1/*
2 * drivers/mtd/devices/ubi32-m25p80.c
3 *   NOR flash driver, Ubicom processor internal SPI flash interface.
4 *
5 *   This code instantiates the serial flash that contains the
6 *   original bootcode.  The serial flash start at address 0x60000000
7 *   in both Ubicom32V3 and Ubicom32V4 ISAs.
8 *
9 *   This piece of flash is made to appear as a Memory Technology
10 *   Device (MTD) with this driver to allow Read/Write/Erase operations.
11 *
12 * (C) Copyright 2009, Ubicom, Inc.
13 *
14 * This file is part of the Ubicom32 Linux Kernel Port.
15 *
16 * The Ubicom32 Linux Kernel Port is free software: you can redistribute
17 * it and/or modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation, either version 2 of the
19 * License, or (at your option) any later version.
20 *
21 * The Ubicom32 Linux Kernel Port is distributed in the hope that it
22 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
24 * the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with the Ubicom32 Linux Kernel Port.  If not,
28 * see <http://www.gnu.org/licenses/>.
29 *
30 * Ubicom32 implementation derived from (with many thanks):
31 *   arch/m68knommu
32 *   arch/blackfin
33 *   arch/parisc
34 */
35#include <linux/types.h>
36#include <linux/device.h>
37#include <linux/platform_device.h>
38#include <linux/mtd/mtd.h>
39#include <linux/mtd/partitions.h>
40#include <linux/mtd/physmap.h>
41#include <linux/spi/spi.h>
42#include <linux/spi/flash.h>
43
44#include <linux/init.h>
45#include <linux/module.h>
46#include <linux/interrupt.h>
47#include <linux/mutex.h>
48
49#include <asm/ip5000.h>
50#include <asm/devtree.h>
51
52#define UBICOM32_FLASH_BASE	0x60000000
53#define UBICOM32_FLASH_MAX_SIZE 0x01000000
54#define UBICOM32_FLASH_START	0x00000000
55#define UBICOM32_KERNEL_OFFSET	0x00010000 /* The kernel starts after Ubicom
56					    * .protect section. */
57
58static struct mtd_partition ubicom32_flash_partitions[] = {
59	{
60		.name	= "Bootloader",		/* Protected Section
61						 * Partition */
62		.size	= 0x10000,
63		.offset	= UBICOM32_FLASH_START,
64//		.mask_flags = MTD_WRITEABLE	/* Mark Read-only */
65	},
66	{
67		.name	= "Kernel",		/* Kernel Partition. */
68		.size	= 0,			/* this will be set up during
69						 * probe stage. At that time we
70						 * will know end of linux image
71						 * in flash. */
72		.offset	= MTDPART_OFS_APPEND,	/* Starts right after Protected
73						 * section. */
74//		.mask_flags = MTD_WRITEABLE	/* Mark Read-only */
75	},
76	{
77		.name	= "Rest",		/* Rest of the flash. */
78		.size	= 0x200000,		/* Use up what remains in the
79						 * flash. */
80		.offset	= MTDPART_OFS_NXTBLK,	/* Starts right after Protected
81						 * section. */
82	}
83};
84
85static struct flash_platform_data ubicom32_flash_data = {
86	.name = "ubicom32_boot_flash",
87	.parts = ubicom32_flash_partitions,
88	.nr_parts = ARRAY_SIZE(ubicom32_flash_partitions),
89};
90
91static struct resource ubicom32_flash_resource[] = {
92	{
93		.start	= UBICOM32_FLASH_BASE,
94		.end	= UBICOM32_FLASH_BASE +
95		UBICOM32_FLASH_MAX_SIZE - 1,
96		.flags	= IORESOURCE_MEM,
97	},
98};
99
100static struct platform_device ubicom32_flash_device = {
101	.name = "ubicom32flashdriver",
102	.id = 0, /* Bus number */
103	.num_resources = ARRAY_SIZE(ubicom32_flash_resource),
104	.resource = ubicom32_flash_resource,
105	.dev = {
106		.platform_data = &ubicom32_flash_data,
107	},
108};
109
110static struct platform_device *ubicom32_flash_devices[] = {
111	&ubicom32_flash_device,
112};
113
114static int __init ubicom32_flash_init(void)
115{
116	printk(KERN_INFO "%s(): registering device resources\n",
117	       __FUNCTION__);
118	platform_add_devices(ubicom32_flash_devices,
119			     ARRAY_SIZE(ubicom32_flash_devices));
120	return 0;
121}
122
123arch_initcall(ubicom32_flash_init);
124
125/*
126 * MTD SPI driver for ST M25Pxx (and similar) serial flash chips through
127 * Ubicom32 SPI controller.
128 *
129 * Author: Mike Lavender, mike@steroidmicros.com
130 *
131 * Copyright (c) 2005, Intec Automation Inc.
132 *
133 * Some parts are based on lart.c by Abraham Van Der Merwe
134 *
135 * Cleaned up and generalized based on mtd_dataflash.c
136 *
137 * This code is free software; you can redistribute it and/or modify
138 * it under the terms of the GNU General Public License version 2 as
139 * published by the Free Software Foundation.
140 *
141 */
142
143#define FLASH_PAGESIZE		256
144
145/* Flash opcodes. */
146#define	OPCODE_WREN		0x06	/* Write enable */
147#define	OPCODE_RDSR		0x05	/* Read status register */
148#define	OPCODE_READ		0x03	/* Read data bytes (low frequency) */
149#define	OPCODE_FAST_READ	0x0b	/* Read data bytes (high frequency) */
150#define	OPCODE_PP		0x02	/* Page program (up to 256 bytes) */
151#define	OPCODE_BE_4K		0x20	/* Erase 4KiB block */
152#define	OPCODE_BE_32K		0x52	/* Erase 32KiB block */
153#define	OPCODE_SE		0xd8	/* Sector erase (usually 64KiB) */
154#define	OPCODE_RDID		0x9f	/* Read JEDEC ID */
155
156/* Status Register bits. */
157#define	SR_WIP			1	/* Write in progress */
158#define	SR_WEL			2	/* Write enable latch */
159/* meaning of other SR_* bits may differ between vendors */
160#define	SR_BP0			4	/* Block protect 0 */
161#define	SR_BP1			8	/* Block protect 1 */
162#define	SR_BP2			0x10	/* Block protect 2 */
163#define	SR_SRWD			0x80	/* SR write protect */
164
165/* Define max times to check status register before we give up. */
166#define	MAX_READY_WAIT_COUNT	100000
167
168
169#ifdef CONFIG_MTD_PARTITIONS
170#define	mtd_has_partitions()	(1)
171#else
172#define	mtd_has_partitions()	(0)
173#endif
174
175/*
176 * Ubicom32 FLASH Command Set
177 */
178#define FLASH_FC_INST_CMD	0x00	/* for SPI command only transaction */
179#define FLASH_FC_INST_WR	0x01	/* for SPI write transaction */
180#define FLASH_FC_INST_RD	0x02	/* for SPI read transaction */
181
182#define ALIGN_DOWN(v, a) ((v) & ~((a) - 1))
183#define ALIGN_UP(v, a) (((v) + ((a) - 1)) & ~((a) - 1))
184
185#define	FLASH_COMMAND_KICK_OFF(io)							\
186	asm volatile(									\
187	"	bset	"D(IO_INT_CLR)"(%0), #0, #%%bit("D(IO_XFL_INT_DONE)")	\n\t"	\
188	"	jmpt.t	.+4							\n\t"	\
189	"	bset	"D(IO_INT_SET)"(%0), #0, #%%bit("D(IO_XFL_INT_START)")	\n\t"	\
190		:									\
191		: "a" (io)								\
192		: "memory", "cc"							\
193	);
194
195#define	FLASH_COMMAND_WAIT_FOR_COMPLETION(io)						\
196	asm volatile(									\
197	"	btst	"D(IO_INT_STATUS)"(%0), #%%bit("D(IO_XFL_INT_DONE)")	\n\t"	\
198	"	jmpeq.f	.-4							\n\t"	\
199		:									\
200		: "a" (io)								\
201		: "memory", "cc"									\
202	);
203
204#define	FLASH_COMMAND_EXEC(io)								\
205	FLASH_COMMAND_KICK_OFF(io)							\
206	FLASH_COMMAND_WAIT_FOR_COMPLETION(io)
207
208
209#define OSC1_FREQ 12000000
210#define TEN_MICRO_SECONDS (OSC1_FREQ * 10 / 1000000)
211
212/*
213 * We will have to eventually replace this null definition with the real thing.
214 */
215#define WATCHDOG_RESET()
216
217#define EXTFLASH_WRITE_FIFO_SIZE 32
218#define EXTFLASH_WRITE_BLOCK_SIZE EXTFLASH_WRITE_FIFO_SIZE /* limit the size to
219							    * FIFO capacity, so
220							    * the thread can be
221							    * suspended. */
222
223#define JFFS2_FILESYSTEM_SIZE 0x100000
224
225/****************************************************************************/
226
227struct m25p {
228	struct platform_device	*plt_dev;
229	struct mutex		lock;
230	struct mtd_info		mtd;
231	unsigned		partitioned:1;
232	u8			erase_opcode;
233	u8			command[4];
234};
235
236static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
237{
238	return container_of(mtd, struct m25p, mtd);
239}
240
241/****************************************************************************/
242
243/*
244 * Internal helper functions
245 */
246
247/*
248 * Read the status register, returning its value in the location
249 * Return the status register value.
250 * Returns negative if error occurred.
251 */
252static int read_sr(struct m25p *flash)
253{
254	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
255
256	io->ctl1 &= ~IO_XFL_CTL1_MASK;
257	io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_RD) |
258		IO_XFL_CTL1_FC_DATA(1);
259	io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_RDSR);
260	FLASH_COMMAND_EXEC(io);
261
262	return io->status1 & 0xff;
263}
264
265/*
266 * mem_flash_io_read_u32()
267 */
268static u32 mem_flash_io_read_u32(u32 addr)
269{
270	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
271	io->ctl1 &= ~IO_XFL_CTL1_MASK;
272	io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_RD) |
273		IO_XFL_CTL1_FC_DATA(4) | IO_XFL_CTL1_FC_DUMMY(1) |
274		IO_XFL_CTL1_FC_ADDR;
275	io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_FAST_READ) |
276		IO_XFL_CTL2_FC_ADDR(addr);
277	FLASH_COMMAND_EXEC(io);
278	return io->status1;
279}
280
281/*
282 * mem_flash_read_u8()
283 */
284static u8 mem_flash_read_u8(u32 addr)
285{
286	u32 tmp_addr = ALIGN_DOWN(addr, 4);
287	u32 tmp_data = mem_flash_io_read_u32(tmp_addr);
288	u8 *ptr = (u8 *)&tmp_data;
289	return ptr[addr & 0x3];
290}
291
292/*
293 * mem_flash_read()
294 *	No need to lock as read is implemented with ireads (same as normal flash
295 *	execution).
296 */
297static void mem_flash_read(u32 addr, void *dst, size_t length)
298{
299	/*
300	 * Range check
301	 */
302	/*
303	 * Fix source alignment.
304	 */
305	while (addr & 0x03) {
306		if (length == 0) {
307			return;
308		}
309		*((u8 *)dst) = mem_flash_read_u8(addr++);
310		dst++;
311		length--;
312	}
313
314	while (length >= 4) {
315		u32 tmp_data = mem_flash_io_read_u32(addr);
316		addr += 4;
317		length -= 4;
318
319		/*
320		 * Send the data to the destination.
321		 */
322		memcpy((void *)dst, (void *)&tmp_data, 4);
323		dst += 4;
324	}
325
326	while (length--) {
327		*((u8 *)dst) = mem_flash_read_u8(addr++);
328		dst++;
329	}
330}
331
332/*
333 * mem_flash_wait_until_complete()
334 */
335static void mem_flash_wait_until_complete(void)
336{
337	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
338
339	do {
340		/*
341		 * Put a delay here to deal with flash programming problem.
342		 */
343		u32 mptval = UBICOM32_IO_TIMER->mptval + TEN_MICRO_SECONDS;
344		while (UBICOM32_IO_TIMER->mptval < mptval)
345			;
346
347		io->ctl1 &= ~IO_XFL_CTL1_MASK;
348		io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_RD) |
349			IO_XFL_CTL1_FC_DATA(1);
350		io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_RDSR);
351		FLASH_COMMAND_EXEC(io);
352	} while (io->status1 & SR_WIP);
353}
354
355/*
356 * mem_flash_write_next()
357 */
358static size_t mem_flash_write_next(u32 addr, u8 *buf, size_t length)
359{
360	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
361	u32 data_start = addr;
362	u32 data_end = addr + length;
363	size_t count;
364	u32 i, j;
365
366	/*
367	 * Top limit address.
368	 */
369	u32 block_start = ALIGN_DOWN(data_start, 4);
370	u32 block_end = block_start + EXTFLASH_WRITE_BLOCK_SIZE;
371
372	union {
373		u8 byte[EXTFLASH_WRITE_BLOCK_SIZE];
374		u32 word[EXTFLASH_WRITE_BLOCK_SIZE / 4];
375	} write_buf;
376
377	u32 *flash_addr = (u32 *)block_start;
378
379	/*
380	 * The write block must be limited by FLASH internal buffer.
381	 */
382	u32 block_end_align = ALIGN_DOWN(block_end, 256);
383	bool write_needed;
384
385	block_end = (block_end_align > block_start)
386		? block_end_align : block_end;
387	data_end = (data_end <= block_end) ? data_end : block_end;
388	block_end = ALIGN_UP(data_end, 4);
389	count = data_end - data_start;
390
391	/*
392	 * Transfer data to a buffer.
393	 */
394	for (i = 0; i < (block_end - block_start) / 4; i++) {
395		/*
396		 * The FLASH read can hold D-cache for a long time.
397		 * Use I/O operation to read FLASH to avoid starving other
398		 * threads, especially HRT.  (Do this for application only)
399		 */
400		write_buf.word[i] = mem_flash_io_read_u32(
401			(u32)(&flash_addr[i]));
402	}
403
404	write_needed = false;
405	for (i = 0, j = (data_start - block_start);
406	     i < (data_end - data_start); i++, j++) {
407		write_needed = write_needed || (write_buf.byte[j] != buf[i]);
408		write_buf.byte[j] &= buf[i];
409	}
410
411
412	/*
413	 * If the data in FLASH is identical to what to be written. Then skip
414	 * it.
415	 */
416	if (write_needed) {
417		/*
418		 * Write to flash.
419		 */
420		void *tmp __attribute__((unused));
421		s32 extra_words;
422
423		asm volatile(
424		"	move.4	%0, %2									\n\t"
425		"	bset	"D(IO_INT_SET)"(%1), #0, #%%bit("D(IO_PORTX_INT_FIFO_TX_RESET)")	\n\t"
426		"	pipe_flush 0									\n\t"
427		"	.rept	"D(EXTFLASH_WRITE_FIFO_SIZE / 4)"					\n\t"
428		"	move.4	"D(IO_TX_FIFO)"(%1), (%0)4++						\n\t"
429		"	.endr										\n\t"
430			: "=&a" (tmp)
431			: "a" (io), "r" (&write_buf.word[0])
432			: "memory", "cc"
433		);
434
435		/* Lock FLASH for write access. */
436		io->ctl0 |= IO_XFL_CTL0_MCB_LOCK;
437
438		/* Command: WREN */
439		io->ctl1 &= ~IO_XFL_CTL1_MASK;
440		io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_CMD);
441		io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_WREN);
442		FLASH_COMMAND_EXEC(io);
443
444		/* Command: BYTE PROGRAM */
445		io->ctl1 &= ~IO_XFL_CTL1_MASK;
446		io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_WR) |
447			IO_XFL_CTL1_FC_DATA(block_end - block_start) |
448			IO_XFL_CTL1_FC_ADDR;
449		io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_PP) |
450			IO_XFL_CTL2_FC_ADDR(block_start);
451		FLASH_COMMAND_KICK_OFF(io);
452
453		extra_words = (s32)(block_end - block_start -
454				    EXTFLASH_WRITE_FIFO_SIZE) / 4;
455		if (extra_words > 0) {
456			asm volatile(
457			"	move.4		%0, %3				\n\t"
458			"1:	cmpi		"D(IO_FIFO_LEVEL)"(%1), #4	\n\t"
459			"	jmpgt.s.t	1b				\n\t"
460			"	move.4		"D(IO_TX_FIFO)"(%1), (%0)4++	\n\t"
461			"	add.4		%2, #-1, %2			\n\t"
462			"	jmpgt.t		1b				\n\t"
463				: "=&a" (tmp)
464				: "a" (io), "d" (extra_words),
465				  "r" (&write_buf.word[EXTFLASH_WRITE_FIFO_SIZE / 4])
466				: "memory", "cc"
467			);
468		}
469		FLASH_COMMAND_WAIT_FOR_COMPLETION(io);
470
471		mem_flash_wait_until_complete();
472
473
474		/* Unlock FLASH for cache access. */
475		io->ctl0 &= ~IO_XFL_CTL0_MCB_LOCK;
476	}
477
478	/*
479	 * Complete.
480	 */
481	return count;
482}
483
484/*
485 * mem_flash_write()
486 */
487static void mem_flash_write(u32 addr, const void *src, size_t length)
488{
489	/*
490	 * Write data
491	 */
492	u8_t *ptr = (u8_t *)src;
493	while (length) {
494		size_t count = mem_flash_write_next(addr, ptr, length);
495		addr += count;
496		ptr += count;
497		length -= count;
498	}
499}
500
501/*
502 * Service routine to read status register until ready, or timeout occurs.
503 * Returns non-zero if error.
504 */
505static int wait_till_ready(struct m25p *flash)
506{
507	int count;
508	int sr;
509
510	/* one chip guarantees max 5 msec wait here after page writes,
511	 * but potentially three seconds (!) after page erase.
512	 */
513	for (count = 0; count < MAX_READY_WAIT_COUNT; count++) {
514		u32 mptval;
515		sr = read_sr(flash);
516		if (sr < 0)
517			break;
518		else if (!(sr & SR_WIP))
519			return 0;
520
521		/*
522		 * Put a 10us delay here to deal with flash programming problem.
523		 */
524		mptval = UBICOM32_IO_TIMER->mptval + TEN_MICRO_SECONDS;
525		while ((s32)(mptval - UBICOM32_IO_TIMER->mptval) > 0) {
526			WATCHDOG_RESET();
527		}
528		/* REVISIT sometimes sleeping would be best */
529	}
530
531	return 1;
532}
533
534/*
535 * mem_flash_erase_page()
536 */
537static void mem_flash_erase_page(u32 addr)
538{
539	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
540
541	/* Lock FLASH for write access. */
542	io->ctl0 |= IO_XFL_CTL0_MCB_LOCK;
543
544	/* Command: WREN */
545	io->ctl1 &= ~IO_XFL_CTL1_MASK;
546	io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_CMD);
547	io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_WREN);
548	FLASH_COMMAND_EXEC(io);
549
550	/* Command: ERASE */
551	io->ctl1 &= ~IO_XFL_CTL1_MASK;
552	io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_CMD) |
553		IO_XFL_CTL1_FC_ADDR;
554	io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_SE) |
555		IO_XFL_CTL2_FC_ADDR(addr);
556	FLASH_COMMAND_EXEC(io);
557
558	mem_flash_wait_until_complete();
559
560	/* Unlock FLASH for cache access. */
561	io->ctl0 &= ~IO_XFL_CTL0_MCB_LOCK;
562}
563
564/*
565 * mem_flash_erase()
566 */
567static u32 mem_flash_erase(u32 addr, u32 length)
568{
569	/*
570	 * Calculate the endaddress to be the first address of the page
571	 * just beyond this erase section of pages.
572	 */
573	u32 endaddr = addr + length;
574
575	/*
576	 * Erase.
577	 */
578	while (addr < endaddr) {
579		u32 test_addr = addr;
580		mem_flash_erase_page(addr);
581
582		/*
583		 * Test how much was erased as actual flash page at this address
584		 * may be smaller than the expected page size.
585		 */
586		while (test_addr < endaddr) {
587			/*
588			 * The FLASH read can hold D-cache for a long time.  Use
589			 * I/O operation to read FLASH to avoid starving other
590			 * threads, especially HRT.  (Do this for application
591			 * only)
592			 */
593			if (mem_flash_io_read_u32(test_addr) != 0xFFFFFFFF) {
594				break;
595			}
596			test_addr += 4;
597		}
598		if (test_addr == addr) {
599			printk("erase failed at address 0x%x, skipping",
600			       test_addr);
601			test_addr += 4;
602			return 1;
603		}
604		addr = test_addr;
605	}
606	return 0;
607}
608
609
610/****************************************************************************/
611
612/*
613 * MTD implementation
614 */
615
616/*
617 * Erase an address range on the flash chip.  The address range may extend
618 * one or more erase sectors.  Return an error is there is a problem erasing.
619 */
620static int ubicom32_flash_driver_erase(struct mtd_info *mtd,
621				       struct erase_info *instr)
622{
623	struct m25p *flash = mtd_to_m25p(mtd);
624	u32 addr, len;
625
626	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %lld\n",
627	      dev_name(&flash->plt_dev->dev), __FUNCTION__, "at",
628	      (u32)instr->addr, instr->len);
629
630	/* sanity checks */
631	if (instr->addr + instr->len > flash->mtd.size)
632		return -EINVAL;
633	if ((instr->addr % mtd->erasesize) != 0
634			|| (instr->len % mtd->erasesize) != 0) {
635		return -EINVAL;
636	}
637
638	addr = instr->addr + UBICOM32_FLASH_BASE;
639	len = instr->len;
640
641	mutex_lock(&flash->lock);
642
643	/* REVISIT in some cases we could speed up erasing large regions
644	 * by using OPCODE_SE instead of OPCODE_BE_4K
645	 */
646
647	/* now erase those sectors */
648	if (mem_flash_erase(addr, len)) {
649		instr->state = MTD_ERASE_FAILED;
650		mutex_unlock(&flash->lock);
651		return -EIO;
652	}
653
654	mutex_unlock(&flash->lock);
655	instr->state = MTD_ERASE_DONE;
656	mtd_erase_callback(instr);
657	return 0;
658}
659
660/*
661 * Read an address range from the flash chip.  The address range
662 * may be any size provided it is within the physical boundaries.
663 */
664static int ubicom32_flash_driver_read(struct mtd_info *mtd, loff_t from,
665				      size_t len, size_t *retlen, u_char *buf)
666{
667	struct m25p *flash = mtd_to_m25p(mtd);
668	u32 base_addr = UBICOM32_FLASH_BASE + from;
669
670	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %d\n",
671	      dev_name(&flash->plt_dev->dev), __FUNCTION__, "from",
672	      (u32)from, len);
673
674	/* sanity checks */
675	if (!len)
676		return 0;
677
678	if (from + len > flash->mtd.size)
679		return -EINVAL;
680
681	/* Byte count starts at zero. */
682	if (retlen)
683		*retlen = 0;
684
685	mutex_lock(&flash->lock);
686
687	/* Wait till previous write/erase is done. */
688	if (wait_till_ready(flash)) {
689		/* REVISIT status return?? */
690		mutex_unlock(&flash->lock);
691		return 1;
692	}
693
694	mem_flash_read(base_addr, (void *)buf, len);
695
696	if (retlen)
697		*retlen = len;
698
699	mutex_unlock(&flash->lock);
700
701	return 0;
702}
703
704/*
705 * Write an address range to the flash chip.  Data must be written in
706 * FLASH_PAGESIZE chunks.  The address range may be any size provided
707 * it is within the physical boundaries.
708 */
709static int ubicom32_flash_driver_write(struct mtd_info *mtd, loff_t to,
710				       size_t len, size_t *retlen,
711				       const u_char *buf)
712{
713	struct m25p *flash = mtd_to_m25p(mtd);
714	u32 base_addr = UBICOM32_FLASH_BASE + to;
715	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %d\n",
716	      dev_name(&flash->plt_dev->dev), __FUNCTION__, "to",
717	      (u32)to, len);
718
719	if (retlen)
720		*retlen = 0;
721
722	/* sanity checks */
723	if (!len)
724		return 0;
725
726	if (to + len > flash->mtd.size)
727		return -EINVAL;
728
729	mutex_lock(&flash->lock);
730
731	mem_flash_write(base_addr, (void *) buf, len);
732
733	/* Wait until finished previous write command. */
734	if (wait_till_ready(flash)) {
735		mutex_unlock(&flash->lock);
736		return 1;
737	}
738
739	if (retlen)
740		*retlen = len;
741
742	mutex_unlock(&flash->lock);
743	return 0;
744}
745
746
747/****************************************************************************/
748
749/*
750 * SPI device driver setup and teardown
751 */
752
753struct flash_info {
754	char		*name;
755
756	/* JEDEC id zero means "no ID" (most older chips); otherwise it has
757	 * a high byte of zero plus three data bytes: the manufacturer id,
758	 * then a two byte device id.
759	 */
760	u32		jedec_id;
761
762	/* The size listed here is what works with OPCODE_SE, which isn't
763	 * necessarily called a "sector" by the vendor.
764	 */
765	unsigned	sector_size;
766	u16		n_sectors;
767
768	u16		flags;
769#define	SECT_4K		0x01		/* OPCODE_BE_4K works uniformly */
770};
771
772
773/* NOTE: double check command sets and memory organization when you add
774 * more flash chips.  This current list focusses on newer chips, which
775 * have been converging on command sets which including JEDEC ID.
776 */
777static struct flash_info __devinitdata m25p_data[] = {
778
779	/* Atmel -- some are (confusingly) marketed as "DataFlash" */
780	{ "at25fs010",  0x1f6601, 32 * 1024, 4, SECT_4K, },
781	{ "at25fs040",  0x1f6604, 64 * 1024, 8, SECT_4K, },
782
783	{ "at25df041a", 0x1f4401, 64 * 1024, 8, SECT_4K, },
784
785	{ "at26f004",   0x1f0400, 64 * 1024, 8, SECT_4K, },
786	{ "at26df081a", 0x1f4501, 64 * 1024, 16, SECT_4K, },
787	{ "at26df161a", 0x1f4601, 64 * 1024, 32, SECT_4K, },
788	{ "at26df321",  0x1f4701, 64 * 1024, 64, SECT_4K, },
789
790	/* Spansion -- single (large) sector size only, at least
791	 * for the chips listed here (without boot sectors).
792	 */
793	{ "s25sl004a", 0x010212, 64 * 1024, 8, },
794	{ "s25sl008a", 0x010213, 64 * 1024, 16, },
795	{ "s25sl016a", 0x010214, 64 * 1024, 32, },
796	{ "s25sl032a", 0x010215, 64 * 1024, 64, },
797	{ "s25sl064a", 0x010216, 64 * 1024, 128, },
798
799	/* SST -- large erase sizes are "overlays", "sectors" are 4K */
800	{ "sst25vf040b", 0xbf258d, 64 * 1024, 8, SECT_4K, },
801	{ "sst25vf080b", 0xbf258e, 64 * 1024, 16, SECT_4K, },
802	{ "sst25vf016b", 0xbf2541, 64 * 1024, 32, SECT_4K, },
803	{ "sst25vf032b", 0xbf254a, 64 * 1024, 64, SECT_4K, },
804
805	/* ST Microelectronics -- newer production may have feature updates */
806	{ "m25p05",  0x202010,  32 * 1024, 2, },
807	{ "m25p10",  0x202011,  32 * 1024, 4, },
808	{ "m25p20",  0x202012,  64 * 1024, 4, },
809	{ "m25p40",  0x202013,  64 * 1024, 8, },
810	{ "m25p80",         0,  64 * 1024, 16, },
811	{ "m25p16",  0x202015,  64 * 1024, 32, },
812	{ "m25p32",  0x202016,  64 * 1024, 64, },
813	{ "m25p64",  0x202017,  64 * 1024, 128, },
814	{ "m25p128", 0x202018, 256 * 1024, 64, },
815
816	{ "m45pe80", 0x204014,  64 * 1024, 16, },
817	{ "m45pe16", 0x204015,  64 * 1024, 32, },
818
819	{ "m25pe80", 0x208014,  64 * 1024, 16, },
820	{ "m25pe16", 0x208015,  64 * 1024, 32, SECT_4K, },
821
822	/* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
823	{ "w25x10", 0xef3011, 64 * 1024, 2, SECT_4K, },
824	{ "w25x20", 0xef3012, 64 * 1024, 4, SECT_4K, },
825	{ "w25x40", 0xef3013, 64 * 1024, 8, SECT_4K, },
826	{ "w25x80", 0xef3014, 64 * 1024, 16, SECT_4K, },
827	{ "w25x16", 0xef3015, 64 * 1024, 32, SECT_4K, },
828	{ "w25x32", 0xef3016, 64 * 1024, 64, SECT_4K, },
829	{ "w25x64", 0xef3017, 64 * 1024, 128, SECT_4K, },
830
831	/* Macronix -- mx25lxxx */
832	{ "mx25l32",  0xc22016, 64 * 1024,  64, },
833	{ "mx25l64",  0xc22017, 64 * 1024, 128, },
834	{ "mx25l128", 0xc22018, 64 * 1024, 256, },
835
836};
837
838struct flash_info *__devinit jedec_probe(struct platform_device *spi)
839{
840	int			tmp;
841	u32			jedec;
842	struct flash_info	*info;
843	struct ubicom32_io_port *io = (struct ubicom32_io_port *)RA;
844
845	/*
846	 * Setup and run RDID command on the flash.
847	 */
848	io->ctl1 &= ~IO_XFL_CTL1_MASK;
849	io->ctl1 |= IO_XFL_CTL1_FC_INST(FLASH_FC_INST_RD) |
850		IO_XFL_CTL1_FC_DATA(3);
851	io->ctl2 = IO_XFL_CTL2_FC_CMD(OPCODE_RDID);
852	FLASH_COMMAND_EXEC(io);
853
854	jedec = io->status1 & 0x00ffffff;
855
856	for (tmp = 0, info = m25p_data;
857			tmp < ARRAY_SIZE(m25p_data);
858			tmp++, info++) {
859		if (info->jedec_id == jedec)
860			return info;
861	}
862	dev_err(&spi->dev, "unrecognized JEDEC id %06x\n", jedec);
863	return NULL;
864}
865
866
867/*
868 * board specific setup should have ensured the SPI clock used here
869 * matches what the READ command supports, at least until this driver
870 * understands FAST_READ (for clocks over 25 MHz).
871 */
872static int __devinit ubicom32_flash_probe(struct platform_device *spi)
873{
874	struct flash_platform_data	*data;
875	struct m25p			*flash;
876	struct flash_info		*info;
877	unsigned			i;
878
879	/* Platform data helps sort out which chip type we have, as
880	 * well as how this board partitions it.  If we don't have
881	 * a chip ID, try the JEDEC id commands; they'll work for most
882	 * newer chips, even if we don't recognize the particular chip.
883	 */
884	data = spi->dev.platform_data;
885	if (data && data->type) {
886		for (i = 0, info = m25p_data;
887				i < ARRAY_SIZE(m25p_data);
888				i++, info++) {
889			if (strcmp(data->type, info->name) == 0)
890				break;
891		}
892
893		/* unrecognized chip? */
894		if (i == ARRAY_SIZE(m25p_data)) {
895			DEBUG(MTD_DEBUG_LEVEL0, "%s: unrecognized id %s\n",
896			      dev_name(&spi->dev), data->type);
897			info = NULL;
898
899		/* recognized; is that chip really what's there? */
900		} else if (info->jedec_id) {
901			struct flash_info	*chip = jedec_probe(spi);
902
903			if (!chip || chip != info) {
904				dev_warn(&spi->dev, "found %s, expected %s\n",
905						chip ? chip->name : "UNKNOWN",
906						info->name);
907				info = NULL;
908			}
909		}
910	} else
911		info = jedec_probe(spi);
912
913	if (!info)
914		return -ENODEV;
915
916	flash = kzalloc(sizeof *flash, GFP_KERNEL);
917	if (!flash)
918		return -ENOMEM;
919
920	flash->plt_dev = spi;
921	mutex_init(&flash->lock);
922	dev_set_drvdata(&spi->dev, flash);
923
924	if (data && data->name)
925		flash->mtd.name = data->name;
926	else
927		flash->mtd.name = dev_name(&spi->dev);
928
929	flash->mtd.type = MTD_NORFLASH;
930	flash->mtd.writesize = 1;
931	flash->mtd.flags = MTD_CAP_NORFLASH;
932	flash->mtd.size = info->sector_size * info->n_sectors;
933	flash->mtd.erase = ubicom32_flash_driver_erase;
934	flash->mtd.read = ubicom32_flash_driver_read;
935	flash->mtd.write = ubicom32_flash_driver_write;
936
937	/* prefer "small sector" erase if possible */
938	/*
939	 * The Ubicom erase code does not use the opcode for smaller sectors,
940	 * so disable that functionality and keep erasesize == sector_size
941	 * so that the test in ubicom32_flash_driver_erase works properly.
942	 *
943	 * This was: `if (info->flags & SECT_4K) {' instead of `if (0) {'
944	 */
945	if (0) {
946		flash->erase_opcode = OPCODE_BE_4K;
947		flash->mtd.erasesize = 4096;
948	} else {
949		flash->erase_opcode = OPCODE_SE;
950		flash->mtd.erasesize = info->sector_size;
951	}
952
953	dev_info(&spi->dev, "%s (%lld Kbytes)\n", info->name,
954		 flash->mtd.size / 1024);
955
956	DEBUG(MTD_DEBUG_LEVEL2,
957		"mtd .name = %s, .size = 0x%.8llx (%lluMiB) "
958			".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
959		flash->mtd.name,
960		flash->mtd.size, flash->mtd.size / (1024*1024),
961		flash->mtd.erasesize, flash->mtd.erasesize / 1024,
962		flash->mtd.numeraseregions);
963
964	if (flash->mtd.numeraseregions)
965		for (i = 0; i < flash->mtd.numeraseregions; i++)
966			DEBUG(MTD_DEBUG_LEVEL2,
967				"mtd.eraseregions[%d] = { .offset = 0x%.8llx, "
968				".erasesize = 0x%.8x (%uKiB), "
969				".numblocks = %d }\n",
970				i, flash->mtd.eraseregions[i].offset,
971				flash->mtd.eraseregions[i].erasesize,
972				flash->mtd.eraseregions[i].erasesize / 1024,
973				flash->mtd.eraseregions[i].numblocks);
974
975
976	/* partitions should match sector boundaries; and it may be good to
977	 * use readonly partitions for writeprotected sectors (BP2..BP0).
978	 */
979	if (mtd_has_partitions()) {
980		struct mtd_partition	*parts = NULL;
981		int			nr_parts = 0;
982
983#ifdef CONFIG_MTD_CMDLINE_PARTS
984		static const char *part_probes[] = { "cmdlinepart", NULL, };
985
986		nr_parts = parse_mtd_partitions(&flash->mtd,
987				part_probes, &parts, 0);
988#endif
989
990		if (nr_parts <= 0 && data && data->parts) {
991			parts = data->parts;
992			nr_parts = data->nr_parts;
993			if (nr_parts >= 2) {
994				/*
995				 * Set last partition size to be 1M.
996				 */
997				parts[1].size = flash->mtd.size -
998					parts[0].size - JFFS2_FILESYSTEM_SIZE;
999				parts[2].size = JFFS2_FILESYSTEM_SIZE;
1000			}
1001		}
1002
1003		if (nr_parts > 0) {
1004			for (i = 0; i < nr_parts; i++) {
1005				DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
1006					"{.name = %s, .offset = 0x%.8llx, "
1007						".size = 0x%.8llx (%lluKiB) }\n",
1008					i, parts[i].name,
1009					parts[i].offset,
1010					parts[i].size,
1011					parts[i].size / 1024);
1012			}
1013			flash->partitioned = 1;
1014			return add_mtd_partitions(&flash->mtd, parts, nr_parts);
1015		}
1016	} else if (data->nr_parts)
1017		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
1018				data->nr_parts, data->name);
1019
1020	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;
1021}
1022
1023
1024static int __devexit ubicom32_flash_remove(struct spi_device *spi)
1025{
1026	struct m25p	*flash = dev_get_drvdata(&spi->dev);
1027	int		status;
1028
1029	/* Clean up MTD stuff. */
1030	if (mtd_has_partitions() && flash->partitioned)
1031		status = del_mtd_partitions(&flash->mtd);
1032	else
1033		status = del_mtd_device(&flash->mtd);
1034	if (status == 0)
1035		kfree(flash);
1036	return 0;
1037}
1038
1039static struct platform_driver ubicom32_flash_driver = {
1040	.driver = {
1041		.name	= "ubicom32flashdriver",
1042		.bus	= &platform_bus_type,
1043		.owner	= THIS_MODULE,
1044	},
1045	.probe	= ubicom32_flash_probe,
1046	.remove	= NULL,
1047};
1048
1049static int ubicom32_flash_driver_init(void)
1050{
1051	return platform_driver_register(&ubicom32_flash_driver);
1052}
1053
1054
1055static void ubicom32_flash_driver_exit(void)
1056{
1057	platform_driver_unregister(&ubicom32_flash_driver);
1058}
1059
1060
1061module_init(ubicom32_flash_driver_init);
1062module_exit(ubicom32_flash_driver_exit);
1063
1064MODULE_LICENSE("GPL");
1065MODULE_AUTHOR("Mike Lavender");
1066MODULE_DESCRIPTION("Ubicom32 MTD SPI driver for ST M25Pxx flash chips");
1067