1 /*
2 * drivers/mtd/nand/ams-delta.c
3 *
4 * Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
5 *
6 * Derived from drivers/mtd/toto.c
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Overview:
13 * This is a device driver for the NAND flash device found on the
14 * Amstrad E3 (Delta).
15 */
16
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/delay.h>
21 #include <linux/mtd/mtd.h>
22 #include <linux/mtd/nand.h>
23 #include <linux/mtd/partitions.h>
24 #include <asm/io.h>
25 #include <mach/hardware.h>
26 #include <asm/sizes.h>
27 #include <mach/gpio.h>
28 #include <mach/board-ams-delta.h>
29
30 /*
31 * MTD structure for E3 (Delta)
32 */
33 static struct mtd_info *ams_delta_mtd = NULL;
34
35 #define NAND_MASK (AMS_DELTA_LATCH2_NAND_NRE | AMS_DELTA_LATCH2_NAND_NWE | AMS_DELTA_LATCH2_NAND_CLE | AMS_DELTA_LATCH2_NAND_ALE | AMS_DELTA_LATCH2_NAND_NCE | AMS_DELTA_LATCH2_NAND_NWP)
36
37 /*
38 * Define partitions for flash devices
39 */
40
41 static struct mtd_partition partition_info[] = {
42 { .name = "Kernel",
43 .offset = 0,
44 .size = 3 * SZ_1M + SZ_512K },
45 { .name = "u-boot",
46 .offset = 3 * SZ_1M + SZ_512K,
47 .size = SZ_256K },
48 { .name = "u-boot params",
49 .offset = 3 * SZ_1M + SZ_512K + SZ_256K,
50 .size = SZ_256K },
51 { .name = "Amstrad LDR",
52 .offset = 4 * SZ_1M,
53 .size = SZ_256K },
54 { .name = "File system",
55 .offset = 4 * SZ_1M + 1 * SZ_256K,
56 .size = 27 * SZ_1M },
57 { .name = "PBL reserved",
58 .offset = 32 * SZ_1M - 3 * SZ_256K,
59 .size = 3 * SZ_256K },
60 };
61
62 static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
63 {
64 struct nand_chip *this = mtd->priv;
65
66 omap_writew(0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL));
67 omap_writew(byte, this->IO_ADDR_W);
68 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, 0);
69 ndelay(40);
70 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE,
71 AMS_DELTA_LATCH2_NAND_NWE);
72 }
73
74 static u_char ams_delta_read_byte(struct mtd_info *mtd)
75 {
76 u_char res;
77 struct nand_chip *this = mtd->priv;
78
79 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, 0);
80 ndelay(40);
81 omap_writew(~0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL));
82 res = omap_readw(this->IO_ADDR_R);
83 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE,
84 AMS_DELTA_LATCH2_NAND_NRE);
85
86 return res;
87 }
88
89 static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
90 int len)
91 {
92 int i;
93
94 for (i=0; i<len; i++)
95 ams_delta_write_byte(mtd, buf[i]);
96 }
97
98 static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
99 {
100 int i;
101
102 for (i=0; i<len; i++)
103 buf[i] = ams_delta_read_byte(mtd);
104 }
105
106 static int ams_delta_verify_buf(struct mtd_info *mtd, const u_char *buf,
107 int len)
108 {
109 int i;
110
111 for (i=0; i<len; i++)
112 if (buf[i] != ams_delta_read_byte(mtd))
113 return -EFAULT;
114
115 return 0;
116 }
117
118 /*
119 * Command control function
120 *
121 * ctrl:
122 * NAND_NCE: bit 0 -> bit 2
123 * NAND_CLE: bit 1 -> bit 7
124 * NAND_ALE: bit 2 -> bit 6
125 */
126 static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
127 unsigned int ctrl)
128 {
129
130 if (ctrl & NAND_CTRL_CHANGE) {
131 unsigned long bits;
132
133 bits = (~ctrl & NAND_NCE) ? AMS_DELTA_LATCH2_NAND_NCE : 0;
134 bits |= (ctrl & NAND_CLE) ? AMS_DELTA_LATCH2_NAND_CLE : 0;
135 bits |= (ctrl & NAND_ALE) ? AMS_DELTA_LATCH2_NAND_ALE : 0;
136
137 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_CLE |
138 AMS_DELTA_LATCH2_NAND_ALE |
139 AMS_DELTA_LATCH2_NAND_NCE, bits);
140 }
141
142 if (cmd != NAND_CMD_NONE)
143 ams_delta_write_byte(mtd, cmd);
144 }
145
146 static int ams_delta_nand_ready(struct mtd_info *mtd)
147 {
148 return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
149 }
150
151 /*
152 * Main initialization routine
153 */
154 static int __init ams_delta_init(void)
155 {
156 struct nand_chip *this;
157 int err = 0;
158
159 /* Allocate memory for MTD device structure and private data */
160 ams_delta_mtd = kmalloc(sizeof(struct mtd_info) +
161 sizeof(struct nand_chip), GFP_KERNEL);
162 if (!ams_delta_mtd) {
163 printk (KERN_WARNING "Unable to allocate E3 NAND MTD device structure.\n");
164 err = -ENOMEM;
165 goto out;
166 }
167
168 ams_delta_mtd->owner = THIS_MODULE;
169
170 /* Get pointer to private data */
171 this = (struct nand_chip *) (&ams_delta_mtd[1]);
172
173 /* Initialize structures */
174 memset(ams_delta_mtd, 0, sizeof(struct mtd_info));
175 memset(this, 0, sizeof(struct nand_chip));
176
177 /* Link the private data with the MTD structure */
178 ams_delta_mtd->priv = this;
179
180 /* Set address of NAND IO lines */
181 this->IO_ADDR_R = (OMAP_MPUIO_BASE + OMAP_MPUIO_INPUT_LATCH);
182 this->IO_ADDR_W = (OMAP_MPUIO_BASE + OMAP_MPUIO_OUTPUT);
183 this->read_byte = ams_delta_read_byte;
184 this->write_buf = ams_delta_write_buf;
185 this->read_buf = ams_delta_read_buf;
186 this->verify_buf = ams_delta_verify_buf;
187 this->cmd_ctrl = ams_delta_hwcontrol;
188 if (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
189 this->dev_ready = ams_delta_nand_ready;
190 } else {
191 this->dev_ready = NULL;
192 printk(KERN_NOTICE "Couldn't request gpio for Delta NAND ready.\n");
193 }
194 /* 25 us command delay time */
195 this->chip_delay = 30;
196 this->ecc.mode = NAND_ECC_SOFT;
197
198 /* Set chip enabled, but */
199 ams_delta_latch2_write(NAND_MASK, AMS_DELTA_LATCH2_NAND_NRE |
200 AMS_DELTA_LATCH2_NAND_NWE |
201 AMS_DELTA_LATCH2_NAND_NCE |
202 AMS_DELTA_LATCH2_NAND_NWP);
203
204 /* Scan to find existance of the device */
205 if (nand_scan(ams_delta_mtd, 1)) {
206 err = -ENXIO;
207 goto out_mtd;
208 }
209
210 /* Register the partitions */
211 add_mtd_partitions(ams_delta_mtd, partition_info,
212 ARRAY_SIZE(partition_info));
213
214 goto out;
215
216 out_mtd:
217 kfree(ams_delta_mtd);
218 out:
219 return err;
220 }
221
222 module_init(ams_delta_init);
223
224 /*
225 * Clean up routine
226 */
227 static void __exit ams_delta_cleanup(void)
228 {
229 /* Release resources, unregister device */
230 nand_release(ams_delta_mtd);
231
232 /* Free the MTD device structure */
233 kfree(ams_delta_mtd);
234 }
235 module_exit(ams_delta_cleanup);
236
237 MODULE_LICENSE("GPL");
238 MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
239 MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");
240
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