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1b578193 WG |
1 | /* |
2 | * drivers/mtd/nand/socrates_nand.c | |
3 | * | |
4 | * Copyright © 2008 Ilya Yanok, Emcraft Systems | |
5 | * | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <linux/slab.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/mtd/mtd.h> | |
16 | #include <linux/mtd/nand.h> | |
17 | #include <linux/mtd/partitions.h> | |
c11eede6 | 18 | #include <linux/of_address.h> |
1b578193 WG |
19 | #include <linux/of_platform.h> |
20 | #include <linux/io.h> | |
21 | ||
22 | #define FPGA_NAND_CMD_MASK (0x7 << 28) | |
23 | #define FPGA_NAND_CMD_COMMAND (0x0 << 28) | |
24 | #define FPGA_NAND_CMD_ADDR (0x1 << 28) | |
25 | #define FPGA_NAND_CMD_READ (0x2 << 28) | |
26 | #define FPGA_NAND_CMD_WRITE (0x3 << 28) | |
27 | #define FPGA_NAND_BUSY (0x1 << 15) | |
28 | #define FPGA_NAND_ENABLE (0x1 << 31) | |
29 | #define FPGA_NAND_DATA_SHIFT 16 | |
30 | ||
31 | struct socrates_nand_host { | |
32 | struct nand_chip nand_chip; | |
33 | struct mtd_info mtd; | |
34 | void __iomem *io_base; | |
35 | struct device *dev; | |
36 | }; | |
37 | ||
38 | /** | |
39 | * socrates_nand_write_buf - write buffer to chip | |
40 | * @mtd: MTD device structure | |
41 | * @buf: data buffer | |
42 | * @len: number of bytes to write | |
43 | */ | |
44 | static void socrates_nand_write_buf(struct mtd_info *mtd, | |
45 | const uint8_t *buf, int len) | |
46 | { | |
47 | int i; | |
48 | struct nand_chip *this = mtd->priv; | |
49 | struct socrates_nand_host *host = this->priv; | |
50 | ||
51 | for (i = 0; i < len; i++) { | |
52 | out_be32(host->io_base, FPGA_NAND_ENABLE | | |
53 | FPGA_NAND_CMD_WRITE | | |
54 | (buf[i] << FPGA_NAND_DATA_SHIFT)); | |
55 | } | |
56 | } | |
57 | ||
58 | /** | |
59 | * socrates_nand_read_buf - read chip data into buffer | |
60 | * @mtd: MTD device structure | |
61 | * @buf: buffer to store date | |
62 | * @len: number of bytes to read | |
63 | */ | |
64 | static void socrates_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) | |
65 | { | |
66 | int i; | |
67 | struct nand_chip *this = mtd->priv; | |
68 | struct socrates_nand_host *host = this->priv; | |
69 | uint32_t val; | |
70 | ||
71 | val = FPGA_NAND_ENABLE | FPGA_NAND_CMD_READ; | |
72 | ||
73 | out_be32(host->io_base, val); | |
74 | for (i = 0; i < len; i++) { | |
75 | buf[i] = (in_be32(host->io_base) >> | |
76 | FPGA_NAND_DATA_SHIFT) & 0xff; | |
77 | } | |
78 | } | |
79 | ||
80 | /** | |
81 | * socrates_nand_read_byte - read one byte from the chip | |
82 | * @mtd: MTD device structure | |
83 | */ | |
84 | static uint8_t socrates_nand_read_byte(struct mtd_info *mtd) | |
85 | { | |
86 | uint8_t byte; | |
87 | socrates_nand_read_buf(mtd, &byte, sizeof(byte)); | |
88 | return byte; | |
89 | } | |
90 | ||
91 | /** | |
92 | * socrates_nand_read_word - read one word from the chip | |
93 | * @mtd: MTD device structure | |
94 | */ | |
95 | static uint16_t socrates_nand_read_word(struct mtd_info *mtd) | |
96 | { | |
97 | uint16_t word; | |
98 | socrates_nand_read_buf(mtd, (uint8_t *)&word, sizeof(word)); | |
99 | return word; | |
100 | } | |
101 | ||
1b578193 WG |
102 | /* |
103 | * Hardware specific access to control-lines | |
104 | */ | |
105 | static void socrates_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, | |
106 | unsigned int ctrl) | |
107 | { | |
108 | struct nand_chip *nand_chip = mtd->priv; | |
109 | struct socrates_nand_host *host = nand_chip->priv; | |
110 | uint32_t val; | |
111 | ||
112 | if (cmd == NAND_CMD_NONE) | |
113 | return; | |
114 | ||
115 | if (ctrl & NAND_CLE) | |
116 | val = FPGA_NAND_CMD_COMMAND; | |
117 | else | |
118 | val = FPGA_NAND_CMD_ADDR; | |
119 | ||
120 | if (ctrl & NAND_NCE) | |
121 | val |= FPGA_NAND_ENABLE; | |
122 | ||
123 | val |= (cmd & 0xff) << FPGA_NAND_DATA_SHIFT; | |
124 | ||
125 | out_be32(host->io_base, val); | |
126 | } | |
127 | ||
128 | /* | |
129 | * Read the Device Ready pin. | |
130 | */ | |
131 | static int socrates_nand_device_ready(struct mtd_info *mtd) | |
132 | { | |
133 | struct nand_chip *nand_chip = mtd->priv; | |
134 | struct socrates_nand_host *host = nand_chip->priv; | |
135 | ||
136 | if (in_be32(host->io_base) & FPGA_NAND_BUSY) | |
137 | return 0; /* busy */ | |
138 | return 1; | |
139 | } | |
140 | ||
1b578193 WG |
141 | /* |
142 | * Probe for the NAND device. | |
143 | */ | |
06f25510 | 144 | static int socrates_nand_probe(struct platform_device *ofdev) |
1b578193 WG |
145 | { |
146 | struct socrates_nand_host *host; | |
147 | struct mtd_info *mtd; | |
148 | struct nand_chip *nand_chip; | |
149 | int res; | |
1b578193 WG |
150 | |
151 | /* Allocate memory for the device structure (and zero it) */ | |
cf3a9b56 SK |
152 | host = devm_kzalloc(&ofdev->dev, sizeof(*host), GFP_KERNEL); |
153 | if (!host) | |
1b578193 | 154 | return -ENOMEM; |
1b578193 | 155 | |
c8a4d0fd | 156 | host->io_base = of_iomap(ofdev->dev.of_node, 0); |
1b578193 | 157 | if (host->io_base == NULL) { |
5422933d | 158 | dev_err(&ofdev->dev, "ioremap failed\n"); |
1b578193 WG |
159 | return -EIO; |
160 | } | |
161 | ||
162 | mtd = &host->mtd; | |
163 | nand_chip = &host->nand_chip; | |
164 | host->dev = &ofdev->dev; | |
165 | ||
166 | nand_chip->priv = host; /* link the private data structures */ | |
a61ae81a | 167 | nand_set_flash_node(nand_chip, ofdev->dev.of_node); |
1b578193 WG |
168 | mtd->priv = nand_chip; |
169 | mtd->name = "socrates_nand"; | |
1b578193 WG |
170 | mtd->dev.parent = &ofdev->dev; |
171 | ||
172 | /*should never be accessed directly */ | |
173 | nand_chip->IO_ADDR_R = (void *)0xdeadbeef; | |
174 | nand_chip->IO_ADDR_W = (void *)0xdeadbeef; | |
175 | ||
176 | nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl; | |
177 | nand_chip->read_byte = socrates_nand_read_byte; | |
178 | nand_chip->read_word = socrates_nand_read_word; | |
179 | nand_chip->write_buf = socrates_nand_write_buf; | |
180 | nand_chip->read_buf = socrates_nand_read_buf; | |
1b578193 WG |
181 | nand_chip->dev_ready = socrates_nand_device_ready; |
182 | ||
183 | nand_chip->ecc.mode = NAND_ECC_SOFT; /* enable ECC */ | |
184 | ||
185 | /* TODO: I have no idea what real delay is. */ | |
186 | nand_chip->chip_delay = 20; /* 20us command delay time */ | |
187 | ||
188 | dev_set_drvdata(&ofdev->dev, host); | |
189 | ||
190 | /* first scan to find the device and get the page size */ | |
5e81e88a | 191 | if (nand_scan_ident(mtd, 1, NULL)) { |
1b578193 WG |
192 | res = -ENXIO; |
193 | goto out; | |
194 | } | |
195 | ||
196 | /* second phase scan */ | |
197 | if (nand_scan_tail(mtd)) { | |
198 | res = -ENXIO; | |
199 | goto out; | |
200 | } | |
201 | ||
a61ae81a | 202 | res = mtd_device_register(mtd, NULL, 0); |
1b578193 WG |
203 | if (!res) |
204 | return res; | |
205 | ||
1b578193 WG |
206 | nand_release(mtd); |
207 | ||
208 | out: | |
1b578193 | 209 | iounmap(host->io_base); |
1b578193 WG |
210 | return res; |
211 | } | |
212 | ||
213 | /* | |
214 | * Remove a NAND device. | |
215 | */ | |
810b7e06 | 216 | static int socrates_nand_remove(struct platform_device *ofdev) |
1b578193 WG |
217 | { |
218 | struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev); | |
219 | struct mtd_info *mtd = &host->mtd; | |
220 | ||
221 | nand_release(mtd); | |
222 | ||
1b578193 | 223 | iounmap(host->io_base); |
1b578193 WG |
224 | |
225 | return 0; | |
226 | } | |
227 | ||
b2d4fbab | 228 | static const struct of_device_id socrates_nand_match[] = |
1b578193 WG |
229 | { |
230 | { | |
231 | .compatible = "abb,socrates-nand", | |
232 | }, | |
233 | {}, | |
234 | }; | |
235 | ||
236 | MODULE_DEVICE_TABLE(of, socrates_nand_match); | |
237 | ||
1c48a5c9 | 238 | static struct platform_driver socrates_nand_driver = { |
4018294b GL |
239 | .driver = { |
240 | .name = "socrates_nand", | |
4018294b GL |
241 | .of_match_table = socrates_nand_match, |
242 | }, | |
1b578193 | 243 | .probe = socrates_nand_probe, |
5153b88c | 244 | .remove = socrates_nand_remove, |
1b578193 WG |
245 | }; |
246 | ||
f99640de | 247 | module_platform_driver(socrates_nand_driver); |
1b578193 WG |
248 | |
249 | MODULE_LICENSE("GPL"); | |
250 | MODULE_AUTHOR("Ilya Yanok"); | |
251 | MODULE_DESCRIPTION("NAND driver for Socrates board"); |