xref: /openbmc/linux/drivers/mtd/nand/raw/ndfc.c (revision d4295e12)
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 nand_chip *nchip, int chip)
48 {
49 	uint32_t ccr;
50 	struct ndfc_controller *ndfc = nand_get_controller_data(nchip);
51 
52 	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
53 	if (chip >= 0) {
54 		ccr &= ~NDFC_CCR_BS_MASK;
55 		ccr |= NDFC_CCR_BS(chip + ndfc->chip_select);
56 	} else
57 		ccr |= NDFC_CCR_RESET_CE;
58 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
59 }
60 
61 static void ndfc_hwcontrol(struct nand_chip *chip, int cmd, unsigned int ctrl)
62 {
63 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
64 
65 	if (cmd == NAND_CMD_NONE)
66 		return;
67 
68 	if (ctrl & NAND_CLE)
69 		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_CMD);
70 	else
71 		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_ALE);
72 }
73 
74 static int ndfc_ready(struct nand_chip *chip)
75 {
76 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
77 
78 	return in_be32(ndfc->ndfcbase + NDFC_STAT) & NDFC_STAT_IS_READY;
79 }
80 
81 static void ndfc_enable_hwecc(struct nand_chip *chip, int mode)
82 {
83 	uint32_t ccr;
84 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
85 
86 	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
87 	ccr |= NDFC_CCR_RESET_ECC;
88 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
89 	wmb();
90 }
91 
92 static int ndfc_calculate_ecc(struct nand_chip *chip,
93 			      const u_char *dat, u_char *ecc_code)
94 {
95 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
96 	uint32_t ecc;
97 	uint8_t *p = (uint8_t *)&ecc;
98 
99 	wmb();
100 	ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
101 	/* The NDFC uses Smart Media (SMC) bytes order */
102 	ecc_code[0] = p[1];
103 	ecc_code[1] = p[2];
104 	ecc_code[2] = p[3];
105 
106 	return 0;
107 }
108 
109 /*
110  * Speedups for buffer read/write/verify
111  *
112  * NDFC allows 32bit read/write of data. So we can speed up the buffer
113  * functions. No further checking, as nand_base will always read/write
114  * page aligned.
115  */
116 static void ndfc_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
117 {
118 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
119 	uint32_t *p = (uint32_t *) buf;
120 
121 	for(;len > 0; len -= 4)
122 		*p++ = in_be32(ndfc->ndfcbase + NDFC_DATA);
123 }
124 
125 static void ndfc_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
126 {
127 	struct ndfc_controller *ndfc = nand_get_controller_data(chip);
128 	uint32_t *p = (uint32_t *) buf;
129 
130 	for(;len > 0; len -= 4)
131 		out_be32(ndfc->ndfcbase + NDFC_DATA, *p++);
132 }
133 
134 /*
135  * Initialize chip structure
136  */
137 static int ndfc_chip_init(struct ndfc_controller *ndfc,
138 			  struct device_node *node)
139 {
140 	struct device_node *flash_np;
141 	struct nand_chip *chip = &ndfc->chip;
142 	struct mtd_info *mtd = nand_to_mtd(chip);
143 	int ret;
144 
145 	chip->legacy.IO_ADDR_R = ndfc->ndfcbase + NDFC_DATA;
146 	chip->legacy.IO_ADDR_W = ndfc->ndfcbase + NDFC_DATA;
147 	chip->legacy.cmd_ctrl = ndfc_hwcontrol;
148 	chip->legacy.dev_ready = ndfc_ready;
149 	chip->select_chip = ndfc_select_chip;
150 	chip->legacy.chip_delay = 50;
151 	chip->controller = &ndfc->ndfc_control;
152 	chip->legacy.read_buf = ndfc_read_buf;
153 	chip->legacy.write_buf = ndfc_write_buf;
154 	chip->ecc.correct = nand_correct_data;
155 	chip->ecc.hwctl = ndfc_enable_hwecc;
156 	chip->ecc.calculate = ndfc_calculate_ecc;
157 	chip->ecc.mode = NAND_ECC_HW;
158 	chip->ecc.size = 256;
159 	chip->ecc.bytes = 3;
160 	chip->ecc.strength = 1;
161 	nand_set_controller_data(chip, ndfc);
162 
163 	mtd->dev.parent = &ndfc->ofdev->dev;
164 
165 	flash_np = of_get_next_child(node, NULL);
166 	if (!flash_np)
167 		return -ENODEV;
168 	nand_set_flash_node(chip, flash_np);
169 
170 	mtd->name = kasprintf(GFP_KERNEL, "%s.%pOFn", dev_name(&ndfc->ofdev->dev),
171 			      flash_np);
172 	if (!mtd->name) {
173 		ret = -ENOMEM;
174 		goto err;
175 	}
176 
177 	ret = nand_scan(chip, 1);
178 	if (ret)
179 		goto err;
180 
181 	ret = mtd_device_register(mtd, NULL, 0);
182 
183 err:
184 	of_node_put(flash_np);
185 	if (ret)
186 		kfree(mtd->name);
187 	return ret;
188 }
189 
190 static int ndfc_probe(struct platform_device *ofdev)
191 {
192 	struct ndfc_controller *ndfc;
193 	const __be32 *reg;
194 	u32 ccr;
195 	u32 cs;
196 	int err, len;
197 
198 	/* Read the reg property to get the chip select */
199 	reg = of_get_property(ofdev->dev.of_node, "reg", &len);
200 	if (reg == NULL || len != 12) {
201 		dev_err(&ofdev->dev, "unable read reg property (%d)\n", len);
202 		return -ENOENT;
203 	}
204 
205 	cs = be32_to_cpu(reg[0]);
206 	if (cs >= NDFC_MAX_CS) {
207 		dev_err(&ofdev->dev, "invalid CS number (%d)\n", cs);
208 		return -EINVAL;
209 	}
210 
211 	ndfc = &ndfc_ctrl[cs];
212 	ndfc->chip_select = cs;
213 
214 	nand_controller_init(&ndfc->ndfc_control);
215 	ndfc->ofdev = ofdev;
216 	dev_set_drvdata(&ofdev->dev, ndfc);
217 
218 	ndfc->ndfcbase = of_iomap(ofdev->dev.of_node, 0);
219 	if (!ndfc->ndfcbase) {
220 		dev_err(&ofdev->dev, "failed to get memory\n");
221 		return -EIO;
222 	}
223 
224 	ccr = NDFC_CCR_BS(ndfc->chip_select);
225 
226 	/* It is ok if ccr does not exist - just default to 0 */
227 	reg = of_get_property(ofdev->dev.of_node, "ccr", NULL);
228 	if (reg)
229 		ccr |= be32_to_cpup(reg);
230 
231 	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
232 
233 	/* Set the bank settings if given */
234 	reg = of_get_property(ofdev->dev.of_node, "bank-settings", NULL);
235 	if (reg) {
236 		int offset = NDFC_BCFG0 + (ndfc->chip_select << 2);
237 		out_be32(ndfc->ndfcbase + offset, be32_to_cpup(reg));
238 	}
239 
240 	err = ndfc_chip_init(ndfc, ofdev->dev.of_node);
241 	if (err) {
242 		iounmap(ndfc->ndfcbase);
243 		return err;
244 	}
245 
246 	return 0;
247 }
248 
249 static int ndfc_remove(struct platform_device *ofdev)
250 {
251 	struct ndfc_controller *ndfc = dev_get_drvdata(&ofdev->dev);
252 	struct mtd_info *mtd = nand_to_mtd(&ndfc->chip);
253 
254 	nand_release(&ndfc->chip);
255 	kfree(mtd->name);
256 
257 	return 0;
258 }
259 
260 static const struct of_device_id ndfc_match[] = {
261 	{ .compatible = "ibm,ndfc", },
262 	{}
263 };
264 MODULE_DEVICE_TABLE(of, ndfc_match);
265 
266 static struct platform_driver ndfc_driver = {
267 	.driver = {
268 		.name = "ndfc",
269 		.of_match_table = ndfc_match,
270 	},
271 	.probe = ndfc_probe,
272 	.remove = ndfc_remove,
273 };
274 
275 module_platform_driver(ndfc_driver);
276 
277 MODULE_LICENSE("GPL");
278 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
279 MODULE_DESCRIPTION("OF Platform driver for NDFC");
280