From 70e038f89b467995708207fb57bbf46aec32dc2c Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Thu, 16 Dec 2021 12:16:42 +0100 Subject: mtd: nand: mxic-ecc: Support SPI pipelined mode Introduce the support for another possible configuration: the ECC engine may work as DMA master (pipelined) and move itself the data to/from the NAND chip into the buffer, applying the necessary corrections/computations on the fly. This driver offers an ECC engine implementation that must be instatiated from a SPI controller driver. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20211216111654.238086-17-miquel.raynal@bootlin.com --- drivers/mtd/nand/ecc-mxic.c | 186 +++++++++++++++++++++++++++++++++++++- include/linux/mtd/nand-ecc-mxic.h | 49 ++++++++++ 2 files changed, 234 insertions(+), 1 deletion(-) create mode 100644 include/linux/mtd/nand-ecc-mxic.h diff --git a/drivers/mtd/nand/ecc-mxic.c b/drivers/mtd/nand/ecc-mxic.c index 3e8fbe62547e..c122139255e5 100644 --- a/drivers/mtd/nand/ecc-mxic.c +++ b/drivers/mtd/nand/ecc-mxic.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -40,7 +41,9 @@ #define INTRPT_SIG_EN 0x0C /* Host Controller Configuration */ #define HC_CONFIG 0x10 +#define DEV2MEM 0 /* TRANS_TYP_DMA in the spec */ #define MEM2MEM BIT(4) /* TRANS_TYP_IO in the spec */ +#define MAPPING BIT(5) /* TRANS_TYP_MAPPING in the spec */ #define ECC_PACKED 0 /* LAYOUT_TYP_INTEGRATED in the spec */ #define ECC_INTERLEAVED BIT(2) /* LAYOUT_TYP_DISTRIBUTED in the spec */ #define BURST_TYP_FIXED 0 @@ -87,6 +90,7 @@ struct mxic_ecc_engine { int irq; struct completion complete; struct nand_ecc_engine external_engine; + struct nand_ecc_engine pipelined_engine; struct mutex lock; }; @@ -104,6 +108,7 @@ struct mxic_ecc_ctx { u8 *oobwithstat; struct scatterlist sg[2]; struct nand_page_io_req *req; + unsigned int pageoffs; }; static struct mxic_ecc_engine *ext_ecc_eng_to_mxic(struct nand_ecc_engine *eng) @@ -111,11 +116,19 @@ static struct mxic_ecc_engine *ext_ecc_eng_to_mxic(struct nand_ecc_engine *eng) return container_of(eng, struct mxic_ecc_engine, external_engine); } +static struct mxic_ecc_engine *pip_ecc_eng_to_mxic(struct nand_ecc_engine *eng) +{ + return container_of(eng, struct mxic_ecc_engine, pipelined_engine); +} + static struct mxic_ecc_engine *nand_to_mxic(struct nand_device *nand) { struct nand_ecc_engine *eng = nand->ecc.engine; - return ext_ecc_eng_to_mxic(eng); + if (eng->integration == NAND_ECC_ENGINE_INTEGRATION_EXTERNAL) + return ext_ecc_eng_to_mxic(eng); + else + return pip_ecc_eng_to_mxic(eng); } static int mxic_ecc_ooblayout_ecc(struct mtd_info *mtd, int section, @@ -364,6 +377,38 @@ static int mxic_ecc_init_ctx_external(struct nand_device *nand) return 0; } +static int mxic_ecc_init_ctx_pipelined(struct nand_device *nand) +{ + struct mxic_ecc_engine *mxic = nand_to_mxic(nand); + struct mxic_ecc_ctx *ctx; + struct device *dev; + int ret; + + dev = nand_ecc_get_engine_dev(nand->ecc.engine->dev); + if (!dev) + return -EINVAL; + + dev_info(dev, "Macronix ECC engine in pipelined/mapping mode\n"); + + ret = mxic_ecc_init_ctx(nand, dev); + if (ret) + return ret; + + ctx = nand_to_ecc_ctx(nand); + + /* All steps should be handled in one go directly by the internal DMA */ + writel(ctx->steps, mxic->regs + CHUNK_CNT); + + /* + * Interleaved ECC scheme cannot be used otherwise factory bad block + * markers would be lost. A packed layout is mandatory. + */ + writel(BURST_TYP_INCREASING | ECC_PACKED | MAPPING, + mxic->regs + HC_CONFIG); + + return 0; +} + static void mxic_ecc_cleanup_ctx(struct nand_device *nand) { struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand); @@ -419,6 +464,18 @@ static int mxic_ecc_process_data(struct mxic_ecc_engine *mxic, return ret; } +int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng, + unsigned int direction, dma_addr_t dirmap) +{ + struct mxic_ecc_engine *mxic = pip_ecc_eng_to_mxic(eng); + + if (dirmap) + writel(dirmap, mxic->regs + HC_SLV_ADDR); + + return mxic_ecc_process_data(mxic, direction); +} +EXPORT_SYMBOL_GPL(mxic_ecc_process_data_pipelined); + static void mxic_ecc_extract_status_bytes(struct mxic_ecc_ctx *ctx) { u8 *buf = ctx->oobwithstat; @@ -592,6 +649,11 @@ static int mxic_ecc_finish_io_req_external(struct nand_device *nand, dma_unmap_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL); + if (ret) { + nand_ecc_restore_req(&ctx->req_ctx, req); + return ret; + } + /* Extract the status bytes and reconstruct the buffer */ mxic_ecc_extract_status_bytes(ctx); mxic_ecc_reconstruct_oobbuf(ctx, ctx->req->oobbuf.in, ctx->oobwithstat); @@ -601,6 +663,65 @@ static int mxic_ecc_finish_io_req_external(struct nand_device *nand, return mxic_ecc_count_biterrs(mxic, nand); } +/* Pipelined ECC engine helpers */ +static int mxic_ecc_prepare_io_req_pipelined(struct nand_device *nand, + struct nand_page_io_req *req) +{ + struct mxic_ecc_engine *mxic = nand_to_mxic(nand); + struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand); + int nents; + + if (req->mode == MTD_OPS_RAW) + return 0; + + nand_ecc_tweak_req(&ctx->req_ctx, req); + ctx->req = req; + + /* Copy the OOB buffer and add room for the ECC engine status bytes */ + mxic_ecc_add_room_in_oobbuf(ctx, ctx->oobwithstat, ctx->req->oobbuf.in); + + sg_set_buf(&ctx->sg[0], req->databuf.in, req->datalen); + sg_set_buf(&ctx->sg[1], ctx->oobwithstat, + req->ooblen + (ctx->steps * STAT_BYTES)); + + nents = dma_map_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL); + if (!nents) + return -EINVAL; + + mutex_lock(&mxic->lock); + + writel(sg_dma_address(&ctx->sg[0]), mxic->regs + SDMA_MAIN_ADDR); + writel(sg_dma_address(&ctx->sg[1]), mxic->regs + SDMA_SPARE_ADDR); + + return 0; +} + +static int mxic_ecc_finish_io_req_pipelined(struct nand_device *nand, + struct nand_page_io_req *req) +{ + struct mxic_ecc_engine *mxic = nand_to_mxic(nand); + struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand); + int ret = 0; + + if (req->mode == MTD_OPS_RAW) + return 0; + + mutex_unlock(&mxic->lock); + + dma_unmap_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL); + + if (req->type == NAND_PAGE_READ) { + mxic_ecc_extract_status_bytes(ctx); + mxic_ecc_reconstruct_oobbuf(ctx, ctx->req->oobbuf.in, + ctx->oobwithstat); + ret = mxic_ecc_count_biterrs(mxic, nand); + } + + nand_ecc_restore_req(&ctx->req_ctx, req); + + return ret; +} + static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = { .init_ctx = mxic_ecc_init_ctx_external, .cleanup_ctx = mxic_ecc_cleanup_ctx, @@ -608,6 +729,69 @@ static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = { .finish_io_req = mxic_ecc_finish_io_req_external, }; +static struct nand_ecc_engine_ops mxic_ecc_engine_pipelined_ops = { + .init_ctx = mxic_ecc_init_ctx_pipelined, + .cleanup_ctx = mxic_ecc_cleanup_ctx, + .prepare_io_req = mxic_ecc_prepare_io_req_pipelined, + .finish_io_req = mxic_ecc_finish_io_req_pipelined, +}; + +struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void) +{ + return &mxic_ecc_engine_pipelined_ops; +} +EXPORT_SYMBOL_GPL(mxic_ecc_get_pipelined_ops); + +static struct platform_device * +mxic_ecc_get_pdev(struct platform_device *spi_pdev) +{ + struct platform_device *eng_pdev; + struct device_node *np; + + /* Retrieve the nand-ecc-engine phandle */ + np = of_parse_phandle(spi_pdev->dev.of_node, "nand-ecc-engine", 0); + if (!np) + return NULL; + + /* Jump to the engine's device node */ + eng_pdev = of_find_device_by_node(np); + of_node_put(np); + + return eng_pdev; +} + +void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng) +{ + struct mxic_ecc_engine *mxic = pip_ecc_eng_to_mxic(eng); + + platform_device_put(to_platform_device(mxic->dev)); +} +EXPORT_SYMBOL_GPL(mxic_ecc_put_pipelined_engine); + +struct nand_ecc_engine * +mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev) +{ + struct platform_device *eng_pdev; + struct mxic_ecc_engine *mxic; + + eng_pdev = mxic_ecc_get_pdev(spi_pdev); + if (!eng_pdev) + return ERR_PTR(-ENODEV); + + mxic = platform_get_drvdata(eng_pdev); + if (!mxic) { + platform_device_put(eng_pdev); + return ERR_PTR(-EPROBE_DEFER); + } + + return &mxic->pipelined_engine; +} +EXPORT_SYMBOL_GPL(mxic_ecc_get_pipelined_engine); + +/* + * Only the external ECC engine is exported as the pipelined is SoC specific, so + * it is registered directly by the drivers that wrap it. + */ static int mxic_ecc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; diff --git a/include/linux/mtd/nand-ecc-mxic.h b/include/linux/mtd/nand-ecc-mxic.h new file mode 100644 index 000000000000..f3aa1ac82aed --- /dev/null +++ b/include/linux/mtd/nand-ecc-mxic.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright © 2019 Macronix + * Author: Miquèl Raynal + * + * Header for the Macronix external ECC engine. + */ + +#ifndef __MTD_NAND_ECC_MXIC_H__ +#define __MTD_NAND_ECC_MXIC_H__ + +#include +#include + +struct mxic_ecc_engine; + +#if IS_ENABLED(CONFIG_MTD_NAND_ECC_MXIC) + +struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void); +struct nand_ecc_engine *mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev); +void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng); +int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng, + unsigned int direction, dma_addr_t dirmap); + +#else /* !CONFIG_MTD_NAND_ECC_MXIC */ + +static inline struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void) +{ + return NULL; +} + +static inline struct nand_ecc_engine * +mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng) {} + +static inline int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng, + unsigned int direction, + dma_addr_t dirmap) +{ + return -EOPNOTSUPP; +} + +#endif /* CONFIG_MTD_NAND_ECC_MXIC */ + +#endif /* __MTD_NAND_ECC_MXIC_H__ */ -- cgit v1.2.3