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