xref: /linux/drivers/mtd/nand/raw/r852.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright © 2009 - Maxim Levitsky
4  * driver for Ricoh xD readers
5  */
6 
7 #define DRV_NAME "r852"
8 #define pr_fmt(fmt)  DRV_NAME ": " fmt
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/jiffies.h>
13 #include <linux/workqueue.h>
14 #include <linux/interrupt.h>
15 #include <linux/pci.h>
16 #include <linux/pci_ids.h>
17 #include <linux/delay.h>
18 #include <linux/slab.h>
19 #include <asm/byteorder.h>
20 #include <linux/sched.h>
21 #include "sm_common.h"
22 #include "r852.h"
23 
24 
25 static bool r852_enable_dma = 1;
26 module_param(r852_enable_dma, bool, S_IRUGO);
27 MODULE_PARM_DESC(r852_enable_dma, "Enable usage of the DMA (default)");
28 
29 static int debug;
30 module_param(debug, int, S_IRUGO | S_IWUSR);
31 MODULE_PARM_DESC(debug, "Debug level (0-2)");
32 
33 /* read register */
34 static inline uint8_t r852_read_reg(struct r852_device *dev, int address)
35 {
36 	uint8_t reg = readb(dev->mmio + address);
37 	return reg;
38 }
39 
40 /* write register */
41 static inline void r852_write_reg(struct r852_device *dev,
42 						int address, uint8_t value)
43 {
44 	writeb(value, dev->mmio + address);
45 }
46 
47 
48 /* read dword sized register */
49 static inline uint32_t r852_read_reg_dword(struct r852_device *dev, int address)
50 {
51 	uint32_t reg = le32_to_cpu(readl(dev->mmio + address));
52 	return reg;
53 }
54 
55 /* write dword sized register */
56 static inline void r852_write_reg_dword(struct r852_device *dev,
57 							int address, uint32_t value)
58 {
59 	writel(cpu_to_le32(value), dev->mmio + address);
60 }
61 
62 /* returns pointer to our private structure */
63 static inline struct r852_device *r852_get_dev(struct mtd_info *mtd)
64 {
65 	struct nand_chip *chip = mtd_to_nand(mtd);
66 	return nand_get_controller_data(chip);
67 }
68 
69 
70 /* check if controller supports dma */
71 static void r852_dma_test(struct r852_device *dev)
72 {
73 	dev->dma_usable = (r852_read_reg(dev, R852_DMA_CAP) &
74 		(R852_DMA1 | R852_DMA2)) == (R852_DMA1 | R852_DMA2);
75 
76 	if (!dev->dma_usable)
77 		message("Non dma capable device detected, dma disabled");
78 
79 	if (!r852_enable_dma) {
80 		message("disabling dma on user request");
81 		dev->dma_usable = 0;
82 	}
83 }
84 
85 /*
86  * Enable dma. Enables ether first or second stage of the DMA,
87  * Expects dev->dma_dir and dev->dma_state be set
88  */
89 static void r852_dma_enable(struct r852_device *dev)
90 {
91 	uint8_t dma_reg, dma_irq_reg;
92 
93 	/* Set up dma settings */
94 	dma_reg = r852_read_reg_dword(dev, R852_DMA_SETTINGS);
95 	dma_reg &= ~(R852_DMA_READ | R852_DMA_INTERNAL | R852_DMA_MEMORY);
96 
97 	if (dev->dma_dir)
98 		dma_reg |= R852_DMA_READ;
99 
100 	if (dev->dma_state == DMA_INTERNAL) {
101 		dma_reg |= R852_DMA_INTERNAL;
102 		/* Precaution to make sure HW doesn't write */
103 			/* to random kernel memory */
104 		r852_write_reg_dword(dev, R852_DMA_ADDR,
105 			cpu_to_le32(dev->phys_bounce_buffer));
106 	} else {
107 		dma_reg |= R852_DMA_MEMORY;
108 		r852_write_reg_dword(dev, R852_DMA_ADDR,
109 			cpu_to_le32(dev->phys_dma_addr));
110 	}
111 
112 	/* Precaution: make sure write reached the device */
113 	r852_read_reg_dword(dev, R852_DMA_ADDR);
114 
115 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, dma_reg);
116 
117 	/* Set dma irq */
118 	dma_irq_reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
119 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
120 		dma_irq_reg |
121 		R852_DMA_IRQ_INTERNAL |
122 		R852_DMA_IRQ_ERROR |
123 		R852_DMA_IRQ_MEMORY);
124 }
125 
126 /*
127  * Disable dma, called from the interrupt handler, which specifies
128  * success of the operation via 'error' argument
129  */
130 static void r852_dma_done(struct r852_device *dev, int error)
131 {
132 	WARN_ON(dev->dma_stage == 0);
133 
134 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA,
135 			r852_read_reg_dword(dev, R852_DMA_IRQ_STA));
136 
137 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, 0);
138 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE, 0);
139 
140 	/* Precaution to make sure HW doesn't write to random kernel memory */
141 	r852_write_reg_dword(dev, R852_DMA_ADDR,
142 		cpu_to_le32(dev->phys_bounce_buffer));
143 	r852_read_reg_dword(dev, R852_DMA_ADDR);
144 
145 	dev->dma_error = error;
146 	dev->dma_stage = 0;
147 
148 	if (dev->phys_dma_addr && dev->phys_dma_addr != dev->phys_bounce_buffer)
149 		dma_unmap_single(&dev->pci_dev->dev, dev->phys_dma_addr,
150 			R852_DMA_LEN,
151 			dev->dma_dir ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
152 }
153 
154 /*
155  * Wait, till dma is done, which includes both phases of it
156  */
157 static int r852_dma_wait(struct r852_device *dev)
158 {
159 	long timeout = wait_for_completion_timeout(&dev->dma_done,
160 				msecs_to_jiffies(1000));
161 	if (!timeout) {
162 		dbg("timeout waiting for DMA interrupt");
163 		return -ETIMEDOUT;
164 	}
165 
166 	return 0;
167 }
168 
169 /*
170  * Read/Write one page using dma. Only pages can be read (512 bytes)
171 */
172 static void r852_do_dma(struct r852_device *dev, uint8_t *buf, int do_read)
173 {
174 	int bounce = 0;
175 	unsigned long flags;
176 	int error;
177 
178 	dev->dma_error = 0;
179 
180 	/* Set dma direction */
181 	dev->dma_dir = do_read;
182 	dev->dma_stage = 1;
183 	reinit_completion(&dev->dma_done);
184 
185 	dbg_verbose("doing dma %s ", do_read ? "read" : "write");
186 
187 	/* Set initial dma state: for reading first fill on board buffer,
188 	  from device, for writes first fill the buffer  from memory*/
189 	dev->dma_state = do_read ? DMA_INTERNAL : DMA_MEMORY;
190 
191 	/* if incoming buffer is not page aligned, we should do bounce */
192 	if ((unsigned long)buf & (R852_DMA_LEN-1))
193 		bounce = 1;
194 
195 	if (!bounce) {
196 		dev->phys_dma_addr = dma_map_single(&dev->pci_dev->dev, buf,
197 			R852_DMA_LEN,
198 			do_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
199 		if (dma_mapping_error(&dev->pci_dev->dev, dev->phys_dma_addr))
200 			bounce = 1;
201 	}
202 
203 	if (bounce) {
204 		dbg_verbose("dma: using bounce buffer");
205 		dev->phys_dma_addr = dev->phys_bounce_buffer;
206 		if (!do_read)
207 			memcpy(dev->bounce_buffer, buf, R852_DMA_LEN);
208 	}
209 
210 	/* Enable DMA */
211 	spin_lock_irqsave(&dev->irqlock, flags);
212 	r852_dma_enable(dev);
213 	spin_unlock_irqrestore(&dev->irqlock, flags);
214 
215 	/* Wait till complete */
216 	error = r852_dma_wait(dev);
217 
218 	if (error) {
219 		r852_dma_done(dev, error);
220 		return;
221 	}
222 
223 	if (do_read && bounce)
224 		memcpy((void *)buf, dev->bounce_buffer, R852_DMA_LEN);
225 }
226 
227 /*
228  * Program data lines of the nand chip to send data to it
229  */
230 static void r852_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
231 {
232 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
233 	uint32_t reg;
234 
235 	/* Don't allow any access to hardware if we suspect card removal */
236 	if (dev->card_unstable)
237 		return;
238 
239 	/* Special case for whole sector read */
240 	if (len == R852_DMA_LEN && dev->dma_usable) {
241 		r852_do_dma(dev, (uint8_t *)buf, 0);
242 		return;
243 	}
244 
245 	/* write DWORD chinks - faster */
246 	while (len >= 4) {
247 		reg = buf[0] | buf[1] << 8 | buf[2] << 16 | buf[3] << 24;
248 		r852_write_reg_dword(dev, R852_DATALINE, reg);
249 		buf += 4;
250 		len -= 4;
251 
252 	}
253 
254 	/* write rest */
255 	while (len > 0) {
256 		r852_write_reg(dev, R852_DATALINE, *buf++);
257 		len--;
258 	}
259 }
260 
261 /*
262  * Read data lines of the nand chip to retrieve data
263  */
264 static void r852_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
265 {
266 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
267 	uint32_t reg;
268 
269 	if (dev->card_unstable) {
270 		/* since we can't signal error here, at least, return
271 			predictable buffer */
272 		memset(buf, 0, len);
273 		return;
274 	}
275 
276 	/* special case for whole sector read */
277 	if (len == R852_DMA_LEN && dev->dma_usable) {
278 		r852_do_dma(dev, buf, 1);
279 		return;
280 	}
281 
282 	/* read in dword sized chunks */
283 	while (len >= 4) {
284 
285 		reg = r852_read_reg_dword(dev, R852_DATALINE);
286 		*buf++ = reg & 0xFF;
287 		*buf++ = (reg >> 8) & 0xFF;
288 		*buf++ = (reg >> 16) & 0xFF;
289 		*buf++ = (reg >> 24) & 0xFF;
290 		len -= 4;
291 	}
292 
293 	/* read the reset by bytes */
294 	while (len--)
295 		*buf++ = r852_read_reg(dev, R852_DATALINE);
296 }
297 
298 /*
299  * Read one byte from nand chip
300  */
301 static uint8_t r852_read_byte(struct nand_chip *chip)
302 {
303 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
304 
305 	/* Same problem as in r852_read_buf.... */
306 	if (dev->card_unstable)
307 		return 0;
308 
309 	return r852_read_reg(dev, R852_DATALINE);
310 }
311 
312 /*
313  * Control several chip lines & send commands
314  */
315 static void r852_cmdctl(struct nand_chip *chip, int dat, unsigned int ctrl)
316 {
317 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
318 
319 	if (dev->card_unstable)
320 		return;
321 
322 	if (ctrl & NAND_CTRL_CHANGE) {
323 
324 		dev->ctlreg &= ~(R852_CTL_DATA | R852_CTL_COMMAND |
325 				 R852_CTL_ON | R852_CTL_CARDENABLE);
326 
327 		if (ctrl & NAND_ALE)
328 			dev->ctlreg |= R852_CTL_DATA;
329 
330 		if (ctrl & NAND_CLE)
331 			dev->ctlreg |= R852_CTL_COMMAND;
332 
333 		if (ctrl & NAND_NCE)
334 			dev->ctlreg |= (R852_CTL_CARDENABLE | R852_CTL_ON);
335 		else
336 			dev->ctlreg &= ~R852_CTL_WRITE;
337 
338 		/* when write is stareted, enable write access */
339 		if (dat == NAND_CMD_ERASE1)
340 			dev->ctlreg |= R852_CTL_WRITE;
341 
342 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
343 	}
344 
345 	 /* HACK: NAND_CMD_SEQIN is called without NAND_CTRL_CHANGE, but we need
346 		to set write mode */
347 	if (dat == NAND_CMD_SEQIN && (dev->ctlreg & R852_CTL_COMMAND)) {
348 		dev->ctlreg |= R852_CTL_WRITE;
349 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
350 	}
351 
352 	if (dat != NAND_CMD_NONE)
353 		r852_write_reg(dev, R852_DATALINE, dat);
354 }
355 
356 /*
357  * Wait till card is ready.
358  * based on nand_wait, but returns errors on DMA error
359  */
360 static int r852_wait(struct nand_chip *chip)
361 {
362 	struct r852_device *dev = nand_get_controller_data(chip);
363 
364 	unsigned long timeout;
365 	u8 status;
366 
367 	timeout = jiffies + msecs_to_jiffies(400);
368 
369 	while (time_before(jiffies, timeout))
370 		if (chip->legacy.dev_ready(chip))
371 			break;
372 
373 	nand_status_op(chip, &status);
374 
375 	/* Unfortunelly, no way to send detailed error status... */
376 	if (dev->dma_error) {
377 		status |= NAND_STATUS_FAIL;
378 		dev->dma_error = 0;
379 	}
380 	return status;
381 }
382 
383 /*
384  * Check if card is ready
385  */
386 
387 static int r852_ready(struct nand_chip *chip)
388 {
389 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
390 	return !(r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_BUSY);
391 }
392 
393 
394 /*
395  * Set ECC engine mode
396 */
397 
398 static void r852_ecc_hwctl(struct nand_chip *chip, int mode)
399 {
400 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
401 
402 	if (dev->card_unstable)
403 		return;
404 
405 	switch (mode) {
406 	case NAND_ECC_READ:
407 	case NAND_ECC_WRITE:
408 		/* enable ecc generation/check*/
409 		dev->ctlreg |= R852_CTL_ECC_ENABLE;
410 
411 		/* flush ecc buffer */
412 		r852_write_reg(dev, R852_CTL,
413 			dev->ctlreg | R852_CTL_ECC_ACCESS);
414 
415 		r852_read_reg_dword(dev, R852_DATALINE);
416 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
417 		return;
418 
419 	case NAND_ECC_READSYN:
420 		/* disable ecc generation */
421 		dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
422 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
423 	}
424 }
425 
426 /*
427  * Calculate ECC, only used for writes
428  */
429 
430 static int r852_ecc_calculate(struct nand_chip *chip, const uint8_t *dat,
431 			      uint8_t *ecc_code)
432 {
433 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
434 	struct sm_oob *oob = (struct sm_oob *)ecc_code;
435 	uint32_t ecc1, ecc2;
436 
437 	if (dev->card_unstable)
438 		return 0;
439 
440 	dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
441 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
442 
443 	ecc1 = r852_read_reg_dword(dev, R852_DATALINE);
444 	ecc2 = r852_read_reg_dword(dev, R852_DATALINE);
445 
446 	oob->ecc1[0] = (ecc1) & 0xFF;
447 	oob->ecc1[1] = (ecc1 >> 8) & 0xFF;
448 	oob->ecc1[2] = (ecc1 >> 16) & 0xFF;
449 
450 	oob->ecc2[0] = (ecc2) & 0xFF;
451 	oob->ecc2[1] = (ecc2 >> 8) & 0xFF;
452 	oob->ecc2[2] = (ecc2 >> 16) & 0xFF;
453 
454 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
455 	return 0;
456 }
457 
458 /*
459  * Correct the data using ECC, hw did almost everything for us
460  */
461 
462 static int r852_ecc_correct(struct nand_chip *chip, uint8_t *dat,
463 			    uint8_t *read_ecc, uint8_t *calc_ecc)
464 {
465 	uint32_t ecc_reg;
466 	uint8_t ecc_status, err_byte;
467 	int i, error = 0;
468 
469 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
470 
471 	if (dev->card_unstable)
472 		return 0;
473 
474 	if (dev->dma_error) {
475 		dev->dma_error = 0;
476 		return -EIO;
477 	}
478 
479 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
480 	ecc_reg = r852_read_reg_dword(dev, R852_DATALINE);
481 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
482 
483 	for (i = 0 ; i <= 1 ; i++) {
484 
485 		ecc_status = (ecc_reg >> 8) & 0xFF;
486 
487 		/* ecc uncorrectable error */
488 		if (ecc_status & R852_ECC_FAIL) {
489 			dbg("ecc: unrecoverable error, in half %d", i);
490 			error = -EBADMSG;
491 			goto exit;
492 		}
493 
494 		/* correctable error */
495 		if (ecc_status & R852_ECC_CORRECTABLE) {
496 
497 			err_byte = ecc_reg & 0xFF;
498 			dbg("ecc: recoverable error, "
499 				"in half %d, byte %d, bit %d", i,
500 				err_byte, ecc_status & R852_ECC_ERR_BIT_MSK);
501 
502 			dat[err_byte] ^=
503 				1 << (ecc_status & R852_ECC_ERR_BIT_MSK);
504 			error++;
505 		}
506 
507 		dat += 256;
508 		ecc_reg >>= 16;
509 	}
510 exit:
511 	return error;
512 }
513 
514 /*
515  * This is copy of nand_read_oob_std
516  * nand_read_oob_syndrome assumes we can send column address - we can't
517  */
518 static int r852_read_oob(struct nand_chip *chip, int page)
519 {
520 	struct mtd_info *mtd = nand_to_mtd(chip);
521 
522 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
523 }
524 
525 /*
526  * Start the nand engine
527  */
528 
529 static void r852_engine_enable(struct r852_device *dev)
530 {
531 	if (r852_read_reg_dword(dev, R852_HW) & R852_HW_UNKNOWN) {
532 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
533 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
534 	} else {
535 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
536 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
537 	}
538 	msleep(300);
539 	r852_write_reg(dev, R852_CTL, 0);
540 }
541 
542 
543 /*
544  * Stop the nand engine
545  */
546 
547 static void r852_engine_disable(struct r852_device *dev)
548 {
549 	r852_write_reg_dword(dev, R852_HW, 0);
550 	r852_write_reg(dev, R852_CTL, R852_CTL_RESET);
551 }
552 
553 /*
554  * Test if card is present
555  */
556 
557 static void r852_card_update_present(struct r852_device *dev)
558 {
559 	unsigned long flags;
560 	uint8_t reg;
561 
562 	spin_lock_irqsave(&dev->irqlock, flags);
563 	reg = r852_read_reg(dev, R852_CARD_STA);
564 	dev->card_detected = !!(reg & R852_CARD_STA_PRESENT);
565 	spin_unlock_irqrestore(&dev->irqlock, flags);
566 }
567 
568 /*
569  * Update card detection IRQ state according to current card state
570  * which is read in r852_card_update_present
571  */
572 static void r852_update_card_detect(struct r852_device *dev)
573 {
574 	int card_detect_reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
575 	dev->card_unstable = 0;
576 
577 	card_detect_reg &= ~(R852_CARD_IRQ_REMOVE | R852_CARD_IRQ_INSERT);
578 	card_detect_reg |= R852_CARD_IRQ_GENABLE;
579 
580 	card_detect_reg |= dev->card_detected ?
581 		R852_CARD_IRQ_REMOVE : R852_CARD_IRQ_INSERT;
582 
583 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, card_detect_reg);
584 }
585 
586 static ssize_t media_type_show(struct device *sys_dev,
587 			       struct device_attribute *attr, char *buf)
588 {
589 	struct mtd_info *mtd = container_of(sys_dev, struct mtd_info, dev);
590 	struct r852_device *dev = r852_get_dev(mtd);
591 	char *data = dev->sm ? "smartmedia" : "xd";
592 
593 	strcpy(buf, data);
594 	return strlen(data);
595 }
596 static DEVICE_ATTR_RO(media_type);
597 
598 
599 /* Detect properties of card in slot */
600 static void r852_update_media_status(struct r852_device *dev)
601 {
602 	uint8_t reg;
603 	unsigned long flags;
604 	int readonly;
605 
606 	spin_lock_irqsave(&dev->irqlock, flags);
607 	if (!dev->card_detected) {
608 		message("card removed");
609 		spin_unlock_irqrestore(&dev->irqlock, flags);
610 		return ;
611 	}
612 
613 	readonly  = r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_RO;
614 	reg = r852_read_reg(dev, R852_DMA_CAP);
615 	dev->sm = (reg & (R852_DMA1 | R852_DMA2)) && (reg & R852_SMBIT);
616 
617 	message("detected %s %s card in slot",
618 		dev->sm ? "SmartMedia" : "xD",
619 		readonly ? "readonly" : "writeable");
620 
621 	dev->readonly = readonly;
622 	spin_unlock_irqrestore(&dev->irqlock, flags);
623 }
624 
625 /*
626  * Register the nand device
627  * Called when the card is detected
628  */
629 static int r852_register_nand_device(struct r852_device *dev)
630 {
631 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
632 
633 	WARN_ON(dev->card_registered);
634 
635 	mtd->dev.parent = &dev->pci_dev->dev;
636 
637 	if (dev->readonly)
638 		dev->chip->options |= NAND_ROM;
639 
640 	r852_engine_enable(dev);
641 
642 	if (sm_register_device(mtd, dev->sm))
643 		goto error1;
644 
645 	if (device_create_file(&mtd->dev, &dev_attr_media_type)) {
646 		message("can't create media type sysfs attribute");
647 		goto error3;
648 	}
649 
650 	dev->card_registered = 1;
651 	return 0;
652 error3:
653 	WARN_ON(mtd_device_unregister(nand_to_mtd(dev->chip)));
654 	nand_cleanup(dev->chip);
655 error1:
656 	/* Force card redetect */
657 	dev->card_detected = 0;
658 	return -1;
659 }
660 
661 /*
662  * Unregister the card
663  */
664 
665 static void r852_unregister_nand_device(struct r852_device *dev)
666 {
667 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
668 
669 	if (!dev->card_registered)
670 		return;
671 
672 	device_remove_file(&mtd->dev, &dev_attr_media_type);
673 	WARN_ON(mtd_device_unregister(mtd));
674 	nand_cleanup(dev->chip);
675 	r852_engine_disable(dev);
676 	dev->card_registered = 0;
677 }
678 
679 /* Card state updater */
680 static void r852_card_detect_work(struct work_struct *work)
681 {
682 	struct r852_device *dev =
683 		container_of(work, struct r852_device, card_detect_work.work);
684 
685 	r852_card_update_present(dev);
686 	r852_update_card_detect(dev);
687 	dev->card_unstable = 0;
688 
689 	/* False alarm */
690 	if (dev->card_detected == dev->card_registered)
691 		goto exit;
692 
693 	/* Read media properties */
694 	r852_update_media_status(dev);
695 
696 	/* Register the card */
697 	if (dev->card_detected)
698 		r852_register_nand_device(dev);
699 	else
700 		r852_unregister_nand_device(dev);
701 exit:
702 	r852_update_card_detect(dev);
703 }
704 
705 /* Ack + disable IRQ generation */
706 static void r852_disable_irqs(struct r852_device *dev)
707 {
708 	uint8_t reg;
709 	reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
710 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, reg & ~R852_CARD_IRQ_MASK);
711 
712 	reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
713 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
714 					reg & ~R852_DMA_IRQ_MASK);
715 
716 	r852_write_reg(dev, R852_CARD_IRQ_STA, R852_CARD_IRQ_MASK);
717 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, R852_DMA_IRQ_MASK);
718 }
719 
720 /* Interrupt handler */
721 static irqreturn_t r852_irq(int irq, void *data)
722 {
723 	struct r852_device *dev = (struct r852_device *)data;
724 
725 	uint8_t card_status, dma_status;
726 	irqreturn_t ret = IRQ_NONE;
727 
728 	spin_lock(&dev->irqlock);
729 
730 	/* handle card detection interrupts first */
731 	card_status = r852_read_reg(dev, R852_CARD_IRQ_STA);
732 	r852_write_reg(dev, R852_CARD_IRQ_STA, card_status);
733 
734 	if (card_status & (R852_CARD_IRQ_INSERT|R852_CARD_IRQ_REMOVE)) {
735 
736 		ret = IRQ_HANDLED;
737 		dev->card_detected = !!(card_status & R852_CARD_IRQ_INSERT);
738 
739 		/* we shouldn't receive any interrupts if we wait for card
740 			to settle */
741 		WARN_ON(dev->card_unstable);
742 
743 		/* disable irqs while card is unstable */
744 		/* this will timeout DMA if active, but better that garbage */
745 		r852_disable_irqs(dev);
746 
747 		if (dev->card_unstable)
748 			goto out;
749 
750 		/* let, card state to settle a bit, and then do the work */
751 		dev->card_unstable = 1;
752 		queue_delayed_work(dev->card_workqueue,
753 			&dev->card_detect_work, msecs_to_jiffies(100));
754 		goto out;
755 	}
756 
757 
758 	/* Handle dma interrupts */
759 	dma_status = r852_read_reg_dword(dev, R852_DMA_IRQ_STA);
760 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, dma_status);
761 
762 	if (dma_status & R852_DMA_IRQ_MASK) {
763 
764 		ret = IRQ_HANDLED;
765 
766 		if (dma_status & R852_DMA_IRQ_ERROR) {
767 			dbg("received dma error IRQ");
768 			r852_dma_done(dev, -EIO);
769 			complete(&dev->dma_done);
770 			goto out;
771 		}
772 
773 		/* received DMA interrupt out of nowhere? */
774 		WARN_ON_ONCE(dev->dma_stage == 0);
775 
776 		if (dev->dma_stage == 0)
777 			goto out;
778 
779 		/* done device access */
780 		if (dev->dma_state == DMA_INTERNAL &&
781 				(dma_status & R852_DMA_IRQ_INTERNAL)) {
782 
783 			dev->dma_state = DMA_MEMORY;
784 			dev->dma_stage++;
785 		}
786 
787 		/* done memory DMA */
788 		if (dev->dma_state == DMA_MEMORY &&
789 				(dma_status & R852_DMA_IRQ_MEMORY)) {
790 			dev->dma_state = DMA_INTERNAL;
791 			dev->dma_stage++;
792 		}
793 
794 		/* Enable 2nd half of dma dance */
795 		if (dev->dma_stage == 2)
796 			r852_dma_enable(dev);
797 
798 		/* Operation done */
799 		if (dev->dma_stage == 3) {
800 			r852_dma_done(dev, 0);
801 			complete(&dev->dma_done);
802 		}
803 		goto out;
804 	}
805 
806 	/* Handle unknown interrupts */
807 	if (dma_status)
808 		dbg("bad dma IRQ status = %x", dma_status);
809 
810 	if (card_status & ~R852_CARD_STA_CD)
811 		dbg("strange card status = %x", card_status);
812 
813 out:
814 	spin_unlock(&dev->irqlock);
815 	return ret;
816 }
817 
818 static int r852_attach_chip(struct nand_chip *chip)
819 {
820 	if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
821 		return 0;
822 
823 	chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
824 	chip->ecc.size = R852_DMA_LEN;
825 	chip->ecc.bytes = SM_OOB_SIZE;
826 	chip->ecc.strength = 2;
827 	chip->ecc.hwctl = r852_ecc_hwctl;
828 	chip->ecc.calculate = r852_ecc_calculate;
829 	chip->ecc.correct = r852_ecc_correct;
830 
831 	/* TODO: hack */
832 	chip->ecc.read_oob = r852_read_oob;
833 
834 	return 0;
835 }
836 
837 static const struct nand_controller_ops r852_ops = {
838 	.attach_chip = r852_attach_chip,
839 };
840 
841 static int  r852_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
842 {
843 	int error;
844 	struct nand_chip *chip;
845 	struct r852_device *dev;
846 
847 	/* pci initialization */
848 	error = pci_enable_device(pci_dev);
849 
850 	if (error)
851 		goto error1;
852 
853 	pci_set_master(pci_dev);
854 
855 	error = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
856 	if (error)
857 		goto error2;
858 
859 	error = pci_request_regions(pci_dev, DRV_NAME);
860 
861 	if (error)
862 		goto error3;
863 
864 	error = -ENOMEM;
865 
866 	/* init nand chip, but register it only on card insert */
867 	chip = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
868 
869 	if (!chip)
870 		goto error4;
871 
872 	/* commands */
873 	chip->legacy.cmd_ctrl = r852_cmdctl;
874 	chip->legacy.waitfunc = r852_wait;
875 	chip->legacy.dev_ready = r852_ready;
876 
877 	/* I/O */
878 	chip->legacy.read_byte = r852_read_byte;
879 	chip->legacy.read_buf = r852_read_buf;
880 	chip->legacy.write_buf = r852_write_buf;
881 
882 	/* init our device structure */
883 	dev = kzalloc(sizeof(struct r852_device), GFP_KERNEL);
884 
885 	if (!dev)
886 		goto error5;
887 
888 	nand_set_controller_data(chip, dev);
889 	dev->chip = chip;
890 	dev->pci_dev = pci_dev;
891 	pci_set_drvdata(pci_dev, dev);
892 
893 	nand_controller_init(&dev->controller);
894 	dev->controller.ops = &r852_ops;
895 	chip->controller = &dev->controller;
896 
897 	dev->bounce_buffer = dma_alloc_coherent(&pci_dev->dev, R852_DMA_LEN,
898 		&dev->phys_bounce_buffer, GFP_KERNEL);
899 
900 	if (!dev->bounce_buffer)
901 		goto error6;
902 
903 
904 	error = -ENODEV;
905 	dev->mmio = pci_ioremap_bar(pci_dev, 0);
906 
907 	if (!dev->mmio)
908 		goto error7;
909 
910 	error = -ENOMEM;
911 	dev->tmp_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
912 
913 	if (!dev->tmp_buffer)
914 		goto error8;
915 
916 	init_completion(&dev->dma_done);
917 
918 	dev->card_workqueue = create_freezable_workqueue(DRV_NAME);
919 
920 	if (!dev->card_workqueue)
921 		goto error9;
922 
923 	INIT_DELAYED_WORK(&dev->card_detect_work, r852_card_detect_work);
924 
925 	/* shutdown everything - precation */
926 	r852_engine_disable(dev);
927 	r852_disable_irqs(dev);
928 
929 	r852_dma_test(dev);
930 
931 	dev->irq = pci_dev->irq;
932 	spin_lock_init(&dev->irqlock);
933 
934 	dev->card_detected = 0;
935 	r852_card_update_present(dev);
936 
937 	/*register irq handler*/
938 	error = -ENODEV;
939 	if (request_irq(pci_dev->irq, &r852_irq, IRQF_SHARED,
940 			  DRV_NAME, dev))
941 		goto error10;
942 
943 	/* kick initial present test */
944 	queue_delayed_work(dev->card_workqueue,
945 		&dev->card_detect_work, 0);
946 
947 
948 	pr_notice("driver loaded successfully\n");
949 	return 0;
950 
951 error10:
952 	destroy_workqueue(dev->card_workqueue);
953 error9:
954 	kfree(dev->tmp_buffer);
955 error8:
956 	pci_iounmap(pci_dev, dev->mmio);
957 error7:
958 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
959 			  dev->phys_bounce_buffer);
960 error6:
961 	kfree(dev);
962 error5:
963 	kfree(chip);
964 error4:
965 	pci_release_regions(pci_dev);
966 error3:
967 error2:
968 	pci_disable_device(pci_dev);
969 error1:
970 	return error;
971 }
972 
973 static void r852_remove(struct pci_dev *pci_dev)
974 {
975 	struct r852_device *dev = pci_get_drvdata(pci_dev);
976 
977 	/* Stop detect workqueue -
978 		we are going to unregister the device anyway*/
979 	cancel_delayed_work_sync(&dev->card_detect_work);
980 	destroy_workqueue(dev->card_workqueue);
981 
982 	/* Unregister the device, this might make more IO */
983 	r852_unregister_nand_device(dev);
984 
985 	/* Stop interrupts */
986 	r852_disable_irqs(dev);
987 	free_irq(dev->irq, dev);
988 
989 	/* Cleanup */
990 	kfree(dev->tmp_buffer);
991 	pci_iounmap(pci_dev, dev->mmio);
992 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
993 			  dev->phys_bounce_buffer);
994 
995 	kfree(dev->chip);
996 	kfree(dev);
997 
998 	/* Shutdown the PCI device */
999 	pci_release_regions(pci_dev);
1000 	pci_disable_device(pci_dev);
1001 }
1002 
1003 static void r852_shutdown(struct pci_dev *pci_dev)
1004 {
1005 	struct r852_device *dev = pci_get_drvdata(pci_dev);
1006 
1007 	cancel_delayed_work_sync(&dev->card_detect_work);
1008 	r852_disable_irqs(dev);
1009 	synchronize_irq(dev->irq);
1010 	pci_disable_device(pci_dev);
1011 }
1012 
1013 #ifdef CONFIG_PM_SLEEP
1014 static int r852_suspend(struct device *device)
1015 {
1016 	struct r852_device *dev = dev_get_drvdata(device);
1017 
1018 	if (dev->ctlreg & R852_CTL_CARDENABLE)
1019 		return -EBUSY;
1020 
1021 	/* First make sure the detect work is gone */
1022 	cancel_delayed_work_sync(&dev->card_detect_work);
1023 
1024 	/* Turn off the interrupts and stop the device */
1025 	r852_disable_irqs(dev);
1026 	r852_engine_disable(dev);
1027 
1028 	/* If card was pulled off just during the suspend, which is very
1029 		unlikely, we will remove it on resume, it too late now
1030 		anyway... */
1031 	dev->card_unstable = 0;
1032 	return 0;
1033 }
1034 
1035 static int r852_resume(struct device *device)
1036 {
1037 	struct r852_device *dev = dev_get_drvdata(device);
1038 
1039 	r852_disable_irqs(dev);
1040 	r852_card_update_present(dev);
1041 	r852_engine_disable(dev);
1042 
1043 
1044 	/* If card status changed, just do the work */
1045 	if (dev->card_detected != dev->card_registered) {
1046 		dbg("card was %s during low power state",
1047 			dev->card_detected ? "added" : "removed");
1048 
1049 		queue_delayed_work(dev->card_workqueue,
1050 		&dev->card_detect_work, msecs_to_jiffies(1000));
1051 		return 0;
1052 	}
1053 
1054 	/* Otherwise, initialize the card */
1055 	if (dev->card_registered) {
1056 		r852_engine_enable(dev);
1057 		nand_select_target(dev->chip, 0);
1058 		nand_reset_op(dev->chip);
1059 		nand_deselect_target(dev->chip);
1060 	}
1061 
1062 	/* Program card detection IRQ */
1063 	r852_update_card_detect(dev);
1064 	return 0;
1065 }
1066 #endif
1067 
1068 static const struct pci_device_id r852_pci_id_tbl[] = {
1069 
1070 	{ PCI_VDEVICE(RICOH, 0x0852), },
1071 	{ },
1072 };
1073 
1074 MODULE_DEVICE_TABLE(pci, r852_pci_id_tbl);
1075 
1076 static SIMPLE_DEV_PM_OPS(r852_pm_ops, r852_suspend, r852_resume);
1077 
1078 static struct pci_driver r852_pci_driver = {
1079 	.name		= DRV_NAME,
1080 	.id_table	= r852_pci_id_tbl,
1081 	.probe		= r852_probe,
1082 	.remove		= r852_remove,
1083 	.shutdown	= r852_shutdown,
1084 	.driver.pm	= &r852_pm_ops,
1085 };
1086 
1087 module_pci_driver(r852_pci_driver);
1088 
1089 MODULE_LICENSE("GPL");
1090 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1091 MODULE_DESCRIPTION("Ricoh 85xx xD/smartmedia card reader driver");
1092