| /* |
| * drivers/mtd/nand/nomadik_nand.c |
| * |
| * Overview: |
| * Driver for on-board NAND flash on Nomadik Platforms |
| * |
| * Copyright (C) 2007 STMicroelectronics Pvt. Ltd. |
| * Author: Sachin Verma <sachin.verma@st.com> |
| * |
| * Copyright (C) 2009 Alessandro Rubini |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <common.h> |
| #include <driver.h> |
| #include <malloc.h> |
| #include <init.h> |
| |
| #include <linux/types.h> |
| #include <linux/mtd/mtd.h> |
| #include <linux/mtd/nand.h> |
| |
| #include <asm/io.h> |
| #include <mach/nand.h> |
| #include <mach/fsmc.h> |
| |
| #include <errno.h> |
| |
| struct nomadik_nand_host { |
| struct mtd_info mtd; |
| struct nand_chip nand; |
| void __iomem *cmd_va; |
| void __iomem *addr_va; |
| struct nand_bbt_descr *bbt_desc; |
| }; |
| |
| static inline int parity(int b) /* uses low 8 bits: returns 0 or all-1 */ |
| { |
| b = b ^ (b >> 4); |
| b = b ^ (b >> 2); |
| return (b ^ (b >> 1)) & 1 |
| ? ~0 : 0; |
| } |
| |
| /* |
| * This is the ECC routine used in hardware, according to the manual. |
| * HW claims to make the calculation but not the correction. However, |
| * I haven't managed to get the desired data out of it; so do it in sw. |
| * There is problably some errata involved, but currently miss the info. |
| */ |
| static int nomadik_ecc512_calc(struct mtd_info *mtd, const u_char *data, |
| u_char *ecc) |
| { |
| int gpar = 0; |
| int i, val, par; |
| int pbits = 0; /* P8, P16, ... P2048 */ |
| int pprime = 0; /* P8', P16', ... P2048' */ |
| int lowbits; /* P1, P2, P4 and primes */ |
| |
| for (i = 0; i < 512; i++) { |
| par = parity((val = data[i])); |
| gpar ^= val; |
| pbits ^= (i & par); |
| } |
| /* |
| * Ok, now gpar is global parity (xor of all bytes) |
| * pbits are all the parity bits (non-prime ones) |
| */ |
| par = parity(gpar); |
| pprime = pbits ^ par; |
| /* Put low bits in the right position for ecc[2] (bits 7..2) */ |
| lowbits = 0 |
| | (parity(gpar & 0xf0) & 0x80) /* P4 */ |
| | (parity(gpar & 0x0f) & 0x40) /* P4' */ |
| | (parity(gpar & 0xcc) & 0x20) /* P2 */ |
| | (parity(gpar & 0x33) & 0x10) /* P2' */ |
| | (parity(gpar & 0xaa) & 0x08) /* P1 */ |
| | (parity(gpar & 0x55) & 0x04); /* P1' */ |
| |
| ecc[2] = ~(lowbits | ((pbits & 0x100) >> 7) | ((pprime & 0x100) >> 8)); |
| /* now intermix bits for ecc[1] (P1024..P128') and ecc[0] (P64..P8') */ |
| ecc[1] = ~( (pbits & 0x80) >> 0 | ((pprime & 0x80) >> 1) |
| | ((pbits & 0x40) >> 1) | ((pprime & 0x40) >> 2) |
| | ((pbits & 0x20) >> 2) | ((pprime & 0x20) >> 3) |
| | ((pbits & 0x10) >> 3) | ((pprime & 0x10) >> 4)); |
| |
| ecc[0] = ~( (pbits & 0x8) << 4 | ((pprime & 0x8) << 3) |
| | ((pbits & 0x4) << 3) | ((pprime & 0x4) << 2) |
| | ((pbits & 0x2) << 2) | ((pprime & 0x2) << 1) |
| | ((pbits & 0x1) << 1) | ((pprime & 0x1) << 0)); |
| return 0; |
| } |
| |
| static int nomadik_ecc512_correct(struct mtd_info *mtd, uint8_t *dat, |
| uint8_t *r_ecc, uint8_t *c_ecc) |
| { |
| struct nand_chip *chip = mtd->priv; |
| uint32_t r, c, d, diff; /*read, calculated, xor of them */ |
| |
| if (!memcmp(r_ecc, c_ecc, chip->ecc.bytes)) |
| return 0; |
| |
| /* Reorder the bytes into ascending-order 24 bits -- see manual */ |
| r = r_ecc[2] << 22 | r_ecc[1] << 14 | r_ecc[0] << 6 | r_ecc[2] >> 2; |
| c = c_ecc[2] << 22 | c_ecc[1] << 14 | c_ecc[0] << 6 | c_ecc[2] >> 2; |
| diff = (r ^ c) & ((1 << 24) - 1); /* use 24 bits only */ |
| |
| /* If 12 bits are different, one per pair, it's correctable */ |
| if (((diff | (diff>>1)) & 0x555555) == 0x555555) { |
| int bit = ((diff & 2) >> 1) |
| | ((diff & 0x8) >> 2) | ((diff & 0x20) >> 3); |
| int byte; |
| |
| d = diff >> 6; /* remove bit-order info */ |
| byte = ((d & 2) >> 1) |
| | ((d & 0x8) >> 2) | ((d & 0x20) >> 3) |
| | ((d & 0x80) >> 4) | ((d & 0x200) >> 5) |
| | ((d & 0x800) >> 6) | ((d & 0x2000) >> 7) |
| | ((d & 0x8000) >> 8) | ((d & 0x20000) >> 9); |
| /* correct the single bit */ |
| dat[byte] ^= 1 << bit; |
| return 0; |
| } |
| /* If 1 bit only differs, it's one bit error in ECC, ignore */ |
| if ((diff ^ (1 << (ffs(diff) - 1))) == 0) |
| return 0; |
| /* Otherwise, uncorrectable */ |
| return -1; |
| } |
| |
| static struct nand_ecclayout nomadik_ecc_layout = { |
| .eccbytes = 3 * 4, |
| .eccpos = { /* each subpage has 16 bytes: pos 2,3,4 hosts ECC */ |
| 0x02, 0x03, 0x04, |
| 0x12, 0x13, 0x14, |
| 0x22, 0x23, 0x24, |
| 0x32, 0x33, 0x34}, |
| /* let's keep bytes 5,6,7 for us, just in case we change ECC algo */ |
| .oobfree = { {0x08, 0x08}, {0x18, 0x08}, {0x28, 0x08}, {0x38, 0x08} }, |
| }; |
| |
| static void nomadik_ecc_control(struct mtd_info *mtd, int mode) |
| { |
| /* No need to enable hw ecc, it's on by default */ |
| } |
| |
| static void nomadik_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) |
| { |
| struct nand_chip *nand = mtd->priv; |
| struct nomadik_nand_host *host = nand->priv; |
| |
| if (cmd == NAND_CMD_NONE) |
| return; |
| |
| if (ctrl & NAND_CLE) |
| writeb(cmd, host->cmd_va); |
| else |
| writeb(cmd, host->addr_va); |
| } |
| |
| static int nomadik_nand_probe(struct device_d *dev) |
| { |
| struct nomadik_nand_platform_data *pdata = dev->platform_data; |
| struct nomadik_nand_host *host; |
| struct mtd_info *mtd; |
| struct nand_chip *nand; |
| int ret = 0; |
| |
| /* Allocate memory for the device structure (and zero it) */ |
| host = kzalloc(sizeof(struct nomadik_nand_host), GFP_KERNEL); |
| if (!host) { |
| dev_err(dev, "Failed to allocate device structure.\n"); |
| return -ENOMEM; |
| } |
| |
| /* Call the client's init function, if any */ |
| if (pdata->init && (ret = pdata->init()) < 0) { |
| dev_err(dev, "Init function failed\n"); |
| goto err; |
| } |
| |
| host->cmd_va = (void __iomem*)pdata->cmd_va; |
| host->addr_va = (void __iomem*)pdata->addr_va; |
| |
| /* Link all private pointers */ |
| mtd = &host->mtd; |
| nand = &host->nand; |
| mtd->priv = nand; |
| nand->priv = host; |
| |
| nand->IO_ADDR_R = (void __iomem*)pdata->data_va; |
| nand->IO_ADDR_W = (void __iomem*)pdata->data_va; |
| nand->cmd_ctrl = nomadik_cmd_ctrl; |
| |
| nand->ecc.mode = NAND_ECC_HW; |
| nand->ecc.layout = &nomadik_ecc_layout; |
| nand->ecc.calculate = nomadik_ecc512_calc; |
| nand->ecc.correct = nomadik_ecc512_correct; |
| nand->ecc.hwctl = nomadik_ecc_control; |
| nand->ecc.size = 512; |
| nand->ecc.bytes = 3; |
| |
| nand->options = pdata->options; |
| |
| /* |
| * Scan to find existance of the device |
| */ |
| if (nand_scan(&host->mtd, 1)) { |
| ret = -ENXIO; |
| goto err; |
| } |
| |
| pr_info("Registering %s as whole device\n", mtd->name); |
| add_mtd_device(mtd); |
| |
| return 0; |
| |
| err: |
| kfree(host); |
| return ret; |
| } |
| |
| static struct driver_d nomadik_nand_driver = { |
| .probe = nomadik_nand_probe, |
| .name = "nomadik_nand", |
| }; |
| |
| static int __init nand_nomadik_init(void) |
| { |
| pr_info("Nomadik NAND driver\n"); |
| return register_driver(&nomadik_nand_driver); |
| } |
| |
| device_initcall(nand_nomadik_init); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("ST Microelectronics (sachin.verma@st.com)"); |
| MODULE_DESCRIPTION("NAND driver for Nomadik Platform"); |