[go: nahoru, domu]

1/*
2 * SMI (Serial Memory Controller) device driver for Serial NOR Flash on
3 * SPEAr platform
4 * The serial nor interface is largely based on drivers/mtd/m25p80.c,
5 * however the SPI interface has been replaced by SMI.
6 *
7 * Copyright © 2010 STMicroelectronics.
8 * Ashish Priyadarshi
9 * Shiraz Hashim <shiraz.linux.kernel@gmail.com>
10 *
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
14 */
15
16#include <linux/clk.h>
17#include <linux/delay.h>
18#include <linux/device.h>
19#include <linux/err.h>
20#include <linux/errno.h>
21#include <linux/interrupt.h>
22#include <linux/io.h>
23#include <linux/ioport.h>
24#include <linux/jiffies.h>
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/param.h>
28#include <linux/platform_device.h>
29#include <linux/pm.h>
30#include <linux/mtd/mtd.h>
31#include <linux/mtd/partitions.h>
32#include <linux/mtd/spear_smi.h>
33#include <linux/mutex.h>
34#include <linux/sched.h>
35#include <linux/slab.h>
36#include <linux/wait.h>
37#include <linux/of.h>
38#include <linux/of_address.h>
39
40/* SMI clock rate */
41#define SMI_MAX_CLOCK_FREQ	50000000 /* 50 MHz */
42
43/* MAX time out to safely come out of a erase or write busy conditions */
44#define SMI_PROBE_TIMEOUT	(HZ / 10)
45#define SMI_MAX_TIME_OUT	(3 * HZ)
46
47/* timeout for command completion */
48#define SMI_CMD_TIMEOUT		(HZ / 10)
49
50/* registers of smi */
51#define SMI_CR1		0x0	/* SMI control register 1 */
52#define SMI_CR2		0x4	/* SMI control register 2 */
53#define SMI_SR		0x8	/* SMI status register */
54#define SMI_TR		0xC	/* SMI transmit register */
55#define SMI_RR		0x10	/* SMI receive register */
56
57/* defines for control_reg 1 */
58#define BANK_EN		(0xF << 0)	/* enables all banks */
59#define DSEL_TIME	(0x6 << 4)	/* Deselect time 6 + 1 SMI_CK periods */
60#define SW_MODE		(0x1 << 28)	/* enables SW Mode */
61#define WB_MODE		(0x1 << 29)	/* Write Burst Mode */
62#define FAST_MODE	(0x1 << 15)	/* Fast Mode */
63#define HOLD1		(0x1 << 16)	/* Clock Hold period selection */
64
65/* defines for control_reg 2 */
66#define SEND		(0x1 << 7)	/* Send data */
67#define TFIE		(0x1 << 8)	/* Transmission Flag Interrupt Enable */
68#define WCIE		(0x1 << 9)	/* Write Complete Interrupt Enable */
69#define RD_STATUS_REG	(0x1 << 10)	/* reads status reg */
70#define WE		(0x1 << 11)	/* Write Enable */
71
72#define TX_LEN_SHIFT	0
73#define RX_LEN_SHIFT	4
74#define BANK_SHIFT	12
75
76/* defines for status register */
77#define SR_WIP		0x1	/* Write in progress */
78#define SR_WEL		0x2	/* Write enable latch */
79#define SR_BP0		0x4	/* Block protect 0 */
80#define SR_BP1		0x8	/* Block protect 1 */
81#define SR_BP2		0x10	/* Block protect 2 */
82#define SR_SRWD		0x80	/* SR write protect */
83#define TFF		0x100	/* Transfer Finished Flag */
84#define WCF		0x200	/* Transfer Finished Flag */
85#define ERF1		0x400	/* Forbidden Write Request */
86#define ERF2		0x800	/* Forbidden Access */
87
88#define WM_SHIFT	12
89
90/* flash opcodes */
91#define OPCODE_RDID	0x9f	/* Read JEDEC ID */
92
93/* Flash Device Ids maintenance section */
94
95/* data structure to maintain flash ids from different vendors */
96struct flash_device {
97	char *name;
98	u8 erase_cmd;
99	u32 device_id;
100	u32 pagesize;
101	unsigned long sectorsize;
102	unsigned long size_in_bytes;
103};
104
105#define FLASH_ID(n, es, id, psize, ssize, size)	\
106{				\
107	.name = n,		\
108	.erase_cmd = es,	\
109	.device_id = id,	\
110	.pagesize = psize,	\
111	.sectorsize = ssize,	\
112	.size_in_bytes = size	\
113}
114
115static struct flash_device flash_devices[] = {
116	FLASH_ID("st m25p16"     , 0xd8, 0x00152020, 0x100, 0x10000, 0x200000),
117	FLASH_ID("st m25p32"     , 0xd8, 0x00162020, 0x100, 0x10000, 0x400000),
118	FLASH_ID("st m25p64"     , 0xd8, 0x00172020, 0x100, 0x10000, 0x800000),
119	FLASH_ID("st m25p128"    , 0xd8, 0x00182020, 0x100, 0x40000, 0x1000000),
120	FLASH_ID("st m25p05"     , 0xd8, 0x00102020, 0x80 , 0x8000 , 0x10000),
121	FLASH_ID("st m25p10"     , 0xd8, 0x00112020, 0x80 , 0x8000 , 0x20000),
122	FLASH_ID("st m25p20"     , 0xd8, 0x00122020, 0x100, 0x10000, 0x40000),
123	FLASH_ID("st m25p40"     , 0xd8, 0x00132020, 0x100, 0x10000, 0x80000),
124	FLASH_ID("st m25p80"     , 0xd8, 0x00142020, 0x100, 0x10000, 0x100000),
125	FLASH_ID("st m45pe10"    , 0xd8, 0x00114020, 0x100, 0x10000, 0x20000),
126	FLASH_ID("st m45pe20"    , 0xd8, 0x00124020, 0x100, 0x10000, 0x40000),
127	FLASH_ID("st m45pe40"    , 0xd8, 0x00134020, 0x100, 0x10000, 0x80000),
128	FLASH_ID("st m45pe80"    , 0xd8, 0x00144020, 0x100, 0x10000, 0x100000),
129	FLASH_ID("sp s25fl004"   , 0xd8, 0x00120201, 0x100, 0x10000, 0x80000),
130	FLASH_ID("sp s25fl008"   , 0xd8, 0x00130201, 0x100, 0x10000, 0x100000),
131	FLASH_ID("sp s25fl016"   , 0xd8, 0x00140201, 0x100, 0x10000, 0x200000),
132	FLASH_ID("sp s25fl032"   , 0xd8, 0x00150201, 0x100, 0x10000, 0x400000),
133	FLASH_ID("sp s25fl064"   , 0xd8, 0x00160201, 0x100, 0x10000, 0x800000),
134	FLASH_ID("atmel 25f512"  , 0x52, 0x0065001F, 0x80 , 0x8000 , 0x10000),
135	FLASH_ID("atmel 25f1024" , 0x52, 0x0060001F, 0x100, 0x8000 , 0x20000),
136	FLASH_ID("atmel 25f2048" , 0x52, 0x0063001F, 0x100, 0x10000, 0x40000),
137	FLASH_ID("atmel 25f4096" , 0x52, 0x0064001F, 0x100, 0x10000, 0x80000),
138	FLASH_ID("atmel 25fs040" , 0xd7, 0x0004661F, 0x100, 0x10000, 0x80000),
139	FLASH_ID("mac 25l512"    , 0xd8, 0x001020C2, 0x010, 0x10000, 0x10000),
140	FLASH_ID("mac 25l1005"   , 0xd8, 0x001120C2, 0x010, 0x10000, 0x20000),
141	FLASH_ID("mac 25l2005"   , 0xd8, 0x001220C2, 0x010, 0x10000, 0x40000),
142	FLASH_ID("mac 25l4005"   , 0xd8, 0x001320C2, 0x010, 0x10000, 0x80000),
143	FLASH_ID("mac 25l4005a"  , 0xd8, 0x001320C2, 0x010, 0x10000, 0x80000),
144	FLASH_ID("mac 25l8005"   , 0xd8, 0x001420C2, 0x010, 0x10000, 0x100000),
145	FLASH_ID("mac 25l1605"   , 0xd8, 0x001520C2, 0x100, 0x10000, 0x200000),
146	FLASH_ID("mac 25l1605a"  , 0xd8, 0x001520C2, 0x010, 0x10000, 0x200000),
147	FLASH_ID("mac 25l3205"   , 0xd8, 0x001620C2, 0x100, 0x10000, 0x400000),
148	FLASH_ID("mac 25l3205a"  , 0xd8, 0x001620C2, 0x100, 0x10000, 0x400000),
149	FLASH_ID("mac 25l6405"   , 0xd8, 0x001720C2, 0x100, 0x10000, 0x800000),
150};
151
152/* Define spear specific structures */
153
154struct spear_snor_flash;
155
156/**
157 * struct spear_smi - Structure for SMI Device
158 *
159 * @clk: functional clock
160 * @status: current status register of SMI.
161 * @clk_rate: functional clock rate of SMI (default: SMI_MAX_CLOCK_FREQ)
162 * @lock: lock to prevent parallel access of SMI.
163 * @io_base: base address for registers of SMI.
164 * @pdev: platform device
165 * @cmd_complete: queue to wait for command completion of NOR-flash.
166 * @num_flashes: number of flashes actually present on board.
167 * @flash: separate structure for each Serial NOR-flash attached to SMI.
168 */
169struct spear_smi {
170	struct clk *clk;
171	u32 status;
172	unsigned long clk_rate;
173	struct mutex lock;
174	void __iomem *io_base;
175	struct platform_device *pdev;
176	wait_queue_head_t cmd_complete;
177	u32 num_flashes;
178	struct spear_snor_flash *flash[MAX_NUM_FLASH_CHIP];
179};
180
181/**
182 * struct spear_snor_flash - Structure for Serial NOR Flash
183 *
184 * @bank: Bank number(0, 1, 2, 3) for each NOR-flash.
185 * @dev_id: Device ID of NOR-flash.
186 * @lock: lock to manage flash read, write and erase operations
187 * @mtd: MTD info for each NOR-flash.
188 * @num_parts: Total number of partition in each bank of NOR-flash.
189 * @parts: Partition info for each bank of NOR-flash.
190 * @page_size: Page size of NOR-flash.
191 * @base_addr: Base address of NOR-flash.
192 * @erase_cmd: erase command may vary on different flash types
193 * @fast_mode: flash supports read in fast mode
194 */
195struct spear_snor_flash {
196	u32 bank;
197	u32 dev_id;
198	struct mutex lock;
199	struct mtd_info mtd;
200	u32 num_parts;
201	struct mtd_partition *parts;
202	u32 page_size;
203	void __iomem *base_addr;
204	u8 erase_cmd;
205	u8 fast_mode;
206};
207
208static inline struct spear_snor_flash *get_flash_data(struct mtd_info *mtd)
209{
210	return container_of(mtd, struct spear_snor_flash, mtd);
211}
212
213/**
214 * spear_smi_read_sr - Read status register of flash through SMI
215 * @dev: structure of SMI information.
216 * @bank: bank to which flash is connected
217 *
218 * This routine will return the status register of the flash chip present at the
219 * given bank.
220 */
221static int spear_smi_read_sr(struct spear_smi *dev, u32 bank)
222{
223	int ret;
224	u32 ctrlreg1;
225
226	mutex_lock(&dev->lock);
227	dev->status = 0; /* Will be set in interrupt handler */
228
229	ctrlreg1 = readl(dev->io_base + SMI_CR1);
230	/* program smi in hw mode */
231	writel(ctrlreg1 & ~(SW_MODE | WB_MODE), dev->io_base + SMI_CR1);
232
233	/* performing a rsr instruction in hw mode */
234	writel((bank << BANK_SHIFT) | RD_STATUS_REG | TFIE,
235			dev->io_base + SMI_CR2);
236
237	/* wait for tff */
238	ret = wait_event_interruptible_timeout(dev->cmd_complete,
239			dev->status & TFF, SMI_CMD_TIMEOUT);
240
241	/* copy dev->status (lower 16 bits) in order to release lock */
242	if (ret > 0)
243		ret = dev->status & 0xffff;
244	else if (ret == 0)
245		ret = -ETIMEDOUT;
246
247	/* restore the ctrl regs state */
248	writel(ctrlreg1, dev->io_base + SMI_CR1);
249	writel(0, dev->io_base + SMI_CR2);
250	mutex_unlock(&dev->lock);
251
252	return ret;
253}
254
255/**
256 * spear_smi_wait_till_ready - wait till flash is ready
257 * @dev: structure of SMI information.
258 * @bank: flash corresponding to this bank
259 * @timeout: timeout for busy wait condition
260 *
261 * This routine checks for WIP (write in progress) bit in Status register
262 * If successful the routine returns 0 else -EBUSY
263 */
264static int spear_smi_wait_till_ready(struct spear_smi *dev, u32 bank,
265		unsigned long timeout)
266{
267	unsigned long finish;
268	int status;
269
270	finish = jiffies + timeout;
271	do {
272		status = spear_smi_read_sr(dev, bank);
273		if (status < 0) {
274			if (status == -ETIMEDOUT)
275				continue; /* try till finish */
276			return status;
277		} else if (!(status & SR_WIP)) {
278			return 0;
279		}
280
281		cond_resched();
282	} while (!time_after_eq(jiffies, finish));
283
284	dev_err(&dev->pdev->dev, "smi controller is busy, timeout\n");
285	return -EBUSY;
286}
287
288/**
289 * spear_smi_int_handler - SMI Interrupt Handler.
290 * @irq: irq number
291 * @dev_id: structure of SMI device, embedded in dev_id.
292 *
293 * The handler clears all interrupt conditions and records the status in
294 * dev->status which is used by the driver later.
295 */
296static irqreturn_t spear_smi_int_handler(int irq, void *dev_id)
297{
298	u32 status = 0;
299	struct spear_smi *dev = dev_id;
300
301	status = readl(dev->io_base + SMI_SR);
302
303	if (unlikely(!status))
304		return IRQ_NONE;
305
306	/* clear all interrupt conditions */
307	writel(0, dev->io_base + SMI_SR);
308
309	/* copy the status register in dev->status */
310	dev->status |= status;
311
312	/* send the completion */
313	wake_up_interruptible(&dev->cmd_complete);
314
315	return IRQ_HANDLED;
316}
317
318/**
319 * spear_smi_hw_init - initializes the smi controller.
320 * @dev: structure of smi device
321 *
322 * this routine initializes the smi controller wit the default values
323 */
324static void spear_smi_hw_init(struct spear_smi *dev)
325{
326	unsigned long rate = 0;
327	u32 prescale = 0;
328	u32 val;
329
330	rate = clk_get_rate(dev->clk);
331
332	/* functional clock of smi */
333	prescale = DIV_ROUND_UP(rate, dev->clk_rate);
334
335	/*
336	 * setting the standard values, fast mode, prescaler for
337	 * SMI_MAX_CLOCK_FREQ (50MHz) operation and bank enable
338	 */
339	val = HOLD1 | BANK_EN | DSEL_TIME | (prescale << 8);
340
341	mutex_lock(&dev->lock);
342	/* clear all interrupt conditions */
343	writel(0, dev->io_base + SMI_SR);
344
345	writel(val, dev->io_base + SMI_CR1);
346	mutex_unlock(&dev->lock);
347}
348
349/**
350 * get_flash_index - match chip id from a flash list.
351 * @flash_id: a valid nor flash chip id obtained from board.
352 *
353 * try to validate the chip id by matching from a list, if not found then simply
354 * returns negative. In case of success returns index in to the flash devices
355 * array.
356 */
357static int get_flash_index(u32 flash_id)
358{
359	int index;
360
361	/* Matches chip-id to entire list of 'serial-nor flash' ids */
362	for (index = 0; index < ARRAY_SIZE(flash_devices); index++) {
363		if (flash_devices[index].device_id == flash_id)
364			return index;
365	}
366
367	/* Memory chip is not listed and not supported */
368	return -ENODEV;
369}
370
371/**
372 * spear_smi_write_enable - Enable the flash to do write operation
373 * @dev: structure of SMI device
374 * @bank: enable write for flash connected to this bank
375 *
376 * Set write enable latch with Write Enable command.
377 * Returns 0 on success.
378 */
379static int spear_smi_write_enable(struct spear_smi *dev, u32 bank)
380{
381	int ret;
382	u32 ctrlreg1;
383
384	mutex_lock(&dev->lock);
385	dev->status = 0; /* Will be set in interrupt handler */
386
387	ctrlreg1 = readl(dev->io_base + SMI_CR1);
388	/* program smi in h/w mode */
389	writel(ctrlreg1 & ~SW_MODE, dev->io_base + SMI_CR1);
390
391	/* give the flash, write enable command */
392	writel((bank << BANK_SHIFT) | WE | TFIE, dev->io_base + SMI_CR2);
393
394	ret = wait_event_interruptible_timeout(dev->cmd_complete,
395			dev->status & TFF, SMI_CMD_TIMEOUT);
396
397	/* restore the ctrl regs state */
398	writel(ctrlreg1, dev->io_base + SMI_CR1);
399	writel(0, dev->io_base + SMI_CR2);
400
401	if (ret == 0) {
402		ret = -EIO;
403		dev_err(&dev->pdev->dev,
404			"smi controller failed on write enable\n");
405	} else if (ret > 0) {
406		/* check whether write mode status is set for required bank */
407		if (dev->status & (1 << (bank + WM_SHIFT)))
408			ret = 0;
409		else {
410			dev_err(&dev->pdev->dev, "couldn't enable write\n");
411			ret = -EIO;
412		}
413	}
414
415	mutex_unlock(&dev->lock);
416	return ret;
417}
418
419static inline u32
420get_sector_erase_cmd(struct spear_snor_flash *flash, u32 offset)
421{
422	u32 cmd;
423	u8 *x = (u8 *)&cmd;
424
425	x[0] = flash->erase_cmd;
426	x[1] = offset >> 16;
427	x[2] = offset >> 8;
428	x[3] = offset;
429
430	return cmd;
431}
432
433/**
434 * spear_smi_erase_sector - erase one sector of flash
435 * @dev: structure of SMI information
436 * @command: erase command to be send
437 * @bank: bank to which this command needs to be send
438 * @bytes: size of command
439 *
440 * Erase one sector of flash memory at offset ``offset'' which is any
441 * address within the sector which should be erased.
442 * Returns 0 if successful, non-zero otherwise.
443 */
444static int spear_smi_erase_sector(struct spear_smi *dev,
445		u32 bank, u32 command, u32 bytes)
446{
447	u32 ctrlreg1 = 0;
448	int ret;
449
450	ret = spear_smi_wait_till_ready(dev, bank, SMI_MAX_TIME_OUT);
451	if (ret)
452		return ret;
453
454	ret = spear_smi_write_enable(dev, bank);
455	if (ret)
456		return ret;
457
458	mutex_lock(&dev->lock);
459
460	ctrlreg1 = readl(dev->io_base + SMI_CR1);
461	writel((ctrlreg1 | SW_MODE) & ~WB_MODE, dev->io_base + SMI_CR1);
462
463	/* send command in sw mode */
464	writel(command, dev->io_base + SMI_TR);
465
466	writel((bank << BANK_SHIFT) | SEND | TFIE | (bytes << TX_LEN_SHIFT),
467			dev->io_base + SMI_CR2);
468
469	ret = wait_event_interruptible_timeout(dev->cmd_complete,
470			dev->status & TFF, SMI_CMD_TIMEOUT);
471
472	if (ret == 0) {
473		ret = -EIO;
474		dev_err(&dev->pdev->dev, "sector erase failed\n");
475	} else if (ret > 0)
476		ret = 0; /* success */
477
478	/* restore ctrl regs */
479	writel(ctrlreg1, dev->io_base + SMI_CR1);
480	writel(0, dev->io_base + SMI_CR2);
481
482	mutex_unlock(&dev->lock);
483	return ret;
484}
485
486/**
487 * spear_mtd_erase - perform flash erase operation as requested by user
488 * @mtd: Provides the memory characteristics
489 * @e_info: Provides the erase information
490 *
491 * Erase an address range on the flash chip. The address range may extend
492 * one or more erase sectors. Return an error is there is a problem erasing.
493 */
494static int spear_mtd_erase(struct mtd_info *mtd, struct erase_info *e_info)
495{
496	struct spear_snor_flash *flash = get_flash_data(mtd);
497	struct spear_smi *dev = mtd->priv;
498	u32 addr, command, bank;
499	int len, ret;
500
501	if (!flash || !dev)
502		return -ENODEV;
503
504	bank = flash->bank;
505	if (bank > dev->num_flashes - 1) {
506		dev_err(&dev->pdev->dev, "Invalid Bank Num");
507		return -EINVAL;
508	}
509
510	addr = e_info->addr;
511	len = e_info->len;
512
513	mutex_lock(&flash->lock);
514
515	/* now erase sectors in loop */
516	while (len) {
517		command = get_sector_erase_cmd(flash, addr);
518		/* preparing the command for flash */
519		ret = spear_smi_erase_sector(dev, bank, command, 4);
520		if (ret) {
521			e_info->state = MTD_ERASE_FAILED;
522			mutex_unlock(&flash->lock);
523			return ret;
524		}
525		addr += mtd->erasesize;
526		len -= mtd->erasesize;
527	}
528
529	mutex_unlock(&flash->lock);
530	e_info->state = MTD_ERASE_DONE;
531	mtd_erase_callback(e_info);
532
533	return 0;
534}
535
536/**
537 * spear_mtd_read - performs flash read operation as requested by the user
538 * @mtd: MTD information of the memory bank
539 * @from: Address from which to start read
540 * @len: Number of bytes to be read
541 * @retlen: Fills the Number of bytes actually read
542 * @buf: Fills this after reading
543 *
544 * Read an address range from the flash chip. The address range
545 * may be any size provided it is within the physical boundaries.
546 * Returns 0 on success, non zero otherwise
547 */
548static int spear_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
549		size_t *retlen, u8 *buf)
550{
551	struct spear_snor_flash *flash = get_flash_data(mtd);
552	struct spear_smi *dev = mtd->priv;
553	void __iomem *src;
554	u32 ctrlreg1, val;
555	int ret;
556
557	if (!flash || !dev)
558		return -ENODEV;
559
560	if (flash->bank > dev->num_flashes - 1) {
561		dev_err(&dev->pdev->dev, "Invalid Bank Num");
562		return -EINVAL;
563	}
564
565	/* select address as per bank number */
566	src = flash->base_addr + from;
567
568	mutex_lock(&flash->lock);
569
570	/* wait till previous write/erase is done. */
571	ret = spear_smi_wait_till_ready(dev, flash->bank, SMI_MAX_TIME_OUT);
572	if (ret) {
573		mutex_unlock(&flash->lock);
574		return ret;
575	}
576
577	mutex_lock(&dev->lock);
578	/* put smi in hw mode not wbt mode */
579	ctrlreg1 = val = readl(dev->io_base + SMI_CR1);
580	val &= ~(SW_MODE | WB_MODE);
581	if (flash->fast_mode)
582		val |= FAST_MODE;
583
584	writel(val, dev->io_base + SMI_CR1);
585
586	memcpy_fromio(buf, src, len);
587
588	/* restore ctrl reg1 */
589	writel(ctrlreg1, dev->io_base + SMI_CR1);
590	mutex_unlock(&dev->lock);
591
592	*retlen = len;
593	mutex_unlock(&flash->lock);
594
595	return 0;
596}
597
598static inline int spear_smi_cpy_toio(struct spear_smi *dev, u32 bank,
599		void __iomem *dest, const void *src, size_t len)
600{
601	int ret;
602	u32 ctrlreg1;
603
604	/* wait until finished previous write command. */
605	ret = spear_smi_wait_till_ready(dev, bank, SMI_MAX_TIME_OUT);
606	if (ret)
607		return ret;
608
609	/* put smi in write enable */
610	ret = spear_smi_write_enable(dev, bank);
611	if (ret)
612		return ret;
613
614	/* put smi in hw, write burst mode */
615	mutex_lock(&dev->lock);
616
617	ctrlreg1 = readl(dev->io_base + SMI_CR1);
618	writel((ctrlreg1 | WB_MODE) & ~SW_MODE, dev->io_base + SMI_CR1);
619
620	memcpy_toio(dest, src, len);
621
622	writel(ctrlreg1, dev->io_base + SMI_CR1);
623
624	mutex_unlock(&dev->lock);
625	return 0;
626}
627
628/**
629 * spear_mtd_write - performs write operation as requested by the user.
630 * @mtd: MTD information of the memory bank.
631 * @to:	Address to write.
632 * @len: Number of bytes to be written.
633 * @retlen: Number of bytes actually wrote.
634 * @buf: Buffer from which the data to be taken.
635 *
636 * Write an address range to the flash chip. Data must be written in
637 * flash_page_size chunks. The address range may be any size provided
638 * it is within the physical boundaries.
639 * Returns 0 on success, non zero otherwise
640 */
641static int spear_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
642		size_t *retlen, const u8 *buf)
643{
644	struct spear_snor_flash *flash = get_flash_data(mtd);
645	struct spear_smi *dev = mtd->priv;
646	void __iomem *dest;
647	u32 page_offset, page_size;
648	int ret;
649
650	if (!flash || !dev)
651		return -ENODEV;
652
653	if (flash->bank > dev->num_flashes - 1) {
654		dev_err(&dev->pdev->dev, "Invalid Bank Num");
655		return -EINVAL;
656	}
657
658	/* select address as per bank number */
659	dest = flash->base_addr + to;
660	mutex_lock(&flash->lock);
661
662	page_offset = (u32)to % flash->page_size;
663
664	/* do if all the bytes fit onto one page */
665	if (page_offset + len <= flash->page_size) {
666		ret = spear_smi_cpy_toio(dev, flash->bank, dest, buf, len);
667		if (!ret)
668			*retlen += len;
669	} else {
670		u32 i;
671
672		/* the size of data remaining on the first page */
673		page_size = flash->page_size - page_offset;
674
675		ret = spear_smi_cpy_toio(dev, flash->bank, dest, buf,
676				page_size);
677		if (ret)
678			goto err_write;
679		else
680			*retlen += page_size;
681
682		/* write everything in pagesize chunks */
683		for (i = page_size; i < len; i += page_size) {
684			page_size = len - i;
685			if (page_size > flash->page_size)
686				page_size = flash->page_size;
687
688			ret = spear_smi_cpy_toio(dev, flash->bank, dest + i,
689					buf + i, page_size);
690			if (ret)
691				break;
692			else
693				*retlen += page_size;
694		}
695	}
696
697err_write:
698	mutex_unlock(&flash->lock);
699
700	return ret;
701}
702
703/**
704 * spear_smi_probe_flash - Detects the NOR Flash chip.
705 * @dev: structure of SMI information.
706 * @bank: bank on which flash must be probed
707 *
708 * This routine will check whether there exists a flash chip on a given memory
709 * bank ID.
710 * Return index of the probed flash in flash devices structure
711 */
712static int spear_smi_probe_flash(struct spear_smi *dev, u32 bank)
713{
714	int ret;
715	u32 val = 0;
716
717	ret = spear_smi_wait_till_ready(dev, bank, SMI_PROBE_TIMEOUT);
718	if (ret)
719		return ret;
720
721	mutex_lock(&dev->lock);
722
723	dev->status = 0; /* Will be set in interrupt handler */
724	/* put smi in sw mode */
725	val = readl(dev->io_base + SMI_CR1);
726	writel(val | SW_MODE, dev->io_base + SMI_CR1);
727
728	/* send readid command in sw mode */
729	writel(OPCODE_RDID, dev->io_base + SMI_TR);
730
731	val = (bank << BANK_SHIFT) | SEND | (1 << TX_LEN_SHIFT) |
732		(3 << RX_LEN_SHIFT) | TFIE;
733	writel(val, dev->io_base + SMI_CR2);
734
735	/* wait for TFF */
736	ret = wait_event_interruptible_timeout(dev->cmd_complete,
737			dev->status & TFF, SMI_CMD_TIMEOUT);
738	if (ret <= 0) {
739		ret = -ENODEV;
740		goto err_probe;
741	}
742
743	/* get memory chip id */
744	val = readl(dev->io_base + SMI_RR);
745	val &= 0x00ffffff;
746	ret = get_flash_index(val);
747
748err_probe:
749	/* clear sw mode */
750	val = readl(dev->io_base + SMI_CR1);
751	writel(val & ~SW_MODE, dev->io_base + SMI_CR1);
752
753	mutex_unlock(&dev->lock);
754	return ret;
755}
756
757
758#ifdef CONFIG_OF
759static int spear_smi_probe_config_dt(struct platform_device *pdev,
760				     struct device_node *np)
761{
762	struct spear_smi_plat_data *pdata = dev_get_platdata(&pdev->dev);
763	struct device_node *pp = NULL;
764	const __be32 *addr;
765	u32 val;
766	int len;
767	int i = 0;
768
769	if (!np)
770		return -ENODEV;
771
772	of_property_read_u32(np, "clock-rate", &val);
773	pdata->clk_rate = val;
774
775	pdata->board_flash_info = devm_kzalloc(&pdev->dev,
776					       sizeof(*pdata->board_flash_info),
777					       GFP_KERNEL);
778
779	/* Fill structs for each subnode (flash device) */
780	while ((pp = of_get_next_child(np, pp))) {
781		struct spear_smi_flash_info *flash_info;
782
783		flash_info = &pdata->board_flash_info[i];
784		pdata->np[i] = pp;
785
786		/* Read base-addr and size from DT */
787		addr = of_get_property(pp, "reg", &len);
788		pdata->board_flash_info->mem_base = be32_to_cpup(&addr[0]);
789		pdata->board_flash_info->size = be32_to_cpup(&addr[1]);
790
791		if (of_get_property(pp, "st,smi-fast-mode", NULL))
792			pdata->board_flash_info->fast_mode = 1;
793
794		i++;
795	}
796
797	pdata->num_flashes = i;
798
799	return 0;
800}
801#else
802static int spear_smi_probe_config_dt(struct platform_device *pdev,
803				     struct device_node *np)
804{
805	return -ENOSYS;
806}
807#endif
808
809static int spear_smi_setup_banks(struct platform_device *pdev,
810				 u32 bank, struct device_node *np)
811{
812	struct spear_smi *dev = platform_get_drvdata(pdev);
813	struct mtd_part_parser_data ppdata = {};
814	struct spear_smi_flash_info *flash_info;
815	struct spear_smi_plat_data *pdata;
816	struct spear_snor_flash *flash;
817	struct mtd_partition *parts = NULL;
818	int count = 0;
819	int flash_index;
820	int ret = 0;
821
822	pdata = dev_get_platdata(&pdev->dev);
823	if (bank > pdata->num_flashes - 1)
824		return -EINVAL;
825
826	flash_info = &pdata->board_flash_info[bank];
827	if (!flash_info)
828		return -ENODEV;
829
830	flash = devm_kzalloc(&pdev->dev, sizeof(*flash), GFP_ATOMIC);
831	if (!flash)
832		return -ENOMEM;
833	flash->bank = bank;
834	flash->fast_mode = flash_info->fast_mode ? 1 : 0;
835	mutex_init(&flash->lock);
836
837	/* verify whether nor flash is really present on board */
838	flash_index = spear_smi_probe_flash(dev, bank);
839	if (flash_index < 0) {
840		dev_info(&dev->pdev->dev, "smi-nor%d not found\n", bank);
841		return flash_index;
842	}
843	/* map the memory for nor flash chip */
844	flash->base_addr = devm_ioremap(&pdev->dev, flash_info->mem_base,
845					flash_info->size);
846	if (!flash->base_addr)
847		return -EIO;
848
849	dev->flash[bank] = flash;
850	flash->mtd.priv = dev;
851
852	if (flash_info->name)
853		flash->mtd.name = flash_info->name;
854	else
855		flash->mtd.name = flash_devices[flash_index].name;
856
857	flash->mtd.type = MTD_NORFLASH;
858	flash->mtd.writesize = 1;
859	flash->mtd.flags = MTD_CAP_NORFLASH;
860	flash->mtd.size = flash_info->size;
861	flash->mtd.erasesize = flash_devices[flash_index].sectorsize;
862	flash->page_size = flash_devices[flash_index].pagesize;
863	flash->mtd.writebufsize = flash->page_size;
864	flash->erase_cmd = flash_devices[flash_index].erase_cmd;
865	flash->mtd._erase = spear_mtd_erase;
866	flash->mtd._read = spear_mtd_read;
867	flash->mtd._write = spear_mtd_write;
868	flash->dev_id = flash_devices[flash_index].device_id;
869
870	dev_info(&dev->pdev->dev, "mtd .name=%s .size=%llx(%lluM)\n",
871			flash->mtd.name, flash->mtd.size,
872			flash->mtd.size / (1024 * 1024));
873
874	dev_info(&dev->pdev->dev, ".erasesize = 0x%x(%uK)\n",
875			flash->mtd.erasesize, flash->mtd.erasesize / 1024);
876
877#ifndef CONFIG_OF
878	if (flash_info->partitions) {
879		parts = flash_info->partitions;
880		count = flash_info->nr_partitions;
881	}
882#endif
883	ppdata.of_node = np;
884
885	ret = mtd_device_parse_register(&flash->mtd, NULL, &ppdata, parts,
886					count);
887	if (ret) {
888		dev_err(&dev->pdev->dev, "Err MTD partition=%d\n", ret);
889		return ret;
890	}
891
892	return 0;
893}
894
895/**
896 * spear_smi_probe - Entry routine
897 * @pdev: platform device structure
898 *
899 * This is the first routine which gets invoked during booting and does all
900 * initialization/allocation work. The routine looks for available memory banks,
901 * and do proper init for any found one.
902 * Returns 0 on success, non zero otherwise
903 */
904static int spear_smi_probe(struct platform_device *pdev)
905{
906	struct device_node *np = pdev->dev.of_node;
907	struct spear_smi_plat_data *pdata = NULL;
908	struct spear_smi *dev;
909	struct resource *smi_base;
910	int irq, ret = 0;
911	int i;
912
913	if (np) {
914		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
915		if (!pdata) {
916			ret = -ENOMEM;
917			goto err;
918		}
919		pdev->dev.platform_data = pdata;
920		ret = spear_smi_probe_config_dt(pdev, np);
921		if (ret) {
922			ret = -ENODEV;
923			dev_err(&pdev->dev, "no platform data\n");
924			goto err;
925		}
926	} else {
927		pdata = dev_get_platdata(&pdev->dev);
928		if (!pdata) {
929			ret = -ENODEV;
930			dev_err(&pdev->dev, "no platform data\n");
931			goto err;
932		}
933	}
934
935	irq = platform_get_irq(pdev, 0);
936	if (irq < 0) {
937		ret = -ENODEV;
938		dev_err(&pdev->dev, "invalid smi irq\n");
939		goto err;
940	}
941
942	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_ATOMIC);
943	if (!dev) {
944		ret = -ENOMEM;
945		goto err;
946	}
947
948	smi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
949
950	dev->io_base = devm_ioremap_resource(&pdev->dev, smi_base);
951	if (IS_ERR(dev->io_base)) {
952		ret = PTR_ERR(dev->io_base);
953		goto err;
954	}
955
956	dev->pdev = pdev;
957	dev->clk_rate = pdata->clk_rate;
958
959	if (dev->clk_rate > SMI_MAX_CLOCK_FREQ)
960		dev->clk_rate = SMI_MAX_CLOCK_FREQ;
961
962	dev->num_flashes = pdata->num_flashes;
963
964	if (dev->num_flashes > MAX_NUM_FLASH_CHIP) {
965		dev_err(&pdev->dev, "exceeding max number of flashes\n");
966		dev->num_flashes = MAX_NUM_FLASH_CHIP;
967	}
968
969	dev->clk = devm_clk_get(&pdev->dev, NULL);
970	if (IS_ERR(dev->clk)) {
971		ret = PTR_ERR(dev->clk);
972		goto err;
973	}
974
975	ret = clk_prepare_enable(dev->clk);
976	if (ret)
977		goto err;
978
979	ret = devm_request_irq(&pdev->dev, irq, spear_smi_int_handler, 0,
980			       pdev->name, dev);
981	if (ret) {
982		dev_err(&dev->pdev->dev, "SMI IRQ allocation failed\n");
983		goto err_irq;
984	}
985
986	mutex_init(&dev->lock);
987	init_waitqueue_head(&dev->cmd_complete);
988	spear_smi_hw_init(dev);
989	platform_set_drvdata(pdev, dev);
990
991	/* loop for each serial nor-flash which is connected to smi */
992	for (i = 0; i < dev->num_flashes; i++) {
993		ret = spear_smi_setup_banks(pdev, i, pdata->np[i]);
994		if (ret) {
995			dev_err(&dev->pdev->dev, "bank setup failed\n");
996			goto err_irq;
997		}
998	}
999
1000	return 0;
1001
1002err_irq:
1003	clk_disable_unprepare(dev->clk);
1004err:
1005	return ret;
1006}
1007
1008/**
1009 * spear_smi_remove - Exit routine
1010 * @pdev: platform device structure
1011 *
1012 * free all allocations and delete the partitions.
1013 */
1014static int spear_smi_remove(struct platform_device *pdev)
1015{
1016	struct spear_smi *dev;
1017	struct spear_snor_flash *flash;
1018	int ret, i;
1019
1020	dev = platform_get_drvdata(pdev);
1021	if (!dev) {
1022		dev_err(&pdev->dev, "dev is null\n");
1023		return -ENODEV;
1024	}
1025
1026	/* clean up for all nor flash */
1027	for (i = 0; i < dev->num_flashes; i++) {
1028		flash = dev->flash[i];
1029		if (!flash)
1030			continue;
1031
1032		/* clean up mtd stuff */
1033		ret = mtd_device_unregister(&flash->mtd);
1034		if (ret)
1035			dev_err(&pdev->dev, "error removing mtd\n");
1036	}
1037
1038	clk_disable_unprepare(dev->clk);
1039
1040	return 0;
1041}
1042
1043#ifdef CONFIG_PM_SLEEP
1044static int spear_smi_suspend(struct device *dev)
1045{
1046	struct spear_smi *sdev = dev_get_drvdata(dev);
1047
1048	if (sdev && sdev->clk)
1049		clk_disable_unprepare(sdev->clk);
1050
1051	return 0;
1052}
1053
1054static int spear_smi_resume(struct device *dev)
1055{
1056	struct spear_smi *sdev = dev_get_drvdata(dev);
1057	int ret = -EPERM;
1058
1059	if (sdev && sdev->clk)
1060		ret = clk_prepare_enable(sdev->clk);
1061
1062	if (!ret)
1063		spear_smi_hw_init(sdev);
1064	return ret;
1065}
1066#endif
1067
1068static SIMPLE_DEV_PM_OPS(spear_smi_pm_ops, spear_smi_suspend, spear_smi_resume);
1069
1070#ifdef CONFIG_OF
1071static const struct of_device_id spear_smi_id_table[] = {
1072	{ .compatible = "st,spear600-smi" },
1073	{}
1074};
1075MODULE_DEVICE_TABLE(of, spear_smi_id_table);
1076#endif
1077
1078static struct platform_driver spear_smi_driver = {
1079	.driver = {
1080		.name = "smi",
1081		.bus = &platform_bus_type,
1082		.owner = THIS_MODULE,
1083		.of_match_table = of_match_ptr(spear_smi_id_table),
1084		.pm = &spear_smi_pm_ops,
1085	},
1086	.probe = spear_smi_probe,
1087	.remove = spear_smi_remove,
1088};
1089module_platform_driver(spear_smi_driver);
1090
1091MODULE_LICENSE("GPL");
1092MODULE_AUTHOR("Ashish Priyadarshi, Shiraz Hashim <shiraz.linux.kernel@gmail.com>");
1093MODULE_DESCRIPTION("MTD SMI driver for serial nor flash chips");
1094