xref: /openbmc/linux/drivers/mtd/nand/raw/au1550nd.c (revision 002dff36)
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_controller controller;
20 	struct nand_chip chip;
21 
22 	int cs;
23 	void __iomem *base;
24 };
25 
26 static struct au1550nd_ctx *chip_to_au_ctx(struct nand_chip *this)
27 {
28 	return container_of(this, struct au1550nd_ctx, chip);
29 }
30 
31 /**
32  * au_write_buf -  write buffer to chip
33  * @this:	NAND chip object
34  * @buf:	data buffer
35  * @len:	number of bytes to write
36  *
37  * write function for 8bit buswidth
38  */
39 static void au_write_buf(struct nand_chip *this, const void *buf,
40 			 unsigned int len)
41 {
42 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
43 	const u8 *p = buf;
44 	int i;
45 
46 	for (i = 0; i < len; i++) {
47 		writeb(p[i], ctx->base + MEM_STNAND_DATA);
48 		wmb(); /* drain writebuffer */
49 	}
50 }
51 
52 /**
53  * au_read_buf -  read chip data into buffer
54  * @this:	NAND chip object
55  * @buf:	buffer to store date
56  * @len:	number of bytes to read
57  *
58  * read function for 8bit buswidth
59  */
60 static void au_read_buf(struct nand_chip *this, void *buf,
61 			unsigned int len)
62 {
63 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
64 	u8 *p = buf;
65 	int i;
66 
67 	for (i = 0; i < len; i++) {
68 		p[i] = readb(ctx->base + MEM_STNAND_DATA);
69 		wmb(); /* drain writebuffer */
70 	}
71 }
72 
73 /**
74  * au_write_buf16 -  write buffer to chip
75  * @this:	NAND chip object
76  * @buf:	data buffer
77  * @len:	number of bytes to write
78  *
79  * write function for 16bit buswidth
80  */
81 static void au_write_buf16(struct nand_chip *this, const void *buf,
82 			   unsigned int len)
83 {
84 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
85 	const u16 *p = buf;
86 	unsigned int i;
87 
88 	len >>= 1;
89 	for (i = 0; i < len; i++) {
90 		writew(p[i], ctx->base + MEM_STNAND_DATA);
91 		wmb(); /* drain writebuffer */
92 	}
93 }
94 
95 /**
96  * au_read_buf16 -  read chip data into buffer
97  * @this:	NAND chip object
98  * @buf:	buffer to store date
99  * @len:	number of bytes to read
100  *
101  * read function for 16bit buswidth
102  */
103 static void au_read_buf16(struct nand_chip *this, void *buf, unsigned int len)
104 {
105 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
106 	unsigned int i;
107 	u16 *p = buf;
108 
109 	len >>= 1;
110 	for (i = 0; i < len; i++) {
111 		p[i] = readw(ctx->base + MEM_STNAND_DATA);
112 		wmb(); /* drain writebuffer */
113 	}
114 }
115 
116 static int find_nand_cs(unsigned long nand_base)
117 {
118 	void __iomem *base =
119 			(void __iomem *)KSEG1ADDR(AU1000_STATIC_MEM_PHYS_ADDR);
120 	unsigned long addr, staddr, start, mask, end;
121 	int i;
122 
123 	for (i = 0; i < 4; i++) {
124 		addr = 0x1000 + (i * 0x10);			/* CSx */
125 		staddr = __raw_readl(base + addr + 0x08);	/* STADDRx */
126 		/* figure out the decoded range of this CS */
127 		start = (staddr << 4) & 0xfffc0000;
128 		mask = (staddr << 18) & 0xfffc0000;
129 		end = (start | (start - 1)) & ~(start ^ mask);
130 		if ((nand_base >= start) && (nand_base < end))
131 			return i;
132 	}
133 
134 	return -ENODEV;
135 }
136 
137 static int au1550nd_waitrdy(struct nand_chip *this, unsigned int timeout_ms)
138 {
139 	unsigned long timeout_jiffies = jiffies;
140 
141 	timeout_jiffies += msecs_to_jiffies(timeout_ms) + 1;
142 	do {
143 		if (alchemy_rdsmem(AU1000_MEM_STSTAT) & 0x1)
144 			return 0;
145 
146 		usleep_range(10, 100);
147 	} while (time_before(jiffies, timeout_jiffies));
148 
149 	return -ETIMEDOUT;
150 }
151 
152 static int au1550nd_exec_instr(struct nand_chip *this,
153 			       const struct nand_op_instr *instr)
154 {
155 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
156 	unsigned int i;
157 	int ret = 0;
158 
159 	switch (instr->type) {
160 	case NAND_OP_CMD_INSTR:
161 		writeb(instr->ctx.cmd.opcode,
162 		       ctx->base + MEM_STNAND_CMD);
163 		/* Drain the writebuffer */
164 		wmb();
165 		break;
166 
167 	case NAND_OP_ADDR_INSTR:
168 		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
169 			writeb(instr->ctx.addr.addrs[i],
170 			       ctx->base + MEM_STNAND_ADDR);
171 			/* Drain the writebuffer */
172 			wmb();
173 		}
174 		break;
175 
176 	case NAND_OP_DATA_IN_INSTR:
177 		if ((this->options & NAND_BUSWIDTH_16) &&
178 		    !instr->ctx.data.force_8bit)
179 			au_read_buf16(this, instr->ctx.data.buf.in,
180 				      instr->ctx.data.len);
181 		else
182 			au_read_buf(this, instr->ctx.data.buf.in,
183 				    instr->ctx.data.len);
184 		break;
185 
186 	case NAND_OP_DATA_OUT_INSTR:
187 		if ((this->options & NAND_BUSWIDTH_16) &&
188 		    !instr->ctx.data.force_8bit)
189 			au_write_buf16(this, instr->ctx.data.buf.out,
190 				       instr->ctx.data.len);
191 		else
192 			au_write_buf(this, instr->ctx.data.buf.out,
193 				     instr->ctx.data.len);
194 		break;
195 
196 	case NAND_OP_WAITRDY_INSTR:
197 		ret = au1550nd_waitrdy(this, instr->ctx.waitrdy.timeout_ms);
198 		break;
199 	default:
200 		return -EINVAL;
201 	}
202 
203 	if (instr->delay_ns)
204 		ndelay(instr->delay_ns);
205 
206 	return ret;
207 }
208 
209 static int au1550nd_exec_op(struct nand_chip *this,
210 			    const struct nand_operation *op,
211 			    bool check_only)
212 {
213 	struct au1550nd_ctx *ctx = chip_to_au_ctx(this);
214 	unsigned int i;
215 	int ret;
216 
217 	if (check_only)
218 		return 0;
219 
220 	/* assert (force assert) chip enable */
221 	alchemy_wrsmem((1 << (4 + ctx->cs)), AU1000_MEM_STNDCTL);
222 	/* Drain the writebuffer */
223 	wmb();
224 
225 	for (i = 0; i < op->ninstrs; i++) {
226 		ret = au1550nd_exec_instr(this, &op->instrs[i]);
227 		if (ret)
228 			break;
229 	}
230 
231 	/* deassert chip enable */
232 	alchemy_wrsmem(0, AU1000_MEM_STNDCTL);
233 	/* Drain the writebuffer */
234 	wmb();
235 
236 	return ret;
237 }
238 
239 static const struct nand_controller_ops au1550nd_ops = {
240 	.exec_op = au1550nd_exec_op,
241 };
242 
243 static int au1550nd_probe(struct platform_device *pdev)
244 {
245 	struct au1550nd_platdata *pd;
246 	struct au1550nd_ctx *ctx;
247 	struct nand_chip *this;
248 	struct mtd_info *mtd;
249 	struct resource *r;
250 	int ret, cs;
251 
252 	pd = dev_get_platdata(&pdev->dev);
253 	if (!pd) {
254 		dev_err(&pdev->dev, "missing platform data\n");
255 		return -ENODEV;
256 	}
257 
258 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
259 	if (!ctx)
260 		return -ENOMEM;
261 
262 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
263 	if (!r) {
264 		dev_err(&pdev->dev, "no NAND memory resource\n");
265 		ret = -ENODEV;
266 		goto out1;
267 	}
268 	if (request_mem_region(r->start, resource_size(r), "au1550-nand")) {
269 		dev_err(&pdev->dev, "cannot claim NAND memory area\n");
270 		ret = -ENOMEM;
271 		goto out1;
272 	}
273 
274 	ctx->base = ioremap(r->start, 0x1000);
275 	if (!ctx->base) {
276 		dev_err(&pdev->dev, "cannot remap NAND memory area\n");
277 		ret = -ENODEV;
278 		goto out2;
279 	}
280 
281 	this = &ctx->chip;
282 	mtd = nand_to_mtd(this);
283 	mtd->dev.parent = &pdev->dev;
284 
285 	/* figure out which CS# r->start belongs to */
286 	cs = find_nand_cs(r->start);
287 	if (cs < 0) {
288 		dev_err(&pdev->dev, "cannot detect NAND chipselect\n");
289 		ret = -ENODEV;
290 		goto out3;
291 	}
292 	ctx->cs = cs;
293 
294 	nand_controller_init(&ctx->controller);
295 	ctx->controller.ops = &au1550nd_ops;
296 	this->controller = &ctx->controller;
297 	this->ecc.mode = NAND_ECC_SOFT;
298 	this->ecc.algo = NAND_ECC_HAMMING;
299 
300 	if (pd->devwidth)
301 		this->options |= NAND_BUSWIDTH_16;
302 
303 	ret = nand_scan(this, 1);
304 	if (ret) {
305 		dev_err(&pdev->dev, "NAND scan failed with %d\n", ret);
306 		goto out3;
307 	}
308 
309 	mtd_device_register(mtd, pd->parts, pd->num_parts);
310 
311 	platform_set_drvdata(pdev, ctx);
312 
313 	return 0;
314 
315 out3:
316 	iounmap(ctx->base);
317 out2:
318 	release_mem_region(r->start, resource_size(r));
319 out1:
320 	kfree(ctx);
321 	return ret;
322 }
323 
324 static int au1550nd_remove(struct platform_device *pdev)
325 {
326 	struct au1550nd_ctx *ctx = platform_get_drvdata(pdev);
327 	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
328 	struct nand_chip *chip = &ctx->chip;
329 	int ret;
330 
331 	ret = mtd_device_unregister(nand_to_mtd(chip));
332 	WARN_ON(ret);
333 	nand_cleanup(chip);
334 	iounmap(ctx->base);
335 	release_mem_region(r->start, 0x1000);
336 	kfree(ctx);
337 	return 0;
338 }
339 
340 static struct platform_driver au1550nd_driver = {
341 	.driver = {
342 		.name	= "au1550-nand",
343 	},
344 	.probe		= au1550nd_probe,
345 	.remove		= au1550nd_remove,
346 };
347 
348 module_platform_driver(au1550nd_driver);
349 
350 MODULE_LICENSE("GPL");
351 MODULE_AUTHOR("Embedded Edge, LLC");
352 MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on Pb1550 board");
353