xref: /openbmc/u-boot/board/socrates/nand.c (revision f13606b7)
1 /*
2  * (C) Copyright 2008
3  * Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 
10 #if defined(CONFIG_SYS_NAND_BASE)
11 #include <nand.h>
12 #include <asm/errno.h>
13 #include <asm/io.h>
14 
15 static int state;
16 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte);
17 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
18 static u_char sc_nand_read_byte(struct mtd_info *mtd);
19 static u16 sc_nand_read_word(struct mtd_info *mtd);
20 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
21 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
22 static int sc_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);
23 #endif
24 static int sc_nand_device_ready(struct mtd_info *mtdinfo);
25 
26 #define FPGA_NAND_CMD_MASK		(0x7 << 28)
27 #define FPGA_NAND_CMD_COMMAND		(0x0 << 28)
28 #define FPGA_NAND_CMD_ADDR		(0x1 << 28)
29 #define FPGA_NAND_CMD_READ		(0x2 << 28)
30 #define FPGA_NAND_CMD_WRITE		(0x3 << 28)
31 #define FPGA_NAND_BUSY			(0x1 << 15)
32 #define FPGA_NAND_ENABLE		(0x1 << 31)
33 #define FPGA_NAND_DATA_SHIFT		16
34 
35 /**
36  * sc_nand_write_byte -  write one byte to the chip
37  * @mtd:	MTD device structure
38  * @byte:	pointer to data byte to write
39  */
40 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte)
41 {
42 	sc_nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
43 }
44 
45 /**
46  * sc_nand_write_buf -  write buffer to chip
47  * @mtd:	MTD device structure
48  * @buf:	data buffer
49  * @len:	number of bytes to write
50  */
51 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
52 {
53 	int i;
54 	struct nand_chip *this = mtd->priv;
55 
56 	for (i = 0; i < len; i++) {
57 		out_be32(this->IO_ADDR_W,
58 			 state | (buf[i] << FPGA_NAND_DATA_SHIFT));
59 	}
60 }
61 
62 
63 /**
64  * sc_nand_read_byte -  read one byte from the chip
65  * @mtd:	MTD device structure
66  */
67 static u_char sc_nand_read_byte(struct mtd_info *mtd)
68 {
69 	u8 byte;
70 	sc_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
71 	return byte;
72 }
73 
74 /**
75  * sc_nand_read_word -  read one word from the chip
76  * @mtd:	MTD device structure
77  */
78 static u16 sc_nand_read_word(struct mtd_info *mtd)
79 {
80 	u16 word;
81 	sc_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
82 	return word;
83 }
84 
85 /**
86  * sc_nand_read_buf -  read chip data into buffer
87  * @mtd:	MTD device structure
88  * @buf:	buffer to store date
89  * @len:	number of bytes to read
90  */
91 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
92 {
93 	int i;
94 	struct nand_chip *this = mtd->priv;
95 	int val;
96 
97 	val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
98 
99 	out_be32(this->IO_ADDR_W, val);
100 	for (i = 0; i < len; i++) {
101 		buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
102 	}
103 }
104 
105 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
106 /**
107  * sc_nand_verify_buf -  Verify chip data against buffer
108  * @mtd:	MTD device structure
109  * @buf:	buffer containing the data to compare
110  * @len:	number of bytes to compare
111  */
112 static int sc_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
113 {
114 	int i;
115 
116 	for (i = 0; i < len; i++) {
117 		if (buf[i] != sc_nand_read_byte(mtd));
118 			return -EFAULT;
119 	}
120 	return 0;
121 }
122 #endif
123 
124 /**
125  * sc_nand_device_ready - Check the NAND device is ready for next command.
126  * @mtd:	MTD device structure
127  */
128 static int sc_nand_device_ready(struct mtd_info *mtdinfo)
129 {
130 	struct nand_chip *this = mtdinfo->priv;
131 
132 	if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
133 		return 0; /* busy */
134 	return 1;
135 }
136 
137 /**
138  * sc_nand_hwcontrol - NAND control functions wrapper.
139  * @mtd:	MTD device structure
140  * @cmd:	Command
141  */
142 static void sc_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
143 {
144 	if (ctrl & NAND_CTRL_CHANGE) {
145 		state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
146 
147 		switch (ctrl & (NAND_ALE | NAND_CLE)) {
148 		case 0:
149 			state |= FPGA_NAND_CMD_WRITE;
150 			break;
151 
152 		case NAND_ALE:
153 			state |= FPGA_NAND_CMD_ADDR;
154 			break;
155 
156 		case NAND_CLE:
157 			state |= FPGA_NAND_CMD_COMMAND;
158 			break;
159 
160 		default:
161 			printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
162 		}
163 
164 		if (ctrl & NAND_NCE)
165 			state |= FPGA_NAND_ENABLE;
166 	}
167 
168 	if (cmd != NAND_CMD_NONE)
169 		sc_nand_write_byte(mtdinfo, cmd);
170 }
171 
172 int board_nand_init(struct nand_chip *nand)
173 {
174 	nand->cmd_ctrl = sc_nand_hwcontrol;
175 	nand->ecc.mode = NAND_ECC_SOFT;
176 	nand->dev_ready = sc_nand_device_ready;
177 	nand->read_byte = sc_nand_read_byte;
178 	nand->read_word = sc_nand_read_word;
179 	nand->write_buf = sc_nand_write_buf;
180 	nand->read_buf = sc_nand_read_buf;
181 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
182 	nand->verify_buf = sc_nand_verify_buf;
183 #endif
184 
185 	return 0;
186 }
187 
188 #endif
189