diff options
Diffstat (limited to 'drivers/mtd/nand/raw/atmel/pmecc.c')
| -rw-r--r-- | drivers/mtd/nand/raw/atmel/pmecc.c | 1012 |
1 files changed, 1012 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/atmel/pmecc.c b/drivers/mtd/nand/raw/atmel/pmecc.c new file mode 100644 index 0000000..555a74e --- /dev/null +++ b/drivers/mtd/nand/raw/atmel/pmecc.c @@ -0,0 +1,1012 @@ +/* + * Copyright 2017 ATMEL + * Copyright 2017 Free Electrons + * + * Author: Boris Brezillon <boris.brezillon@free-electrons.com> + * + * Derived from the atmel_nand.c driver which contained the following + * copyrights: + * + * Copyright 2003 Rick Bronson + * + * Derived from drivers/mtd/nand/autcpu12.c (removed in v3.8) + * Copyright 2001 Thomas Gleixner (gleixner@autronix.de) + * + * Derived from drivers/mtd/spia.c (removed in v3.8) + * Copyright 2000 Steven J. Hill (sjhill@cotw.com) + * + * Add Hardware ECC support for AT91SAM9260 / AT91SAM9263 + * Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright 2007 + * + * Derived from Das U-Boot source code + * (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c) + * Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas + * + * Add Programmable Multibit ECC support for various AT91 SoC + * Copyright 2012 ATMEL, Hong Xu + * + * Add Nand Flash Controller support for SAMA5 SoC + * Copyright 2013 ATMEL, Josh Wu (josh.wu@atmel.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * The PMECC is an hardware assisted BCH engine, which means part of the + * ECC algorithm is left to the software. The hardware/software repartition + * is explained in the "PMECC Controller Functional Description" chapter in + * Atmel datasheets, and some of the functions in this file are directly + * implementing the algorithms described in the "Software Implementation" + * sub-section. + * + * TODO: it seems that the software BCH implementation in lib/bch.c is already + * providing some of the logic we are implementing here. It would be smart + * to expose the needed lib/bch.c helpers/functions and re-use them here. + */ + +#include <linux/genalloc.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/mtd/rawnand.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "pmecc.h" + +/* Galois field dimension */ +#define PMECC_GF_DIMENSION_13 13 +#define PMECC_GF_DIMENSION_14 14 + +/* Primitive Polynomial used by PMECC */ +#define PMECC_GF_13_PRIMITIVE_POLY 0x201b +#define PMECC_GF_14_PRIMITIVE_POLY 0x4443 + +#define PMECC_LOOKUP_TABLE_SIZE_512 0x2000 +#define PMECC_LOOKUP_TABLE_SIZE_1024 0x4000 + +/* Time out value for reading PMECC status register */ +#define PMECC_MAX_TIMEOUT_MS 100 + +/* PMECC Register Definitions */ +#define ATMEL_PMECC_CFG 0x0 +#define PMECC_CFG_BCH_STRENGTH(x) (x) +#define PMECC_CFG_BCH_STRENGTH_MASK GENMASK(2, 0) +#define PMECC_CFG_SECTOR512 (0 << 4) +#define PMECC_CFG_SECTOR1024 (1 << 4) +#define PMECC_CFG_NSECTORS(x) ((fls(x) - 1) << 8) +#define PMECC_CFG_READ_OP (0 << 12) +#define PMECC_CFG_WRITE_OP (1 << 12) +#define PMECC_CFG_SPARE_ENABLE BIT(16) +#define PMECC_CFG_AUTO_ENABLE BIT(20) + +#define ATMEL_PMECC_SAREA 0x4 +#define ATMEL_PMECC_SADDR 0x8 +#define ATMEL_PMECC_EADDR 0xc + +#define ATMEL_PMECC_CLK 0x10 +#define PMECC_CLK_133MHZ (2 << 0) + +#define ATMEL_PMECC_CTRL 0x14 +#define PMECC_CTRL_RST BIT(0) +#define PMECC_CTRL_DATA BIT(1) +#define PMECC_CTRL_USER BIT(2) +#define PMECC_CTRL_ENABLE BIT(4) +#define PMECC_CTRL_DISABLE BIT(5) + +#define ATMEL_PMECC_SR 0x18 +#define PMECC_SR_BUSY BIT(0) +#define PMECC_SR_ENABLE BIT(4) + +#define ATMEL_PMECC_IER 0x1c +#define ATMEL_PMECC_IDR 0x20 +#define ATMEL_PMECC_IMR 0x24 +#define ATMEL_PMECC_ISR 0x28 +#define PMECC_ERROR_INT BIT(0) + +#define ATMEL_PMECC_ECC(sector, n) \ + ((((sector) + 1) * 0x40) + (n)) + +#define ATMEL_PMECC_REM(sector, n) \ + ((((sector) + 1) * 0x40) + ((n) * 4) + 0x200) + +/* PMERRLOC Register Definitions */ +#define ATMEL_PMERRLOC_ELCFG 0x0 +#define PMERRLOC_ELCFG_SECTOR_512 (0 << 0) +#define PMERRLOC_ELCFG_SECTOR_1024 (1 << 0) +#define PMERRLOC_ELCFG_NUM_ERRORS(n) ((n) << 16) + +#define ATMEL_PMERRLOC_ELPRIM 0x4 +#define ATMEL_PMERRLOC_ELEN 0x8 +#define ATMEL_PMERRLOC_ELDIS 0xc +#define PMERRLOC_DISABLE BIT(0) + +#define ATMEL_PMERRLOC_ELSR 0x10 +#define PMERRLOC_ELSR_BUSY BIT(0) + +#define ATMEL_PMERRLOC_ELIER 0x14 +#define ATMEL_PMERRLOC_ELIDR 0x18 +#define ATMEL_PMERRLOC_ELIMR 0x1c +#define ATMEL_PMERRLOC_ELISR 0x20 +#define PMERRLOC_ERR_NUM_MASK GENMASK(12, 8) +#define PMERRLOC_CALC_DONE BIT(0) + +#define ATMEL_PMERRLOC_SIGMA(x) (((x) * 0x4) + 0x28) + +#define ATMEL_PMERRLOC_EL(offs, x) (((x) * 0x4) + (offs)) + +struct atmel_pmecc_gf_tables { + u16 *alpha_to; + u16 *index_of; +}; + +struct atmel_pmecc_caps { + const int *strengths; + int nstrengths; + int el_offset; + bool correct_erased_chunks; +}; + +struct atmel_pmecc { + struct device *dev; + const struct atmel_pmecc_caps *caps; + + struct { + void __iomem *base; + void __iomem *errloc; + } regs; + + struct mutex lock; +}; + +struct atmel_pmecc_user_conf_cache { + u32 cfg; + u32 sarea; + u32 saddr; + u32 eaddr; +}; + +struct atmel_pmecc_user { + struct atmel_pmecc_user_conf_cache cache; + struct atmel_pmecc *pmecc; + const struct atmel_pmecc_gf_tables *gf_tables; + int eccbytes; + s16 *partial_syn; + s16 *si; + s16 *lmu; + s16 *smu; + s32 *mu; + s32 *dmu; + s32 *delta; + u32 isr; +}; + +static DEFINE_MUTEX(pmecc_gf_tables_lock); +static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_512; +static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_1024; + +static inline int deg(unsigned int poly) +{ + /* polynomial degree is the most-significant bit index */ + return fls(poly) - 1; +} + +static int atmel_pmecc_build_gf_tables(int mm, unsigned int poly, + struct atmel_pmecc_gf_tables *gf_tables) +{ + unsigned int i, x = 1; + const unsigned int k = BIT(deg(poly)); + unsigned int nn = BIT(mm) - 1; + + /* primitive polynomial must be of degree m */ + if (k != (1u << mm)) + return -EINVAL; + + for (i = 0; i < nn; i++) { + gf_tables->alpha_to[i] = x; + gf_tables->index_of[x] = i; + if (i && (x == 1)) + /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */ + return -EINVAL; + x <<= 1; + if (x & k) + x ^= poly; + } + gf_tables->alpha_to[nn] = 1; + gf_tables->index_of[0] = 0; + + return 0; +} + +static const struct atmel_pmecc_gf_tables * +atmel_pmecc_create_gf_tables(const struct atmel_pmecc_user_req *req) +{ + struct atmel_pmecc_gf_tables *gf_tables; + unsigned int poly, degree, table_size; + int ret; + + if (req->ecc.sectorsize == 512) { + degree = PMECC_GF_DIMENSION_13; + poly = PMECC_GF_13_PRIMITIVE_POLY; + table_size = PMECC_LOOKUP_TABLE_SIZE_512; + } else { + degree = PMECC_GF_DIMENSION_14; + poly = PMECC_GF_14_PRIMITIVE_POLY; + table_size = PMECC_LOOKUP_TABLE_SIZE_1024; + } + + gf_tables = kzalloc(sizeof(*gf_tables) + + (2 * table_size * sizeof(u16)), + GFP_KERNEL); + if (!gf_tables) + return ERR_PTR(-ENOMEM); + + gf_tables->alpha_to = (void *)(gf_tables + 1); + gf_tables->index_of = gf_tables->alpha_to + table_size; + + ret = atmel_pmecc_build_gf_tables(degree, poly, gf_tables); + if (ret) { + kfree(gf_tables); + return ERR_PTR(ret); + } + + return gf_tables; +} + +static const struct atmel_pmecc_gf_tables * +atmel_pmecc_get_gf_tables(const struct atmel_pmecc_user_req *req) +{ + const struct atmel_pmecc_gf_tables **gf_tables, *ret; + + mutex_lock(&pmecc_gf_tables_lock); + if (req->ecc.sectorsize == 512) + gf_tables = &pmecc_gf_tables_512; + else + gf_tables = &pmecc_gf_tables_1024; + + ret = *gf_tables; + + if (!ret) { + ret = atmel_pmecc_create_gf_tables(req); + if (!IS_ERR(ret)) + *gf_tables = ret; + } + mutex_unlock(&pmecc_gf_tables_lock); + + return ret; +} + +static int atmel_pmecc_prepare_user_req(struct atmel_pmecc *pmecc, + struct atmel_pmecc_user_req *req) +{ + int i, max_eccbytes, eccbytes = 0, eccstrength = 0; + + if (req->pagesize <= 0 || req->oobsize <= 0 || req->ecc.bytes <= 0) + return -EINVAL; + + if (req->ecc.ooboffset >= 0 && + req->ecc.ooboffset + req->ecc.bytes > req->oobsize) + return -EINVAL; + + if (req->ecc.sectorsize == ATMEL_PMECC_SECTOR_SIZE_AUTO) { + if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH) + return -EINVAL; + + if (req->pagesize > 512) + req->ecc.sectorsize = 1024; + else + req->ecc.sectorsize = 512; + } + + if (req->ecc.sectorsize != 512 && req->ecc.sectorsize != 1024) + return -EINVAL; + + if (req->pagesize % req->ecc.sectorsize) + return -EINVAL; + + req->ecc.nsectors = req->pagesize / req->ecc.sectorsize; + + max_eccbytes = req->ecc.bytes; + + for (i = 0; i < pmecc->caps->nstrengths; i++) { + int nbytes, strength = pmecc->caps->strengths[i]; + + if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH && + strength < req->ecc.strength) + continue; + + nbytes = DIV_ROUND_UP(strength * fls(8 * req->ecc.sectorsize), + 8); + nbytes *= req->ecc.nsectors; + + if (nbytes > max_eccbytes) + break; + + eccstrength = strength; + eccbytes = nbytes; + + if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH) + break; + } + + if (!eccstrength) + return -EINVAL; + + req->ecc.bytes = eccbytes; + req->ecc.strength = eccstrength; + + if (req->ecc.ooboffset < 0) + req->ecc.ooboffset = req->oobsize - eccbytes; + + return 0; +} + +struct atmel_pmecc_user * +atmel_pmecc_create_user(struct atmel_pmecc *pmecc, + struct atmel_pmecc_user_req *req) +{ + struct atmel_pmecc_user *user; + const struct atmel_pmecc_gf_tables *gf_tables; + int strength, size, ret; + + ret = atmel_pmecc_prepare_user_req(pmecc, req); + if (ret) + return ERR_PTR(ret); + + size = sizeof(*user); + size = ALIGN(size, sizeof(u16)); + /* Reserve space for partial_syn, si and smu */ + size += ((2 * req->ecc.strength) + 1) * sizeof(u16) * + (2 + req->ecc.strength + 2); + /* Reserve space for lmu. */ + size += (req->ecc.strength + 1) * sizeof(u16); + /* Reserve space for mu, dmu and delta. */ + size = ALIGN(size, sizeof(s32)); + size += (req->ecc.strength + 1) * sizeof(s32) * 3; + + user = kzalloc(size, GFP_KERNEL); + if (!user) + return ERR_PTR(-ENOMEM); + + user->pmecc = pmecc; + + user->partial_syn = (s16 *)PTR_ALIGN(user + 1, sizeof(u16)); + user->si = user->partial_syn + ((2 * req->ecc.strength) + 1); + user->lmu = user->si + ((2 * req->ecc.strength) + 1); + user->smu = user->lmu + (req->ecc.strength + 1); + user->mu = (s32 *)PTR_ALIGN(user->smu + + (((2 * req->ecc.strength) + 1) * + (req->ecc.strength + 2)), + sizeof(s32)); + user->dmu = user->mu + req->ecc.strength + 1; + user->delta = user->dmu + req->ecc.strength + 1; + + gf_tables = atmel_pmecc_get_gf_tables(req); + if (IS_ERR(gf_tables)) { + kfree(user); + return ERR_CAST(gf_tables); + } + + user->gf_tables = gf_tables; + + user->eccbytes = req->ecc.bytes / req->ecc.nsectors; + + for (strength = 0; strength < pmecc->caps->nstrengths; strength++) { + if (pmecc->caps->strengths[strength] == req->ecc.strength) + break; + } + + user->cache.cfg = PMECC_CFG_BCH_STRENGTH(strength) | + PMECC_CFG_NSECTORS(req->ecc.nsectors); + + if (req->ecc.sectorsize == 1024) + user->cache.cfg |= PMECC_CFG_SECTOR1024; + + user->cache.sarea = req->oobsize - 1; + user->cache.saddr = req->ecc.ooboffset; + user->cache.eaddr = req->ecc.ooboffset + req->ecc.bytes - 1; + + return user; +} +EXPORT_SYMBOL_GPL(atmel_pmecc_create_user); + +void atmel_pmecc_destroy_user(struct atmel_pmecc_user *user) +{ + kfree(user); +} +EXPORT_SYMBOL_GPL(atmel_pmecc_destroy_user); + +static int get_strength(struct atmel_pmecc_user *user) +{ + const int *strengths = user->pmecc->caps->strengths; + + return strengths[user->cache.cfg & PMECC_CFG_BCH_STRENGTH_MASK]; +} + +static int get_sectorsize(struct atmel_pmecc_user *user) +{ + return user->cache.cfg & PMECC_CFG_SECTOR1024 ? 1024 : 512; +} + +static void atmel_pmecc_gen_syndrome(struct atmel_pmecc_user *user, int sector) +{ + int strength = get_strength(user); + u32 value; + int i; + + /* Fill odd syndromes */ + for (i = 0; i < strength; i++) { + value = readl_relaxed(user->pmecc->regs.base + + ATMEL_PMECC_REM(sector, i / 2)); + if (i & 1) + value >>= 16; + + user->partial_syn[(2 * i) + 1] = value; + } +} + +static void atmel_pmecc_substitute(struct atmel_pmecc_user *user) +{ + int degree = get_sectorsize(user) == 512 ? 13 : 14; + int cw_len = BIT(degree) - 1; + int strength = get_strength(user); + s16 *alpha_to = user->gf_tables->alpha_to; + s16 *index_of = user->gf_tables->index_of; + s16 *partial_syn = user->partial_syn; + s16 *si; + int i, j; + + /* + * si[] is a table that holds the current syndrome value, + * an element of that table belongs to the field + */ + si = user->si; + + memset(&si[1], 0, sizeof(s16) * ((2 * strength) - 1)); + + /* Computation 2t syndromes based on S(x) */ + /* Odd syndromes */ + for (i = 1; i < 2 * strength; i += 2) { + for (j = 0; j < degree; j++) { + if (partial_syn[i] & BIT(j)) + si[i] = alpha_to[i * j] ^ si[i]; + } + } + /* Even syndrome = (Odd syndrome) ** 2 */ + for (i = 2, j = 1; j <= strength; i = ++j << 1) { + if (si[j] == 0) { + si[i] = 0; + } else { + s16 tmp; + + tmp = index_of[si[j]]; + tmp = (tmp * 2) % cw_len; + si[i] = alpha_to[tmp]; + } + } +} + +static void atmel_pmecc_get_sigma(struct atmel_pmecc_user *user) +{ + s16 *lmu = user->lmu; + s16 *si = user->si; + s32 *mu = user->mu; + s32 *dmu = user->dmu; + s32 *delta = user->delta; + int degree = get_sectorsize(user) == 512 ? 13 : 14; + int cw_len = BIT(degree) - 1; + int strength = get_strength(user); + int num = 2 * strength + 1; + s16 *index_of = user->gf_tables->index_of; + s16 *alpha_to = user->gf_tables->alpha_to; + int i, j, k; + u32 dmu_0_count, tmp; + s16 *smu = user->smu; + + /* index of largest delta */ + int ro; + int largest; + int diff; + + dmu_0_count = 0; + + /* First Row */ + + /* Mu */ + mu[0] = -1; + + memset(smu, 0, sizeof(s16) * num); + smu[0] = 1; + + /* discrepancy set to 1 */ + dmu[0] = 1; + /* polynom order set to 0 */ + lmu[0] = 0; + delta[0] = (mu[0] * 2 - lmu[0]) >> 1; + + /* Second Row */ + + /* Mu */ + mu[1] = 0; + /* Sigma(x) set to 1 */ + memset(&smu[num], 0, sizeof(s16) * num); + smu[num] = 1; + + /* discrepancy set to S1 */ + dmu[1] = si[1]; + + /* polynom order set to 0 */ + lmu[1] = 0; + + delta[1] = (mu[1] * 2 - lmu[1]) >> 1; + + /* Init the Sigma(x) last row */ + memset(&smu[(strength + 1) * num], 0, sizeof(s16) * num); + + for (i = 1; i <= strength; i++) { + mu[i + 1] = i << 1; + /* Begin Computing Sigma (Mu+1) and L(mu) */ + /* check if discrepancy is set to 0 */ + if (dmu[i] == 0) { + dmu_0_count++; + + tmp = ((strength - (lmu[i] >> 1) - 1) / 2); + if ((strength - (lmu[i] >> 1) - 1) & 0x1) + tmp += 2; + else + tmp += 1; + + if (dmu_0_count == tmp) { + for (j = 0; j <= (lmu[i] >> 1) + 1; j++) + smu[(strength + 1) * num + j] = + smu[i * num + j]; + + lmu[strength + 1] = lmu[i]; + return; + } + + /* copy polynom */ + for (j = 0; j <= lmu[i] >> 1; j++) + smu[(i + 1) * num + j] = smu[i * num + j]; + + /* copy previous polynom order to the next */ + lmu[i + 1] = lmu[i]; + } else { + ro = 0; + largest = -1; + /* find largest delta with dmu != 0 */ + for (j = 0; j < i; j++) { + if ((dmu[j]) && (delta[j] > largest)) { + largest = delta[j]; + ro = j; + } + } + + /* compute difference */ + diff = (mu[i] - mu[ro]); + + /* Compute degree of the new smu polynomial */ + if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff)) + lmu[i + 1] = lmu[i]; + else + lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2; + + /* Init smu[i+1] with 0 */ + for (k = 0; k < num; k++) + smu[(i + 1) * num + k] = 0; + + /* Compute smu[i+1] */ + for (k = 0; k <= lmu[ro] >> 1; k++) { + s16 a, b, c; + + if (!(smu[ro * num + k] && dmu[i])) + continue; + + a = index_of[dmu[i]]; + b = index_of[dmu[ro]]; + c = index_of[smu[ro * num + k]]; + tmp = a + (cw_len - b) + c; + a = alpha_to[tmp % cw_len]; + smu[(i + 1) * num + (k + diff)] = a; + } + + for (k = 0; k <= lmu[i] >> 1; k++) + smu[(i + 1) * num + k] ^= smu[i * num + k]; + } + + /* End Computing Sigma (Mu+1) and L(mu) */ + /* In either case compute delta */ + delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1; + + /* Do not compute discrepancy for the last iteration */ + if (i >= strength) + continue; + + for (k = 0; k <= (lmu[i + 1] >> 1); k++) { + tmp = 2 * (i - 1); + if (k == 0) { + dmu[i + 1] = si[tmp + 3]; + } else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) { + s16 a, b, c; + + a = index_of[smu[(i + 1) * num + k]]; + b = si[2 * (i - 1) + 3 - k]; + c = index_of[b]; + tmp = a + c; + tmp %= cw_len; + dmu[i + 1] = alpha_to[tmp] ^ dmu[i + 1]; + } + } + } +} + +static int atmel_pmecc_err_location(struct atmel_pmecc_user *user) +{ + int sector_size = get_sectorsize(user); + int degree = sector_size == 512 ? 13 : 14; + struct atmel_pmecc *pmecc = user->pmecc; + int strength = get_strength(user); + int ret, roots_nbr, i, err_nbr = 0; + int num = (2 * strength) + 1; + s16 *smu = user->smu; + u32 val; + + writel(PMERRLOC_DISABLE, pmecc->regs.errloc + ATMEL_PMERRLOC_ELDIS); + + for (i = 0; i <= user->lmu[strength + 1] >> 1; i++) { + writel_relaxed(smu[(strength + 1) * num + i], + pmecc->regs.errloc + ATMEL_PMERRLOC_SIGMA(i)); + err_nbr++; + } + + val = (err_nbr - 1) << 16; + if (sector_size == 1024) + val |= 1; + + writel(val, pmecc->regs.errloc + ATMEL_PMERRLOC_ELCFG); + writel((sector_size * 8) + (degree * strength), + pmecc->regs.errloc + ATMEL_PMERRLOC_ELEN); + + ret = readl_relaxed_poll_timeout(pmecc->regs.errloc + + ATMEL_PMERRLOC_ELISR, + val, val & PMERRLOC_CALC_DONE, 0, + PMECC_MAX_TIMEOUT_MS * 1000); + if (ret) { + dev_err(pmecc->dev, + "PMECC: Timeout to calculate error location.\n"); + return ret; + } + + roots_nbr = (val & PMERRLOC_ERR_NUM_MASK) >> 8; + /* Number of roots == degree of smu hence <= cap */ + if (roots_nbr == user->lmu[strength + 1] >> 1) + return err_nbr - 1; + + /* + * Number of roots does not match the degree of smu + * unable to correct error. + */ + return -EBADMSG; +} + +int atmel_pmecc_correct_sector(struct atmel_pmecc_user *user, int sector, + void *data, void *ecc) +{ + struct atmel_pmecc *pmecc = user->pmecc; + int sectorsize = get_sectorsize(user); + int eccbytes = user->eccbytes; + int i, nerrors; + + if (!(user->isr & BIT(sector))) + return 0; + + atmel_pmecc_gen_syndrome(user, sector); + atmel_pmecc_substitute(user); + atmel_pmecc_get_sigma(user); + + nerrors = atmel_pmecc_err_location(user); + if (nerrors < 0) + return nerrors; + + for (i = 0; i < nerrors; i++) { + const char *area; + int byte, bit; + u32 errpos; + u8 *ptr; + + errpos = readl_relaxed(pmecc->regs.errloc + + ATMEL_PMERRLOC_EL(pmecc->caps->el_offset, i)); + errpos--; + + byte = errpos / 8; + bit = errpos % 8; + + if (byte < sectorsize) { + ptr = data + byte; + area = "data"; + } else if (byte < sectorsize + eccbytes) { + ptr = ecc + byte - sectorsize; + area = "ECC"; + } else { + dev_dbg(pmecc->dev, + "Invalid errpos value (%d, max is %d)\n", + errpos, (sectorsize + eccbytes) * 8); + return -EINVAL; + } + + dev_dbg(pmecc->dev, + "Bit flip in %s area, byte %d: 0x%02x -> 0x%02x\n", + area, byte, *ptr, (unsigned int)(*ptr ^ BIT(bit))); + + *ptr ^= BIT(bit); + } + + return nerrors; +} +EXPORT_SYMBOL_GPL(atmel_pmecc_correct_sector); + +bool atmel_pmecc_correct_erased_chunks(struct atmel_pmecc_user *user) +{ + return user->pmecc->caps->correct_erased_chunks; +} +EXPORT_SYMBOL_GPL(atmel_pmecc_correct_erased_chunks); + +void atmel_pmecc_get_generated_eccbytes(struct atmel_pmecc_user *user, + int sector, void *ecc) +{ + struct atmel_pmecc *pmecc = user->pmecc; + u8 *ptr = ecc; + int i; + + for (i = 0; i < user->eccbytes; i++) + ptr[i] = readb_relaxed(pmecc->regs.base + + ATMEL_PMECC_ECC(sector, i)); +} +EXPORT_SYMBOL_GPL(atmel_pmecc_get_generated_eccbytes); + +void atmel_pmecc_reset(struct atmel_pmecc *pmecc) +{ + writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); + writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); +} +EXPORT_SYMBOL_GPL(atmel_pmecc_reset); + +int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op) +{ + struct atmel_pmecc *pmecc = user->pmecc; + u32 cfg; + + if (op != NAND_ECC_READ && op != NAND_ECC_WRITE) { + dev_err(pmecc->dev, "Bad ECC operation!"); + return -EINVAL; + } + + mutex_lock(&user->pmecc->lock); + + cfg = user->cache.cfg; + if (op == NAND_ECC_WRITE) + cfg |= PMECC_CFG_WRITE_OP; + else + cfg |= PMECC_CFG_AUTO_ENABLE; + + writel(cfg, pmecc->regs.base + ATMEL_PMECC_CFG); + writel(user->cache.sarea, pmecc->regs.base + ATMEL_PMECC_SAREA); + writel(user->cache.saddr, pmecc->regs.base + ATMEL_PMECC_SADDR); + writel(user->cache.eaddr, pmecc->regs.base + ATMEL_PMECC_EADDR); + + writel(PMECC_CTRL_ENABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); + writel(PMECC_CTRL_DATA, pmecc->regs.base + ATMEL_PMECC_CTRL); + + return 0; +} +EXPORT_SYMBOL_GPL(atmel_pmecc_enable); + +void atmel_pmecc_disable(struct atmel_pmecc_user *user) +{ + atmel_pmecc_reset(user->pmecc); + mutex_unlock(&user->pmecc->lock); +} +EXPORT_SYMBOL_GPL(atmel_pmecc_disable); + +int atmel_pmecc_wait_rdy(struct atmel_pmecc_user *user) +{ + struct atmel_pmecc *pmecc = user->pmecc; + u32 status; + int ret; + + ret = readl_relaxed_poll_timeout(pmecc->regs.base + + ATMEL_PMECC_SR, + status, !(status & PMECC_SR_BUSY), 0, + PMECC_MAX_TIMEOUT_MS * 1000); + if (ret) { + dev_err(pmecc->dev, + "Timeout while waiting for PMECC ready.\n"); + return ret; + } + + user->isr = readl_relaxed(pmecc->regs.base + ATMEL_PMECC_ISR); + + return 0; +} +EXPORT_SYMBOL_GPL(atmel_pmecc_wait_rdy); + +static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev, + const struct atmel_pmecc_caps *caps, + int pmecc_res_idx, int errloc_res_idx) +{ + struct device *dev = &pdev->dev; + struct atmel_pmecc *pmecc; + struct resource *res; + + pmecc = devm_kzalloc(dev, sizeof(*pmecc), GFP_KERNEL); + if (!pmecc) + return ERR_PTR(-ENOMEM); + + pmecc->caps = caps; + pmecc->dev = dev; + mutex_init(&pmecc->lock); + + res = platform_get_resource(pdev, IORESOURCE_MEM, pmecc_res_idx); + pmecc->regs.base = devm_ioremap_resource(dev, res); + if (IS_ERR(pmecc->regs.base)) + return ERR_CAST(pmecc->regs.base); + + res = platform_get_resource(pdev, IORESOURCE_MEM, errloc_res_idx); + pmecc->regs.errloc = devm_ioremap_resource(dev, res); + if (IS_ERR(pmecc->regs.errloc)) + return ERR_CAST(pmecc->regs.errloc); + + /* Disable all interrupts before registering the PMECC handler. */ + writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR); + atmel_pmecc_reset(pmecc); + + return pmecc; +} + +static void devm_atmel_pmecc_put(struct device *dev, void *res) +{ + struct atmel_pmecc **pmecc = res; + + put_device((*pmecc)->dev); +} + +static struct atmel_pmecc *atmel_pmecc_get_by_node(struct device *userdev, + struct device_node *np) +{ + struct platform_device *pdev; + struct atmel_pmecc *pmecc, **ptr; + + pdev = of_find_device_by_node(np); + if (!pdev || !platform_get_drvdata(pdev)) + return ERR_PTR(-EPROBE_DEFER); + + ptr = devres_alloc(devm_atmel_pmecc_put, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + get_device(&pdev->dev); + pmecc = platform_get_drvdata(pdev); + + *ptr = pmecc; + + devres_add(userdev, ptr); + + return pmecc; +} + +static const int atmel_pmecc_strengths[] = { 2, 4, 8, 12, 24, 32 }; + +static struct atmel_pmecc_caps at91sam9g45_caps = { + .strengths = atmel_pmecc_strengths, + .nstrengths = 5, + .el_offset = 0x8c, +}; + +static struct atmel_pmecc_caps sama5d4_caps = { + .strengths = atmel_pmecc_strengths, + .nstrengths = 5, + .el_offset = 0x8c, + .correct_erased_chunks = true, +}; + +static struct atmel_pmecc_caps sama5d2_caps = { + .strengths = atmel_pmecc_strengths, + .nstrengths = 6, + .el_offset = 0xac, + .correct_erased_chunks = true, +}; + +static const struct of_device_id atmel_pmecc_legacy_match[] = { + { .compatible = "atmel,sama5d4-nand", &sama5d4_caps }, + { .compatible = "atmel,sama5d2-nand", &sama5d2_caps }, + { /* sentinel */ } +}; + +struct atmel_pmecc *devm_atmel_pmecc_get(struct device *userdev) +{ + struct atmel_pmecc *pmecc; + struct device_node *np; + + if (!userdev) + return ERR_PTR(-EINVAL); + + if (!userdev->of_node) + return NULL; + + np = of_parse_phandle(userdev->of_node, "ecc-engine", 0); + if (np) { + pmecc = atmel_pmecc_get_by_node(userdev, np); + of_node_put(np); + } else { + /* + * Support old DT bindings: in this case the PMECC iomem + * resources are directly defined in the user pdev at position + * 1 and 2. Extract all relevant information from there. + */ + struct platform_device *pdev = to_platform_device(userdev); + const struct atmel_pmecc_caps *caps; + const struct of_device_id *match; + + /* No PMECC engine available. */ + if (!of_property_read_bool(userdev->of_node, + "atmel,has-pmecc")) + return NULL; + + caps = &at91sam9g45_caps; + + /* Find the caps associated to the NAND dev node. */ + match = of_match_node(atmel_pmecc_legacy_match, + userdev->of_node); + if (match && match->data) + caps = match->data; + + pmecc = atmel_pmecc_create(pdev, caps, 1, 2); + } + + return pmecc; +} +EXPORT_SYMBOL(devm_atmel_pmecc_get); + +static const struct of_device_id atmel_pmecc_match[] = { + { .compatible = "atmel,at91sam9g45-pmecc", &at91sam9g45_caps }, + { .compatible = "atmel,sama5d4-pmecc", &sama5d4_caps }, + { .compatible = "atmel,sama5d2-pmecc", &sama5d2_caps }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, atmel_pmecc_match); + +static int atmel_pmecc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct atmel_pmecc_caps *caps; + struct atmel_pmecc *pmecc; + + caps = of_device_get_match_data(&pdev->dev); + if (!caps) { + dev_err(dev, "Invalid caps\n"); + return -EINVAL; + } + + pmecc = atmel_pmecc_create(pdev, caps, 0, 1); + if (IS_ERR(pmecc)) + return PTR_ERR(pmecc); + + platform_set_drvdata(pdev, pmecc); + + return 0; +} + +static struct platform_driver atmel_pmecc_driver = { + .driver = { + .name = "atmel-pmecc", + .of_match_table = of_match_ptr(atmel_pmecc_match), + }, + .probe = atmel_pmecc_probe, +}; +module_platform_driver(atmel_pmecc_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>"); +MODULE_DESCRIPTION("PMECC engine driver"); +MODULE_ALIAS("platform:atmel_pmecc"); |
