Merge branch 'master' of /home/wd/git/u-boot/custodians
[oweals/u-boot.git] / board / socrates / nand.c
1 /*
2  * (C) Copyright 2008
3  * Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23
24 #include <common.h>
25
26 #if defined(CFG_NAND_BASE)
27 #include <nand.h>
28 #include <asm/errno.h>
29 #include <asm/io.h>
30
31 static int state;
32 static void nand_write_byte(struct mtd_info *mtd, u_char byte);
33 static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
34 static u_char nand_read_byte(struct mtd_info *mtd);
35 static u16 nand_read_word(struct mtd_info *mtd);
36 static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
37 static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);
38 static int nand_device_ready(struct mtd_info *mtdinfo);
39
40 #define FPGA_NAND_CMD_MASK              (0x7 << 28)
41 #define FPGA_NAND_CMD_COMMAND           (0x0 << 28)
42 #define FPGA_NAND_CMD_ADDR              (0x1 << 28)
43 #define FPGA_NAND_CMD_READ              (0x2 << 28)
44 #define FPGA_NAND_CMD_WRITE             (0x3 << 28)
45 #define FPGA_NAND_BUSY                  (0x1 << 15)
46 #define FPGA_NAND_ENABLE                (0x1 << 31)
47 #define FPGA_NAND_DATA_SHIFT            16
48
49 /**
50  * nand_write_byte -  write one byte to the chip
51  * @mtd:        MTD device structure
52  * @byte:       pointer to data byte to write
53  */
54 static void nand_write_byte(struct mtd_info *mtd, u_char byte)
55 {
56         nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
57 }
58
59 /**
60  * nand_write_buf -  write buffer to chip
61  * @mtd:        MTD device structure
62  * @buf:        data buffer
63  * @len:        number of bytes to write
64  */
65 static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
66 {
67         int i;
68         struct nand_chip *this = mtd->priv;
69
70         for (i = 0; i < len; i++) {
71                 out_be32(this->IO_ADDR_W,
72                          state | (buf[i] << FPGA_NAND_DATA_SHIFT));
73         }
74 }
75
76
77 /**
78  * nand_read_byte -  read one byte from the chip
79  * @mtd:        MTD device structure
80  */
81 static u_char nand_read_byte(struct mtd_info *mtd)
82 {
83         u8 byte;
84         nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
85         return byte;
86 }
87
88 /**
89  * nand_read_word -  read one word from the chip
90  * @mtd:        MTD device structure
91  */
92 static u16 nand_read_word(struct mtd_info *mtd)
93 {
94         u16 word;
95         nand_read_buf(mtd, (uchar *)&word, sizeof(word));
96         return word;
97 }
98
99 /**
100  * nand_read_buf -  read chip data into buffer
101  * @mtd:        MTD device structure
102  * @buf:        buffer to store date
103  * @len:        number of bytes to read
104  */
105 static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
106 {
107         int i;
108         struct nand_chip *this = mtd->priv;
109         int val;
110
111         val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
112
113         out_be32(this->IO_ADDR_W, val);
114         for (i = 0; i < len; i++) {
115                 buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
116         }
117 }
118
119 /**
120  * nand_verify_buf -  Verify chip data against buffer
121  * @mtd:        MTD device structure
122  * @buf:        buffer containing the data to compare
123  * @len:        number of bytes to compare
124  */
125 static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
126 {
127         int i;
128
129         for (i = 0; i < len; i++) {
130                 if (buf[i] != nand_read_byte(mtd));
131                         return -EFAULT;
132         }
133         return 0;
134 }
135
136 /**
137  * nand_device_ready - Check the NAND device is ready for next command.
138  * @mtd:        MTD device structure
139  */
140 static int nand_device_ready(struct mtd_info *mtdinfo)
141 {
142         struct nand_chip *this = mtdinfo->priv;
143
144         if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
145                 return 0; /* busy */
146         return 1;
147 }
148
149 /**
150  * nand_hwcontrol - NAND control functions wrapper.
151  * @mtd:        MTD device structure
152  * @cmd:        Command
153  */
154 static void nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
155 {
156         if (ctrl & NAND_CTRL_CHANGE) {
157                 state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
158
159                 switch (ctrl & (NAND_ALE | NAND_CLE)) {
160                 case 0:
161                         state |= FPGA_NAND_CMD_WRITE;
162                         break;
163
164                 case NAND_ALE:
165                         state |= FPGA_NAND_CMD_ADDR;
166                         break;
167
168                 case NAND_CLE:
169                         state |= FPGA_NAND_CMD_COMMAND;
170                         break;
171
172                 default:
173                         printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
174                 }
175
176                 if (ctrl & NAND_NCE)
177                         state |= FPGA_NAND_ENABLE;
178         }
179
180         if (cmd != NAND_CMD_NONE)
181                 nand_write_byte(mtdinfo, cmd);
182 }
183
184 int board_nand_init(struct nand_chip *nand)
185 {
186         nand->cmd_ctrl = nand_hwcontrol;
187         nand->ecc.mode = NAND_ECC_SOFT;
188         nand->dev_ready = nand_device_ready;
189         nand->read_byte = nand_read_byte;
190         nand->read_word = nand_read_word;
191         nand->write_buf = nand_write_buf;
192         nand->read_buf = nand_read_buf;
193         nand->verify_buf = nand_verify_buf;
194
195         return 0;
196 }
197
198 #endif