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 <linux/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 static int sc_nand_device_ready(struct mtd_info *mtdinfo); 22 23 #define FPGA_NAND_CMD_MASK (0x7 << 28) 24 #define FPGA_NAND_CMD_COMMAND (0x0 << 28) 25 #define FPGA_NAND_CMD_ADDR (0x1 << 28) 26 #define FPGA_NAND_CMD_READ (0x2 << 28) 27 #define FPGA_NAND_CMD_WRITE (0x3 << 28) 28 #define FPGA_NAND_BUSY (0x1 << 15) 29 #define FPGA_NAND_ENABLE (0x1 << 31) 30 #define FPGA_NAND_DATA_SHIFT 16 31 32 /** 33 * sc_nand_write_byte - write one byte to the chip 34 * @mtd: MTD device structure 35 * @byte: pointer to data byte to write 36 */ 37 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte) 38 { 39 sc_nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte)); 40 } 41 42 /** 43 * sc_nand_write_buf - write buffer to chip 44 * @mtd: MTD device structure 45 * @buf: data buffer 46 * @len: number of bytes to write 47 */ 48 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len) 49 { 50 int i; 51 struct nand_chip *this = mtd_to_nand(mtd); 52 53 for (i = 0; i < len; i++) { 54 out_be32(this->IO_ADDR_W, 55 state | (buf[i] << FPGA_NAND_DATA_SHIFT)); 56 } 57 } 58 59 60 /** 61 * sc_nand_read_byte - read one byte from the chip 62 * @mtd: MTD device structure 63 */ 64 static u_char sc_nand_read_byte(struct mtd_info *mtd) 65 { 66 u8 byte; 67 sc_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte)); 68 return byte; 69 } 70 71 /** 72 * sc_nand_read_word - read one word from the chip 73 * @mtd: MTD device structure 74 */ 75 static u16 sc_nand_read_word(struct mtd_info *mtd) 76 { 77 u16 word; 78 sc_nand_read_buf(mtd, (uchar *)&word, sizeof(word)); 79 return word; 80 } 81 82 /** 83 * sc_nand_read_buf - read chip data into buffer 84 * @mtd: MTD device structure 85 * @buf: buffer to store date 86 * @len: number of bytes to read 87 */ 88 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len) 89 { 90 int i; 91 struct nand_chip *this = mtd_to_nand(mtd); 92 int val; 93 94 val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ; 95 96 out_be32(this->IO_ADDR_W, val); 97 for (i = 0; i < len; i++) { 98 buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff; 99 } 100 } 101 102 /** 103 * sc_nand_device_ready - Check the NAND device is ready for next command. 104 * @mtd: MTD device structure 105 */ 106 static int sc_nand_device_ready(struct mtd_info *mtdinfo) 107 { 108 struct nand_chip *this = mtd_to_nand(mtdinfo); 109 110 if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY) 111 return 0; /* busy */ 112 return 1; 113 } 114 115 /** 116 * sc_nand_hwcontrol - NAND control functions wrapper. 117 * @mtd: MTD device structure 118 * @cmd: Command 119 */ 120 static void sc_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl) 121 { 122 if (ctrl & NAND_CTRL_CHANGE) { 123 state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE); 124 125 switch (ctrl & (NAND_ALE | NAND_CLE)) { 126 case 0: 127 state |= FPGA_NAND_CMD_WRITE; 128 break; 129 130 case NAND_ALE: 131 state |= FPGA_NAND_CMD_ADDR; 132 break; 133 134 case NAND_CLE: 135 state |= FPGA_NAND_CMD_COMMAND; 136 break; 137 138 default: 139 printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl); 140 } 141 142 if (ctrl & NAND_NCE) 143 state |= FPGA_NAND_ENABLE; 144 } 145 146 if (cmd != NAND_CMD_NONE) 147 sc_nand_write_byte(mtdinfo, cmd); 148 } 149 150 int board_nand_init(struct nand_chip *nand) 151 { 152 nand->cmd_ctrl = sc_nand_hwcontrol; 153 nand->ecc.mode = NAND_ECC_SOFT; 154 nand->dev_ready = sc_nand_device_ready; 155 nand->read_byte = sc_nand_read_byte; 156 nand->read_word = sc_nand_read_word; 157 nand->write_buf = sc_nand_write_buf; 158 nand->read_buf = sc_nand_read_buf; 159 160 return 0; 161 } 162 163 #endif 164