |
1da177e4 LT |
285 | } |
286 | } | |
56acc7a3 | 287 | mutex_unlock(&adapter_list_lock); |
1da177e4 LT |
288 | } |
289 | ||
6c129be8 | 290 | static struct parport_driver i2c_parport_driver = { |
8891f41a SM |
291 | .name = "i2c-parport", |
292 | .match_port = i2c_parport_attach, | |
293 | .detach = i2c_parport_detach, | |
294 | .devmodel = true, | |
1da177e4 LT |
295 | }; |
296 | ||
297 | /* ----- Module loading, unloading and information ------------------------ */ | |
298 | ||
299 | static int __init i2c_parport_init(void) | |
300 | { | |
e97b81dd | 301 | if (type < 0) { |
20226118 | 302 | pr_warn("adapter type unspecified\n"); |
e97b81dd MH |
303 | return -ENODEV; |
304 | } | |
305 | ||
306 | if (type >= ARRAY_SIZE(adapter_parm)) { | |
20226118 | 307 | pr_warn("invalid type (%d)\n", type); |
e97b81dd | 308 | return -ENODEV; |
1da177e4 | 309 | } |
7e3d7db5 | 310 | |
6c129be8 | 311 | return parport_register_driver(&i2c_parport_driver); |
1da177e4 LT |
312 | } |
313 | ||
314 | static void __exit i2c_parport_exit(void) | |
315 | { | |
6c129be8 | 316 | parport_unregister_driver(&i2c_parport_driver); |
1da177e4 LT |
317 | } |
318 | ||
7c81c60f | 319 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
1da177e4 LT |
320 | MODULE_DESCRIPTION("I2C bus over parallel port"); |
321 | MODULE_LICENSE("GPL"); | |
322 | ||
19a4fb21 SM |
323 | module_param_array(parport, int, NULL, 0); |
324 | MODULE_PARM_DESC(parport, | |
325 | "List of parallel ports to bind to, by index.\n" | |
326 | " Atmost " __stringify(MAX_DEVICE) " devices are supported.\n" | |
327 | " Default is one device connected to parport0.\n" | |
328 | ); | |
329 | ||
1da177e4 LT |
330 | module_init(i2c_parport_init); |
331 | module_exit(i2c_parport_exit); |