xref: /openbmc/linux/drivers/w1/masters/omap_hdq.c (revision 95e9fd10)
1 /*
2  * drivers/w1/masters/omap_hdq.c
3  *
4  * Copyright (C) 2007,2012 Texas Instruments, Inc.
5  *
6  * This file is licensed under the terms of the GNU General Public License
7  * version 2. This program is licensed "as is" without any warranty of any
8  * kind, whether express or implied.
9  *
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/sched.h>
19 #include <linux/pm_runtime.h>
20 
21 #include <asm/irq.h>
22 #include <mach/hardware.h>
23 
24 #include "../w1.h"
25 #include "../w1_int.h"
26 
27 #define	MOD_NAME	"OMAP_HDQ:"
28 
29 #define OMAP_HDQ_REVISION			0x00
30 #define OMAP_HDQ_TX_DATA			0x04
31 #define OMAP_HDQ_RX_DATA			0x08
32 #define OMAP_HDQ_CTRL_STATUS			0x0c
33 #define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK	(1<<6)
34 #define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE	(1<<5)
35 #define OMAP_HDQ_CTRL_STATUS_GO			(1<<4)
36 #define OMAP_HDQ_CTRL_STATUS_INITIALIZATION	(1<<2)
37 #define OMAP_HDQ_CTRL_STATUS_DIR		(1<<1)
38 #define OMAP_HDQ_CTRL_STATUS_MODE		(1<<0)
39 #define OMAP_HDQ_INT_STATUS			0x10
40 #define OMAP_HDQ_INT_STATUS_TXCOMPLETE		(1<<2)
41 #define OMAP_HDQ_INT_STATUS_RXCOMPLETE		(1<<1)
42 #define OMAP_HDQ_INT_STATUS_TIMEOUT		(1<<0)
43 #define OMAP_HDQ_SYSCONFIG			0x14
44 #define OMAP_HDQ_SYSCONFIG_SOFTRESET		(1<<1)
45 #define OMAP_HDQ_SYSCONFIG_AUTOIDLE		(1<<0)
46 #define OMAP_HDQ_SYSSTATUS			0x18
47 #define OMAP_HDQ_SYSSTATUS_RESETDONE		(1<<0)
48 
49 #define OMAP_HDQ_FLAG_CLEAR			0
50 #define OMAP_HDQ_FLAG_SET			1
51 #define OMAP_HDQ_TIMEOUT			(HZ/5)
52 
53 #define OMAP_HDQ_MAX_USER			4
54 
55 static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue);
56 static int w1_id;
57 
58 struct hdq_data {
59 	struct device		*dev;
60 	void __iomem		*hdq_base;
61 	/* lock status update */
62 	struct  mutex		hdq_mutex;
63 	int			hdq_usecount;
64 	u8			hdq_irqstatus;
65 	/* device lock */
66 	spinlock_t		hdq_spinlock;
67 	/*
68 	 * Used to control the call to omap_hdq_get and omap_hdq_put.
69 	 * HDQ Protocol: Write the CMD|REG_address first, followed by
70 	 * the data wrire or read.
71 	 */
72 	int			init_trans;
73 };
74 
75 static int __devinit omap_hdq_probe(struct platform_device *pdev);
76 static int omap_hdq_remove(struct platform_device *pdev);
77 
78 static struct platform_driver omap_hdq_driver = {
79 	.probe =	omap_hdq_probe,
80 	.remove =	omap_hdq_remove,
81 	.driver =	{
82 		.name =	"omap_hdq",
83 	},
84 };
85 
86 static u8 omap_w1_read_byte(void *_hdq);
87 static void omap_w1_write_byte(void *_hdq, u8 byte);
88 static u8 omap_w1_reset_bus(void *_hdq);
89 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
90 		u8 search_type,	w1_slave_found_callback slave_found);
91 
92 
93 static struct w1_bus_master omap_w1_master = {
94 	.read_byte	= omap_w1_read_byte,
95 	.write_byte	= omap_w1_write_byte,
96 	.reset_bus	= omap_w1_reset_bus,
97 	.search		= omap_w1_search_bus,
98 };
99 
100 /* HDQ register I/O routines */
101 static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset)
102 {
103 	return __raw_readl(hdq_data->hdq_base + offset);
104 }
105 
106 static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val)
107 {
108 	__raw_writel(val, hdq_data->hdq_base + offset);
109 }
110 
111 static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset,
112 			u8 val, u8 mask)
113 {
114 	u8 new_val = (__raw_readl(hdq_data->hdq_base + offset) & ~mask)
115 			| (val & mask);
116 	__raw_writel(new_val, hdq_data->hdq_base + offset);
117 
118 	return new_val;
119 }
120 
121 /*
122  * Wait for one or more bits in flag change.
123  * HDQ_FLAG_SET: wait until any bit in the flag is set.
124  * HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared.
125  * return 0 on success and -ETIMEDOUT in the case of timeout.
126  */
127 static int hdq_wait_for_flag(struct hdq_data *hdq_data, u32 offset,
128 		u8 flag, u8 flag_set, u8 *status)
129 {
130 	int ret = 0;
131 	unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
132 
133 	if (flag_set == OMAP_HDQ_FLAG_CLEAR) {
134 		/* wait for the flag clear */
135 		while (((*status = hdq_reg_in(hdq_data, offset)) & flag)
136 			&& time_before(jiffies, timeout)) {
137 			schedule_timeout_uninterruptible(1);
138 		}
139 		if (*status & flag)
140 			ret = -ETIMEDOUT;
141 	} else if (flag_set == OMAP_HDQ_FLAG_SET) {
142 		/* wait for the flag set */
143 		while (!((*status = hdq_reg_in(hdq_data, offset)) & flag)
144 			&& time_before(jiffies, timeout)) {
145 			schedule_timeout_uninterruptible(1);
146 		}
147 		if (!(*status & flag))
148 			ret = -ETIMEDOUT;
149 	} else
150 		return -EINVAL;
151 
152 	return ret;
153 }
154 
155 /* write out a byte and fill *status with HDQ_INT_STATUS */
156 static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
157 {
158 	int ret;
159 	u8 tmp_status;
160 	unsigned long irqflags;
161 
162 	*status = 0;
163 
164 	spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
165 	/* clear interrupt flags via a dummy read */
166 	hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
167 	/* ISR loads it with new INT_STATUS */
168 	hdq_data->hdq_irqstatus = 0;
169 	spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
170 
171 	hdq_reg_out(hdq_data, OMAP_HDQ_TX_DATA, val);
172 
173 	/* set the GO bit */
174 	hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, OMAP_HDQ_CTRL_STATUS_GO,
175 		OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
176 	/* wait for the TXCOMPLETE bit */
177 	ret = wait_event_timeout(hdq_wait_queue,
178 		hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
179 	if (ret == 0) {
180 		dev_dbg(hdq_data->dev, "TX wait elapsed\n");
181 		ret = -ETIMEDOUT;
182 		goto out;
183 	}
184 
185 	*status = hdq_data->hdq_irqstatus;
186 	/* check irqstatus */
187 	if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) {
188 		dev_dbg(hdq_data->dev, "timeout waiting for"
189 			" TXCOMPLETE/RXCOMPLETE, %x", *status);
190 		ret = -ETIMEDOUT;
191 		goto out;
192 	}
193 
194 	/* wait for the GO bit return to zero */
195 	ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
196 			OMAP_HDQ_CTRL_STATUS_GO,
197 			OMAP_HDQ_FLAG_CLEAR, &tmp_status);
198 	if (ret) {
199 		dev_dbg(hdq_data->dev, "timeout waiting GO bit"
200 			" return to zero, %x", tmp_status);
201 	}
202 
203 out:
204 	return ret;
205 }
206 
207 /* HDQ Interrupt service routine */
208 static irqreturn_t hdq_isr(int irq, void *_hdq)
209 {
210 	struct hdq_data *hdq_data = _hdq;
211 	unsigned long irqflags;
212 
213 	spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
214 	hdq_data->hdq_irqstatus = hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
215 	spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
216 	dev_dbg(hdq_data->dev, "hdq_isr: %x", hdq_data->hdq_irqstatus);
217 
218 	if (hdq_data->hdq_irqstatus &
219 		(OMAP_HDQ_INT_STATUS_TXCOMPLETE | OMAP_HDQ_INT_STATUS_RXCOMPLETE
220 		| OMAP_HDQ_INT_STATUS_TIMEOUT)) {
221 		/* wake up sleeping process */
222 		wake_up(&hdq_wait_queue);
223 	}
224 
225 	return IRQ_HANDLED;
226 }
227 
228 /* HDQ Mode: always return success */
229 static u8 omap_w1_reset_bus(void *_hdq)
230 {
231 	return 0;
232 }
233 
234 /* W1 search callback function */
235 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
236 		u8 search_type, w1_slave_found_callback slave_found)
237 {
238 	u64 module_id, rn_le, cs, id;
239 
240 	if (w1_id)
241 		module_id = w1_id;
242 	else
243 		module_id = 0x1;
244 
245 	rn_le = cpu_to_le64(module_id);
246 	/*
247 	 * HDQ might not obey truly the 1-wire spec.
248 	 * So calculate CRC based on module parameter.
249 	 */
250 	cs = w1_calc_crc8((u8 *)&rn_le, 7);
251 	id = (cs << 56) | module_id;
252 
253 	slave_found(master_dev, id);
254 }
255 
256 static int _omap_hdq_reset(struct hdq_data *hdq_data)
257 {
258 	int ret;
259 	u8 tmp_status;
260 
261 	hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, OMAP_HDQ_SYSCONFIG_SOFTRESET);
262 	/*
263 	 * Select HDQ mode & enable clocks.
264 	 * It is observed that INT flags can't be cleared via a read and GO/INIT
265 	 * won't return to zero if interrupt is disabled. So we always enable
266 	 * interrupt.
267 	 */
268 	hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
269 		OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
270 		OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
271 
272 	/* wait for reset to complete */
273 	ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_SYSSTATUS,
274 		OMAP_HDQ_SYSSTATUS_RESETDONE, OMAP_HDQ_FLAG_SET, &tmp_status);
275 	if (ret)
276 		dev_dbg(hdq_data->dev, "timeout waiting HDQ reset, %x",
277 				tmp_status);
278 	else {
279 		hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
280 			OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
281 			OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
282 		hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
283 			OMAP_HDQ_SYSCONFIG_AUTOIDLE);
284 	}
285 
286 	return ret;
287 }
288 
289 /* Issue break pulse to the device */
290 static int omap_hdq_break(struct hdq_data *hdq_data)
291 {
292 	int ret = 0;
293 	u8 tmp_status;
294 	unsigned long irqflags;
295 
296 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
297 	if (ret < 0) {
298 		dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
299 		ret = -EINTR;
300 		goto rtn;
301 	}
302 
303 	spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
304 	/* clear interrupt flags via a dummy read */
305 	hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
306 	/* ISR loads it with new INT_STATUS */
307 	hdq_data->hdq_irqstatus = 0;
308 	spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
309 
310 	/* set the INIT and GO bit */
311 	hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
312 		OMAP_HDQ_CTRL_STATUS_INITIALIZATION | OMAP_HDQ_CTRL_STATUS_GO,
313 		OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
314 		OMAP_HDQ_CTRL_STATUS_GO);
315 
316 	/* wait for the TIMEOUT bit */
317 	ret = wait_event_timeout(hdq_wait_queue,
318 		hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
319 	if (ret == 0) {
320 		dev_dbg(hdq_data->dev, "break wait elapsed\n");
321 		ret = -EINTR;
322 		goto out;
323 	}
324 
325 	tmp_status = hdq_data->hdq_irqstatus;
326 	/* check irqstatus */
327 	if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) {
328 		dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x",
329 				tmp_status);
330 		ret = -ETIMEDOUT;
331 		goto out;
332 	}
333 	/*
334 	 * wait for both INIT and GO bits rerurn to zero.
335 	 * zero wait time expected for interrupt mode.
336 	 */
337 	ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
338 			OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
339 			OMAP_HDQ_CTRL_STATUS_GO, OMAP_HDQ_FLAG_CLEAR,
340 			&tmp_status);
341 	if (ret)
342 		dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits"
343 			" return to zero, %x", tmp_status);
344 
345 out:
346 	mutex_unlock(&hdq_data->hdq_mutex);
347 rtn:
348 	return ret;
349 }
350 
351 static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
352 {
353 	int ret = 0;
354 	u8 status;
355 
356 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
357 	if (ret < 0) {
358 		ret = -EINTR;
359 		goto rtn;
360 	}
361 
362 	if (!hdq_data->hdq_usecount) {
363 		ret = -EINVAL;
364 		goto out;
365 	}
366 
367 	if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
368 		hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
369 			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
370 			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
371 		/*
372 		 * The RX comes immediately after TX.
373 		 */
374 		wait_event_timeout(hdq_wait_queue,
375 				   (hdq_data->hdq_irqstatus
376 				    & OMAP_HDQ_INT_STATUS_RXCOMPLETE),
377 				   OMAP_HDQ_TIMEOUT);
378 
379 		hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
380 			OMAP_HDQ_CTRL_STATUS_DIR);
381 		status = hdq_data->hdq_irqstatus;
382 		/* check irqstatus */
383 		if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
384 			dev_dbg(hdq_data->dev, "timeout waiting for"
385 				" RXCOMPLETE, %x", status);
386 			ret = -ETIMEDOUT;
387 			goto out;
388 		}
389 	}
390 	/* the data is ready. Read it in! */
391 	*val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA);
392 out:
393 	mutex_unlock(&hdq_data->hdq_mutex);
394 rtn:
395 	return ret;
396 
397 }
398 
399 /* Enable clocks and set the controller to HDQ mode */
400 static int omap_hdq_get(struct hdq_data *hdq_data)
401 {
402 	int ret = 0;
403 
404 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
405 	if (ret < 0) {
406 		ret = -EINTR;
407 		goto rtn;
408 	}
409 
410 	if (OMAP_HDQ_MAX_USER == hdq_data->hdq_usecount) {
411 		dev_dbg(hdq_data->dev, "attempt to exceed the max use count");
412 		ret = -EINVAL;
413 		goto out;
414 	} else {
415 		hdq_data->hdq_usecount++;
416 		try_module_get(THIS_MODULE);
417 		if (1 == hdq_data->hdq_usecount) {
418 
419 			pm_runtime_get_sync(hdq_data->dev);
420 
421 			/* make sure HDQ is out of reset */
422 			if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) &
423 				OMAP_HDQ_SYSSTATUS_RESETDONE)) {
424 				ret = _omap_hdq_reset(hdq_data);
425 				if (ret)
426 					/* back up the count */
427 					hdq_data->hdq_usecount--;
428 			} else {
429 				/* select HDQ mode & enable clocks */
430 				hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
431 					OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
432 					OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
433 				hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
434 					OMAP_HDQ_SYSCONFIG_AUTOIDLE);
435 				hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
436 			}
437 		}
438 	}
439 
440 out:
441 	mutex_unlock(&hdq_data->hdq_mutex);
442 rtn:
443 	return ret;
444 }
445 
446 /* Disable clocks to the module */
447 static int omap_hdq_put(struct hdq_data *hdq_data)
448 {
449 	int ret = 0;
450 
451 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
452 	if (ret < 0)
453 		return -EINTR;
454 
455 	if (0 == hdq_data->hdq_usecount) {
456 		dev_dbg(hdq_data->dev, "attempt to decrement use count"
457 			" when it is zero");
458 		ret = -EINVAL;
459 	} else {
460 		hdq_data->hdq_usecount--;
461 		module_put(THIS_MODULE);
462 		if (0 == hdq_data->hdq_usecount)
463 			pm_runtime_put_sync(hdq_data->dev);
464 	}
465 	mutex_unlock(&hdq_data->hdq_mutex);
466 
467 	return ret;
468 }
469 
470 /* Read a byte of data from the device */
471 static u8 omap_w1_read_byte(void *_hdq)
472 {
473 	struct hdq_data *hdq_data = _hdq;
474 	u8 val = 0;
475 	int ret;
476 
477 	ret = hdq_read_byte(hdq_data, &val);
478 	if (ret) {
479 		ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
480 		if (ret < 0) {
481 			dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
482 			return -EINTR;
483 		}
484 		hdq_data->init_trans = 0;
485 		mutex_unlock(&hdq_data->hdq_mutex);
486 		omap_hdq_put(hdq_data);
487 		return -1;
488 	}
489 
490 	/* Write followed by a read, release the module */
491 	if (hdq_data->init_trans) {
492 		ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
493 		if (ret < 0) {
494 			dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
495 			return -EINTR;
496 		}
497 		hdq_data->init_trans = 0;
498 		mutex_unlock(&hdq_data->hdq_mutex);
499 		omap_hdq_put(hdq_data);
500 	}
501 
502 	return val;
503 }
504 
505 /* Write a byte of data to the device */
506 static void omap_w1_write_byte(void *_hdq, u8 byte)
507 {
508 	struct hdq_data *hdq_data = _hdq;
509 	int ret;
510 	u8 status;
511 
512 	/* First write to initialize the transfer */
513 	if (hdq_data->init_trans == 0)
514 		omap_hdq_get(hdq_data);
515 
516 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
517 	if (ret < 0) {
518 		dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
519 		return;
520 	}
521 	hdq_data->init_trans++;
522 	mutex_unlock(&hdq_data->hdq_mutex);
523 
524 	ret = hdq_write_byte(hdq_data, byte, &status);
525 	if (ret < 0) {
526 		dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status);
527 		return;
528 	}
529 
530 	/* Second write, data transferred. Release the module */
531 	if (hdq_data->init_trans > 1) {
532 		omap_hdq_put(hdq_data);
533 		ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
534 		if (ret < 0) {
535 			dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
536 			return;
537 		}
538 		hdq_data->init_trans = 0;
539 		mutex_unlock(&hdq_data->hdq_mutex);
540 	}
541 
542 	return;
543 }
544 
545 static int __devinit omap_hdq_probe(struct platform_device *pdev)
546 {
547 	struct hdq_data *hdq_data;
548 	struct resource *res;
549 	int ret, irq;
550 	u8 rev;
551 
552 	hdq_data = kmalloc(sizeof(*hdq_data), GFP_KERNEL);
553 	if (!hdq_data) {
554 		dev_dbg(&pdev->dev, "unable to allocate memory\n");
555 		ret = -ENOMEM;
556 		goto err_kmalloc;
557 	}
558 
559 	hdq_data->dev = &pdev->dev;
560 	platform_set_drvdata(pdev, hdq_data);
561 
562 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
563 	if (!res) {
564 		dev_dbg(&pdev->dev, "unable to get resource\n");
565 		ret = -ENXIO;
566 		goto err_resource;
567 	}
568 
569 	hdq_data->hdq_base = ioremap(res->start, SZ_4K);
570 	if (!hdq_data->hdq_base) {
571 		dev_dbg(&pdev->dev, "ioremap failed\n");
572 		ret = -EINVAL;
573 		goto err_ioremap;
574 	}
575 
576 	hdq_data->hdq_usecount = 0;
577 	mutex_init(&hdq_data->hdq_mutex);
578 
579 	pm_runtime_enable(&pdev->dev);
580 	pm_runtime_get_sync(&pdev->dev);
581 
582 	rev = hdq_reg_in(hdq_data, OMAP_HDQ_REVISION);
583 	dev_info(&pdev->dev, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n",
584 		(rev >> 4) + '0', (rev & 0x0f) + '0', "Interrupt");
585 
586 	spin_lock_init(&hdq_data->hdq_spinlock);
587 
588 	irq = platform_get_irq(pdev, 0);
589 	if (irq	< 0) {
590 		ret = -ENXIO;
591 		goto err_irq;
592 	}
593 
594 	ret = request_irq(irq, hdq_isr, IRQF_DISABLED, "omap_hdq", hdq_data);
595 	if (ret < 0) {
596 		dev_dbg(&pdev->dev, "could not request irq\n");
597 		goto err_irq;
598 	}
599 
600 	omap_hdq_break(hdq_data);
601 
602 	pm_runtime_put_sync(&pdev->dev);
603 
604 	omap_w1_master.data = hdq_data;
605 
606 	ret = w1_add_master_device(&omap_w1_master);
607 	if (ret) {
608 		dev_dbg(&pdev->dev, "Failure in registering w1 master\n");
609 		goto err_w1;
610 	}
611 
612 	return 0;
613 
614 err_irq:
615 	pm_runtime_put_sync(&pdev->dev);
616 err_w1:
617 	pm_runtime_disable(&pdev->dev);
618 
619 	iounmap(hdq_data->hdq_base);
620 
621 err_ioremap:
622 err_resource:
623 	platform_set_drvdata(pdev, NULL);
624 	kfree(hdq_data);
625 
626 err_kmalloc:
627 	return ret;
628 
629 }
630 
631 static int omap_hdq_remove(struct platform_device *pdev)
632 {
633 	struct hdq_data *hdq_data = platform_get_drvdata(pdev);
634 
635 	mutex_lock(&hdq_data->hdq_mutex);
636 
637 	if (hdq_data->hdq_usecount) {
638 		dev_dbg(&pdev->dev, "removed when use count is not zero\n");
639 		mutex_unlock(&hdq_data->hdq_mutex);
640 		return -EBUSY;
641 	}
642 
643 	mutex_unlock(&hdq_data->hdq_mutex);
644 
645 	/* remove module dependency */
646 	pm_runtime_disable(&pdev->dev);
647 	free_irq(INT_24XX_HDQ_IRQ, hdq_data);
648 	platform_set_drvdata(pdev, NULL);
649 	iounmap(hdq_data->hdq_base);
650 	kfree(hdq_data);
651 
652 	return 0;
653 }
654 
655 static int __init
656 omap_hdq_init(void)
657 {
658 	return platform_driver_register(&omap_hdq_driver);
659 }
660 module_init(omap_hdq_init);
661 
662 static void __exit
663 omap_hdq_exit(void)
664 {
665 	platform_driver_unregister(&omap_hdq_driver);
666 }
667 module_exit(omap_hdq_exit);
668 
669 module_param(w1_id, int, S_IRUSR);
670 MODULE_PARM_DESC(w1_id, "1-wire id for the slave detection");
671 
672 MODULE_AUTHOR("Texas Instruments");
673 MODULE_DESCRIPTION("HDQ driver Library");
674 MODULE_LICENSE("GPL");
675