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  1/*
  2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
  3 *  JZ4740 SoC NAND controller driver
  4 *
  5 *  This program is free software; you can redistribute it and/or modify it
  6 *  under  the terms of the GNU General  Public License as published by the
  7 *  Free Software Foundation;  either version 2 of the License, or (at your
  8 *  option) any later version.
  9 *
 10 *  You should have received a copy of the GNU General Public License along
 11 *  with this program; if not, write to the Free Software Foundation, Inc.,
 12 *  675 Mass Ave, Cambridge, MA 02139, USA.
 13 *
 14 */
 15
 16#include <linux/ioport.h>
 17#include <linux/kernel.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/slab.h>
 21
 22#include <linux/mtd/mtd.h>
 23#include <linux/mtd/nand.h>
 24#include <linux/mtd/partitions.h>
 25
 26#include <linux/gpio.h>
 27
 28#include <asm/mach-jz4740/jz4740_nand.h>
 29
 30#define JZ_REG_NAND_CTRL	0x50
 31#define JZ_REG_NAND_ECC_CTRL	0x100
 32#define JZ_REG_NAND_DATA	0x104
 33#define JZ_REG_NAND_PAR0	0x108
 34#define JZ_REG_NAND_PAR1	0x10C
 35#define JZ_REG_NAND_PAR2	0x110
 36#define JZ_REG_NAND_IRQ_STAT	0x114
 37#define JZ_REG_NAND_IRQ_CTRL	0x118
 38#define JZ_REG_NAND_ERR(x)	(0x11C + ((x) << 2))
 39
 40#define JZ_NAND_ECC_CTRL_PAR_READY	BIT(4)
 41#define JZ_NAND_ECC_CTRL_ENCODING	BIT(3)
 42#define JZ_NAND_ECC_CTRL_RS		BIT(2)
 43#define JZ_NAND_ECC_CTRL_RESET		BIT(1)
 44#define JZ_NAND_ECC_CTRL_ENABLE		BIT(0)
 45
 46#define JZ_NAND_STATUS_ERR_COUNT	(BIT(31) | BIT(30) | BIT(29))
 47#define JZ_NAND_STATUS_PAD_FINISH	BIT(4)
 48#define JZ_NAND_STATUS_DEC_FINISH	BIT(3)
 49#define JZ_NAND_STATUS_ENC_FINISH	BIT(2)
 50#define JZ_NAND_STATUS_UNCOR_ERROR	BIT(1)
 51#define JZ_NAND_STATUS_ERROR		BIT(0)
 52
 53#define JZ_NAND_CTRL_ENABLE_CHIP(x) BIT((x) << 1)
 54#define JZ_NAND_CTRL_ASSERT_CHIP(x) BIT(((x) << 1) + 1)
 55#define JZ_NAND_CTRL_ASSERT_CHIP_MASK 0xaa
 56
 57#define JZ_NAND_MEM_CMD_OFFSET 0x08000
 58#define JZ_NAND_MEM_ADDR_OFFSET 0x10000
 59
 60struct jz_nand {
 61	struct mtd_info mtd;
 62	struct nand_chip chip;
 63	void __iomem *base;
 64	struct resource *mem;
 65
 66	unsigned char banks[JZ_NAND_NUM_BANKS];
 67	void __iomem *bank_base[JZ_NAND_NUM_BANKS];
 68	struct resource *bank_mem[JZ_NAND_NUM_BANKS];
 69
 70	int selected_bank;
 71
 72	struct jz_nand_platform_data *pdata;
 73	bool is_reading;
 74};
 75
 76static inline struct jz_nand *mtd_to_jz_nand(struct mtd_info *mtd)
 77{
 78	return container_of(mtd, struct jz_nand, mtd);
 79}
 80
 81static void jz_nand_select_chip(struct mtd_info *mtd, int chipnr)
 82{
 83	struct jz_nand *nand = mtd_to_jz_nand(mtd);
 84	struct nand_chip *chip = mtd->priv;
 85	uint32_t ctrl;
 86	int banknr;
 87
 88	ctrl = readl(nand->base + JZ_REG_NAND_CTRL);
 89	ctrl &= ~JZ_NAND_CTRL_ASSERT_CHIP_MASK;
 90
 91	if (chipnr == -1) {
 92		banknr = -1;
 93	} else {
 94		banknr = nand->banks[chipnr] - 1;
 95		chip->IO_ADDR_R = nand->bank_base[banknr];
 96		chip->IO_ADDR_W = nand->bank_base[banknr];
 97	}
 98	writel(ctrl, nand->base + JZ_REG_NAND_CTRL);
 99
100	nand->selected_bank = banknr;
101}
102
103static void jz_nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
104{
105	struct jz_nand *nand = mtd_to_jz_nand(mtd);
106	struct nand_chip *chip = mtd->priv;
107	uint32_t reg;
108	void __iomem *bank_base = nand->bank_base[nand->selected_bank];
109
110	BUG_ON(nand->selected_bank < 0);
111
112	if (ctrl & NAND_CTRL_CHANGE) {
113		BUG_ON((ctrl & NAND_ALE) && (ctrl & NAND_CLE));
114		if (ctrl & NAND_ALE)
115			bank_base += JZ_NAND_MEM_ADDR_OFFSET;
116		else if (ctrl & NAND_CLE)
117			bank_base += JZ_NAND_MEM_CMD_OFFSET;
118		chip->IO_ADDR_W = bank_base;
119
120		reg = readl(nand->base + JZ_REG_NAND_CTRL);
121		if (ctrl & NAND_NCE)
122			reg |= JZ_NAND_CTRL_ASSERT_CHIP(nand->selected_bank);
123		else
124			reg &= ~JZ_NAND_CTRL_ASSERT_CHIP(nand->selected_bank);
125		writel(reg, nand->base + JZ_REG_NAND_CTRL);
126	}
127	if (dat != NAND_CMD_NONE)
128		writeb(dat, chip->IO_ADDR_W);
129}
130
131static int jz_nand_dev_ready(struct mtd_info *mtd)
132{
133	struct jz_nand *nand = mtd_to_jz_nand(mtd);
134	return gpio_get_value_cansleep(nand->pdata->busy_gpio);
135}
136
137static void jz_nand_hwctl(struct mtd_info *mtd, int mode)
138{
139	struct jz_nand *nand = mtd_to_jz_nand(mtd);
140	uint32_t reg;
141
142	writel(0, nand->base + JZ_REG_NAND_IRQ_STAT);
143	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
144
145	reg |= JZ_NAND_ECC_CTRL_RESET;
146	reg |= JZ_NAND_ECC_CTRL_ENABLE;
147	reg |= JZ_NAND_ECC_CTRL_RS;
148
149	switch (mode) {
150	case NAND_ECC_READ:
151		reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
152		nand->is_reading = true;
153		break;
154	case NAND_ECC_WRITE:
155		reg |= JZ_NAND_ECC_CTRL_ENCODING;
156		nand->is_reading = false;
157		break;
158	default:
159		break;
160	}
161
162	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
163}
164
165static int jz_nand_calculate_ecc_rs(struct mtd_info *mtd, const uint8_t *dat,
166	uint8_t *ecc_code)
167{
168	struct jz_nand *nand = mtd_to_jz_nand(mtd);
169	uint32_t reg, status;
170	int i;
171	unsigned int timeout = 1000;
172	static uint8_t empty_block_ecc[] = {0xcd, 0x9d, 0x90, 0x58, 0xf4,
173						0x8b, 0xff, 0xb7, 0x6f};
174
175	if (nand->is_reading)
176		return 0;
177
178	do {
179		status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
180	} while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
181
182	if (timeout == 0)
183	    return -1;
184
185	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
186	reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
187	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
188
189	for (i = 0; i < 9; ++i)
190		ecc_code[i] = readb(nand->base + JZ_REG_NAND_PAR0 + i);
191
192	/* If the written data is completly 0xff, we also want to write 0xff as
193	 * ecc, otherwise we will get in trouble when doing subpage writes. */
194	if (memcmp(ecc_code, empty_block_ecc, 9) == 0)
195		memset(ecc_code, 0xff, 9);
196
197	return 0;
198}
199
200static void jz_nand_correct_data(uint8_t *dat, int index, int mask)
201{
202	int offset = index & 0x7;
203	uint16_t data;
204
205	index += (index >> 3);
206
207	data = dat[index];
208	data |= dat[index+1] << 8;
209
210	mask ^= (data >> offset) & 0x1ff;
211	data &= ~(0x1ff << offset);
212	data |= (mask << offset);
213
214	dat[index] = data & 0xff;
215	dat[index+1] = (data >> 8) & 0xff;
216}
217
218static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
219	uint8_t *read_ecc, uint8_t *calc_ecc)
220{
221	struct jz_nand *nand = mtd_to_jz_nand(mtd);
222	int i, error_count, index;
223	uint32_t reg, status, error;
224	uint32_t t;
225	unsigned int timeout = 1000;
226
227	t = read_ecc[0];
228
229	if (t == 0xff) {
230		for (i = 1; i < 9; ++i)
231			t &= read_ecc[i];
232
233		t &= dat[0];
234		t &= dat[nand->chip.ecc.size / 2];
235		t &= dat[nand->chip.ecc.size - 1];
236
237		if (t == 0xff) {
238			for (i = 1; i < nand->chip.ecc.size - 1; ++i)
239				t &= dat[i];
240			if (t == 0xff)
241				return 0;
242		}
243	}
244
245	for (i = 0; i < 9; ++i)
246		writeb(read_ecc[i], nand->base + JZ_REG_NAND_PAR0 + i);
247
248	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
249	reg |= JZ_NAND_ECC_CTRL_PAR_READY;
250	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
251
252	do {
253		status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
254	} while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
255
256	if (timeout == 0)
257	    return -1;
258
259	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
260	reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
261	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
262
263	if (status & JZ_NAND_STATUS_ERROR) {
264		if (status & JZ_NAND_STATUS_UNCOR_ERROR)
265			return -1;
266
267		error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
268
269		for (i = 0; i < error_count; ++i) {
270			error = readl(nand->base + JZ_REG_NAND_ERR(i));
271			index = ((error >> 16) & 0x1ff) - 1;
272			if (index >= 0 && index < 512)
273				jz_nand_correct_data(dat, index, error & 0x1ff);
274		}
275
276		return error_count;
277	}
278
279	return 0;
280}
281
282static int jz_nand_ioremap_resource(struct platform_device *pdev,
283	const char *name, struct resource **res, void *__iomem *base)
284{
285	int ret;
286
287	*res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
288	if (!*res) {
289		dev_err(&pdev->dev, "Failed to get platform %s memory\n", name);
290		ret = -ENXIO;
291		goto err;
292	}
293
294	*res = request_mem_region((*res)->start, resource_size(*res),
295				pdev->name);
296	if (!*res) {
297		dev_err(&pdev->dev, "Failed to request %s memory region\n", name);
298		ret = -EBUSY;
299		goto err;
300	}
301
302	*base = ioremap((*res)->start, resource_size(*res));
303	if (!*base) {
304		dev_err(&pdev->dev, "Failed to ioremap %s memory region\n", name);
305		ret = -EBUSY;
306		goto err_release_mem;
307	}
308
309	return 0;
310
311err_release_mem:
312	release_mem_region((*res)->start, resource_size(*res));
313err:
314	*res = NULL;
315	*base = NULL;
316	return ret;
317}
318
319static inline void jz_nand_iounmap_resource(struct resource *res,
320					    void __iomem *base)
321{
322	iounmap(base);
323	release_mem_region(res->start, resource_size(res));
324}
325
326static int jz_nand_detect_bank(struct platform_device *pdev,
327			       struct jz_nand *nand, unsigned char bank,
328			       size_t chipnr, uint8_t *nand_maf_id,
329			       uint8_t *nand_dev_id)
330{
331	int ret;
332	int gpio;
333	char gpio_name[9];
334	char res_name[6];
335	uint32_t ctrl;
336	struct mtd_info *mtd = &nand->mtd;
337	struct nand_chip *chip = &nand->chip;
338
339	/* Request GPIO port. */
340	gpio = JZ_GPIO_MEM_CS0 + bank - 1;
341	sprintf(gpio_name, "NAND CS%d", bank);
342	ret = gpio_request(gpio, gpio_name);
343	if (ret) {
344		dev_warn(&pdev->dev,
345			"Failed to request %s gpio %d: %d\n",
346			gpio_name, gpio, ret);
347		goto notfound_gpio;
348	}
349
350	/* Request I/O resource. */
351	sprintf(res_name, "bank%d", bank);
352	ret = jz_nand_ioremap_resource(pdev, res_name,
353					&nand->bank_mem[bank - 1],
354					&nand->bank_base[bank - 1]);
355	if (ret)
356		goto notfound_resource;
357
358	/* Enable chip in bank. */
359	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_MEM_CS0);
360	ctrl = readl(nand->base + JZ_REG_NAND_CTRL);
361	ctrl |= JZ_NAND_CTRL_ENABLE_CHIP(bank - 1);
362	writel(ctrl, nand->base + JZ_REG_NAND_CTRL);
363
364	if (chipnr == 0) {
365		/* Detect first chip. */
366		ret = nand_scan_ident(mtd, 1, NULL);
367		if (ret)
368			goto notfound_id;
369
370		/* Retrieve the IDs from the first chip. */
371		chip->select_chip(mtd, 0);
372		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
373		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
374		*nand_maf_id = chip->read_byte(mtd);
375		*nand_dev_id = chip->read_byte(mtd);
376	} else {
377		/* Detect additional chip. */
378		chip->select_chip(mtd, chipnr);
379		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
380		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
381		if (*nand_maf_id != chip->read_byte(mtd)
382		 || *nand_dev_id != chip->read_byte(mtd)) {
383			ret = -ENODEV;
384			goto notfound_id;
385		}
386
387		/* Update size of the MTD. */
388		chip->numchips++;
389		mtd->size += chip->chipsize;
390	}
391
392	dev_info(&pdev->dev, "Found chip %i on bank %i\n", chipnr, bank);
393	return 0;
394
395notfound_id:
396	dev_info(&pdev->dev, "No chip found on bank %i\n", bank);
397	ctrl &= ~(JZ_NAND_CTRL_ENABLE_CHIP(bank - 1));
398	writel(ctrl, nand->base + JZ_REG_NAND_CTRL);
399	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_NONE);
400	jz_nand_iounmap_resource(nand->bank_mem[bank - 1],
401				 nand->bank_base[bank - 1]);
402notfound_resource:
403	gpio_free(gpio);
404notfound_gpio:
405	return ret;
406}
407
408static int jz_nand_probe(struct platform_device *pdev)
409{
410	int ret;
411	struct jz_nand *nand;
412	struct nand_chip *chip;
413	struct mtd_info *mtd;
414	struct jz_nand_platform_data *pdata = dev_get_platdata(&pdev->dev);
415	size_t chipnr, bank_idx;
416	uint8_t nand_maf_id = 0, nand_dev_id = 0;
417
418	nand = kzalloc(sizeof(*nand), GFP_KERNEL);
419	if (!nand)
420		return -ENOMEM;
421
422	ret = jz_nand_ioremap_resource(pdev, "mmio", &nand->mem, &nand->base);
423	if (ret)
424		goto err_free;
425
426	if (pdata && gpio_is_valid(pdata->busy_gpio)) {
427		ret = gpio_request(pdata->busy_gpio, "NAND busy pin");
428		if (ret) {
429			dev_err(&pdev->dev,
430				"Failed to request busy gpio %d: %d\n",
431				pdata->busy_gpio, ret);
432			goto err_iounmap_mmio;
433		}
434	}
435
436	mtd		= &nand->mtd;
437	chip		= &nand->chip;
438	mtd->priv	= chip;
439	mtd->owner	= THIS_MODULE;
440	mtd->name	= "jz4740-nand";
441
442	chip->ecc.hwctl		= jz_nand_hwctl;
443	chip->ecc.calculate	= jz_nand_calculate_ecc_rs;
444	chip->ecc.correct	= jz_nand_correct_ecc_rs;
445	chip->ecc.mode		= NAND_ECC_HW_OOB_FIRST;
446	chip->ecc.size		= 512;
447	chip->ecc.bytes		= 9;
448	chip->ecc.strength	= 4;
449
450	if (pdata)
451		chip->ecc.layout = pdata->ecc_layout;
452
453	chip->chip_delay = 50;
454	chip->cmd_ctrl = jz_nand_cmd_ctrl;
455	chip->select_chip = jz_nand_select_chip;
456
457	if (pdata && gpio_is_valid(pdata->busy_gpio))
458		chip->dev_ready = jz_nand_dev_ready;
459
460	nand->pdata = pdata;
461	platform_set_drvdata(pdev, nand);
462
463	/* We are going to autodetect NAND chips in the banks specified in the
464	 * platform data. Although nand_scan_ident() can detect multiple chips,
465	 * it requires those chips to be numbered consecuitively, which is not
466	 * always the case for external memory banks. And a fixed chip-to-bank
467	 * mapping is not practical either, since for example Dingoo units
468	 * produced at different times have NAND chips in different banks.
469	 */
470	chipnr = 0;
471	for (bank_idx = 0; bank_idx < JZ_NAND_NUM_BANKS; bank_idx++) {
472		unsigned char bank;
473
474		/* If there is no platform data, look for NAND in bank 1,
475		 * which is the most likely bank since it is the only one
476		 * that can be booted from.
477		 */
478		bank = pdata ? pdata->banks[bank_idx] : bank_idx ^ 1;
479		if (bank == 0)
480			break;
481		if (bank > JZ_NAND_NUM_BANKS) {
482			dev_warn(&pdev->dev,
483				"Skipping non-existing bank: %d\n", bank);
484			continue;
485		}
486		/* The detection routine will directly or indirectly call
487		 * jz_nand_select_chip(), so nand->banks has to contain the
488		 * bank we're checking.
489		 */
490		nand->banks[chipnr] = bank;
491		if (jz_nand_detect_bank(pdev, nand, bank, chipnr,
492					&nand_maf_id, &nand_dev_id) == 0)
493			chipnr++;
494		else
495			nand->banks[chipnr] = 0;
496	}
497	if (chipnr == 0) {
498		dev_err(&pdev->dev, "No NAND chips found\n");
499		goto err_gpio_busy;
500	}
501
502	if (pdata && pdata->ident_callback) {
503		pdata->ident_callback(pdev, chip, &pdata->partitions,
504					&pdata->num_partitions);
505	}
506
507	ret = nand_scan_tail(mtd);
508	if (ret) {
509		dev_err(&pdev->dev,  "Failed to scan NAND\n");
510		goto err_unclaim_banks;
511	}
512
513	ret = mtd_device_parse_register(mtd, NULL, NULL,
514					pdata ? pdata->partitions : NULL,
515					pdata ? pdata->num_partitions : 0);
516
517	if (ret) {
518		dev_err(&pdev->dev, "Failed to add mtd device\n");
519		goto err_nand_release;
520	}
521
522	dev_info(&pdev->dev, "Successfully registered JZ4740 NAND driver\n");
523
524	return 0;
525
526err_nand_release:
527	nand_release(mtd);
528err_unclaim_banks:
529	while (chipnr--) {
530		unsigned char bank = nand->banks[chipnr];
531		gpio_free(JZ_GPIO_MEM_CS0 + bank - 1);
532		jz_nand_iounmap_resource(nand->bank_mem[bank - 1],
533					 nand->bank_base[bank - 1]);
534	}
535	writel(0, nand->base + JZ_REG_NAND_CTRL);
536err_gpio_busy:
537	if (pdata && gpio_is_valid(pdata->busy_gpio))
538		gpio_free(pdata->busy_gpio);
539err_iounmap_mmio:
540	jz_nand_iounmap_resource(nand->mem, nand->base);
541err_free:
542	kfree(nand);
543	return ret;
544}
545
546static int jz_nand_remove(struct platform_device *pdev)
547{
548	struct jz_nand *nand = platform_get_drvdata(pdev);
549	struct jz_nand_platform_data *pdata = dev_get_platdata(&pdev->dev);
550	size_t i;
551
552	nand_release(&nand->mtd);
553
554	/* Deassert and disable all chips */
555	writel(0, nand->base + JZ_REG_NAND_CTRL);
556
557	for (i = 0; i < JZ_NAND_NUM_BANKS; ++i) {
558		unsigned char bank = nand->banks[i];
559		if (bank != 0) {
560			jz_nand_iounmap_resource(nand->bank_mem[bank - 1],
561						 nand->bank_base[bank - 1]);
562			gpio_free(JZ_GPIO_MEM_CS0 + bank - 1);
563		}
564	}
565	if (pdata && gpio_is_valid(pdata->busy_gpio))
566		gpio_free(pdata->busy_gpio);
567
568	jz_nand_iounmap_resource(nand->mem, nand->base);
569
570	kfree(nand);
571
572	return 0;
573}
574
575static struct platform_driver jz_nand_driver = {
576	.probe = jz_nand_probe,
577	.remove = jz_nand_remove,
578	.driver = {
579		.name = "jz4740-nand",
580		.owner = THIS_MODULE,
581	},
582};
583
584module_platform_driver(jz_nand_driver);
585
586MODULE_LICENSE("GPL");
587MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
588MODULE_DESCRIPTION("NAND controller driver for JZ4740 SoC");
589MODULE_ALIAS("platform:jz4740-nand");