xref: /openbmc/linux/drivers/mtd/nand/raw/r852.c (revision ae213c44)
1 /*
2  * Copyright © 2009 - Maxim Levitsky
3  * driver for Ricoh xD readers
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #define DRV_NAME "r852"
11 #define pr_fmt(fmt)  DRV_NAME ": " fmt
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/jiffies.h>
16 #include <linux/workqueue.h>
17 #include <linux/interrupt.h>
18 #include <linux/pci.h>
19 #include <linux/pci_ids.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 #include <asm/byteorder.h>
23 #include <linux/sched.h>
24 #include "sm_common.h"
25 #include "r852.h"
26 
27 
28 static bool r852_enable_dma = 1;
29 module_param(r852_enable_dma, bool, S_IRUGO);
30 MODULE_PARM_DESC(r852_enable_dma, "Enable usage of the DMA (default)");
31 
32 static int debug;
33 module_param(debug, int, S_IRUGO | S_IWUSR);
34 MODULE_PARM_DESC(debug, "Debug level (0-2)");
35 
36 /* read register */
37 static inline uint8_t r852_read_reg(struct r852_device *dev, int address)
38 {
39 	uint8_t reg = readb(dev->mmio + address);
40 	return reg;
41 }
42 
43 /* write register */
44 static inline void r852_write_reg(struct r852_device *dev,
45 						int address, uint8_t value)
46 {
47 	writeb(value, dev->mmio + address);
48 }
49 
50 
51 /* read dword sized register */
52 static inline uint32_t r852_read_reg_dword(struct r852_device *dev, int address)
53 {
54 	uint32_t reg = le32_to_cpu(readl(dev->mmio + address));
55 	return reg;
56 }
57 
58 /* write dword sized register */
59 static inline void r852_write_reg_dword(struct r852_device *dev,
60 							int address, uint32_t value)
61 {
62 	writel(cpu_to_le32(value), dev->mmio + address);
63 }
64 
65 /* returns pointer to our private structure */
66 static inline struct r852_device *r852_get_dev(struct mtd_info *mtd)
67 {
68 	struct nand_chip *chip = mtd_to_nand(mtd);
69 	return nand_get_controller_data(chip);
70 }
71 
72 
73 /* check if controller supports dma */
74 static void r852_dma_test(struct r852_device *dev)
75 {
76 	dev->dma_usable = (r852_read_reg(dev, R852_DMA_CAP) &
77 		(R852_DMA1 | R852_DMA2)) == (R852_DMA1 | R852_DMA2);
78 
79 	if (!dev->dma_usable)
80 		message("Non dma capable device detected, dma disabled");
81 
82 	if (!r852_enable_dma) {
83 		message("disabling dma on user request");
84 		dev->dma_usable = 0;
85 	}
86 }
87 
88 /*
89  * Enable dma. Enables ether first or second stage of the DMA,
90  * Expects dev->dma_dir and dev->dma_state be set
91  */
92 static void r852_dma_enable(struct r852_device *dev)
93 {
94 	uint8_t dma_reg, dma_irq_reg;
95 
96 	/* Set up dma settings */
97 	dma_reg = r852_read_reg_dword(dev, R852_DMA_SETTINGS);
98 	dma_reg &= ~(R852_DMA_READ | R852_DMA_INTERNAL | R852_DMA_MEMORY);
99 
100 	if (dev->dma_dir)
101 		dma_reg |= R852_DMA_READ;
102 
103 	if (dev->dma_state == DMA_INTERNAL) {
104 		dma_reg |= R852_DMA_INTERNAL;
105 		/* Precaution to make sure HW doesn't write */
106 			/* to random kernel memory */
107 		r852_write_reg_dword(dev, R852_DMA_ADDR,
108 			cpu_to_le32(dev->phys_bounce_buffer));
109 	} else {
110 		dma_reg |= R852_DMA_MEMORY;
111 		r852_write_reg_dword(dev, R852_DMA_ADDR,
112 			cpu_to_le32(dev->phys_dma_addr));
113 	}
114 
115 	/* Precaution: make sure write reached the device */
116 	r852_read_reg_dword(dev, R852_DMA_ADDR);
117 
118 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, dma_reg);
119 
120 	/* Set dma irq */
121 	dma_irq_reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
122 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
123 		dma_irq_reg |
124 		R852_DMA_IRQ_INTERNAL |
125 		R852_DMA_IRQ_ERROR |
126 		R852_DMA_IRQ_MEMORY);
127 }
128 
129 /*
130  * Disable dma, called from the interrupt handler, which specifies
131  * success of the operation via 'error' argument
132  */
133 static void r852_dma_done(struct r852_device *dev, int error)
134 {
135 	WARN_ON(dev->dma_stage == 0);
136 
137 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA,
138 			r852_read_reg_dword(dev, R852_DMA_IRQ_STA));
139 
140 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, 0);
141 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE, 0);
142 
143 	/* Precaution to make sure HW doesn't write to random kernel memory */
144 	r852_write_reg_dword(dev, R852_DMA_ADDR,
145 		cpu_to_le32(dev->phys_bounce_buffer));
146 	r852_read_reg_dword(dev, R852_DMA_ADDR);
147 
148 	dev->dma_error = error;
149 	dev->dma_stage = 0;
150 
151 	if (dev->phys_dma_addr && dev->phys_dma_addr != dev->phys_bounce_buffer)
152 		dma_unmap_single(&dev->pci_dev->dev, dev->phys_dma_addr,
153 			R852_DMA_LEN,
154 			dev->dma_dir ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
155 }
156 
157 /*
158  * Wait, till dma is done, which includes both phases of it
159  */
160 static int r852_dma_wait(struct r852_device *dev)
161 {
162 	long timeout = wait_for_completion_timeout(&dev->dma_done,
163 				msecs_to_jiffies(1000));
164 	if (!timeout) {
165 		dbg("timeout waiting for DMA interrupt");
166 		return -ETIMEDOUT;
167 	}
168 
169 	return 0;
170 }
171 
172 /*
173  * Read/Write one page using dma. Only pages can be read (512 bytes)
174 */
175 static void r852_do_dma(struct r852_device *dev, uint8_t *buf, int do_read)
176 {
177 	int bounce = 0;
178 	unsigned long flags;
179 	int error;
180 
181 	dev->dma_error = 0;
182 
183 	/* Set dma direction */
184 	dev->dma_dir = do_read;
185 	dev->dma_stage = 1;
186 	reinit_completion(&dev->dma_done);
187 
188 	dbg_verbose("doing dma %s ", do_read ? "read" : "write");
189 
190 	/* Set initial dma state: for reading first fill on board buffer,
191 	  from device, for writes first fill the buffer  from memory*/
192 	dev->dma_state = do_read ? DMA_INTERNAL : DMA_MEMORY;
193 
194 	/* if incoming buffer is not page aligned, we should do bounce */
195 	if ((unsigned long)buf & (R852_DMA_LEN-1))
196 		bounce = 1;
197 
198 	if (!bounce) {
199 		dev->phys_dma_addr = dma_map_single(&dev->pci_dev->dev, buf,
200 			R852_DMA_LEN,
201 			do_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
202 		if (dma_mapping_error(&dev->pci_dev->dev, dev->phys_dma_addr))
203 			bounce = 1;
204 	}
205 
206 	if (bounce) {
207 		dbg_verbose("dma: using bounce buffer");
208 		dev->phys_dma_addr = dev->phys_bounce_buffer;
209 		if (!do_read)
210 			memcpy(dev->bounce_buffer, buf, R852_DMA_LEN);
211 	}
212 
213 	/* Enable DMA */
214 	spin_lock_irqsave(&dev->irqlock, flags);
215 	r852_dma_enable(dev);
216 	spin_unlock_irqrestore(&dev->irqlock, flags);
217 
218 	/* Wait till complete */
219 	error = r852_dma_wait(dev);
220 
221 	if (error) {
222 		r852_dma_done(dev, error);
223 		return;
224 	}
225 
226 	if (do_read && bounce)
227 		memcpy((void *)buf, dev->bounce_buffer, R852_DMA_LEN);
228 }
229 
230 /*
231  * Program data lines of the nand chip to send data to it
232  */
233 static void r852_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
234 {
235 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
236 	uint32_t reg;
237 
238 	/* Don't allow any access to hardware if we suspect card removal */
239 	if (dev->card_unstable)
240 		return;
241 
242 	/* Special case for whole sector read */
243 	if (len == R852_DMA_LEN && dev->dma_usable) {
244 		r852_do_dma(dev, (uint8_t *)buf, 0);
245 		return;
246 	}
247 
248 	/* write DWORD chinks - faster */
249 	while (len >= 4) {
250 		reg = buf[0] | buf[1] << 8 | buf[2] << 16 | buf[3] << 24;
251 		r852_write_reg_dword(dev, R852_DATALINE, reg);
252 		buf += 4;
253 		len -= 4;
254 
255 	}
256 
257 	/* write rest */
258 	while (len > 0) {
259 		r852_write_reg(dev, R852_DATALINE, *buf++);
260 		len--;
261 	}
262 }
263 
264 /*
265  * Read data lines of the nand chip to retrieve data
266  */
267 static void r852_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
268 {
269 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
270 	uint32_t reg;
271 
272 	if (dev->card_unstable) {
273 		/* since we can't signal error here, at least, return
274 			predictable buffer */
275 		memset(buf, 0, len);
276 		return;
277 	}
278 
279 	/* special case for whole sector read */
280 	if (len == R852_DMA_LEN && dev->dma_usable) {
281 		r852_do_dma(dev, buf, 1);
282 		return;
283 	}
284 
285 	/* read in dword sized chunks */
286 	while (len >= 4) {
287 
288 		reg = r852_read_reg_dword(dev, R852_DATALINE);
289 		*buf++ = reg & 0xFF;
290 		*buf++ = (reg >> 8) & 0xFF;
291 		*buf++ = (reg >> 16) & 0xFF;
292 		*buf++ = (reg >> 24) & 0xFF;
293 		len -= 4;
294 	}
295 
296 	/* read the reset by bytes */
297 	while (len--)
298 		*buf++ = r852_read_reg(dev, R852_DATALINE);
299 }
300 
301 /*
302  * Read one byte from nand chip
303  */
304 static uint8_t r852_read_byte(struct nand_chip *chip)
305 {
306 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
307 
308 	/* Same problem as in r852_read_buf.... */
309 	if (dev->card_unstable)
310 		return 0;
311 
312 	return r852_read_reg(dev, R852_DATALINE);
313 }
314 
315 /*
316  * Control several chip lines & send commands
317  */
318 static void r852_cmdctl(struct nand_chip *chip, int dat, unsigned int ctrl)
319 {
320 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
321 
322 	if (dev->card_unstable)
323 		return;
324 
325 	if (ctrl & NAND_CTRL_CHANGE) {
326 
327 		dev->ctlreg &= ~(R852_CTL_DATA | R852_CTL_COMMAND |
328 				 R852_CTL_ON | R852_CTL_CARDENABLE);
329 
330 		if (ctrl & NAND_ALE)
331 			dev->ctlreg |= R852_CTL_DATA;
332 
333 		if (ctrl & NAND_CLE)
334 			dev->ctlreg |= R852_CTL_COMMAND;
335 
336 		if (ctrl & NAND_NCE)
337 			dev->ctlreg |= (R852_CTL_CARDENABLE | R852_CTL_ON);
338 		else
339 			dev->ctlreg &= ~R852_CTL_WRITE;
340 
341 		/* when write is stareted, enable write access */
342 		if (dat == NAND_CMD_ERASE1)
343 			dev->ctlreg |= R852_CTL_WRITE;
344 
345 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
346 	}
347 
348 	 /* HACK: NAND_CMD_SEQIN is called without NAND_CTRL_CHANGE, but we need
349 		to set write mode */
350 	if (dat == NAND_CMD_SEQIN && (dev->ctlreg & R852_CTL_COMMAND)) {
351 		dev->ctlreg |= R852_CTL_WRITE;
352 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
353 	}
354 
355 	if (dat != NAND_CMD_NONE)
356 		r852_write_reg(dev, R852_DATALINE, dat);
357 }
358 
359 /*
360  * Wait till card is ready.
361  * based on nand_wait, but returns errors on DMA error
362  */
363 static int r852_wait(struct nand_chip *chip)
364 {
365 	struct r852_device *dev = nand_get_controller_data(chip);
366 
367 	unsigned long timeout;
368 	u8 status;
369 
370 	timeout = jiffies + msecs_to_jiffies(400);
371 
372 	while (time_before(jiffies, timeout))
373 		if (chip->legacy.dev_ready(chip))
374 			break;
375 
376 	nand_status_op(chip, &status);
377 
378 	/* Unfortunelly, no way to send detailed error status... */
379 	if (dev->dma_error) {
380 		status |= NAND_STATUS_FAIL;
381 		dev->dma_error = 0;
382 	}
383 	return status;
384 }
385 
386 /*
387  * Check if card is ready
388  */
389 
390 static int r852_ready(struct nand_chip *chip)
391 {
392 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
393 	return !(r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_BUSY);
394 }
395 
396 
397 /*
398  * Set ECC engine mode
399 */
400 
401 static void r852_ecc_hwctl(struct nand_chip *chip, int mode)
402 {
403 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
404 
405 	if (dev->card_unstable)
406 		return;
407 
408 	switch (mode) {
409 	case NAND_ECC_READ:
410 	case NAND_ECC_WRITE:
411 		/* enable ecc generation/check*/
412 		dev->ctlreg |= R852_CTL_ECC_ENABLE;
413 
414 		/* flush ecc buffer */
415 		r852_write_reg(dev, R852_CTL,
416 			dev->ctlreg | R852_CTL_ECC_ACCESS);
417 
418 		r852_read_reg_dword(dev, R852_DATALINE);
419 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
420 		return;
421 
422 	case NAND_ECC_READSYN:
423 		/* disable ecc generation */
424 		dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
425 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
426 	}
427 }
428 
429 /*
430  * Calculate ECC, only used for writes
431  */
432 
433 static int r852_ecc_calculate(struct nand_chip *chip, const uint8_t *dat,
434 			      uint8_t *ecc_code)
435 {
436 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
437 	struct sm_oob *oob = (struct sm_oob *)ecc_code;
438 	uint32_t ecc1, ecc2;
439 
440 	if (dev->card_unstable)
441 		return 0;
442 
443 	dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
444 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
445 
446 	ecc1 = r852_read_reg_dword(dev, R852_DATALINE);
447 	ecc2 = r852_read_reg_dword(dev, R852_DATALINE);
448 
449 	oob->ecc1[0] = (ecc1) & 0xFF;
450 	oob->ecc1[1] = (ecc1 >> 8) & 0xFF;
451 	oob->ecc1[2] = (ecc1 >> 16) & 0xFF;
452 
453 	oob->ecc2[0] = (ecc2) & 0xFF;
454 	oob->ecc2[1] = (ecc2 >> 8) & 0xFF;
455 	oob->ecc2[2] = (ecc2 >> 16) & 0xFF;
456 
457 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
458 	return 0;
459 }
460 
461 /*
462  * Correct the data using ECC, hw did almost everything for us
463  */
464 
465 static int r852_ecc_correct(struct nand_chip *chip, uint8_t *dat,
466 			    uint8_t *read_ecc, uint8_t *calc_ecc)
467 {
468 	uint32_t ecc_reg;
469 	uint8_t ecc_status, err_byte;
470 	int i, error = 0;
471 
472 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
473 
474 	if (dev->card_unstable)
475 		return 0;
476 
477 	if (dev->dma_error) {
478 		dev->dma_error = 0;
479 		return -EIO;
480 	}
481 
482 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
483 	ecc_reg = r852_read_reg_dword(dev, R852_DATALINE);
484 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
485 
486 	for (i = 0 ; i <= 1 ; i++) {
487 
488 		ecc_status = (ecc_reg >> 8) & 0xFF;
489 
490 		/* ecc uncorrectable error */
491 		if (ecc_status & R852_ECC_FAIL) {
492 			dbg("ecc: unrecoverable error, in half %d", i);
493 			error = -EBADMSG;
494 			goto exit;
495 		}
496 
497 		/* correctable error */
498 		if (ecc_status & R852_ECC_CORRECTABLE) {
499 
500 			err_byte = ecc_reg & 0xFF;
501 			dbg("ecc: recoverable error, "
502 				"in half %d, byte %d, bit %d", i,
503 				err_byte, ecc_status & R852_ECC_ERR_BIT_MSK);
504 
505 			dat[err_byte] ^=
506 				1 << (ecc_status & R852_ECC_ERR_BIT_MSK);
507 			error++;
508 		}
509 
510 		dat += 256;
511 		ecc_reg >>= 16;
512 	}
513 exit:
514 	return error;
515 }
516 
517 /*
518  * This is copy of nand_read_oob_std
519  * nand_read_oob_syndrome assumes we can send column address - we can't
520  */
521 static int r852_read_oob(struct nand_chip *chip, int page)
522 {
523 	struct mtd_info *mtd = nand_to_mtd(chip);
524 
525 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
526 }
527 
528 /*
529  * Start the nand engine
530  */
531 
532 static void r852_engine_enable(struct r852_device *dev)
533 {
534 	if (r852_read_reg_dword(dev, R852_HW) & R852_HW_UNKNOWN) {
535 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
536 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
537 	} else {
538 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
539 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
540 	}
541 	msleep(300);
542 	r852_write_reg(dev, R852_CTL, 0);
543 }
544 
545 
546 /*
547  * Stop the nand engine
548  */
549 
550 static void r852_engine_disable(struct r852_device *dev)
551 {
552 	r852_write_reg_dword(dev, R852_HW, 0);
553 	r852_write_reg(dev, R852_CTL, R852_CTL_RESET);
554 }
555 
556 /*
557  * Test if card is present
558  */
559 
560 static void r852_card_update_present(struct r852_device *dev)
561 {
562 	unsigned long flags;
563 	uint8_t reg;
564 
565 	spin_lock_irqsave(&dev->irqlock, flags);
566 	reg = r852_read_reg(dev, R852_CARD_STA);
567 	dev->card_detected = !!(reg & R852_CARD_STA_PRESENT);
568 	spin_unlock_irqrestore(&dev->irqlock, flags);
569 }
570 
571 /*
572  * Update card detection IRQ state according to current card state
573  * which is read in r852_card_update_present
574  */
575 static void r852_update_card_detect(struct r852_device *dev)
576 {
577 	int card_detect_reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
578 	dev->card_unstable = 0;
579 
580 	card_detect_reg &= ~(R852_CARD_IRQ_REMOVE | R852_CARD_IRQ_INSERT);
581 	card_detect_reg |= R852_CARD_IRQ_GENABLE;
582 
583 	card_detect_reg |= dev->card_detected ?
584 		R852_CARD_IRQ_REMOVE : R852_CARD_IRQ_INSERT;
585 
586 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, card_detect_reg);
587 }
588 
589 static ssize_t r852_media_type_show(struct device *sys_dev,
590 			struct device_attribute *attr, char *buf)
591 {
592 	struct mtd_info *mtd = container_of(sys_dev, struct mtd_info, dev);
593 	struct r852_device *dev = r852_get_dev(mtd);
594 	char *data = dev->sm ? "smartmedia" : "xd";
595 
596 	strcpy(buf, data);
597 	return strlen(data);
598 }
599 
600 static DEVICE_ATTR(media_type, S_IRUGO, r852_media_type_show, NULL);
601 
602 
603 /* Detect properties of card in slot */
604 static void r852_update_media_status(struct r852_device *dev)
605 {
606 	uint8_t reg;
607 	unsigned long flags;
608 	int readonly;
609 
610 	spin_lock_irqsave(&dev->irqlock, flags);
611 	if (!dev->card_detected) {
612 		message("card removed");
613 		spin_unlock_irqrestore(&dev->irqlock, flags);
614 		return ;
615 	}
616 
617 	readonly  = r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_RO;
618 	reg = r852_read_reg(dev, R852_DMA_CAP);
619 	dev->sm = (reg & (R852_DMA1 | R852_DMA2)) && (reg & R852_SMBIT);
620 
621 	message("detected %s %s card in slot",
622 		dev->sm ? "SmartMedia" : "xD",
623 		readonly ? "readonly" : "writeable");
624 
625 	dev->readonly = readonly;
626 	spin_unlock_irqrestore(&dev->irqlock, flags);
627 }
628 
629 /*
630  * Register the nand device
631  * Called when the card is detected
632  */
633 static int r852_register_nand_device(struct r852_device *dev)
634 {
635 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
636 
637 	WARN_ON(dev->card_registered);
638 
639 	mtd->dev.parent = &dev->pci_dev->dev;
640 
641 	if (dev->readonly)
642 		dev->chip->options |= NAND_ROM;
643 
644 	r852_engine_enable(dev);
645 
646 	if (sm_register_device(mtd, dev->sm))
647 		goto error1;
648 
649 	if (device_create_file(&mtd->dev, &dev_attr_media_type)) {
650 		message("can't create media type sysfs attribute");
651 		goto error3;
652 	}
653 
654 	dev->card_registered = 1;
655 	return 0;
656 error3:
657 	nand_release(dev->chip);
658 error1:
659 	/* Force card redetect */
660 	dev->card_detected = 0;
661 	return -1;
662 }
663 
664 /*
665  * Unregister the card
666  */
667 
668 static void r852_unregister_nand_device(struct r852_device *dev)
669 {
670 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
671 
672 	if (!dev->card_registered)
673 		return;
674 
675 	device_remove_file(&mtd->dev, &dev_attr_media_type);
676 	nand_release(dev->chip);
677 	r852_engine_disable(dev);
678 	dev->card_registered = 0;
679 }
680 
681 /* Card state updater */
682 static void r852_card_detect_work(struct work_struct *work)
683 {
684 	struct r852_device *dev =
685 		container_of(work, struct r852_device, card_detect_work.work);
686 
687 	r852_card_update_present(dev);
688 	r852_update_card_detect(dev);
689 	dev->card_unstable = 0;
690 
691 	/* False alarm */
692 	if (dev->card_detected == dev->card_registered)
693 		goto exit;
694 
695 	/* Read media properties */
696 	r852_update_media_status(dev);
697 
698 	/* Register the card */
699 	if (dev->card_detected)
700 		r852_register_nand_device(dev);
701 	else
702 		r852_unregister_nand_device(dev);
703 exit:
704 	r852_update_card_detect(dev);
705 }
706 
707 /* Ack + disable IRQ generation */
708 static void r852_disable_irqs(struct r852_device *dev)
709 {
710 	uint8_t reg;
711 	reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
712 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, reg & ~R852_CARD_IRQ_MASK);
713 
714 	reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
715 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
716 					reg & ~R852_DMA_IRQ_MASK);
717 
718 	r852_write_reg(dev, R852_CARD_IRQ_STA, R852_CARD_IRQ_MASK);
719 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, R852_DMA_IRQ_MASK);
720 }
721 
722 /* Interrupt handler */
723 static irqreturn_t r852_irq(int irq, void *data)
724 {
725 	struct r852_device *dev = (struct r852_device *)data;
726 
727 	uint8_t card_status, dma_status;
728 	unsigned long flags;
729 	irqreturn_t ret = IRQ_NONE;
730 
731 	spin_lock_irqsave(&dev->irqlock, flags);
732 
733 	/* handle card detection interrupts first */
734 	card_status = r852_read_reg(dev, R852_CARD_IRQ_STA);
735 	r852_write_reg(dev, R852_CARD_IRQ_STA, card_status);
736 
737 	if (card_status & (R852_CARD_IRQ_INSERT|R852_CARD_IRQ_REMOVE)) {
738 
739 		ret = IRQ_HANDLED;
740 		dev->card_detected = !!(card_status & R852_CARD_IRQ_INSERT);
741 
742 		/* we shouldn't receive any interrupts if we wait for card
743 			to settle */
744 		WARN_ON(dev->card_unstable);
745 
746 		/* disable irqs while card is unstable */
747 		/* this will timeout DMA if active, but better that garbage */
748 		r852_disable_irqs(dev);
749 
750 		if (dev->card_unstable)
751 			goto out;
752 
753 		/* let, card state to settle a bit, and then do the work */
754 		dev->card_unstable = 1;
755 		queue_delayed_work(dev->card_workqueue,
756 			&dev->card_detect_work, msecs_to_jiffies(100));
757 		goto out;
758 	}
759 
760 
761 	/* Handle dma interrupts */
762 	dma_status = r852_read_reg_dword(dev, R852_DMA_IRQ_STA);
763 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, dma_status);
764 
765 	if (dma_status & R852_DMA_IRQ_MASK) {
766 
767 		ret = IRQ_HANDLED;
768 
769 		if (dma_status & R852_DMA_IRQ_ERROR) {
770 			dbg("received dma error IRQ");
771 			r852_dma_done(dev, -EIO);
772 			complete(&dev->dma_done);
773 			goto out;
774 		}
775 
776 		/* received DMA interrupt out of nowhere? */
777 		WARN_ON_ONCE(dev->dma_stage == 0);
778 
779 		if (dev->dma_stage == 0)
780 			goto out;
781 
782 		/* done device access */
783 		if (dev->dma_state == DMA_INTERNAL &&
784 				(dma_status & R852_DMA_IRQ_INTERNAL)) {
785 
786 			dev->dma_state = DMA_MEMORY;
787 			dev->dma_stage++;
788 		}
789 
790 		/* done memory DMA */
791 		if (dev->dma_state == DMA_MEMORY &&
792 				(dma_status & R852_DMA_IRQ_MEMORY)) {
793 			dev->dma_state = DMA_INTERNAL;
794 			dev->dma_stage++;
795 		}
796 
797 		/* Enable 2nd half of dma dance */
798 		if (dev->dma_stage == 2)
799 			r852_dma_enable(dev);
800 
801 		/* Operation done */
802 		if (dev->dma_stage == 3) {
803 			r852_dma_done(dev, 0);
804 			complete(&dev->dma_done);
805 		}
806 		goto out;
807 	}
808 
809 	/* Handle unknown interrupts */
810 	if (dma_status)
811 		dbg("bad dma IRQ status = %x", dma_status);
812 
813 	if (card_status & ~R852_CARD_STA_CD)
814 		dbg("strange card status = %x", card_status);
815 
816 out:
817 	spin_unlock_irqrestore(&dev->irqlock, flags);
818 	return ret;
819 }
820 
821 static int  r852_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
822 {
823 	int error;
824 	struct nand_chip *chip;
825 	struct r852_device *dev;
826 
827 	/* pci initialization */
828 	error = pci_enable_device(pci_dev);
829 
830 	if (error)
831 		goto error1;
832 
833 	pci_set_master(pci_dev);
834 
835 	error = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
836 	if (error)
837 		goto error2;
838 
839 	error = pci_request_regions(pci_dev, DRV_NAME);
840 
841 	if (error)
842 		goto error3;
843 
844 	error = -ENOMEM;
845 
846 	/* init nand chip, but register it only on card insert */
847 	chip = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
848 
849 	if (!chip)
850 		goto error4;
851 
852 	/* commands */
853 	chip->legacy.cmd_ctrl = r852_cmdctl;
854 	chip->legacy.waitfunc = r852_wait;
855 	chip->legacy.dev_ready = r852_ready;
856 
857 	/* I/O */
858 	chip->legacy.read_byte = r852_read_byte;
859 	chip->legacy.read_buf = r852_read_buf;
860 	chip->legacy.write_buf = r852_write_buf;
861 
862 	/* ecc */
863 	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
864 	chip->ecc.size = R852_DMA_LEN;
865 	chip->ecc.bytes = SM_OOB_SIZE;
866 	chip->ecc.strength = 2;
867 	chip->ecc.hwctl = r852_ecc_hwctl;
868 	chip->ecc.calculate = r852_ecc_calculate;
869 	chip->ecc.correct = r852_ecc_correct;
870 
871 	/* TODO: hack */
872 	chip->ecc.read_oob = r852_read_oob;
873 
874 	/* init our device structure */
875 	dev = kzalloc(sizeof(struct r852_device), GFP_KERNEL);
876 
877 	if (!dev)
878 		goto error5;
879 
880 	nand_set_controller_data(chip, dev);
881 	dev->chip = chip;
882 	dev->pci_dev = pci_dev;
883 	pci_set_drvdata(pci_dev, dev);
884 
885 	dev->bounce_buffer = dma_alloc_coherent(&pci_dev->dev, R852_DMA_LEN,
886 		&dev->phys_bounce_buffer, GFP_KERNEL);
887 
888 	if (!dev->bounce_buffer)
889 		goto error6;
890 
891 
892 	error = -ENODEV;
893 	dev->mmio = pci_ioremap_bar(pci_dev, 0);
894 
895 	if (!dev->mmio)
896 		goto error7;
897 
898 	error = -ENOMEM;
899 	dev->tmp_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
900 
901 	if (!dev->tmp_buffer)
902 		goto error8;
903 
904 	init_completion(&dev->dma_done);
905 
906 	dev->card_workqueue = create_freezable_workqueue(DRV_NAME);
907 
908 	if (!dev->card_workqueue)
909 		goto error9;
910 
911 	INIT_DELAYED_WORK(&dev->card_detect_work, r852_card_detect_work);
912 
913 	/* shutdown everything - precation */
914 	r852_engine_disable(dev);
915 	r852_disable_irqs(dev);
916 
917 	r852_dma_test(dev);
918 
919 	dev->irq = pci_dev->irq;
920 	spin_lock_init(&dev->irqlock);
921 
922 	dev->card_detected = 0;
923 	r852_card_update_present(dev);
924 
925 	/*register irq handler*/
926 	error = -ENODEV;
927 	if (request_irq(pci_dev->irq, &r852_irq, IRQF_SHARED,
928 			  DRV_NAME, dev))
929 		goto error10;
930 
931 	/* kick initial present test */
932 	queue_delayed_work(dev->card_workqueue,
933 		&dev->card_detect_work, 0);
934 
935 
936 	pr_notice("driver loaded successfully\n");
937 	return 0;
938 
939 error10:
940 	destroy_workqueue(dev->card_workqueue);
941 error9:
942 	kfree(dev->tmp_buffer);
943 error8:
944 	pci_iounmap(pci_dev, dev->mmio);
945 error7:
946 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
947 			  dev->phys_bounce_buffer);
948 error6:
949 	kfree(dev);
950 error5:
951 	kfree(chip);
952 error4:
953 	pci_release_regions(pci_dev);
954 error3:
955 error2:
956 	pci_disable_device(pci_dev);
957 error1:
958 	return error;
959 }
960 
961 static void r852_remove(struct pci_dev *pci_dev)
962 {
963 	struct r852_device *dev = pci_get_drvdata(pci_dev);
964 
965 	/* Stop detect workqueue -
966 		we are going to unregister the device anyway*/
967 	cancel_delayed_work_sync(&dev->card_detect_work);
968 	destroy_workqueue(dev->card_workqueue);
969 
970 	/* Unregister the device, this might make more IO */
971 	r852_unregister_nand_device(dev);
972 
973 	/* Stop interrupts */
974 	r852_disable_irqs(dev);
975 	free_irq(dev->irq, dev);
976 
977 	/* Cleanup */
978 	kfree(dev->tmp_buffer);
979 	pci_iounmap(pci_dev, dev->mmio);
980 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
981 			  dev->phys_bounce_buffer);
982 
983 	kfree(dev->chip);
984 	kfree(dev);
985 
986 	/* Shutdown the PCI device */
987 	pci_release_regions(pci_dev);
988 	pci_disable_device(pci_dev);
989 }
990 
991 static void r852_shutdown(struct pci_dev *pci_dev)
992 {
993 	struct r852_device *dev = pci_get_drvdata(pci_dev);
994 
995 	cancel_delayed_work_sync(&dev->card_detect_work);
996 	r852_disable_irqs(dev);
997 	synchronize_irq(dev->irq);
998 	pci_disable_device(pci_dev);
999 }
1000 
1001 #ifdef CONFIG_PM_SLEEP
1002 static int r852_suspend(struct device *device)
1003 {
1004 	struct r852_device *dev = pci_get_drvdata(to_pci_dev(device));
1005 
1006 	if (dev->ctlreg & R852_CTL_CARDENABLE)
1007 		return -EBUSY;
1008 
1009 	/* First make sure the detect work is gone */
1010 	cancel_delayed_work_sync(&dev->card_detect_work);
1011 
1012 	/* Turn off the interrupts and stop the device */
1013 	r852_disable_irqs(dev);
1014 	r852_engine_disable(dev);
1015 
1016 	/* If card was pulled off just during the suspend, which is very
1017 		unlikely, we will remove it on resume, it too late now
1018 		anyway... */
1019 	dev->card_unstable = 0;
1020 	return 0;
1021 }
1022 
1023 static int r852_resume(struct device *device)
1024 {
1025 	struct r852_device *dev = pci_get_drvdata(to_pci_dev(device));
1026 
1027 	r852_disable_irqs(dev);
1028 	r852_card_update_present(dev);
1029 	r852_engine_disable(dev);
1030 
1031 
1032 	/* If card status changed, just do the work */
1033 	if (dev->card_detected != dev->card_registered) {
1034 		dbg("card was %s during low power state",
1035 			dev->card_detected ? "added" : "removed");
1036 
1037 		queue_delayed_work(dev->card_workqueue,
1038 		&dev->card_detect_work, msecs_to_jiffies(1000));
1039 		return 0;
1040 	}
1041 
1042 	/* Otherwise, initialize the card */
1043 	if (dev->card_registered) {
1044 		r852_engine_enable(dev);
1045 		nand_select_target(dev->chip, 0);
1046 		nand_reset_op(dev->chip);
1047 		nand_deselect_target(dev->chip);
1048 	}
1049 
1050 	/* Program card detection IRQ */
1051 	r852_update_card_detect(dev);
1052 	return 0;
1053 }
1054 #endif
1055 
1056 static const struct pci_device_id r852_pci_id_tbl[] = {
1057 
1058 	{ PCI_VDEVICE(RICOH, 0x0852), },
1059 	{ },
1060 };
1061 
1062 MODULE_DEVICE_TABLE(pci, r852_pci_id_tbl);
1063 
1064 static SIMPLE_DEV_PM_OPS(r852_pm_ops, r852_suspend, r852_resume);
1065 
1066 static struct pci_driver r852_pci_driver = {
1067 	.name		= DRV_NAME,
1068 	.id_table	= r852_pci_id_tbl,
1069 	.probe		= r852_probe,
1070 	.remove		= r852_remove,
1071 	.shutdown	= r852_shutdown,
1072 	.driver.pm	= &r852_pm_ops,
1073 };
1074 
1075 module_pci_driver(r852_pci_driver);
1076 
1077 MODULE_LICENSE("GPL");
1078 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1079 MODULE_DESCRIPTION("Ricoh 85xx xD/smartmedia card reader driver");
1080