xref: /openbmc/u-boot/board/socrates/nand.c (revision 7d9b5bae)
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
199