xref: /openbmc/linux/drivers/mtd/nand/raw/ndfc.c (revision 5b394b2d)
1 /*
2  *  Overview:
3  *   Platform independent driver for NDFC (NanD Flash Controller)
4  *   integrated into EP440 cores
5  *
6  *   Ported to an OF platform driver by Sean MacLennan
7  *
8  *   The NDFC supports multiple chips, but this driver only supports a
9  *   single chip since I do not have access to any boards with
10  *   multiple chips.
11  *
12  *  Author: Thomas Gleixner
13  *
14  *  Copyright 2006 IBM
15  *  Copyright 2008 PIKA Technologies
16  *    Sean MacLennan <smaclennan@pikatech.com>
17  *
18  *  This program is free software; you can redistribute	 it and/or modify it
19  *  under  the terms of	 the GNU General  Public License as published by the
20  *  Free Software Foundation;  either version 2 of the	License, or (at your
21  *  option) any later version.
22  *
23  */
24 #include <linux/module.h>
25 #include <linux/mtd/rawnand.h>
26 #include <linux/mtd/nand_ecc.h>
27 #include <linux/mtd/partitions.h>
28 #include <linux/mtd/ndfc.h>
29 #include <linux/slab.h>
30 #include <linux/mtd/mtd.h>
31 #include <linux/of_address.h>
32 #include <linux/of_platform.h>
33 #include <asm/io.h>
34 
35 #define NDFC_MAX_CS    4
36 
37 struct ndfc_controller {
38 	struct platform_device *ofdev;
39 	void __iomem *ndfcbase;
40 	struct nand_chip chip;
41 	int chip_select;
42 	struct nand_controller ndfc_control;
43 };
44 
45 static struct ndfc_controller ndfc_ctrl[NDFC_MAX_CS];
46 
47 static void ndfc_select_chip(struct mtd_info *mtd, int chip)
48 {
49 	uint32_t ccr;
50 	struct nand_chip *nchip = mtd_to_nand(mtd);
51 	struct ndfc_controller *ndfc = nand_get_controller_data(nchip);
52 
53 	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
54 	if (chip >= 0) {
55 		ccr &= ~NDFC_CCR_BS_MASK;
56 		ccr |= NDFC_CCR_BS(chip + ndfc->chip_select);
57 	} else
58 		ccr |= NDFC_CCR_RESET_CE;
59 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
60 }
61 
62 static void ndfc_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
63 {
64 	struct nand_chip *chip = mtd_to_nand(mtd);
65 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
66 
67 	if (cmd == NAND_CMD_NONE)
68 		return;
69 
70 	if (ctrl & NAND_CLE)
71 		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_CMD);
72 	else
73 		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_ALE);
74 }
75 
76 static int ndfc_ready(struct mtd_info *mtd)
77 {
78 	struct nand_chip *chip = mtd_to_nand(mtd);
79 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
80 
81 	return in_be32(ndfc->ndfcbase + NDFC_STAT) & NDFC_STAT_IS_READY;
82 }
83 
84 static void ndfc_enable_hwecc(struct mtd_info *mtd, int mode)
85 {
86 	uint32_t ccr;
87 	struct nand_chip *chip = mtd_to_nand(mtd);
88 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
89 
90 	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
91 	ccr |= NDFC_CCR_RESET_ECC;
92 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
93 	wmb();
94 }
95 
96 static int ndfc_calculate_ecc(struct mtd_info *mtd,
97 			      const u_char *dat, u_char *ecc_code)
98 {
99 	struct nand_chip *chip = mtd_to_nand(mtd);
100 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
101 	uint32_t ecc;
102 	uint8_t *p = (uint8_t *)&ecc;
103 
104 	wmb();
105 	ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
106 	/* The NDFC uses Smart Media (SMC) bytes order */
107 	ecc_code[0] = p[1];
108 	ecc_code[1] = p[2];
109 	ecc_code[2] = p[3];
110 
111 	return 0;
112 }
113 
114 /*
115  * Speedups for buffer read/write/verify
116  *
117  * NDFC allows 32bit read/write of data. So we can speed up the buffer
118  * functions. No further checking, as nand_base will always read/write
119  * page aligned.
120  */
121 static void ndfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
122 {
123 	struct nand_chip *chip = mtd_to_nand(mtd);
124 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
125 	uint32_t *p = (uint32_t *) buf;
126 
127 	for(;len > 0; len -= 4)
128 		*p++ = in_be32(ndfc->ndfcbase + NDFC_DATA);
129 }
130 
131 static void ndfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
132 {
133 	struct nand_chip *chip = mtd_to_nand(mtd);
134 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
135 	uint32_t *p = (uint32_t *) buf;
136 
137 	for(;len > 0; len -= 4)
138 		out_be32(ndfc->ndfcbase + NDFC_DATA, *p++);
139 }
140 
141 /*
142  * Initialize chip structure
143  */
144 static int ndfc_chip_init(struct ndfc_controller *ndfc,
145 			  struct device_node *node)
146 {
147 	struct device_node *flash_np;
148 	struct nand_chip *chip = &ndfc->chip;
149 	struct mtd_info *mtd = nand_to_mtd(chip);
150 	int ret;
151 
152 	chip->IO_ADDR_R = ndfc->ndfcbase + NDFC_DATA;
153 	chip->IO_ADDR_W = ndfc->ndfcbase + NDFC_DATA;
154 	chip->cmd_ctrl = ndfc_hwcontrol;
155 	chip->dev_ready = ndfc_ready;
156 	chip->select_chip = ndfc_select_chip;
157 	chip->chip_delay = 50;
158 	chip->controller = &ndfc->ndfc_control;
159 	chip->read_buf = ndfc_read_buf;
160 	chip->write_buf = ndfc_write_buf;
161 	chip->ecc.correct = nand_correct_data;
162 	chip->ecc.hwctl = ndfc_enable_hwecc;
163 	chip->ecc.calculate = ndfc_calculate_ecc;
164 	chip->ecc.mode = NAND_ECC_HW;
165 	chip->ecc.size = 256;
166 	chip->ecc.bytes = 3;
167 	chip->ecc.strength = 1;
168 	nand_set_controller_data(chip, ndfc);
169 
170 	mtd->dev.parent = &ndfc->ofdev->dev;
171 
172 	flash_np = of_get_next_child(node, NULL);
173 	if (!flash_np)
174 		return -ENODEV;
175 	nand_set_flash_node(chip, flash_np);
176 
177 	mtd->name = kasprintf(GFP_KERNEL, "%s.%s", dev_name(&ndfc->ofdev->dev),
178 			      flash_np->name);
179 	if (!mtd->name) {
180 		ret = -ENOMEM;
181 		goto err;
182 	}
183 
184 	ret = nand_scan(mtd, 1);
185 	if (ret)
186 		goto err;
187 
188 	ret = mtd_device_register(mtd, NULL, 0);
189 
190 err:
191 	of_node_put(flash_np);
192 	if (ret)
193 		kfree(mtd->name);
194 	return ret;
195 }
196 
197 static int ndfc_probe(struct platform_device *ofdev)
198 {
199 	struct ndfc_controller *ndfc;
200 	const __be32 *reg;
201 	u32 ccr;
202 	u32 cs;
203 	int err, len;
204 
205 	/* Read the reg property to get the chip select */
206 	reg = of_get_property(ofdev->dev.of_node, "reg", &len);
207 	if (reg == NULL || len != 12) {
208 		dev_err(&ofdev->dev, "unable read reg property (%d)\n", len);
209 		return -ENOENT;
210 	}
211 
212 	cs = be32_to_cpu(reg[0]);
213 	if (cs >= NDFC_MAX_CS) {
214 		dev_err(&ofdev->dev, "invalid CS number (%d)\n", cs);
215 		return -EINVAL;
216 	}
217 
218 	ndfc = &ndfc_ctrl[cs];
219 	ndfc->chip_select = cs;
220 
221 	nand_controller_init(&ndfc->ndfc_control);
222 	ndfc->ofdev = ofdev;
223 	dev_set_drvdata(&ofdev->dev, ndfc);
224 
225 	ndfc->ndfcbase = of_iomap(ofdev->dev.of_node, 0);
226 	if (!ndfc->ndfcbase) {
227 		dev_err(&ofdev->dev, "failed to get memory\n");
228 		return -EIO;
229 	}
230 
231 	ccr = NDFC_CCR_BS(ndfc->chip_select);
232 
233 	/* It is ok if ccr does not exist - just default to 0 */
234 	reg = of_get_property(ofdev->dev.of_node, "ccr", NULL);
235 	if (reg)
236 		ccr |= be32_to_cpup(reg);
237 
238 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
239 
240 	/* Set the bank settings if given */
241 	reg = of_get_property(ofdev->dev.of_node, "bank-settings", NULL);
242 	if (reg) {
243 		int offset = NDFC_BCFG0 + (ndfc->chip_select << 2);
244 		out_be32(ndfc->ndfcbase + offset, be32_to_cpup(reg));
245 	}
246 
247 	err = ndfc_chip_init(ndfc, ofdev->dev.of_node);
248 	if (err) {
249 		iounmap(ndfc->ndfcbase);
250 		return err;
251 	}
252 
253 	return 0;
254 }
255 
256 static int ndfc_remove(struct platform_device *ofdev)
257 {
258 	struct ndfc_controller *ndfc = dev_get_drvdata(&ofdev->dev);
259 	struct mtd_info *mtd = nand_to_mtd(&ndfc->chip);
260 
261 	nand_release(mtd);
262 	kfree(mtd->name);
263 
264 	return 0;
265 }
266 
267 static const struct of_device_id ndfc_match[] = {
268 	{ .compatible = "ibm,ndfc", },
269 	{}
270 };
271 MODULE_DEVICE_TABLE(of, ndfc_match);
272 
273 static struct platform_driver ndfc_driver = {
274 	.driver = {
275 		.name = "ndfc",
276 		.of_match_table = ndfc_match,
277 	},
278 	.probe = ndfc_probe,
279 	.remove = ndfc_remove,
280 };
281 
282 module_platform_driver(ndfc_driver);
283 
284 MODULE_LICENSE("GPL");
285 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
286 MODULE_DESCRIPTION("OF Platform driver for NDFC");
287