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 
56 #define JZ_NAND_MEM_ADDR_OFFSET 0x10000
57 #define JZ_NAND_MEM_CMD_OFFSET 0x08000
58 
59 struct jz_nand {
60 	struct mtd_info mtd;
61 	struct nand_chip chip;
62 	void __iomem *base;
63 	struct resource *mem;
64 
65 	void __iomem *bank_base;
66 	struct resource *bank_mem;
67 
68 	struct jz_nand_platform_data *pdata;
69 	bool is_reading;
70 };
71 
mtd_to_jz_nand(struct mtd_info * mtd)72 static inline struct jz_nand *mtd_to_jz_nand(struct mtd_info *mtd)
73 {
74 	return container_of(mtd, struct jz_nand, mtd);
75 }
76 
jz_nand_cmd_ctrl(struct mtd_info * mtd,int dat,unsigned int ctrl)77 static void jz_nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
78 {
79 	struct jz_nand *nand = mtd_to_jz_nand(mtd);
80 	struct nand_chip *chip = mtd->priv;
81 	uint32_t reg;
82 
83 	if (ctrl & NAND_CTRL_CHANGE) {
84 		BUG_ON((ctrl & NAND_ALE) && (ctrl & NAND_CLE));
85 		if (ctrl & NAND_ALE)
86 			chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_ADDR_OFFSET;
87 		else if (ctrl & NAND_CLE)
88 			chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_CMD_OFFSET;
89 		else
90 			chip->IO_ADDR_W = nand->bank_base;
91 
92 		reg = readl(nand->base + JZ_REG_NAND_CTRL);
93 		if (ctrl & NAND_NCE)
94 			reg |= JZ_NAND_CTRL_ASSERT_CHIP(0);
95 		else
96 			reg &= ~JZ_NAND_CTRL_ASSERT_CHIP(0);
97 		writel(reg, nand->base + JZ_REG_NAND_CTRL);
98 	}
99 	if (dat != NAND_CMD_NONE)
100 		writeb(dat, chip->IO_ADDR_W);
101 }
102 
jz_nand_dev_ready(struct mtd_info * mtd)103 static int jz_nand_dev_ready(struct mtd_info *mtd)
104 {
105 	struct jz_nand *nand = mtd_to_jz_nand(mtd);
106 	return gpio_get_value_cansleep(nand->pdata->busy_gpio);
107 }
108 
jz_nand_hwctl(struct mtd_info * mtd,int mode)109 static void jz_nand_hwctl(struct mtd_info *mtd, int mode)
110 {
111 	struct jz_nand *nand = mtd_to_jz_nand(mtd);
112 	uint32_t reg;
113 
114 	writel(0, nand->base + JZ_REG_NAND_IRQ_STAT);
115 	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
116 
117 	reg |= JZ_NAND_ECC_CTRL_RESET;
118 	reg |= JZ_NAND_ECC_CTRL_ENABLE;
119 	reg |= JZ_NAND_ECC_CTRL_RS;
120 
121 	switch (mode) {
122 	case NAND_ECC_READ:
123 		reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
124 		nand->is_reading = true;
125 		break;
126 	case NAND_ECC_WRITE:
127 		reg |= JZ_NAND_ECC_CTRL_ENCODING;
128 		nand->is_reading = false;
129 		break;
130 	default:
131 		break;
132 	}
133 
134 	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
135 }
136 
jz_nand_calculate_ecc_rs(struct mtd_info * mtd,const uint8_t * dat,uint8_t * ecc_code)137 static int jz_nand_calculate_ecc_rs(struct mtd_info *mtd, const uint8_t *dat,
138 	uint8_t *ecc_code)
139 {
140 	struct jz_nand *nand = mtd_to_jz_nand(mtd);
141 	uint32_t reg, status;
142 	int i;
143 	unsigned int timeout = 1000;
144 	static uint8_t empty_block_ecc[] = {0xcd, 0x9d, 0x90, 0x58, 0xf4,
145 						0x8b, 0xff, 0xb7, 0x6f};
146 
147 	if (nand->is_reading)
148 		return 0;
149 
150 	do {
151 		status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
152 	} while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
153 
154 	if (timeout == 0)
155 	    return -1;
156 
157 	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
158 	reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
159 	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
160 
161 	for (i = 0; i < 9; ++i)
162 		ecc_code[i] = readb(nand->base + JZ_REG_NAND_PAR0 + i);
163 
164 	/* If the written data is completly 0xff, we also want to write 0xff as
165 	 * ecc, otherwise we will get in trouble when doing subpage writes. */
166 	if (memcmp(ecc_code, empty_block_ecc, 9) == 0)
167 		memset(ecc_code, 0xff, 9);
168 
169 	return 0;
170 }
171 
jz_nand_correct_data(uint8_t * dat,int index,int mask)172 static void jz_nand_correct_data(uint8_t *dat, int index, int mask)
173 {
174 	int offset = index & 0x7;
175 	uint16_t data;
176 
177 	index += (index >> 3);
178 
179 	data = dat[index];
180 	data |= dat[index+1] << 8;
181 
182 	mask ^= (data >> offset) & 0x1ff;
183 	data &= ~(0x1ff << offset);
184 	data |= (mask << offset);
185 
186 	dat[index] = data & 0xff;
187 	dat[index+1] = (data >> 8) & 0xff;
188 }
189 
jz_nand_correct_ecc_rs(struct mtd_info * mtd,uint8_t * dat,uint8_t * read_ecc,uint8_t * calc_ecc)190 static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
191 	uint8_t *read_ecc, uint8_t *calc_ecc)
192 {
193 	struct jz_nand *nand = mtd_to_jz_nand(mtd);
194 	int i, error_count, index;
195 	uint32_t reg, status, error;
196 	uint32_t t;
197 	unsigned int timeout = 1000;
198 
199 	t = read_ecc[0];
200 
201 	if (t == 0xff) {
202 		for (i = 1; i < 9; ++i)
203 			t &= read_ecc[i];
204 
205 		t &= dat[0];
206 		t &= dat[nand->chip.ecc.size / 2];
207 		t &= dat[nand->chip.ecc.size - 1];
208 
209 		if (t == 0xff) {
210 			for (i = 1; i < nand->chip.ecc.size - 1; ++i)
211 				t &= dat[i];
212 			if (t == 0xff)
213 				return 0;
214 		}
215 	}
216 
217 	for (i = 0; i < 9; ++i)
218 		writeb(read_ecc[i], nand->base + JZ_REG_NAND_PAR0 + i);
219 
220 	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
221 	reg |= JZ_NAND_ECC_CTRL_PAR_READY;
222 	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
223 
224 	do {
225 		status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
226 	} while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
227 
228 	if (timeout == 0)
229 	    return -1;
230 
231 	reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
232 	reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
233 	writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
234 
235 	if (status & JZ_NAND_STATUS_ERROR) {
236 		if (status & JZ_NAND_STATUS_UNCOR_ERROR)
237 			return -1;
238 
239 		error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
240 
241 		for (i = 0; i < error_count; ++i) {
242 			error = readl(nand->base + JZ_REG_NAND_ERR(i));
243 			index = ((error >> 16) & 0x1ff) - 1;
244 			if (index >= 0 && index < 512)
245 				jz_nand_correct_data(dat, index, error & 0x1ff);
246 		}
247 
248 		return error_count;
249 	}
250 
251 	return 0;
252 }
253 
254 #ifdef CONFIG_MTD_CMDLINE_PARTS
255 static const char *part_probes[] = {"cmdline", NULL};
256 #endif
257 
jz_nand_ioremap_resource(struct platform_device * pdev,const char * name,struct resource ** res,void __iomem ** base)258 static int jz_nand_ioremap_resource(struct platform_device *pdev,
259 	const char *name, struct resource **res, void __iomem **base)
260 {
261 	int ret;
262 
263 	*res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
264 	if (!*res) {
265 		dev_err(&pdev->dev, "Failed to get platform %s memory\n", name);
266 		ret = -ENXIO;
267 		goto err;
268 	}
269 
270 	*res = request_mem_region((*res)->start, resource_size(*res),
271 				pdev->name);
272 	if (!*res) {
273 		dev_err(&pdev->dev, "Failed to request %s memory region\n", name);
274 		ret = -EBUSY;
275 		goto err;
276 	}
277 
278 	*base = ioremap((*res)->start, resource_size(*res));
279 	if (!*base) {
280 		dev_err(&pdev->dev, "Failed to ioremap %s memory region\n", name);
281 		ret = -EBUSY;
282 		goto err_release_mem;
283 	}
284 
285 	return 0;
286 
287 err_release_mem:
288 	release_mem_region((*res)->start, resource_size(*res));
289 err:
290 	*res = NULL;
291 	*base = NULL;
292 	return ret;
293 }
294 
jz_nand_probe(struct platform_device * pdev)295 static int __devinit jz_nand_probe(struct platform_device *pdev)
296 {
297 	int ret;
298 	struct jz_nand *nand;
299 	struct nand_chip *chip;
300 	struct mtd_info *mtd;
301 	struct jz_nand_platform_data *pdata = pdev->dev.platform_data;
302 #ifdef CONFIG_MTD_PARTITIONS
303 	struct mtd_partition *partition_info;
304 	int num_partitions = 0;
305 #endif
306 
307 	nand = kzalloc(sizeof(*nand), GFP_KERNEL);
308 	if (!nand) {
309 		dev_err(&pdev->dev, "Failed to allocate device structure.\n");
310 		return -ENOMEM;
311 	}
312 
313 	ret = jz_nand_ioremap_resource(pdev, "mmio", &nand->mem, &nand->base);
314 	if (ret)
315 		goto err_free;
316 	ret = jz_nand_ioremap_resource(pdev, "bank", &nand->bank_mem,
317 			&nand->bank_base);
318 	if (ret)
319 		goto err_iounmap_mmio;
320 
321 	if (pdata && gpio_is_valid(pdata->busy_gpio)) {
322 		ret = gpio_request(pdata->busy_gpio, "NAND busy pin");
323 		if (ret) {
324 			dev_err(&pdev->dev,
325 				"Failed to request busy gpio %d: %d\n",
326 				pdata->busy_gpio, ret);
327 			goto err_iounmap_mem;
328 		}
329 	}
330 
331 	mtd		= &nand->mtd;
332 	chip		= &nand->chip;
333 	mtd->priv	= chip;
334 	mtd->owner	= THIS_MODULE;
335 	mtd->name	= "jz4740-nand";
336 
337 	chip->ecc.hwctl		= jz_nand_hwctl;
338 	chip->ecc.calculate	= jz_nand_calculate_ecc_rs;
339 	chip->ecc.correct	= jz_nand_correct_ecc_rs;
340 	chip->ecc.mode		= NAND_ECC_HW_OOB_FIRST;
341 	chip->ecc.size		= 512;
342 	chip->ecc.bytes		= 9;
343 
344 	if (pdata)
345 		chip->ecc.layout = pdata->ecc_layout;
346 
347 	chip->chip_delay = 50;
348 	chip->cmd_ctrl = jz_nand_cmd_ctrl;
349 
350 	if (pdata && gpio_is_valid(pdata->busy_gpio))
351 		chip->dev_ready = jz_nand_dev_ready;
352 
353 	chip->IO_ADDR_R = nand->bank_base;
354 	chip->IO_ADDR_W = nand->bank_base;
355 
356 	nand->pdata = pdata;
357 	platform_set_drvdata(pdev, nand);
358 
359 	writel(JZ_NAND_CTRL_ENABLE_CHIP(0), nand->base + JZ_REG_NAND_CTRL);
360 
361 	ret = nand_scan_ident(mtd, 1, NULL);
362 	if (ret) {
363 		dev_err(&pdev->dev,  "Failed to scan nand\n");
364 		goto err_gpio_free;
365 	}
366 
367 	if (pdata && pdata->ident_callback) {
368 		pdata->ident_callback(pdev, chip, &pdata->partitions,
369 					&pdata->num_partitions);
370 	}
371 
372 	ret = nand_scan_tail(mtd);
373 	if (ret) {
374 		dev_err(&pdev->dev,  "Failed to scan nand\n");
375 		goto err_gpio_free;
376 	}
377 
378 #ifdef CONFIG_MTD_PARTITIONS
379 #ifdef CONFIG_MTD_CMDLINE_PARTS
380 	num_partitions = parse_mtd_partitions(mtd, part_probes,
381 						&partition_info, 0);
382 #endif
383 	if (num_partitions <= 0 && pdata) {
384 		num_partitions = pdata->num_partitions;
385 		partition_info = pdata->partitions;
386 	}
387 
388 	if (num_partitions > 0)
389 		ret = add_mtd_partitions(mtd, partition_info, num_partitions);
390 	else
391 #endif
392 	ret = add_mtd_device(mtd);
393 
394 	if (ret) {
395 		dev_err(&pdev->dev, "Failed to add mtd device\n");
396 		goto err_nand_release;
397 	}
398 
399 	dev_info(&pdev->dev, "Successfully registered JZ4740 NAND driver\n");
400 
401 	return 0;
402 
403 err_nand_release:
404 	nand_release(&nand->mtd);
405 err_gpio_free:
406 	platform_set_drvdata(pdev, NULL);
407 	gpio_free(pdata->busy_gpio);
408 err_iounmap_mem:
409 	iounmap(nand->bank_base);
410 err_iounmap_mmio:
411 	iounmap(nand->base);
412 err_free:
413 	kfree(nand);
414 	return ret;
415 }
416 
jz_nand_remove(struct platform_device * pdev)417 static int __devexit jz_nand_remove(struct platform_device *pdev)
418 {
419 	struct jz_nand *nand = platform_get_drvdata(pdev);
420 
421 	nand_release(&nand->mtd);
422 
423 	/* Deassert and disable all chips */
424 	writel(0, nand->base + JZ_REG_NAND_CTRL);
425 
426 	iounmap(nand->bank_base);
427 	release_mem_region(nand->bank_mem->start, resource_size(nand->bank_mem));
428 	iounmap(nand->base);
429 	release_mem_region(nand->mem->start, resource_size(nand->mem));
430 
431 	platform_set_drvdata(pdev, NULL);
432 	kfree(nand);
433 
434 	return 0;
435 }
436 
437 static struct platform_driver jz_nand_driver = {
438 	.probe = jz_nand_probe,
439 	.remove = __devexit_p(jz_nand_remove),
440 	.driver = {
441 		.name = "jz4740-nand",
442 		.owner = THIS_MODULE,
443 	},
444 };
445 
jz_nand_init(void)446 static int __init jz_nand_init(void)
447 {
448 	return platform_driver_register(&jz_nand_driver);
449 }
450 module_init(jz_nand_init);
451 
jz_nand_exit(void)452 static void __exit jz_nand_exit(void)
453 {
454 	platform_driver_unregister(&jz_nand_driver);
455 }
456 module_exit(jz_nand_exit);
457 
458 MODULE_LICENSE("GPL");
459 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
460 MODULE_DESCRIPTION("NAND controller driver for JZ4740 SoC");
461 MODULE_ALIAS("platform:jz4740-nand");
462