1
2
3
4
5
6
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/types.h>
10#include <linux/slab.h>
11#include <linux/sched.h>
12#include <linux/wait.h>
13#include <linux/delay.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <asm/bbc.h>
19#include <asm/io.h>
20
21#include "bbc_i2c.h"
22
23
24#define I2C_PCF_PIN 0x80
25#define I2C_PCF_ESO 0x40
26#define I2C_PCF_ES1 0x20
27#define I2C_PCF_ES2 0x10
28#define I2C_PCF_ENI 0x08
29#define I2C_PCF_STA 0x04
30#define I2C_PCF_STO 0x02
31#define I2C_PCF_ACK 0x01
32
33#define I2C_PCF_START (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)
34#define I2C_PCF_STOP (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)
35#define I2C_PCF_REPSTART ( I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)
36#define I2C_PCF_IDLE (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ACK)
37
38#define I2C_PCF_INI 0x40
39#define I2C_PCF_STS 0x20
40#define I2C_PCF_BER 0x10
41#define I2C_PCF_AD0 0x08
42#define I2C_PCF_LRB 0x08
43#define I2C_PCF_AAS 0x04
44#define I2C_PCF_LAB 0x02
45#define I2C_PCF_BB 0x01
46
47
48
49
50
51
52
53
54static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)
55{
56 int i;
57
58 for (i = 0; i < NUM_CHILDREN; i++) {
59 if (bp->devs[i].device == op) {
60 bp->devs[i].client_claimed = val;
61 return;
62 }
63 }
64}
65
66#define claim_device(BP,ECHILD) set_device_claimage(BP,ECHILD,1)
67#define release_device(BP,ECHILD) set_device_claimage(BP,ECHILD,0)
68
69struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)
70{
71 struct platform_device *op = NULL;
72 int curidx = 0, i;
73
74 for (i = 0; i < NUM_CHILDREN; i++) {
75 if (!(op = bp->devs[i].device))
76 break;
77 if (curidx == index)
78 goto out;
79 op = NULL;
80 curidx++;
81 }
82
83out:
84 if (curidx == index)
85 return op;
86 return NULL;
87}
88
89struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)
90{
91 struct bbc_i2c_client *client;
92 const u32 *reg;
93
94 client = kzalloc(sizeof(*client), GFP_KERNEL);
95 if (!client)
96 return NULL;
97 client->bp = bp;
98 client->op = op;
99
100 reg = of_get_property(op->dev.of_node, "reg", NULL);
101 if (!reg) {
102 kfree(client);
103 return NULL;
104 }
105
106 client->bus = reg[0];
107 client->address = reg[1];
108
109 claim_device(bp, op);
110
111 return client;
112}
113
114void bbc_i2c_detach(struct bbc_i2c_client *client)
115{
116 struct bbc_i2c_bus *bp = client->bp;
117 struct platform_device *op = client->op;
118
119 release_device(bp, op);
120 kfree(client);
121}
122
123static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)
124{
125 DECLARE_WAITQUEUE(wait, current);
126 int limit = 32;
127 int ret = 1;
128
129 bp->waiting = 1;
130 add_wait_queue(&bp->wq, &wait);
131 while (limit-- > 0) {
132 long val;
133
134 val = wait_event_interruptible_timeout(
135 bp->wq,
136 (((*status = readb(bp->i2c_control_regs + 0))
137 & I2C_PCF_PIN) == 0),
138 msecs_to_jiffies(250));
139 if (val > 0) {
140 ret = 0;
141 break;
142 }
143 }
144 remove_wait_queue(&bp->wq, &wait);
145 bp->waiting = 0;
146
147 return ret;
148}
149
150int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)
151{
152 struct bbc_i2c_bus *bp = client->bp;
153 int address = client->address;
154 u8 status;
155 int ret = -1;
156
157 if (bp->i2c_bussel_reg != NULL)
158 writeb(client->bus, bp->i2c_bussel_reg);
159
160 writeb(address, bp->i2c_control_regs + 0x1);
161 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
162 if (wait_for_pin(bp, &status))
163 goto out;
164
165 writeb(off, bp->i2c_control_regs + 0x1);
166 if (wait_for_pin(bp, &status) ||
167 (status & I2C_PCF_LRB) != 0)
168 goto out;
169
170 writeb(val, bp->i2c_control_regs + 0x1);
171 if (wait_for_pin(bp, &status))
172 goto out;
173
174 ret = 0;
175
176out:
177 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
178 return ret;
179}
180
181int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)
182{
183 struct bbc_i2c_bus *bp = client->bp;
184 unsigned char address = client->address, status;
185 int ret = -1;
186
187 if (bp->i2c_bussel_reg != NULL)
188 writeb(client->bus, bp->i2c_bussel_reg);
189
190 writeb(address, bp->i2c_control_regs + 0x1);
191 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
192 if (wait_for_pin(bp, &status))
193 goto out;
194
195 writeb(off, bp->i2c_control_regs + 0x1);
196 if (wait_for_pin(bp, &status) ||
197 (status & I2C_PCF_LRB) != 0)
198 goto out;
199
200 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
201
202 address |= 0x1;
203
204 writeb(address, bp->i2c_control_regs + 0x1);
205 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
206 if (wait_for_pin(bp, &status))
207 goto out;
208
209
210
211
212 (void) readb(bp->i2c_control_regs + 0x1);
213 if (wait_for_pin(bp, &status))
214 goto out;
215
216 writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);
217 *byte = readb(bp->i2c_control_regs + 0x1);
218 if (wait_for_pin(bp, &status))
219 goto out;
220
221 ret = 0;
222
223out:
224 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
225 (void) readb(bp->i2c_control_regs + 0x1);
226
227 return ret;
228}
229
230int bbc_i2c_write_buf(struct bbc_i2c_client *client,
231 char *buf, int len, int off)
232{
233 int ret = 0;
234
235 while (len > 0) {
236 ret = bbc_i2c_writeb(client, *buf, off);
237 if (ret < 0)
238 break;
239 len--;
240 buf++;
241 off++;
242 }
243 return ret;
244}
245
246int bbc_i2c_read_buf(struct bbc_i2c_client *client,
247 char *buf, int len, int off)
248{
249 int ret = 0;
250
251 while (len > 0) {
252 ret = bbc_i2c_readb(client, buf, off);
253 if (ret < 0)
254 break;
255 len--;
256 buf++;
257 off++;
258 }
259
260 return ret;
261}
262
263EXPORT_SYMBOL(bbc_i2c_getdev);
264EXPORT_SYMBOL(bbc_i2c_attach);
265EXPORT_SYMBOL(bbc_i2c_detach);
266EXPORT_SYMBOL(bbc_i2c_writeb);
267EXPORT_SYMBOL(bbc_i2c_readb);
268EXPORT_SYMBOL(bbc_i2c_write_buf);
269EXPORT_SYMBOL(bbc_i2c_read_buf);
270
271static irqreturn_t bbc_i2c_interrupt(int irq, void *dev_id)
272{
273 struct bbc_i2c_bus *bp = dev_id;
274
275
276
277
278 if (bp->waiting &&
279 !(readb(bp->i2c_control_regs + 0x0) & I2C_PCF_PIN))
280 wake_up_interruptible(&bp->wq);
281
282 return IRQ_HANDLED;
283}
284
285static void __init reset_one_i2c(struct bbc_i2c_bus *bp)
286{
287 writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
288 writeb(bp->own, bp->i2c_control_regs + 0x1);
289 writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
290 writeb(bp->clock, bp->i2c_control_regs + 0x1);
291 writeb(I2C_PCF_IDLE, bp->i2c_control_regs + 0x0);
292}
293
294static struct bbc_i2c_bus * __init attach_one_i2c(struct platform_device *op, int index)
295{
296 struct bbc_i2c_bus *bp;
297 struct device_node *dp;
298 int entry;
299
300 bp = kzalloc(sizeof(*bp), GFP_KERNEL);
301 if (!bp)
302 return NULL;
303
304 bp->i2c_control_regs = of_ioremap(&op->resource[0], 0, 0x2, "bbc_i2c_regs");
305 if (!bp->i2c_control_regs)
306 goto fail;
307
308 bp->i2c_bussel_reg = of_ioremap(&op->resource[1], 0, 0x1, "bbc_i2c_bussel");
309 if (!bp->i2c_bussel_reg)
310 goto fail;
311
312 bp->waiting = 0;
313 init_waitqueue_head(&bp->wq);
314 if (request_irq(op->archdata.irqs[0], bbc_i2c_interrupt,
315 IRQF_SHARED, "bbc_i2c", bp))
316 goto fail;
317
318 bp->index = index;
319 bp->op = op;
320
321 spin_lock_init(&bp->lock);
322
323 entry = 0;
324 for (dp = op->dev.of_node->child;
325 dp && entry < 8;
326 dp = dp->sibling, entry++) {
327 struct platform_device *child_op;
328
329 child_op = of_find_device_by_node(dp);
330 bp->devs[entry].device = child_op;
331 bp->devs[entry].client_claimed = 0;
332 }
333
334 writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
335 bp->own = readb(bp->i2c_control_regs + 0x01);
336 writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
337 bp->clock = readb(bp->i2c_control_regs + 0x01);
338
339 printk(KERN_INFO "i2c-%d: Regs at %p, %d devices, own %02x, clock %02x.\n",
340 bp->index, bp->i2c_control_regs, entry, bp->own, bp->clock);
341
342 reset_one_i2c(bp);
343
344 return bp;
345
346fail:
347 if (bp->i2c_bussel_reg)
348 of_iounmap(&op->resource[1], bp->i2c_bussel_reg, 1);
349 if (bp->i2c_control_regs)
350 of_iounmap(&op->resource[0], bp->i2c_control_regs, 2);
351 kfree(bp);
352 return NULL;
353}
354
355extern int bbc_envctrl_init(struct bbc_i2c_bus *bp);
356extern void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp);
357
358static int __devinit bbc_i2c_probe(struct platform_device *op)
359{
360 struct bbc_i2c_bus *bp;
361 int err, index = 0;
362
363 bp = attach_one_i2c(op, index);
364 if (!bp)
365 return -EINVAL;
366
367 err = bbc_envctrl_init(bp);
368 if (err) {
369 free_irq(op->archdata.irqs[0], bp);
370 if (bp->i2c_bussel_reg)
371 of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
372 if (bp->i2c_control_regs)
373 of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
374 kfree(bp);
375 } else {
376 dev_set_drvdata(&op->dev, bp);
377 }
378
379 return err;
380}
381
382static int __devexit bbc_i2c_remove(struct platform_device *op)
383{
384 struct bbc_i2c_bus *bp = dev_get_drvdata(&op->dev);
385
386 bbc_envctrl_cleanup(bp);
387
388 free_irq(op->archdata.irqs[0], bp);
389
390 if (bp->i2c_bussel_reg)
391 of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
392 if (bp->i2c_control_regs)
393 of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
394
395 kfree(bp);
396
397 return 0;
398}
399
400static const struct of_device_id bbc_i2c_match[] = {
401 {
402 .name = "i2c",
403 .compatible = "SUNW,bbc-i2c",
404 },
405 {},
406};
407MODULE_DEVICE_TABLE(of, bbc_i2c_match);
408
409static struct platform_driver bbc_i2c_driver = {
410 .driver = {
411 .name = "bbc_i2c",
412 .owner = THIS_MODULE,
413 .of_match_table = bbc_i2c_match,
414 },
415 .probe = bbc_i2c_probe,
416 .remove = __devexit_p(bbc_i2c_remove),
417};
418
419module_platform_driver(bbc_i2c_driver);
420
421MODULE_LICENSE("GPL");
422
