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Diffstat (limited to 'target/linux/mediatek/files-5.10/drivers/mtd/mtk-snand/mtk-snand-ecc.c')
-rw-r--r--target/linux/mediatek/files-5.10/drivers/mtd/mtk-snand/mtk-snand-ecc.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/target/linux/mediatek/files-5.10/drivers/mtd/mtk-snand/mtk-snand-ecc.c b/target/linux/mediatek/files-5.10/drivers/mtd/mtk-snand/mtk-snand-ecc.c
new file mode 100644
index 0000000000..6dd0f346c8
--- /dev/null
+++ b/target/linux/mediatek/files-5.10/drivers/mtd/mtk-snand/mtk-snand-ecc.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include "mtk-snand-def.h"
+
+/* ECC registers */
+#define ECC_ENCCON 0x000
+#define ENC_EN BIT(0)
+
+#define ECC_ENCCNFG 0x004
+#define ENC_MS_S 16
+#define ENC_BURST_EN BIT(8)
+#define ENC_TNUM_S 0
+
+#define ECC_ENCIDLE 0x00c
+#define ENC_IDLE BIT(0)
+
+#define ECC_DECCON 0x100
+#define DEC_EN BIT(0)
+
+#define ECC_DECCNFG 0x104
+#define DEC_EMPTY_EN BIT(31)
+#define DEC_CS_S 16
+#define DEC_CON_S 12
+#define DEC_CON_CORRECT 3
+#define DEC_BURST_EN BIT(8)
+#define DEC_TNUM_S 0
+
+#define ECC_DECIDLE 0x10c
+#define DEC_IDLE BIT(0)
+
+#define ECC_DECENUM0 0x114
+#define ECC_DECENUM(n) (ECC_DECENUM0 + (n) * 4)
+
+/* ECC_ENCIDLE & ECC_DECIDLE */
+#define ECC_IDLE BIT(0)
+
+/* ENC_MODE & DEC_MODE */
+#define ECC_MODE_NFI 1
+
+#define ECC_TIMEOUT 500000
+
+static const uint8_t mt7622_ecc_caps[] = { 4, 6, 8, 10, 12 };
+
+static const uint32_t mt7622_ecc_regs[] = {
+ [ECC_DECDONE] = 0x11c,
+};
+
+static const struct mtk_ecc_soc_data mtk_ecc_socs[__SNAND_SOC_MAX] = {
+ [SNAND_SOC_MT7622] = {
+ .ecc_caps = mt7622_ecc_caps,
+ .num_ecc_cap = ARRAY_SIZE(mt7622_ecc_caps),
+ .regs = mt7622_ecc_regs,
+ .mode_shift = 4,
+ .errnum_bits = 5,
+ .errnum_shift = 5,
+ },
+ [SNAND_SOC_MT7629] = {
+ .ecc_caps = mt7622_ecc_caps,
+ .num_ecc_cap = ARRAY_SIZE(mt7622_ecc_caps),
+ .regs = mt7622_ecc_regs,
+ .mode_shift = 4,
+ .errnum_bits = 5,
+ .errnum_shift = 5,
+ },
+};
+
+static inline uint32_t ecc_read32(struct mtk_snand *snf, uint32_t reg)
+{
+ return readl(snf->ecc_base + reg);
+}
+
+static inline void ecc_write32(struct mtk_snand *snf, uint32_t reg,
+ uint32_t val)
+{
+ writel(val, snf->ecc_base + reg);
+}
+
+static inline void ecc_write16(struct mtk_snand *snf, uint32_t reg,
+ uint16_t val)
+{
+ writew(val, snf->ecc_base + reg);
+}
+
+static int mtk_ecc_poll(struct mtk_snand *snf, uint32_t reg, uint32_t bits)
+{
+ uint32_t val;
+
+ return read16_poll_timeout(snf->ecc_base + reg, val, (val & bits), 0,
+ ECC_TIMEOUT);
+}
+
+static int mtk_ecc_wait_idle(struct mtk_snand *snf, uint32_t reg)
+{
+ int ret;
+
+ ret = mtk_ecc_poll(snf, reg, ECC_IDLE);
+ if (ret) {
+ snand_log_ecc(snf->pdev, "ECC engine is busy\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+int mtk_ecc_setup(struct mtk_snand *snf, void *fmdaddr, uint32_t max_ecc_bytes,
+ uint32_t msg_size)
+{
+ uint32_t i, val, ecc_msg_bits, ecc_strength;
+ int ret;
+
+ snf->ecc_soc = &mtk_ecc_socs[snf->soc];
+
+ snf->ecc_parity_bits = fls(1 + 8 * msg_size);
+ ecc_strength = max_ecc_bytes * 8 / snf->ecc_parity_bits;
+
+ for (i = snf->ecc_soc->num_ecc_cap - 1; i >= 0; i--) {
+ if (snf->ecc_soc->ecc_caps[i] <= ecc_strength)
+ break;
+ }
+
+ if (unlikely(i < 0)) {
+ snand_log_ecc(snf->pdev, "Page size %u+%u is not supported\n",
+ snf->writesize, snf->oobsize);
+ return -ENOTSUPP;
+ }
+
+ snf->ecc_strength = snf->ecc_soc->ecc_caps[i];
+ snf->ecc_bytes = DIV_ROUND_UP(snf->ecc_strength * snf->ecc_parity_bits,
+ 8);
+
+ /* Encoder config */
+ ecc_write16(snf, ECC_ENCCON, 0);
+ ret = mtk_ecc_wait_idle(snf, ECC_ENCIDLE);
+ if (ret)
+ return ret;
+
+ ecc_msg_bits = msg_size * 8;
+ val = (ecc_msg_bits << ENC_MS_S) |
+ (ECC_MODE_NFI << snf->ecc_soc->mode_shift) | i;
+ ecc_write32(snf, ECC_ENCCNFG, val);
+
+ /* Decoder config */
+ ecc_write16(snf, ECC_DECCON, 0);
+ ret = mtk_ecc_wait_idle(snf, ECC_DECIDLE);
+ if (ret)
+ return ret;
+
+ ecc_msg_bits += snf->ecc_strength * snf->ecc_parity_bits;
+ val = DEC_EMPTY_EN | (ecc_msg_bits << DEC_CS_S) |
+ (DEC_CON_CORRECT << DEC_CON_S) |
+ (ECC_MODE_NFI << snf->ecc_soc->mode_shift) | i;
+ ecc_write32(snf, ECC_DECCNFG, val);
+
+ return 0;
+}
+
+int mtk_snand_ecc_encoder_start(struct mtk_snand *snf)
+{
+ int ret;
+
+ ret = mtk_ecc_wait_idle(snf, ECC_ENCIDLE);
+ if (ret) {
+ ecc_write16(snf, ECC_ENCCON, 0);
+ mtk_ecc_wait_idle(snf, ECC_ENCIDLE);
+ }
+
+ ecc_write16(snf, ECC_ENCCON, ENC_EN);
+
+ return 0;
+}
+
+void mtk_snand_ecc_encoder_stop(struct mtk_snand *snf)
+{
+ mtk_ecc_wait_idle(snf, ECC_ENCIDLE);
+ ecc_write16(snf, ECC_ENCCON, 0);
+}
+
+int mtk_snand_ecc_decoder_start(struct mtk_snand *snf)
+{
+ int ret;
+
+ ret = mtk_ecc_wait_idle(snf, ECC_DECIDLE);
+ if (ret) {
+ ecc_write16(snf, ECC_DECCON, 0);
+ mtk_ecc_wait_idle(snf, ECC_DECIDLE);
+ }
+
+ ecc_write16(snf, ECC_DECCON, DEC_EN);
+
+ return 0;
+}
+
+void mtk_snand_ecc_decoder_stop(struct mtk_snand *snf)
+{
+ mtk_ecc_wait_idle(snf, ECC_DECIDLE);
+ ecc_write16(snf, ECC_DECCON, 0);
+}
+
+int mtk_ecc_wait_decoder_done(struct mtk_snand *snf)
+{
+ uint16_t val, step_mask = (1 << snf->ecc_steps) - 1;
+ uint32_t reg = snf->ecc_soc->regs[ECC_DECDONE];
+ int ret;
+
+ ret = read16_poll_timeout(snf->ecc_base + reg, val,
+ (val & step_mask) == step_mask, 0,
+ ECC_TIMEOUT);
+ if (ret)
+ snand_log_ecc(snf->pdev, "ECC decoder is busy\n");
+
+ return ret;
+}
+
+int mtk_ecc_check_decode_error(struct mtk_snand *snf)
+{
+ uint32_t i, regi, fi, errnum;
+ uint32_t errnum_shift = snf->ecc_soc->errnum_shift;
+ uint32_t errnum_mask = (1 << snf->ecc_soc->errnum_bits) - 1;
+ int ret = 0;
+
+ for (i = 0; i < snf->ecc_steps; i++) {
+ regi = i / 4;
+ fi = i % 4;
+
+ errnum = ecc_read32(snf, ECC_DECENUM(regi));
+ errnum = (errnum >> (fi * errnum_shift)) & errnum_mask;
+
+ if (errnum <= snf->ecc_strength) {
+ snf->sect_bf[i] = errnum;
+ } else {
+ snf->sect_bf[i] = -1;
+ ret = -EBADMSG;
+ }
+ }
+
+ return ret;
+}
+
+static int mtk_ecc_check_buf_bitflips(struct mtk_snand *snf, const void *buf,
+ size_t len, uint32_t bitflips)
+{
+ const uint8_t *buf8 = buf;
+ const uint32_t *buf32;
+ uint32_t d, weight;
+
+ while (len && ((uintptr_t)buf8) % sizeof(uint32_t)) {
+ weight = hweight8(*buf8);
+ bitflips += BITS_PER_BYTE - weight;
+ buf8++;
+ len--;
+
+ if (bitflips > snf->ecc_strength)
+ return -EBADMSG;
+ }
+
+ buf32 = (const uint32_t *)buf8;
+ while (len >= sizeof(uint32_t)) {
+ d = *buf32;
+
+ if (d != ~0) {
+ weight = hweight32(d);
+ bitflips += sizeof(uint32_t) * BITS_PER_BYTE - weight;
+ }
+
+ buf32++;
+ len -= sizeof(uint32_t);
+
+ if (bitflips > snf->ecc_strength)
+ return -EBADMSG;
+ }
+
+ buf8 = (const uint8_t *)buf32;
+ while (len) {
+ weight = hweight8(*buf8);
+ bitflips += BITS_PER_BYTE - weight;
+ buf8++;
+ len--;
+
+ if (bitflips > snf->ecc_strength)
+ return -EBADMSG;
+ }
+
+ return bitflips;
+}
+
+static int mtk_ecc_check_parity_bitflips(struct mtk_snand *snf, const void *buf,
+ uint32_t bits, uint32_t bitflips)
+{
+ uint32_t len, i;
+ uint8_t b;
+ int rc;
+
+ len = bits >> 3;
+ bits &= 7;
+
+ rc = mtk_ecc_check_buf_bitflips(snf, buf, len, bitflips);
+ if (!bits || rc < 0)
+ return rc;
+
+ bitflips = rc;
+
+ /* We want a precise count of bits */
+ b = ((const uint8_t *)buf)[len];
+ for (i = 0; i < bits; i++) {
+ if (!(b & BIT(i)))
+ bitflips++;
+ }
+
+ if (bitflips > snf->ecc_strength)
+ return -EBADMSG;
+
+ return bitflips;
+}
+
+static void mtk_ecc_reset_parity(void *buf, uint32_t bits)
+{
+ uint32_t len;
+
+ len = bits >> 3;
+ bits &= 7;
+
+ memset(buf, 0xff, len);
+
+ /* Only reset bits protected by ECC to 1 */
+ if (bits)
+ ((uint8_t *)buf)[len] |= GENMASK(bits - 1, 0);
+}
+
+int mtk_ecc_fixup_empty_sector(struct mtk_snand *snf, uint32_t sect)
+{
+ uint32_t ecc_bytes = snf->spare_per_sector - snf->nfi_soc->fdm_size;
+ uint8_t *oob = snf->page_cache + snf->writesize;
+ uint8_t *data_ptr, *fdm_ptr, *ecc_ptr;
+ int bitflips = 0, ecc_bits, parity_bits;
+
+ parity_bits = fls(snf->nfi_soc->sector_size * 8);
+ ecc_bits = snf->ecc_strength * parity_bits;
+
+ data_ptr = snf->page_cache + sect * snf->nfi_soc->sector_size;
+ fdm_ptr = oob + sect * snf->nfi_soc->fdm_size;
+ ecc_ptr = oob + snf->ecc_steps * snf->nfi_soc->fdm_size +
+ sect * ecc_bytes;
+
+ /*
+ * Check whether DATA + FDM + ECC of a sector contains correctable
+ * bitflips
+ */
+ bitflips = mtk_ecc_check_buf_bitflips(snf, data_ptr,
+ snf->nfi_soc->sector_size,
+ bitflips);
+ if (bitflips < 0)
+ return -EBADMSG;
+
+ bitflips = mtk_ecc_check_buf_bitflips(snf, fdm_ptr,
+ snf->nfi_soc->fdm_ecc_size,
+ bitflips);
+ if (bitflips < 0)
+ return -EBADMSG;
+
+ bitflips = mtk_ecc_check_parity_bitflips(snf, ecc_ptr, ecc_bits,
+ bitflips);
+ if (bitflips < 0)
+ return -EBADMSG;
+
+ if (!bitflips)
+ return 0;
+
+ /* Reset the data of this sector to 0xff */
+ memset(data_ptr, 0xff, snf->nfi_soc->sector_size);
+ memset(fdm_ptr, 0xff, snf->nfi_soc->fdm_ecc_size);
+ mtk_ecc_reset_parity(ecc_ptr, ecc_bits);
+
+ return bitflips;
+}
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