xref: /openbmc/linux/drivers/mtd/nand/raw/r852.c (revision dd5b2498)
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 	mmiowb();
49 }
50 
51 
52 /* read dword sized register */
53 static inline uint32_t r852_read_reg_dword(struct r852_device *dev, int address)
54 {
55 	uint32_t reg = le32_to_cpu(readl(dev->mmio + address));
56 	return reg;
57 }
58 
59 /* write dword sized register */
60 static inline void r852_write_reg_dword(struct r852_device *dev,
61 							int address, uint32_t value)
62 {
63 	writel(cpu_to_le32(value), dev->mmio + address);
64 	mmiowb();
65 }
66 
67 /* returns pointer to our private structure */
68 static inline struct r852_device *r852_get_dev(struct mtd_info *mtd)
69 {
70 	struct nand_chip *chip = mtd_to_nand(mtd);
71 	return nand_get_controller_data(chip);
72 }
73 
74 
75 /* check if controller supports dma */
76 static void r852_dma_test(struct r852_device *dev)
77 {
78 	dev->dma_usable = (r852_read_reg(dev, R852_DMA_CAP) &
79 		(R852_DMA1 | R852_DMA2)) == (R852_DMA1 | R852_DMA2);
80 
81 	if (!dev->dma_usable)
82 		message("Non dma capable device detected, dma disabled");
83 
84 	if (!r852_enable_dma) {
85 		message("disabling dma on user request");
86 		dev->dma_usable = 0;
87 	}
88 }
89 
90 /*
91  * Enable dma. Enables ether first or second stage of the DMA,
92  * Expects dev->dma_dir and dev->dma_state be set
93  */
94 static void r852_dma_enable(struct r852_device *dev)
95 {
96 	uint8_t dma_reg, dma_irq_reg;
97 
98 	/* Set up dma settings */
99 	dma_reg = r852_read_reg_dword(dev, R852_DMA_SETTINGS);
100 	dma_reg &= ~(R852_DMA_READ | R852_DMA_INTERNAL | R852_DMA_MEMORY);
101 
102 	if (dev->dma_dir)
103 		dma_reg |= R852_DMA_READ;
104 
105 	if (dev->dma_state == DMA_INTERNAL) {
106 		dma_reg |= R852_DMA_INTERNAL;
107 		/* Precaution to make sure HW doesn't write */
108 			/* to random kernel memory */
109 		r852_write_reg_dword(dev, R852_DMA_ADDR,
110 			cpu_to_le32(dev->phys_bounce_buffer));
111 	} else {
112 		dma_reg |= R852_DMA_MEMORY;
113 		r852_write_reg_dword(dev, R852_DMA_ADDR,
114 			cpu_to_le32(dev->phys_dma_addr));
115 	}
116 
117 	/* Precaution: make sure write reached the device */
118 	r852_read_reg_dword(dev, R852_DMA_ADDR);
119 
120 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, dma_reg);
121 
122 	/* Set dma irq */
123 	dma_irq_reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
124 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
125 		dma_irq_reg |
126 		R852_DMA_IRQ_INTERNAL |
127 		R852_DMA_IRQ_ERROR |
128 		R852_DMA_IRQ_MEMORY);
129 }
130 
131 /*
132  * Disable dma, called from the interrupt handler, which specifies
133  * success of the operation via 'error' argument
134  */
135 static void r852_dma_done(struct r852_device *dev, int error)
136 {
137 	WARN_ON(dev->dma_stage == 0);
138 
139 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA,
140 			r852_read_reg_dword(dev, R852_DMA_IRQ_STA));
141 
142 	r852_write_reg_dword(dev, R852_DMA_SETTINGS, 0);
143 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE, 0);
144 
145 	/* Precaution to make sure HW doesn't write to random kernel memory */
146 	r852_write_reg_dword(dev, R852_DMA_ADDR,
147 		cpu_to_le32(dev->phys_bounce_buffer));
148 	r852_read_reg_dword(dev, R852_DMA_ADDR);
149 
150 	dev->dma_error = error;
151 	dev->dma_stage = 0;
152 
153 	if (dev->phys_dma_addr && dev->phys_dma_addr != dev->phys_bounce_buffer)
154 		dma_unmap_single(&dev->pci_dev->dev, dev->phys_dma_addr,
155 			R852_DMA_LEN,
156 			dev->dma_dir ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
157 }
158 
159 /*
160  * Wait, till dma is done, which includes both phases of it
161  */
162 static int r852_dma_wait(struct r852_device *dev)
163 {
164 	long timeout = wait_for_completion_timeout(&dev->dma_done,
165 				msecs_to_jiffies(1000));
166 	if (!timeout) {
167 		dbg("timeout waiting for DMA interrupt");
168 		return -ETIMEDOUT;
169 	}
170 
171 	return 0;
172 }
173 
174 /*
175  * Read/Write one page using dma. Only pages can be read (512 bytes)
176 */
177 static void r852_do_dma(struct r852_device *dev, uint8_t *buf, int do_read)
178 {
179 	int bounce = 0;
180 	unsigned long flags;
181 	int error;
182 
183 	dev->dma_error = 0;
184 
185 	/* Set dma direction */
186 	dev->dma_dir = do_read;
187 	dev->dma_stage = 1;
188 	reinit_completion(&dev->dma_done);
189 
190 	dbg_verbose("doing dma %s ", do_read ? "read" : "write");
191 
192 	/* Set initial dma state: for reading first fill on board buffer,
193 	  from device, for writes first fill the buffer  from memory*/
194 	dev->dma_state = do_read ? DMA_INTERNAL : DMA_MEMORY;
195 
196 	/* if incoming buffer is not page aligned, we should do bounce */
197 	if ((unsigned long)buf & (R852_DMA_LEN-1))
198 		bounce = 1;
199 
200 	if (!bounce) {
201 		dev->phys_dma_addr = dma_map_single(&dev->pci_dev->dev, buf,
202 			R852_DMA_LEN,
203 			do_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
204 		if (dma_mapping_error(&dev->pci_dev->dev, dev->phys_dma_addr))
205 			bounce = 1;
206 	}
207 
208 	if (bounce) {
209 		dbg_verbose("dma: using bounce buffer");
210 		dev->phys_dma_addr = dev->phys_bounce_buffer;
211 		if (!do_read)
212 			memcpy(dev->bounce_buffer, buf, R852_DMA_LEN);
213 	}
214 
215 	/* Enable DMA */
216 	spin_lock_irqsave(&dev->irqlock, flags);
217 	r852_dma_enable(dev);
218 	spin_unlock_irqrestore(&dev->irqlock, flags);
219 
220 	/* Wait till complete */
221 	error = r852_dma_wait(dev);
222 
223 	if (error) {
224 		r852_dma_done(dev, error);
225 		return;
226 	}
227 
228 	if (do_read && bounce)
229 		memcpy((void *)buf, dev->bounce_buffer, R852_DMA_LEN);
230 }
231 
232 /*
233  * Program data lines of the nand chip to send data to it
234  */
235 static void r852_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
236 {
237 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
238 	uint32_t reg;
239 
240 	/* Don't allow any access to hardware if we suspect card removal */
241 	if (dev->card_unstable)
242 		return;
243 
244 	/* Special case for whole sector read */
245 	if (len == R852_DMA_LEN && dev->dma_usable) {
246 		r852_do_dma(dev, (uint8_t *)buf, 0);
247 		return;
248 	}
249 
250 	/* write DWORD chinks - faster */
251 	while (len >= 4) {
252 		reg = buf[0] | buf[1] << 8 | buf[2] << 16 | buf[3] << 24;
253 		r852_write_reg_dword(dev, R852_DATALINE, reg);
254 		buf += 4;
255 		len -= 4;
256 
257 	}
258 
259 	/* write rest */
260 	while (len > 0) {
261 		r852_write_reg(dev, R852_DATALINE, *buf++);
262 		len--;
263 	}
264 }
265 
266 /*
267  * Read data lines of the nand chip to retrieve data
268  */
269 static void r852_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
270 {
271 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
272 	uint32_t reg;
273 
274 	if (dev->card_unstable) {
275 		/* since we can't signal error here, at least, return
276 			predictable buffer */
277 		memset(buf, 0, len);
278 		return;
279 	}
280 
281 	/* special case for whole sector read */
282 	if (len == R852_DMA_LEN && dev->dma_usable) {
283 		r852_do_dma(dev, buf, 1);
284 		return;
285 	}
286 
287 	/* read in dword sized chunks */
288 	while (len >= 4) {
289 
290 		reg = r852_read_reg_dword(dev, R852_DATALINE);
291 		*buf++ = reg & 0xFF;
292 		*buf++ = (reg >> 8) & 0xFF;
293 		*buf++ = (reg >> 16) & 0xFF;
294 		*buf++ = (reg >> 24) & 0xFF;
295 		len -= 4;
296 	}
297 
298 	/* read the reset by bytes */
299 	while (len--)
300 		*buf++ = r852_read_reg(dev, R852_DATALINE);
301 }
302 
303 /*
304  * Read one byte from nand chip
305  */
306 static uint8_t r852_read_byte(struct nand_chip *chip)
307 {
308 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
309 
310 	/* Same problem as in r852_read_buf.... */
311 	if (dev->card_unstable)
312 		return 0;
313 
314 	return r852_read_reg(dev, R852_DATALINE);
315 }
316 
317 /*
318  * Control several chip lines & send commands
319  */
320 static void r852_cmdctl(struct nand_chip *chip, int dat, unsigned int ctrl)
321 {
322 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
323 
324 	if (dev->card_unstable)
325 		return;
326 
327 	if (ctrl & NAND_CTRL_CHANGE) {
328 
329 		dev->ctlreg &= ~(R852_CTL_DATA | R852_CTL_COMMAND |
330 				 R852_CTL_ON | R852_CTL_CARDENABLE);
331 
332 		if (ctrl & NAND_ALE)
333 			dev->ctlreg |= R852_CTL_DATA;
334 
335 		if (ctrl & NAND_CLE)
336 			dev->ctlreg |= R852_CTL_COMMAND;
337 
338 		if (ctrl & NAND_NCE)
339 			dev->ctlreg |= (R852_CTL_CARDENABLE | R852_CTL_ON);
340 		else
341 			dev->ctlreg &= ~R852_CTL_WRITE;
342 
343 		/* when write is stareted, enable write access */
344 		if (dat == NAND_CMD_ERASE1)
345 			dev->ctlreg |= R852_CTL_WRITE;
346 
347 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
348 	}
349 
350 	 /* HACK: NAND_CMD_SEQIN is called without NAND_CTRL_CHANGE, but we need
351 		to set write mode */
352 	if (dat == NAND_CMD_SEQIN && (dev->ctlreg & R852_CTL_COMMAND)) {
353 		dev->ctlreg |= R852_CTL_WRITE;
354 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
355 	}
356 
357 	if (dat != NAND_CMD_NONE)
358 		r852_write_reg(dev, R852_DATALINE, dat);
359 }
360 
361 /*
362  * Wait till card is ready.
363  * based on nand_wait, but returns errors on DMA error
364  */
365 static int r852_wait(struct nand_chip *chip)
366 {
367 	struct r852_device *dev = nand_get_controller_data(chip);
368 
369 	unsigned long timeout;
370 	u8 status;
371 
372 	timeout = jiffies + msecs_to_jiffies(400);
373 
374 	while (time_before(jiffies, timeout))
375 		if (chip->legacy.dev_ready(chip))
376 			break;
377 
378 	nand_status_op(chip, &status);
379 
380 	/* Unfortunelly, no way to send detailed error status... */
381 	if (dev->dma_error) {
382 		status |= NAND_STATUS_FAIL;
383 		dev->dma_error = 0;
384 	}
385 	return status;
386 }
387 
388 /*
389  * Check if card is ready
390  */
391 
392 static int r852_ready(struct nand_chip *chip)
393 {
394 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
395 	return !(r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_BUSY);
396 }
397 
398 
399 /*
400  * Set ECC engine mode
401 */
402 
403 static void r852_ecc_hwctl(struct nand_chip *chip, int mode)
404 {
405 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
406 
407 	if (dev->card_unstable)
408 		return;
409 
410 	switch (mode) {
411 	case NAND_ECC_READ:
412 	case NAND_ECC_WRITE:
413 		/* enable ecc generation/check*/
414 		dev->ctlreg |= R852_CTL_ECC_ENABLE;
415 
416 		/* flush ecc buffer */
417 		r852_write_reg(dev, R852_CTL,
418 			dev->ctlreg | R852_CTL_ECC_ACCESS);
419 
420 		r852_read_reg_dword(dev, R852_DATALINE);
421 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
422 		return;
423 
424 	case NAND_ECC_READSYN:
425 		/* disable ecc generation */
426 		dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
427 		r852_write_reg(dev, R852_CTL, dev->ctlreg);
428 	}
429 }
430 
431 /*
432  * Calculate ECC, only used for writes
433  */
434 
435 static int r852_ecc_calculate(struct nand_chip *chip, const uint8_t *dat,
436 			      uint8_t *ecc_code)
437 {
438 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
439 	struct sm_oob *oob = (struct sm_oob *)ecc_code;
440 	uint32_t ecc1, ecc2;
441 
442 	if (dev->card_unstable)
443 		return 0;
444 
445 	dev->ctlreg &= ~R852_CTL_ECC_ENABLE;
446 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
447 
448 	ecc1 = r852_read_reg_dword(dev, R852_DATALINE);
449 	ecc2 = r852_read_reg_dword(dev, R852_DATALINE);
450 
451 	oob->ecc1[0] = (ecc1) & 0xFF;
452 	oob->ecc1[1] = (ecc1 >> 8) & 0xFF;
453 	oob->ecc1[2] = (ecc1 >> 16) & 0xFF;
454 
455 	oob->ecc2[0] = (ecc2) & 0xFF;
456 	oob->ecc2[1] = (ecc2 >> 8) & 0xFF;
457 	oob->ecc2[2] = (ecc2 >> 16) & 0xFF;
458 
459 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
460 	return 0;
461 }
462 
463 /*
464  * Correct the data using ECC, hw did almost everything for us
465  */
466 
467 static int r852_ecc_correct(struct nand_chip *chip, uint8_t *dat,
468 			    uint8_t *read_ecc, uint8_t *calc_ecc)
469 {
470 	uint32_t ecc_reg;
471 	uint8_t ecc_status, err_byte;
472 	int i, error = 0;
473 
474 	struct r852_device *dev = r852_get_dev(nand_to_mtd(chip));
475 
476 	if (dev->card_unstable)
477 		return 0;
478 
479 	if (dev->dma_error) {
480 		dev->dma_error = 0;
481 		return -EIO;
482 	}
483 
484 	r852_write_reg(dev, R852_CTL, dev->ctlreg | R852_CTL_ECC_ACCESS);
485 	ecc_reg = r852_read_reg_dword(dev, R852_DATALINE);
486 	r852_write_reg(dev, R852_CTL, dev->ctlreg);
487 
488 	for (i = 0 ; i <= 1 ; i++) {
489 
490 		ecc_status = (ecc_reg >> 8) & 0xFF;
491 
492 		/* ecc uncorrectable error */
493 		if (ecc_status & R852_ECC_FAIL) {
494 			dbg("ecc: unrecoverable error, in half %d", i);
495 			error = -EBADMSG;
496 			goto exit;
497 		}
498 
499 		/* correctable error */
500 		if (ecc_status & R852_ECC_CORRECTABLE) {
501 
502 			err_byte = ecc_reg & 0xFF;
503 			dbg("ecc: recoverable error, "
504 				"in half %d, byte %d, bit %d", i,
505 				err_byte, ecc_status & R852_ECC_ERR_BIT_MSK);
506 
507 			dat[err_byte] ^=
508 				1 << (ecc_status & R852_ECC_ERR_BIT_MSK);
509 			error++;
510 		}
511 
512 		dat += 256;
513 		ecc_reg >>= 16;
514 	}
515 exit:
516 	return error;
517 }
518 
519 /*
520  * This is copy of nand_read_oob_std
521  * nand_read_oob_syndrome assumes we can send column address - we can't
522  */
523 static int r852_read_oob(struct nand_chip *chip, int page)
524 {
525 	struct mtd_info *mtd = nand_to_mtd(chip);
526 
527 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
528 }
529 
530 /*
531  * Start the nand engine
532  */
533 
534 static void r852_engine_enable(struct r852_device *dev)
535 {
536 	if (r852_read_reg_dword(dev, R852_HW) & R852_HW_UNKNOWN) {
537 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
538 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
539 	} else {
540 		r852_write_reg_dword(dev, R852_HW, R852_HW_ENABLED);
541 		r852_write_reg(dev, R852_CTL, R852_CTL_RESET | R852_CTL_ON);
542 	}
543 	msleep(300);
544 	r852_write_reg(dev, R852_CTL, 0);
545 }
546 
547 
548 /*
549  * Stop the nand engine
550  */
551 
552 static void r852_engine_disable(struct r852_device *dev)
553 {
554 	r852_write_reg_dword(dev, R852_HW, 0);
555 	r852_write_reg(dev, R852_CTL, R852_CTL_RESET);
556 }
557 
558 /*
559  * Test if card is present
560  */
561 
562 static void r852_card_update_present(struct r852_device *dev)
563 {
564 	unsigned long flags;
565 	uint8_t reg;
566 
567 	spin_lock_irqsave(&dev->irqlock, flags);
568 	reg = r852_read_reg(dev, R852_CARD_STA);
569 	dev->card_detected = !!(reg & R852_CARD_STA_PRESENT);
570 	spin_unlock_irqrestore(&dev->irqlock, flags);
571 }
572 
573 /*
574  * Update card detection IRQ state according to current card state
575  * which is read in r852_card_update_present
576  */
577 static void r852_update_card_detect(struct r852_device *dev)
578 {
579 	int card_detect_reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
580 	dev->card_unstable = 0;
581 
582 	card_detect_reg &= ~(R852_CARD_IRQ_REMOVE | R852_CARD_IRQ_INSERT);
583 	card_detect_reg |= R852_CARD_IRQ_GENABLE;
584 
585 	card_detect_reg |= dev->card_detected ?
586 		R852_CARD_IRQ_REMOVE : R852_CARD_IRQ_INSERT;
587 
588 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, card_detect_reg);
589 }
590 
591 static ssize_t r852_media_type_show(struct device *sys_dev,
592 			struct device_attribute *attr, char *buf)
593 {
594 	struct mtd_info *mtd = container_of(sys_dev, struct mtd_info, dev);
595 	struct r852_device *dev = r852_get_dev(mtd);
596 	char *data = dev->sm ? "smartmedia" : "xd";
597 
598 	strcpy(buf, data);
599 	return strlen(data);
600 }
601 
602 static DEVICE_ATTR(media_type, S_IRUGO, r852_media_type_show, NULL);
603 
604 
605 /* Detect properties of card in slot */
606 static void r852_update_media_status(struct r852_device *dev)
607 {
608 	uint8_t reg;
609 	unsigned long flags;
610 	int readonly;
611 
612 	spin_lock_irqsave(&dev->irqlock, flags);
613 	if (!dev->card_detected) {
614 		message("card removed");
615 		spin_unlock_irqrestore(&dev->irqlock, flags);
616 		return ;
617 	}
618 
619 	readonly  = r852_read_reg(dev, R852_CARD_STA) & R852_CARD_STA_RO;
620 	reg = r852_read_reg(dev, R852_DMA_CAP);
621 	dev->sm = (reg & (R852_DMA1 | R852_DMA2)) && (reg & R852_SMBIT);
622 
623 	message("detected %s %s card in slot",
624 		dev->sm ? "SmartMedia" : "xD",
625 		readonly ? "readonly" : "writeable");
626 
627 	dev->readonly = readonly;
628 	spin_unlock_irqrestore(&dev->irqlock, flags);
629 }
630 
631 /*
632  * Register the nand device
633  * Called when the card is detected
634  */
635 static int r852_register_nand_device(struct r852_device *dev)
636 {
637 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
638 
639 	WARN_ON(dev->card_registered);
640 
641 	mtd->dev.parent = &dev->pci_dev->dev;
642 
643 	if (dev->readonly)
644 		dev->chip->options |= NAND_ROM;
645 
646 	r852_engine_enable(dev);
647 
648 	if (sm_register_device(mtd, dev->sm))
649 		goto error1;
650 
651 	if (device_create_file(&mtd->dev, &dev_attr_media_type)) {
652 		message("can't create media type sysfs attribute");
653 		goto error3;
654 	}
655 
656 	dev->card_registered = 1;
657 	return 0;
658 error3:
659 	nand_release(dev->chip);
660 error1:
661 	/* Force card redetect */
662 	dev->card_detected = 0;
663 	return -1;
664 }
665 
666 /*
667  * Unregister the card
668  */
669 
670 static void r852_unregister_nand_device(struct r852_device *dev)
671 {
672 	struct mtd_info *mtd = nand_to_mtd(dev->chip);
673 
674 	if (!dev->card_registered)
675 		return;
676 
677 	device_remove_file(&mtd->dev, &dev_attr_media_type);
678 	nand_release(dev->chip);
679 	r852_engine_disable(dev);
680 	dev->card_registered = 0;
681 }
682 
683 /* Card state updater */
684 static void r852_card_detect_work(struct work_struct *work)
685 {
686 	struct r852_device *dev =
687 		container_of(work, struct r852_device, card_detect_work.work);
688 
689 	r852_card_update_present(dev);
690 	r852_update_card_detect(dev);
691 	dev->card_unstable = 0;
692 
693 	/* False alarm */
694 	if (dev->card_detected == dev->card_registered)
695 		goto exit;
696 
697 	/* Read media properties */
698 	r852_update_media_status(dev);
699 
700 	/* Register the card */
701 	if (dev->card_detected)
702 		r852_register_nand_device(dev);
703 	else
704 		r852_unregister_nand_device(dev);
705 exit:
706 	r852_update_card_detect(dev);
707 }
708 
709 /* Ack + disable IRQ generation */
710 static void r852_disable_irqs(struct r852_device *dev)
711 {
712 	uint8_t reg;
713 	reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);
714 	r852_write_reg(dev, R852_CARD_IRQ_ENABLE, reg & ~R852_CARD_IRQ_MASK);
715 
716 	reg = r852_read_reg_dword(dev, R852_DMA_IRQ_ENABLE);
717 	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE,
718 					reg & ~R852_DMA_IRQ_MASK);
719 
720 	r852_write_reg(dev, R852_CARD_IRQ_STA, R852_CARD_IRQ_MASK);
721 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, R852_DMA_IRQ_MASK);
722 }
723 
724 /* Interrupt handler */
725 static irqreturn_t r852_irq(int irq, void *data)
726 {
727 	struct r852_device *dev = (struct r852_device *)data;
728 
729 	uint8_t card_status, dma_status;
730 	unsigned long flags;
731 	irqreturn_t ret = IRQ_NONE;
732 
733 	spin_lock_irqsave(&dev->irqlock, flags);
734 
735 	/* handle card detection interrupts first */
736 	card_status = r852_read_reg(dev, R852_CARD_IRQ_STA);
737 	r852_write_reg(dev, R852_CARD_IRQ_STA, card_status);
738 
739 	if (card_status & (R852_CARD_IRQ_INSERT|R852_CARD_IRQ_REMOVE)) {
740 
741 		ret = IRQ_HANDLED;
742 		dev->card_detected = !!(card_status & R852_CARD_IRQ_INSERT);
743 
744 		/* we shouldn't receive any interrupts if we wait for card
745 			to settle */
746 		WARN_ON(dev->card_unstable);
747 
748 		/* disable irqs while card is unstable */
749 		/* this will timeout DMA if active, but better that garbage */
750 		r852_disable_irqs(dev);
751 
752 		if (dev->card_unstable)
753 			goto out;
754 
755 		/* let, card state to settle a bit, and then do the work */
756 		dev->card_unstable = 1;
757 		queue_delayed_work(dev->card_workqueue,
758 			&dev->card_detect_work, msecs_to_jiffies(100));
759 		goto out;
760 	}
761 
762 
763 	/* Handle dma interrupts */
764 	dma_status = r852_read_reg_dword(dev, R852_DMA_IRQ_STA);
765 	r852_write_reg_dword(dev, R852_DMA_IRQ_STA, dma_status);
766 
767 	if (dma_status & R852_DMA_IRQ_MASK) {
768 
769 		ret = IRQ_HANDLED;
770 
771 		if (dma_status & R852_DMA_IRQ_ERROR) {
772 			dbg("received dma error IRQ");
773 			r852_dma_done(dev, -EIO);
774 			complete(&dev->dma_done);
775 			goto out;
776 		}
777 
778 		/* received DMA interrupt out of nowhere? */
779 		WARN_ON_ONCE(dev->dma_stage == 0);
780 
781 		if (dev->dma_stage == 0)
782 			goto out;
783 
784 		/* done device access */
785 		if (dev->dma_state == DMA_INTERNAL &&
786 				(dma_status & R852_DMA_IRQ_INTERNAL)) {
787 
788 			dev->dma_state = DMA_MEMORY;
789 			dev->dma_stage++;
790 		}
791 
792 		/* done memory DMA */
793 		if (dev->dma_state == DMA_MEMORY &&
794 				(dma_status & R852_DMA_IRQ_MEMORY)) {
795 			dev->dma_state = DMA_INTERNAL;
796 			dev->dma_stage++;
797 		}
798 
799 		/* Enable 2nd half of dma dance */
800 		if (dev->dma_stage == 2)
801 			r852_dma_enable(dev);
802 
803 		/* Operation done */
804 		if (dev->dma_stage == 3) {
805 			r852_dma_done(dev, 0);
806 			complete(&dev->dma_done);
807 		}
808 		goto out;
809 	}
810 
811 	/* Handle unknown interrupts */
812 	if (dma_status)
813 		dbg("bad dma IRQ status = %x", dma_status);
814 
815 	if (card_status & ~R852_CARD_STA_CD)
816 		dbg("strange card status = %x", card_status);
817 
818 out:
819 	spin_unlock_irqrestore(&dev->irqlock, flags);
820 	return ret;
821 }
822 
823 static int  r852_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
824 {
825 	int error;
826 	struct nand_chip *chip;
827 	struct r852_device *dev;
828 
829 	/* pci initialization */
830 	error = pci_enable_device(pci_dev);
831 
832 	if (error)
833 		goto error1;
834 
835 	pci_set_master(pci_dev);
836 
837 	error = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
838 	if (error)
839 		goto error2;
840 
841 	error = pci_request_regions(pci_dev, DRV_NAME);
842 
843 	if (error)
844 		goto error3;
845 
846 	error = -ENOMEM;
847 
848 	/* init nand chip, but register it only on card insert */
849 	chip = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
850 
851 	if (!chip)
852 		goto error4;
853 
854 	/* commands */
855 	chip->legacy.cmd_ctrl = r852_cmdctl;
856 	chip->legacy.waitfunc = r852_wait;
857 	chip->legacy.dev_ready = r852_ready;
858 
859 	/* I/O */
860 	chip->legacy.read_byte = r852_read_byte;
861 	chip->legacy.read_buf = r852_read_buf;
862 	chip->legacy.write_buf = r852_write_buf;
863 
864 	/* ecc */
865 	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
866 	chip->ecc.size = R852_DMA_LEN;
867 	chip->ecc.bytes = SM_OOB_SIZE;
868 	chip->ecc.strength = 2;
869 	chip->ecc.hwctl = r852_ecc_hwctl;
870 	chip->ecc.calculate = r852_ecc_calculate;
871 	chip->ecc.correct = r852_ecc_correct;
872 
873 	/* TODO: hack */
874 	chip->ecc.read_oob = r852_read_oob;
875 
876 	/* init our device structure */
877 	dev = kzalloc(sizeof(struct r852_device), GFP_KERNEL);
878 
879 	if (!dev)
880 		goto error5;
881 
882 	nand_set_controller_data(chip, dev);
883 	dev->chip = chip;
884 	dev->pci_dev = pci_dev;
885 	pci_set_drvdata(pci_dev, dev);
886 
887 	dev->bounce_buffer = dma_alloc_coherent(&pci_dev->dev, R852_DMA_LEN,
888 		&dev->phys_bounce_buffer, GFP_KERNEL);
889 
890 	if (!dev->bounce_buffer)
891 		goto error6;
892 
893 
894 	error = -ENODEV;
895 	dev->mmio = pci_ioremap_bar(pci_dev, 0);
896 
897 	if (!dev->mmio)
898 		goto error7;
899 
900 	error = -ENOMEM;
901 	dev->tmp_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
902 
903 	if (!dev->tmp_buffer)
904 		goto error8;
905 
906 	init_completion(&dev->dma_done);
907 
908 	dev->card_workqueue = create_freezable_workqueue(DRV_NAME);
909 
910 	if (!dev->card_workqueue)
911 		goto error9;
912 
913 	INIT_DELAYED_WORK(&dev->card_detect_work, r852_card_detect_work);
914 
915 	/* shutdown everything - precation */
916 	r852_engine_disable(dev);
917 	r852_disable_irqs(dev);
918 
919 	r852_dma_test(dev);
920 
921 	dev->irq = pci_dev->irq;
922 	spin_lock_init(&dev->irqlock);
923 
924 	dev->card_detected = 0;
925 	r852_card_update_present(dev);
926 
927 	/*register irq handler*/
928 	error = -ENODEV;
929 	if (request_irq(pci_dev->irq, &r852_irq, IRQF_SHARED,
930 			  DRV_NAME, dev))
931 		goto error10;
932 
933 	/* kick initial present test */
934 	queue_delayed_work(dev->card_workqueue,
935 		&dev->card_detect_work, 0);
936 
937 
938 	pr_notice("driver loaded successfully\n");
939 	return 0;
940 
941 error10:
942 	destroy_workqueue(dev->card_workqueue);
943 error9:
944 	kfree(dev->tmp_buffer);
945 error8:
946 	pci_iounmap(pci_dev, dev->mmio);
947 error7:
948 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
949 			  dev->phys_bounce_buffer);
950 error6:
951 	kfree(dev);
952 error5:
953 	kfree(chip);
954 error4:
955 	pci_release_regions(pci_dev);
956 error3:
957 error2:
958 	pci_disable_device(pci_dev);
959 error1:
960 	return error;
961 }
962 
963 static void r852_remove(struct pci_dev *pci_dev)
964 {
965 	struct r852_device *dev = pci_get_drvdata(pci_dev);
966 
967 	/* Stop detect workqueue -
968 		we are going to unregister the device anyway*/
969 	cancel_delayed_work_sync(&dev->card_detect_work);
970 	destroy_workqueue(dev->card_workqueue);
971 
972 	/* Unregister the device, this might make more IO */
973 	r852_unregister_nand_device(dev);
974 
975 	/* Stop interrupts */
976 	r852_disable_irqs(dev);
977 	free_irq(dev->irq, dev);
978 
979 	/* Cleanup */
980 	kfree(dev->tmp_buffer);
981 	pci_iounmap(pci_dev, dev->mmio);
982 	dma_free_coherent(&pci_dev->dev, R852_DMA_LEN, dev->bounce_buffer,
983 			  dev->phys_bounce_buffer);
984 
985 	kfree(dev->chip);
986 	kfree(dev);
987 
988 	/* Shutdown the PCI device */
989 	pci_release_regions(pci_dev);
990 	pci_disable_device(pci_dev);
991 }
992 
993 static void r852_shutdown(struct pci_dev *pci_dev)
994 {
995 	struct r852_device *dev = pci_get_drvdata(pci_dev);
996 
997 	cancel_delayed_work_sync(&dev->card_detect_work);
998 	r852_disable_irqs(dev);
999 	synchronize_irq(dev->irq);
1000 	pci_disable_device(pci_dev);
1001 }
1002 
1003 #ifdef CONFIG_PM_SLEEP
1004 static int r852_suspend(struct device *device)
1005 {
1006 	struct r852_device *dev = pci_get_drvdata(to_pci_dev(device));
1007 
1008 	if (dev->ctlreg & R852_CTL_CARDENABLE)
1009 		return -EBUSY;
1010 
1011 	/* First make sure the detect work is gone */
1012 	cancel_delayed_work_sync(&dev->card_detect_work);
1013 
1014 	/* Turn off the interrupts and stop the device */
1015 	r852_disable_irqs(dev);
1016 	r852_engine_disable(dev);
1017 
1018 	/* If card was pulled off just during the suspend, which is very
1019 		unlikely, we will remove it on resume, it too late now
1020 		anyway... */
1021 	dev->card_unstable = 0;
1022 	return 0;
1023 }
1024 
1025 static int r852_resume(struct device *device)
1026 {
1027 	struct r852_device *dev = pci_get_drvdata(to_pci_dev(device));
1028 
1029 	r852_disable_irqs(dev);
1030 	r852_card_update_present(dev);
1031 	r852_engine_disable(dev);
1032 
1033 
1034 	/* If card status changed, just do the work */
1035 	if (dev->card_detected != dev->card_registered) {
1036 		dbg("card was %s during low power state",
1037 			dev->card_detected ? "added" : "removed");
1038 
1039 		queue_delayed_work(dev->card_workqueue,
1040 		&dev->card_detect_work, msecs_to_jiffies(1000));
1041 		return 0;
1042 	}
1043 
1044 	/* Otherwise, initialize the card */
1045 	if (dev->card_registered) {
1046 		r852_engine_enable(dev);
1047 		nand_select_target(dev->chip, 0);
1048 		nand_reset_op(dev->chip);
1049 		nand_deselect_target(dev->chip);
1050 	}
1051 
1052 	/* Program card detection IRQ */
1053 	r852_update_card_detect(dev);
1054 	return 0;
1055 }
1056 #endif
1057 
1058 static const struct pci_device_id r852_pci_id_tbl[] = {
1059 
1060 	{ PCI_VDEVICE(RICOH, 0x0852), },
1061 	{ },
1062 };
1063 
1064 MODULE_DEVICE_TABLE(pci, r852_pci_id_tbl);
1065 
1066 static SIMPLE_DEV_PM_OPS(r852_pm_ops, r852_suspend, r852_resume);
1067 
1068 static struct pci_driver r852_pci_driver = {
1069 	.name		= DRV_NAME,
1070 	.id_table	= r852_pci_id_tbl,
1071 	.probe		= r852_probe,
1072 	.remove		= r852_remove,
1073 	.shutdown	= r852_shutdown,
1074 	.driver.pm	= &r852_pm_ops,
1075 };
1076 
1077 module_pci_driver(r852_pci_driver);
1078 
1079 MODULE_LICENSE("GPL");
1080 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1081 MODULE_DESCRIPTION("Ricoh 85xx xD/smartmedia card reader driver");
1082