Remove all inclusions of <linux/config.h>
[linux-2.6.git] / drivers / i2c / busses / i2c-ocores.c
1 /*
2  * i2c-ocores.c: I2C bus driver for OpenCores I2C controller
3  * (http://www.opencores.org/projects.cgi/web/i2c/overview).
4  *
5  * Peter Korsgaard <jacmet@sunsite.dk>
6  *
7  * This file is licensed under the terms of the GNU General Public License
8  * version 2.  This program is licensed "as is" without any warranty of any
9  * kind, whether express or implied.
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/sched.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17 #include <linux/platform_device.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/wait.h>
21 #include <linux/i2c-ocores.h>
22 #include <asm/io.h>
23
24 struct ocores_i2c {
25         void __iomem *base;
26         int regstep;
27         wait_queue_head_t wait;
28         struct i2c_adapter adap;
29         struct i2c_msg *msg;
30         int pos;
31         int nmsgs;
32         int state; /* see STATE_ */
33 };
34
35 /* registers */
36 #define OCI2C_PRELOW            0
37 #define OCI2C_PREHIGH           1
38 #define OCI2C_CONTROL           2
39 #define OCI2C_DATA              3
40 #define OCI2C_CMD               4 /* write only */
41 #define OCI2C_STATUS            4 /* read only, same address as OCI2C_CMD */
42
43 #define OCI2C_CTRL_IEN          0x40
44 #define OCI2C_CTRL_EN           0x80
45
46 #define OCI2C_CMD_START         0x91
47 #define OCI2C_CMD_STOP          0x41
48 #define OCI2C_CMD_READ          0x21
49 #define OCI2C_CMD_WRITE         0x11
50 #define OCI2C_CMD_READ_ACK      0x21
51 #define OCI2C_CMD_READ_NACK     0x29
52 #define OCI2C_CMD_IACK          0x01
53
54 #define OCI2C_STAT_IF           0x01
55 #define OCI2C_STAT_TIP          0x02
56 #define OCI2C_STAT_ARBLOST      0x20
57 #define OCI2C_STAT_BUSY         0x40
58 #define OCI2C_STAT_NACK         0x80
59
60 #define STATE_DONE              0
61 #define STATE_START             1
62 #define STATE_WRITE             2
63 #define STATE_READ              3
64 #define STATE_ERROR             4
65
66 static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
67 {
68         iowrite8(value, i2c->base + reg * i2c->regstep);
69 }
70
71 static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
72 {
73         return ioread8(i2c->base + reg * i2c->regstep);
74 }
75
76 static void ocores_process(struct ocores_i2c *i2c)
77 {
78         struct i2c_msg *msg = i2c->msg;
79         u8 stat = oc_getreg(i2c, OCI2C_STATUS);
80
81         if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) {
82                 /* stop has been sent */
83                 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
84                 wake_up(&i2c->wait);
85                 return;
86         }
87
88         /* error? */
89         if (stat & OCI2C_STAT_ARBLOST) {
90                 i2c->state = STATE_ERROR;
91                 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
92                 return;
93         }
94
95         if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) {
96                 i2c->state =
97                         (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE;
98
99                 if (stat & OCI2C_STAT_NACK) {
100                         i2c->state = STATE_ERROR;
101                         oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
102                         return;
103                 }
104         } else
105                 msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA);
106
107         /* end of msg? */
108         if (i2c->pos == msg->len) {
109                 i2c->nmsgs--;
110                 i2c->msg++;
111                 i2c->pos = 0;
112                 msg = i2c->msg;
113
114                 if (i2c->nmsgs) {       /* end? */
115                         /* send start? */
116                         if (!(msg->flags & I2C_M_NOSTART)) {
117                                 u8 addr = (msg->addr << 1);
118
119                                 if (msg->flags & I2C_M_RD)
120                                         addr |= 1;
121
122                                 i2c->state = STATE_START;
123
124                                 oc_setreg(i2c, OCI2C_DATA, addr);
125                                 oc_setreg(i2c, OCI2C_CMD,  OCI2C_CMD_START);
126                                 return;
127                         } else
128                                 i2c->state = (msg->flags & I2C_M_RD)
129                                         ? STATE_READ : STATE_WRITE;
130                 } else {
131                         i2c->state = STATE_DONE;
132                         oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
133                         return;
134                 }
135         }
136
137         if (i2c->state == STATE_READ) {
138                 oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ?
139                           OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK);
140         } else {
141                 oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]);
142                 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE);
143         }
144 }
145
146 static irqreturn_t ocores_isr(int irq, void *dev_id, struct pt_regs *regs)
147 {
148         struct ocores_i2c *i2c = dev_id;
149
150         ocores_process(i2c);
151
152         return IRQ_HANDLED;
153 }
154
155 static int ocores_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
156 {
157         struct ocores_i2c *i2c = i2c_get_adapdata(adap);
158
159         i2c->msg = msgs;
160         i2c->pos = 0;
161         i2c->nmsgs = num;
162         i2c->state = STATE_START;
163
164         oc_setreg(i2c, OCI2C_DATA,
165                         (i2c->msg->addr << 1) |
166                         ((i2c->msg->flags & I2C_M_RD) ? 1:0));
167
168         oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
169
170         if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
171                                (i2c->state == STATE_DONE), HZ))
172                 return (i2c->state == STATE_DONE) ? num : -EIO;
173         else
174                 return -ETIMEDOUT;
175 }
176
177 static void ocores_init(struct ocores_i2c *i2c,
178                         struct ocores_i2c_platform_data *pdata)
179 {
180         int prescale;
181         u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
182
183         /* make sure the device is disabled */
184         oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
185
186         prescale = (pdata->clock_khz / (5*100)) - 1;
187         oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff);
188         oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
189
190         /* Init the device */
191         oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
192         oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN | OCI2C_CTRL_EN);
193 }
194
195
196 static u32 ocores_func(struct i2c_adapter *adap)
197 {
198         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
199 }
200
201 static const struct i2c_algorithm ocores_algorithm = {
202         .master_xfer    = ocores_xfer,
203         .functionality  = ocores_func,
204 };
205
206 static struct i2c_adapter ocores_adapter = {
207         .owner          = THIS_MODULE,
208         .name           = "i2c-ocores",
209         .class          = I2C_CLASS_HWMON,
210         .algo           = &ocores_algorithm,
211 };
212
213
214 static int __devinit ocores_i2c_probe(struct platform_device *pdev)
215 {
216         struct ocores_i2c *i2c;
217         struct ocores_i2c_platform_data *pdata;
218         struct resource *res, *res2;
219         int ret;
220
221         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
222         if (!res)
223                 return -ENODEV;
224
225         res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
226         if (!res2)
227                 return -ENODEV;
228
229         pdata = (struct ocores_i2c_platform_data*) pdev->dev.platform_data;
230         if (!pdata)
231                 return -ENODEV;
232
233         i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
234         if (!i2c)
235                 return -ENOMEM;
236
237         if (!request_mem_region(res->start, res->end - res->start + 1,
238                                 pdev->name)) {
239                 dev_err(&pdev->dev, "Memory region busy\n");
240                 ret = -EBUSY;
241                 goto request_mem_failed;
242         }
243
244         i2c->base = ioremap(res->start, res->end - res->start + 1);
245         if (!i2c->base) {
246                 dev_err(&pdev->dev, "Unable to map registers\n");
247                 ret = -EIO;
248                 goto map_failed;
249         }
250
251         i2c->regstep = pdata->regstep;
252         ocores_init(i2c, pdata);
253
254         init_waitqueue_head(&i2c->wait);
255         ret = request_irq(res2->start, ocores_isr, 0, pdev->name, i2c);
256         if (ret) {
257                 dev_err(&pdev->dev, "Cannot claim IRQ\n");
258                 goto request_irq_failed;
259         }
260
261         /* hook up driver to tree */
262         platform_set_drvdata(pdev, i2c);
263         i2c->adap = ocores_adapter;
264         i2c_set_adapdata(&i2c->adap, i2c);
265         i2c->adap.dev.parent = &pdev->dev;
266
267         /* add i2c adapter to i2c tree */
268         ret = i2c_add_adapter(&i2c->adap);
269         if (ret) {
270                 dev_err(&pdev->dev, "Failed to add adapter\n");
271                 goto add_adapter_failed;
272         }
273
274         return 0;
275
276 add_adapter_failed:
277         free_irq(res2->start, i2c);
278 request_irq_failed:
279         iounmap(i2c->base);
280 map_failed:
281         release_mem_region(res->start, res->end - res->start + 1);
282 request_mem_failed:
283         kfree(i2c);
284
285         return ret;
286 }
287
288 static int __devexit ocores_i2c_remove(struct platform_device* pdev)
289 {
290         struct ocores_i2c *i2c = platform_get_drvdata(pdev);
291         struct resource *res;
292
293         /* disable i2c logic */
294         oc_setreg(i2c, OCI2C_CONTROL, oc_getreg(i2c, OCI2C_CONTROL)
295                   & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
296
297         /* remove adapter & data */
298         i2c_del_adapter(&i2c->adap);
299         platform_set_drvdata(pdev, NULL);
300
301         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
302         if (res)
303                 free_irq(res->start, i2c);
304
305         iounmap(i2c->base);
306
307         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
308         if (res)
309                 release_mem_region(res->start, res->end - res->start + 1);
310
311         kfree(i2c);
312
313         return 0;
314 }
315
316 static struct platform_driver ocores_i2c_driver = {
317         .probe  = ocores_i2c_probe,
318         .remove = __devexit_p(ocores_i2c_remove),
319         .driver = {
320                 .owner = THIS_MODULE,
321                 .name = "ocores-i2c",
322         },
323 };
324
325 static int __init ocores_i2c_init(void)
326 {
327         return platform_driver_register(&ocores_i2c_driver);
328 }
329
330 static void __exit ocores_i2c_exit(void)
331 {
332         platform_driver_unregister(&ocores_i2c_driver);
333 }
334
335 module_init(ocores_i2c_init);
336 module_exit(ocores_i2c_exit);
337
338 MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
339 MODULE_DESCRIPTION("OpenCores I2C bus driver");
340 MODULE_LICENSE("GPL");