xref: /openbmc/linux/drivers/mtd/nand/raw/au1550nd.c (revision dc6a81c3) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2004 Embedded Edge, LLC
4  */
5 
6 #include <linux/slab.h>
7 #include <linux/module.h>
8 #include <linux/interrupt.h>
9 #include <linux/mtd/mtd.h>
10 #include <linux/mtd/rawnand.h>
11 #include <linux/mtd/partitions.h>
12 #include <linux/platform_device.h>
13 #include <asm/io.h>
14 #include <asm/mach-au1x00/au1000.h>
15 #include <asm/mach-au1x00/au1550nd.h>
16 
17 
18 struct au1550nd_ctx {
19 	struct nand_chip chip;
20 
21 	int cs;
22 	void __iomem *base;
23 	void (*write_byte)(struct nand_chip *, u_char);
24 };
25 
26 /**
27  * au_read_byte -  read one byte from the chip
28  * @this:	NAND chip object
29  *
30  * read function for 8bit buswidth
31  */
32 static u_char au_read_byte(struct nand_chip *this)
33 {
34 	u_char ret = readb(this->legacy.IO_ADDR_R);
35 	wmb(); /* drain writebuffer */
36 	return ret;
37 }
38 
39 /**
40  * au_write_byte -  write one byte to the chip
41  * @this:	NAND chip object
42  * @byte:	pointer to data byte to write
43  *
44  * write function for 8it buswidth
45  */
46 static void au_write_byte(struct nand_chip *this, u_char byte)
47 {
48 	writeb(byte, this->legacy.IO_ADDR_W);
49 	wmb(); /* drain writebuffer */
50 }
51 
52 /**
53  * au_read_byte16 -  read one byte endianness aware from the chip
54  * @this:	NAND chip object
55  *
56  * read function for 16bit buswidth with endianness conversion
57  */
58 static u_char au_read_byte16(struct nand_chip *this)
59 {
60 	u_char ret = (u_char) cpu_to_le16(readw(this->legacy.IO_ADDR_R));
61 	wmb(); /* drain writebuffer */
62 	return ret;
63 }
64 
65 /**
66  * au_write_byte16 -  write one byte endianness aware to the chip
67  * @this:	NAND chip object
68  * @byte:	pointer to data byte to write
69  *
70  * write function for 16bit buswidth with endianness conversion
71  */
72 static void au_write_byte16(struct nand_chip *this, u_char byte)
73 {
74 	writew(le16_to_cpu((u16) byte), this->legacy.IO_ADDR_W);
75 	wmb(); /* drain writebuffer */
76 }
77 
78 /**
79  * au_write_buf -  write buffer to chip
80  * @this:	NAND chip object
81  * @buf:	data buffer
82  * @len:	number of bytes to write
83  *
84  * write function for 8bit buswidth
85  */
86 static void au_write_buf(struct nand_chip *this, const u_char *buf, int len)
87 {
88 	int i;
89 
90 	for (i = 0; i < len; i++) {
91 		writeb(buf[i], this->legacy.IO_ADDR_W);
92 		wmb(); /* drain writebuffer */
93 	}
94 }
95 
96 /**
97  * au_read_buf -  read chip data into buffer
98  * @this:	NAND chip object
99  * @buf:	buffer to store date
100  * @len:	number of bytes to read
101  *
102  * read function for 8bit buswidth
103  */
104 static void au_read_buf(struct nand_chip *this, u_char *buf, int len)
105 {
106 	int i;
107 
108 	for (i = 0; i < len; i++) {
109 		buf[i] = readb(this->legacy.IO_ADDR_R);
110 		wmb(); /* drain writebuffer */
111 	}
112 }
113 
114 /**
115  * au_write_buf16 -  write buffer to chip
116  * @this:	NAND chip object
117  * @buf:	data buffer
118  * @len:	number of bytes to write
119  *
120  * write function for 16bit buswidth
121  */
122 static void au_write_buf16(struct nand_chip *this, const u_char *buf, int len)
123 {
124 	int i;
125 	u16 *p = (u16 *) buf;
126 	len >>= 1;
127 
128 	for (i = 0; i < len; i++) {
129 		writew(p[i], this->legacy.IO_ADDR_W);
130 		wmb(); /* drain writebuffer */
131 	}
132 
133 }
134 
135 /**
136  * au_read_buf16 -  read chip data into buffer
137  * @this:	NAND chip object
138  * @buf:	buffer to store date
139  * @len:	number of bytes to read
140  *
141  * read function for 16bit buswidth
142  */
143 static void au_read_buf16(struct nand_chip *this, u_char *buf, int len)
144 {
145 	int i;
146 	u16 *p = (u16 *) buf;
147 	len >>= 1;
148 
149 	for (i = 0; i < len; i++) {
150 		p[i] = readw(this->legacy.IO_ADDR_R);
151 		wmb(); /* drain writebuffer */
152 	}
153 }
154 
155 /* Select the chip by setting nCE to low */
156 #define NAND_CTL_SETNCE		1
157 /* Deselect the chip by setting nCE to high */
158 #define NAND_CTL_CLRNCE		2
159 /* Select the command latch by setting CLE to high */
160 #define NAND_CTL_SETCLE		3
161 /* Deselect the command latch by setting CLE to low */
162 #define NAND_CTL_CLRCLE		4
163 /* Select the address latch by setting ALE to high */
164 #define NAND_CTL_SETALE		5
165 /* Deselect the address latch by setting ALE to low */
166 #define NAND_CTL_CLRALE		6
167 
168 static void au1550_hwcontrol(struct mtd_info *mtd, int cmd)
169 {
170 	struct nand_chip *this = mtd_to_nand(mtd);
171 	struct au1550nd_ctx *ctx = container_of(this, struct au1550nd_ctx,
172 						chip);
173 
174 	switch (cmd) {
175 
176 	case NAND_CTL_SETCLE:
177 		this->legacy.IO_ADDR_W = ctx->base + MEM_STNAND_CMD;
178 		break;
179 
180 	case NAND_CTL_CLRCLE:
181 		this->legacy.IO_ADDR_W = ctx->base + MEM_STNAND_DATA;
182 		break;
183 
184 	case NAND_CTL_SETALE:
185 		this->legacy.IO_ADDR_W = ctx->base + MEM_STNAND_ADDR;
186 		break;
187 
188 	case NAND_CTL_CLRALE:
189 		this->legacy.IO_ADDR_W = ctx->base + MEM_STNAND_DATA;
190 		/* FIXME: Nobody knows why this is necessary,
191 		 * but it works only that way */
192 		udelay(1);
193 		break;
194 
195 	case NAND_CTL_SETNCE:
196 		/* assert (force assert) chip enable */
197 		alchemy_wrsmem((1 << (4 + ctx->cs)), AU1000_MEM_STNDCTL);
198 		break;
199 
200 	case NAND_CTL_CLRNCE:
201 		/* deassert chip enable */
202 		alchemy_wrsmem(0, AU1000_MEM_STNDCTL);
203 		break;
204 	}
205 
206 	this->legacy.IO_ADDR_R = this->legacy.IO_ADDR_W;
207 
208 	wmb(); /* Drain the writebuffer */
209 }
210 
211 int au1550_device_ready(struct nand_chip *this)
212 {
213 	return (alchemy_rdsmem(AU1000_MEM_STSTAT) & 0x1) ? 1 : 0;
214 }
215 
216 /**
217  * au1550_select_chip - control -CE line
218  *	Forbid driving -CE manually permitting the NAND controller to do this.
219  *	Keeping -CE asserted during the whole sector reads interferes with the
220  *	NOR flash and PCMCIA drivers as it causes contention on the static bus.
221  *	We only have to hold -CE low for the NAND read commands since the flash
222  *	chip needs it to be asserted during chip not ready time but the NAND
223  *	controller keeps it released.
224  *
225  * @this:	NAND chip object
226  * @chip:	chipnumber to select, -1 for deselect
227  */
228 static void au1550_select_chip(struct nand_chip *this, int chip)
229 {
230 }
231 
232 /**
233  * au1550_command - Send command to NAND device
234  * @this:	NAND chip object
235  * @command:	the command to be sent
236  * @column:	the column address for this command, -1 if none
237  * @page_addr:	the page address for this command, -1 if none
238  */
239 static void au1550_command(struct nand_chip *this, unsigned command,
240 			   int column, int page_addr)
241 {
242 	struct mtd_info *mtd = nand_to_mtd(this);
243 	struct au1550nd_ctx *ctx = container_of(this, struct au1550nd_ctx,
244 						chip);
245 	int ce_override = 0, i;
246 	unsigned long flags = 0;
247 
248 	/* Begin command latch cycle */
249 	au1550_hwcontrol(mtd, NAND_CTL_SETCLE);
250 	/*
251 	 * Write out the command to the device.
252 	 */
253 	if (command == NAND_CMD_SEQIN) {
254 		int readcmd;
255 
256 		if (column >= mtd->writesize) {
257 			/* OOB area */
258 			column -= mtd->writesize;
259 			readcmd = NAND_CMD_READOOB;
260 		} else if (column < 256) {
261 			/* First 256 bytes --> READ0 */
262 			readcmd = NAND_CMD_READ0;
263 		} else {
264 			column -= 256;
265 			readcmd = NAND_CMD_READ1;
266 		}
267 		ctx->write_byte(this, readcmd);
268 	}
269 	ctx->write_byte(this, command);
270 
271 	/* Set ALE and clear CLE to start address cycle */
272 	au1550_hwcontrol(mtd, NAND_CTL_CLRCLE);
273 
274 	if (column != -1 || page_addr != -1) {
275 		au1550_hwcontrol(mtd, NAND_CTL_SETALE);
276 
277 		/* Serially input address */
278 		if (column != -1) {
279 			/* Adjust columns for 16 bit buswidth */
280 			if (this->options & NAND_BUSWIDTH_16 &&
281 					!nand_opcode_8bits(command))
282 				column >>= 1;
283 			ctx->write_byte(this, column);
284 		}
285 		if (page_addr != -1) {
286 			ctx->write_byte(this, (u8)(page_addr & 0xff));
287 
288 			if (command == NAND_CMD_READ0 ||
289 			    command == NAND_CMD_READ1 ||
290 			    command == NAND_CMD_READOOB) {
291 				/*
292 				 * NAND controller will release -CE after
293 				 * the last address byte is written, so we'll
294 				 * have to forcibly assert it. No interrupts
295 				 * are allowed while we do this as we don't
296 				 * want the NOR flash or PCMCIA drivers to
297 				 * steal our precious bytes of data...
298 				 */
299 				ce_override = 1;
300 				local_irq_save(flags);
301 				au1550_hwcontrol(mtd, NAND_CTL_SETNCE);
302 			}
303 
304 			ctx->write_byte(this, (u8)(page_addr >> 8));
305 
306 			if (this->options & NAND_ROW_ADDR_3)
307 				ctx->write_byte(this,
308 						((page_addr >> 16) & 0x0f));
309 		}
310 		/* Latch in address */
311 		au1550_hwcontrol(mtd, NAND_CTL_CLRALE);
312 	}
313 
314 	/*
315 	 * Program and erase have their own busy handlers.
316 	 * Status and sequential in need no delay.
317 	 */
318 	switch (command) {
319 
320 	case NAND_CMD_PAGEPROG:
321 	case NAND_CMD_ERASE1:
322 	case NAND_CMD_ERASE2:
323 	case NAND_CMD_SEQIN:
324 	case NAND_CMD_STATUS:
325 		return;
326 
327 	case NAND_CMD_RESET:
328 		break;
329 
330 	case NAND_CMD_READ0:
331 	case NAND_CMD_READ1:
332 	case NAND_CMD_READOOB:
333 		/* Check if we're really driving -CE low (just in case) */
334 		if (unlikely(!ce_override))
335 			break;
336 
337 		/* Apply a short delay always to ensure that we do wait tWB. */
338 		ndelay(100);
339 		/* Wait for a chip to become ready... */
340 		for (i = this->legacy.chip_delay;
341 		     !this->legacy.dev_ready(this) && i > 0; --i)
342 			udelay(1);
343 
344 		/* Release -CE and re-enable interrupts. */
345 		au1550_hwcontrol(mtd, NAND_CTL_CLRNCE);
346 		local_irq_restore(flags);
347 		return;
348 	}
349 	/* Apply this short delay always to ensure that we do wait tWB. */
350 	ndelay(100);
351 
352 	while(!this->legacy.dev_ready(this));
353 }
354 
355 static int find_nand_cs(unsigned long nand_base)
356 {
357 	void __iomem *base =
358 			(void __iomem *)KSEG1ADDR(AU1000_STATIC_MEM_PHYS_ADDR);
359 	unsigned long addr, staddr, start, mask, end;
360 	int i;
361 
362 	for (i = 0; i < 4; i++) {
363 		addr = 0x1000 + (i * 0x10);			/* CSx */
364 		staddr = __raw_readl(base + addr + 0x08);	/* STADDRx */
365 		/* figure out the decoded range of this CS */
366 		start = (staddr << 4) & 0xfffc0000;
367 		mask = (staddr << 18) & 0xfffc0000;
368 		end = (start | (start - 1)) & ~(start ^ mask);
369 		if ((nand_base >= start) && (nand_base < end))
370 			return i;
371 	}
372 
373 	return -ENODEV;
374 }
375 
376 static int au1550nd_probe(struct platform_device *pdev)
377 {
378 	struct au1550nd_platdata *pd;
379 	struct au1550nd_ctx *ctx;
380 	struct nand_chip *this;
381 	struct mtd_info *mtd;
382 	struct resource *r;
383 	int ret, cs;
384 
385 	pd = dev_get_platdata(&pdev->dev);
386 	if (!pd) {
387 		dev_err(&pdev->dev, "missing platform data\n");
388 		return -ENODEV;
389 	}
390 
391 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
392 	if (!ctx)
393 		return -ENOMEM;
394 
395 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
396 	if (!r) {
397 		dev_err(&pdev->dev, "no NAND memory resource\n");
398 		ret = -ENODEV;
399 		goto out1;
400 	}
401 	if (request_mem_region(r->start, resource_size(r), "au1550-nand")) {
402 		dev_err(&pdev->dev, "cannot claim NAND memory area\n");
403 		ret = -ENOMEM;
404 		goto out1;
405 	}
406 
407 	ctx->base = ioremap(r->start, 0x1000);
408 	if (!ctx->base) {
409 		dev_err(&pdev->dev, "cannot remap NAND memory area\n");
410 		ret = -ENODEV;
411 		goto out2;
412 	}
413 
414 	this = &ctx->chip;
415 	mtd = nand_to_mtd(this);
416 	mtd->dev.parent = &pdev->dev;
417 
418 	/* figure out which CS# r->start belongs to */
419 	cs = find_nand_cs(r->start);
420 	if (cs < 0) {
421 		dev_err(&pdev->dev, "cannot detect NAND chipselect\n");
422 		ret = -ENODEV;
423 		goto out3;
424 	}
425 	ctx->cs = cs;
426 
427 	this->legacy.dev_ready = au1550_device_ready;
428 	this->legacy.select_chip = au1550_select_chip;
429 	this->legacy.cmdfunc = au1550_command;
430 
431 	/* 30 us command delay time */
432 	this->legacy.chip_delay = 30;
433 	this->ecc.mode = NAND_ECC_SOFT;
434 	this->ecc.algo = NAND_ECC_HAMMING;
435 
436 	if (pd->devwidth)
437 		this->options |= NAND_BUSWIDTH_16;
438 
439 	this->legacy.read_byte = (pd->devwidth) ? au_read_byte16 : au_read_byte;
440 	ctx->write_byte = (pd->devwidth) ? au_write_byte16 : au_write_byte;
441 	this->legacy.write_buf = (pd->devwidth) ? au_write_buf16 : au_write_buf;
442 	this->legacy.read_buf = (pd->devwidth) ? au_read_buf16 : au_read_buf;
443 
444 	ret = nand_scan(this, 1);
445 	if (ret) {
446 		dev_err(&pdev->dev, "NAND scan failed with %d\n", ret);
447 		goto out3;
448 	}
449 
450 	mtd_device_register(mtd, pd->parts, pd->num_parts);
451 
452 	platform_set_drvdata(pdev, ctx);
453 
454 	return 0;
455 
456 out3:
457 	iounmap(ctx->base);
458 out2:
459 	release_mem_region(r->start, resource_size(r));
460 out1:
461 	kfree(ctx);
462 	return ret;
463 }
464 
465 static int au1550nd_remove(struct platform_device *pdev)
466 {
467 	struct au1550nd_ctx *ctx = platform_get_drvdata(pdev);
468 	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
469 
470 	nand_release(&ctx->chip);
471 	iounmap(ctx->base);
472 	release_mem_region(r->start, 0x1000);
473 	kfree(ctx);
474 	return 0;
475 }
476 
477 static struct platform_driver au1550nd_driver = {
478 	.driver = {
479 		.name	= "au1550-nand",
480 	},
481 	.probe		= au1550nd_probe,
482 	.remove		= au1550nd_remove,
483 };
484 
485 module_platform_driver(au1550nd_driver);
486 
487 MODULE_LICENSE("GPL");
488 MODULE_AUTHOR("Embedded Edge, LLC");
489 MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on Pb1550 board");
490