xref: /openbmc/linux/drivers/mtd/nand/raw/au1550nd.c (revision 0a94608f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2004 Embedded Edge, LLC
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/slab.h>
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/mtd/mtd.h>
11 #include <linux/mtd/rawnand.h>
12 #include <linux/mtd/partitions.h>
13 #include <linux/platform_device.h>
14 #include <asm/io.h>
15 #include <asm/mach-au1x00/au1000.h>
16 #include <asm/mach-au1x00/au1550nd.h>
17 
18 
19 struct au1550nd_ctx {
20 	struct nand_controller controller;
21 	struct nand_chip chip;
22 
23 	int cs;
24 	void __iomem *base;
25 };
26 
27 static struct au1550nd_ctx *chip_to_au_ctx(struct nand_chip *this)
28 {
29 	return container_of(this, struct au1550nd_ctx, chip);
30 }
31 
32 /**
33  * au_write_buf -  write buffer to chip
34  * @this:	NAND chip object
35  * @buf:	data buffer
36  * @len:	number of bytes to write
37  *
38  * write function for 8bit buswidth
39  */
40 static void au_write_buf(struct nand_chip *this, const void *buf,
41 			 unsigned int len)
42 {
43 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
44 	const u8 *p = buf;
45 	int i;
46 
47 	for (i = 0; i < len; i++) {
48 		writeb(p[i], ctx->base + MEM_STNAND_DATA);
49 		wmb(); /* drain writebuffer */
50 	}
51 }
52 
53 /**
54  * au_read_buf -  read chip data into buffer
55  * @this:	NAND chip object
56  * @buf:	buffer to store date
57  * @len:	number of bytes to read
58  *
59  * read function for 8bit buswidth
60  */
61 static void au_read_buf(struct nand_chip *this, void *buf,
62 			unsigned int len)
63 {
64 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
65 	u8 *p = buf;
66 	int i;
67 
68 	for (i = 0; i < len; i++) {
69 		p[i] = readb(ctx->base + MEM_STNAND_DATA);
70 		wmb(); /* drain writebuffer */
71 	}
72 }
73 
74 /**
75  * au_write_buf16 -  write buffer to chip
76  * @this:	NAND chip object
77  * @buf:	data buffer
78  * @len:	number of bytes to write
79  *
80  * write function for 16bit buswidth
81  */
82 static void au_write_buf16(struct nand_chip *this, const void *buf,
83 			   unsigned int len)
84 {
85 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
86 	const u16 *p = buf;
87 	unsigned int i;
88 
89 	len >>= 1;
90 	for (i = 0; i < len; i++) {
91 		writew(p[i], ctx->base + MEM_STNAND_DATA);
92 		wmb(); /* drain writebuffer */
93 	}
94 }
95 
96 /**
97  * au_read_buf16 -  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 16bit buswidth
103  */
104 static void au_read_buf16(struct nand_chip *this, void *buf, unsigned int len)
105 {
106 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
107 	unsigned int i;
108 	u16 *p = buf;
109 
110 	len >>= 1;
111 	for (i = 0; i < len; i++) {
112 		p[i] = readw(ctx->base + MEM_STNAND_DATA);
113 		wmb(); /* drain writebuffer */
114 	}
115 }
116 
117 static int find_nand_cs(unsigned long nand_base)
118 {
119 	void __iomem *base =
120 			(void __iomem *)KSEG1ADDR(AU1000_STATIC_MEM_PHYS_ADDR);
121 	unsigned long addr, staddr, start, mask, end;
122 	int i;
123 
124 	for (i = 0; i < 4; i++) {
125 		addr = 0x1000 + (i * 0x10);			/* CSx */
126 		staddr = __raw_readl(base + addr + 0x08);	/* STADDRx */
127 		/* figure out the decoded range of this CS */
128 		start = (staddr << 4) & 0xfffc0000;
129 		mask = (staddr << 18) & 0xfffc0000;
130 		end = (start | (start - 1)) & ~(start ^ mask);
131 		if ((nand_base >= start) && (nand_base < end))
132 			return i;
133 	}
134 
135 	return -ENODEV;
136 }
137 
138 static int au1550nd_waitrdy(struct nand_chip *this, unsigned int timeout_ms)
139 {
140 	unsigned long timeout_jiffies = jiffies;
141 
142 	timeout_jiffies += msecs_to_jiffies(timeout_ms) + 1;
143 	do {
144 		if (alchemy_rdsmem(AU1000_MEM_STSTAT) & 0x1)
145 			return 0;
146 
147 		usleep_range(10, 100);
148 	} while (time_before(jiffies, timeout_jiffies));
149 
150 	return -ETIMEDOUT;
151 }
152 
153 static int au1550nd_exec_instr(struct nand_chip *this,
154 			       const struct nand_op_instr *instr)
155 {
156 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
157 	unsigned int i;
158 	int ret = 0;
159 
160 	switch (instr->type) {
161 	case NAND_OP_CMD_INSTR:
162 		writeb(instr->ctx.cmd.opcode,
163 		       ctx->base + MEM_STNAND_CMD);
164 		/* Drain the writebuffer */
165 		wmb();
166 		break;
167 
168 	case NAND_OP_ADDR_INSTR:
169 		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
170 			writeb(instr->ctx.addr.addrs[i],
171 			       ctx->base + MEM_STNAND_ADDR);
172 			/* Drain the writebuffer */
173 			wmb();
174 		}
175 		break;
176 
177 	case NAND_OP_DATA_IN_INSTR:
178 		if ((this->options & NAND_BUSWIDTH_16) &&
179 		    !instr->ctx.data.force_8bit)
180 			au_read_buf16(this, instr->ctx.data.buf.in,
181 				      instr->ctx.data.len);
182 		else
183 			au_read_buf(this, instr->ctx.data.buf.in,
184 				    instr->ctx.data.len);
185 		break;
186 
187 	case NAND_OP_DATA_OUT_INSTR:
188 		if ((this->options & NAND_BUSWIDTH_16) &&
189 		    !instr->ctx.data.force_8bit)
190 			au_write_buf16(this, instr->ctx.data.buf.out,
191 				       instr->ctx.data.len);
192 		else
193 			au_write_buf(this, instr->ctx.data.buf.out,
194 				     instr->ctx.data.len);
195 		break;
196 
197 	case NAND_OP_WAITRDY_INSTR:
198 		ret = au1550nd_waitrdy(this, instr->ctx.waitrdy.timeout_ms);
199 		break;
200 	default:
201 		return -EINVAL;
202 	}
203 
204 	if (instr->delay_ns)
205 		ndelay(instr->delay_ns);
206 
207 	return ret;
208 }
209 
210 static int au1550nd_exec_op(struct nand_chip *this,
211 			    const struct nand_operation *op,
212 			    bool check_only)
213 {
214 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
215 	unsigned int i;
216 	int ret;
217 
218 	if (check_only)
219 		return 0;
220 
221 	/* assert (force assert) chip enable */
222 	alchemy_wrsmem((1 << (4 + ctx->cs)), AU1000_MEM_STNDCTL);
223 	/* Drain the writebuffer */
224 	wmb();
225 
226 	for (i = 0; i < op->ninstrs; i++) {
227 		ret = au1550nd_exec_instr(this, &op->instrs[i]);
228 		if (ret)
229 			break;
230 	}
231 
232 	/* deassert chip enable */
233 	alchemy_wrsmem(0, AU1000_MEM_STNDCTL);
234 	/* Drain the writebuffer */
235 	wmb();
236 
237 	return ret;
238 }
239 
240 static int au1550nd_attach_chip(struct nand_chip *chip)
241 {
242 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
243 	    chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
244 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
245 
246 	return 0;
247 }
248 
249 static const struct nand_controller_ops au1550nd_ops = {
250 	.exec_op = au1550nd_exec_op,
251 	.attach_chip = au1550nd_attach_chip,
252 };
253 
254 static int au1550nd_probe(struct platform_device *pdev)
255 {
256 	struct au1550nd_platdata *pd;
257 	struct au1550nd_ctx *ctx;
258 	struct nand_chip *this;
259 	struct mtd_info *mtd;
260 	struct resource *r;
261 	int ret, cs;
262 
263 	pd = dev_get_platdata(&pdev->dev);
264 	if (!pd) {
265 		dev_err(&pdev->dev, "missing platform data\n");
266 		return -ENODEV;
267 	}
268 
269 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
270 	if (!ctx)
271 		return -ENOMEM;
272 
273 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
274 	if (!r) {
275 		dev_err(&pdev->dev, "no NAND memory resource\n");
276 		ret = -ENODEV;
277 		goto out1;
278 	}
279 	if (request_mem_region(r->start, resource_size(r), "au1550-nand")) {
280 		dev_err(&pdev->dev, "cannot claim NAND memory area\n");
281 		ret = -ENOMEM;
282 		goto out1;
283 	}
284 
285 	ctx->base = ioremap(r->start, 0x1000);
286 	if (!ctx->base) {
287 		dev_err(&pdev->dev, "cannot remap NAND memory area\n");
288 		ret = -ENODEV;
289 		goto out2;
290 	}
291 
292 	this = &ctx->chip;
293 	mtd = nand_to_mtd(this);
294 	mtd->dev.parent = &pdev->dev;
295 
296 	/* figure out which CS# r->start belongs to */
297 	cs = find_nand_cs(r->start);
298 	if (cs < 0) {
299 		dev_err(&pdev->dev, "cannot detect NAND chipselect\n");
300 		ret = -ENODEV;
301 		goto out3;
302 	}
303 	ctx->cs = cs;
304 
305 	nand_controller_init(&ctx->controller);
306 	ctx->controller.ops = &au1550nd_ops;
307 	this->controller = &ctx->controller;
308 
309 	if (pd->devwidth)
310 		this->options |= NAND_BUSWIDTH_16;
311 
312 	/*
313 	 * This driver assumes that the default ECC engine should be TYPE_SOFT.
314 	 * Set ->engine_type before registering the NAND devices in order to
315 	 * provide a driver specific default value.
316 	 */
317 	this->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
318 
319 	ret = nand_scan(this, 1);
320 	if (ret) {
321 		dev_err(&pdev->dev, "NAND scan failed with %d\n", ret);
322 		goto out3;
323 	}
324 
325 	mtd_device_register(mtd, pd->parts, pd->num_parts);
326 
327 	platform_set_drvdata(pdev, ctx);
328 
329 	return 0;
330 
331 out3:
332 	iounmap(ctx->base);
333 out2:
334 	release_mem_region(r->start, resource_size(r));
335 out1:
336 	kfree(ctx);
337 	return ret;
338 }
339 
340 static int au1550nd_remove(struct platform_device *pdev)
341 {
342 	struct au1550nd_ctx *ctx = platform_get_drvdata(pdev);
343 	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
344 	struct nand_chip *chip = &ctx->chip;
345 	int ret;
346 
347 	ret = mtd_device_unregister(nand_to_mtd(chip));
348 	WARN_ON(ret);
349 	nand_cleanup(chip);
350 	iounmap(ctx->base);
351 	release_mem_region(r->start, 0x1000);
352 	kfree(ctx);
353 	return 0;
354 }
355 
356 static struct platform_driver au1550nd_driver = {
357 	.driver = {
358 		.name	= "au1550-nand",
359 	},
360 	.probe		= au1550nd_probe,
361 	.remove		= au1550nd_remove,
362 };
363 
364 module_platform_driver(au1550nd_driver);
365 
366 MODULE_LICENSE("GPL");
367 MODULE_AUTHOR("Embedded Edge, LLC");
368 MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on Pb1550 board");
369