diff options
Diffstat (limited to 'drivers/mtd/nand/raw/nomadik_nand.c')
| -rw-r--r-- | drivers/mtd/nand/raw/nomadik_nand.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/nomadik_nand.c b/drivers/mtd/nand/raw/nomadik_nand.c new file mode 100644 index 0000000000..1be3021e99 --- /dev/null +++ b/drivers/mtd/nand/raw/nomadik_nand.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + * + */ + +#include <common.h> +#include <driver.h> +#include <malloc.h> +#include <init.h> + +#include <linux/err.h> +#include <linux/types.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> +#include <linux/mtd/rawnand.h> + +#include <io.h> +#include <mach/nomadik/nand.h> +#include <mach/nomadik/fsmc.h> + +#include <errno.h> + +struct nomadik_nand_host { + 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 nand_chip *nand, 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 nand_chip *chip, uint8_t *dat, + uint8_t *r_ecc, uint8_t *c_ecc) +{ + 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 nand_chip *nand, int mode) +{ + /* No need to enable hw ecc, it's on by default */ +} + +static void nomadik_cmd_ctrl(struct nand_chip *nand, int cmd, unsigned int ctrl) +{ + 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 *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 = dev_request_mem_region_by_name(dev, "nand_cmd"); + if (IS_ERR(host->cmd_va)) + return PTR_ERR(host->cmd_va); + host->addr_va = dev_request_mem_region_by_name(dev, "nand_addr"); + if (IS_ERR(host->addr_va)) + return PTR_ERR(host->addr_va); + + /* Link all private pointers */ + nand = &host->nand; + mtd = nand_to_mtd(nand); + nand->priv = host; + mtd->dev.parent = dev; + + nand->legacy.IO_ADDR_W = nand->legacy.IO_ADDR_R = + dev_request_mem_region_by_name(dev, "nand_data"); + if (IS_ERR(nand->legacy.IO_ADDR_W)) + return PTR_ERR(nand->legacy.IO_ADDR_W); + nand->legacy.cmd_ctrl = nomadik_cmd_ctrl; + + nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST; + mtd_set_ecclayout(mtd, &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->ecc.strength = 1; + + nand->options = pdata->options; + + /* + * Scan to find existance of the device + */ + if (nand_scan(nand, 1)) { + ret = -ENXIO; + goto err; + } + + pr_info("Registering %s as whole device\n", mtd->name); + add_mtd_nand_device(mtd, "nand"); + + return 0; + +err: + kfree(host); + return ret; +} + +static struct driver nomadik_nand_driver = { + .probe = nomadik_nand_probe, + .name = "nomadik_nand", +}; +device_platform_driver(nomadik_nand_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("ST Microelectronics (sachin.verma@st.com)"); +MODULE_DESCRIPTION("NAND driver for Nomadik Platform"); |