From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Agner Subject: Re: [RESEND PATCH 2/5] mtd: rawnand: add NVIDIA Tegra NAND Flash controller driver Date: Tue, 22 May 2018 16:53:46 +0200 Message-ID: <4e19315d0c44d3f9b7ffb63216f2c179@agner.ch> References: <86fdf19ec92b732709732fb60199f16488b4b727.1526990589.git.stefan@agner.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <86fdf19ec92b732709732fb60199f16488b4b727.1526990589.git.stefan@agner.ch> Sender: linux-kernel-owner@vger.kernel.org To: boris.brezillon@bootlin.com, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com, thierry.reding@gmail.com, mturquette@baylibre.com, sboyd@kernel.org Cc: dev@lynxeye.de, miquel.raynal@bootlin.com, richard@nod.at, marcel@ziswiler.com, krzk@kernel.org, digetx@gmail.com, benjamin.lindqvist@endian.se, jonathanh@nvidia.com, pdeschrijver@nvidia.com, pgaikwad@nvidia.com, mirza.krak@gmail.com, linux-mtd@lists.infradead.org, linux-tegra@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org List-Id: linux-tegra@vger.kernel.org Hi, I do have some questions for some areas I wanted to improve in the next revision. But I would like to make sure that the way I would like to implement aligns with the MTD subsystem. On 22.05.2018 14:07, Stefan Agner wrote: > Add support for the NAND flash controller found on NVIDIA > Tegra 2 SoCs. This implementation does not make use of the > command queue feature. Regular operations/data transfers are > done in PIO mode. Page read/writes with hardware ECC make > use of the DMA for data transfer. > > Signed-off-by: Lucas Stach > Signed-off-by: Stefan Agner > --- > MAINTAINERS | 7 + > drivers/mtd/nand/raw/Kconfig | 6 + > drivers/mtd/nand/raw/Makefile | 1 + > drivers/mtd/nand/raw/tegra_nand.c | 915 ++++++++++++++++++++++++++++++ > 4 files changed, 929 insertions(+) > create mode 100644 drivers/mtd/nand/raw/tegra_nand.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 58b9861ccf99..a65739681279 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -13844,6 +13844,13 @@ M: Laxman Dewangan > S: Supported > F: drivers/input/keyboard/tegra-kbc.c > > +TEGRA NAND DRIVER > +M: Stefan Agner > +M: Lucas Stach > +S: Maintained > +F: Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt > +F: drivers/mtd/nand/tegra_nand.c > + > TEGRA PWM DRIVER > M: Thierry Reding > S: Supported > diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig > index 19a2b283fbbe..bd56264233ca 100644 > --- a/drivers/mtd/nand/raw/Kconfig > +++ b/drivers/mtd/nand/raw/Kconfig > @@ -534,4 +534,10 @@ config MTD_NAND_MTK > Enables support for NAND controller on MTK SoCs. > This controller is found on mt27xx, mt81xx, mt65xx SoCs. > > +config MTD_NAND_TEGRA > + tristate "Support for NAND on NVIDIA Tegra" > + depends on ARCH_TEGRA > + help > + Enables support for NAND flash on NVIDIA Tegra SoC based boards. > + > endif # MTD_NAND > diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile > index 165b7ef9e9a1..d5a5f9832b88 100644 > --- a/drivers/mtd/nand/raw/Makefile > +++ b/drivers/mtd/nand/raw/Makefile > @@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504) += hisi504_nand.o > obj-$(CONFIG_MTD_NAND_BRCMNAND) += brcmnand/ > obj-$(CONFIG_MTD_NAND_QCOM) += qcom_nandc.o > obj-$(CONFIG_MTD_NAND_MTK) += mtk_ecc.o mtk_nand.o > +obj-$(CONFIG_MTD_NAND_TEGRA) += tegra_nand.o > > nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o > nand-objs += nand_amd.o > diff --git a/drivers/mtd/nand/raw/tegra_nand.c > b/drivers/mtd/nand/raw/tegra_nand.c > new file mode 100644 > index 000000000000..fa236e683fb8 > --- /dev/null > +++ b/drivers/mtd/nand/raw/tegra_nand.c > @@ -0,0 +1,915 @@ > +/* > + * Copyright (C) 2018 Stefan Agner > + * Copyright (C) 2014-2015 Lucas Stach > + * Copyright (C) 2012 Avionic Design GmbH > + * > + * 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. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define CMD 0x00 > +#define CMD_GO (1 << 31) > +#define CMD_CLE (1 << 30) > +#define CMD_ALE (1 << 29) > +#define CMD_PIO (1 << 28) > +#define CMD_TX (1 << 27) > +#define CMD_RX (1 << 26) > +#define CMD_SEC_CMD (1 << 25) > +#define CMD_AFT_DAT (1 << 24) > +#define CMD_TRANS_SIZE(x) (((x - 1) & 0xf) << 20) > +#define CMD_A_VALID (1 << 19) > +#define CMD_B_VALID (1 << 18) > +#define CMD_RD_STATUS_CHK (1 << 17) > +#define CMD_RBSY_CHK (1 << 16) > +#define CMD_CE(x) (1 << (8 + ((x) & 0x7))) > +#define CMD_CLE_SIZE(x) (((x - 1) & 0x3) << 4) > +#define CMD_ALE_SIZE(x) (((x - 1) & 0xf) << 0) > + > +#define STATUS 0x04 > + > +#define ISR 0x08 > +#define ISR_CORRFAIL_ERR (1 << 24) > +#define ISR_UND (1 << 7) > +#define ISR_OVR (1 << 6) > +#define ISR_CMD_DONE (1 << 5) > +#define ISR_ECC_ERR (1 << 4) > + > +#define IER 0x0c > +#define IER_ERR_TRIG_VAL(x) (((x) & 0xf) << 16) > +#define IER_UND (1 << 7) > +#define IER_OVR (1 << 6) > +#define IER_CMD_DONE (1 << 5) > +#define IER_ECC_ERR (1 << 4) > +#define IER_GIE (1 << 0) > + > +#define CFG 0x10 > +#define CFG_HW_ECC (1 << 31) > +#define CFG_ECC_SEL (1 << 30) > +#define CFG_ERR_COR (1 << 29) > +#define CFG_PIPE_EN (1 << 28) > +#define CFG_TVAL_4 (0 << 24) > +#define CFG_TVAL_6 (1 << 24) > +#define CFG_TVAL_8 (2 << 24) > +#define CFG_SKIP_SPARE (1 << 23) > +#define CFG_BUS_WIDTH_8 (0 << 21) > +#define CFG_BUS_WIDTH_16 (1 << 21) > +#define CFG_COM_BSY (1 << 20) > +#define CFG_PS_256 (0 << 16) > +#define CFG_PS_512 (1 << 16) > +#define CFG_PS_1024 (2 << 16) > +#define CFG_PS_2048 (3 << 16) > +#define CFG_PS_4096 (4 << 16) > +#define CFG_SKIP_SPARE_SIZE_4 (0 << 14) > +#define CFG_SKIP_SPARE_SIZE_8 (1 << 14) > +#define CFG_SKIP_SPARE_SIZE_12 (2 << 14) > +#define CFG_SKIP_SPARE_SIZE_16 (3 << 14) > +#define CFG_TAG_BYTE_SIZE(x) ((x) & 0xff) > + > +#define TIMING_1 0x14 > +#define TIMING_TRP_RESP(x) (((x) & 0xf) << 28) > +#define TIMING_TWB(x) (((x) & 0xf) << 24) > +#define TIMING_TCR_TAR_TRR(x) (((x) & 0xf) << 20) > +#define TIMING_TWHR(x) (((x) & 0xf) << 16) > +#define TIMING_TCS(x) (((x) & 0x3) << 14) > +#define TIMING_TWH(x) (((x) & 0x3) << 12) > +#define TIMING_TWP(x) (((x) & 0xf) << 8) > +#define TIMING_TRH(x) (((x) & 0xf) << 4) > +#define TIMING_TRP(x) (((x) & 0xf) << 0) > + > +#define RESP 0x18 > + > +#define TIMING_2 0x1c > +#define TIMING_TADL(x) ((x) & 0xf) > + > +#define CMD_1 0x20 > +#define CMD_2 0x24 > +#define ADDR_1 0x28 > +#define ADDR_2 0x2c > + > +#define DMA_CTRL 0x30 > +#define DMA_CTRL_GO (1 << 31) > +#define DMA_CTRL_IN (0 << 30) > +#define DMA_CTRL_OUT (1 << 30) > +#define DMA_CTRL_PERF_EN (1 << 29) > +#define DMA_CTRL_IE_DONE (1 << 28) > +#define DMA_CTRL_REUSE (1 << 27) > +#define DMA_CTRL_BURST_1 (2 << 24) > +#define DMA_CTRL_BURST_4 (3 << 24) > +#define DMA_CTRL_BURST_8 (4 << 24) > +#define DMA_CTRL_BURST_16 (5 << 24) > +#define DMA_CTRL_IS_DONE (1 << 20) > +#define DMA_CTRL_EN_A (1 << 2) > +#define DMA_CTRL_EN_B (1 << 1) > + > +#define DMA_CFG_A 0x34 > +#define DMA_CFG_B 0x38 > + > +#define FIFO_CTRL 0x3c > +#define FIFO_CTRL_CLR_ALL (1 << 3) > + > +#define DATA_PTR 0x40 > +#define TAG_PTR 0x44 > +#define ECC_PTR 0x48 > + > +#define DEC_STATUS 0x4c > +#define DEC_STATUS_A_ECC_FAIL (1 << 1) > +#define DEC_STATUS_ERR_COUNT_MASK 0x00ff0000 > +#define DEC_STATUS_ERR_COUNT_SHIFT 16 > + > +#define HWSTATUS_CMD 0x50 > +#define HWSTATUS_MASK 0x54 > +#define HWSTATUS_RDSTATUS_MASK(x) (((x) & 0xff) << 24) > +#define HWSTATUS_RDSTATUS_VALUE(x) (((x) & 0xff) << 16) > +#define HWSTATUS_RBSY_MASK(x) (((x) & 0xff) << 8) > +#define HWSTATUS_RBSY_VALUE(x) (((x) & 0xff) << 0) > + > +#define DEC_STAT_RESULT 0xd0 > +#define DEC_STAT_BUF 0xd4 > +#define DEC_STAT_BUF_CORR_SEC_FLAG_MASK 0x00ff0000 > +#define DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT 16 > +#define DEC_STAT_BUF_MAX_CORR_CNT_MASK 0x00001f00 > +#define DEC_STAT_BUF_MAX_CORR_CNT_SHIFT 8 > + > +struct tegra_nand { > + void __iomem *regs; > + struct clk *clk; > + struct gpio_desc *wp_gpio; > + > + struct nand_chip chip; > + struct device *dev; > + > + struct completion command_complete; > + struct completion dma_complete; > + bool last_read_error; > + > + dma_addr_t data_dma; > + void *data_buf; > + dma_addr_t oob_dma; > + void *oob_buf; > + > + int cur_chip; > +}; > + > +static inline struct tegra_nand *to_tegra_nand(struct mtd_info *mtd) > +{ > + struct nand_chip *chip = mtd_to_nand(mtd); > + > + return nand_get_controller_data(chip); > +} > + > +static int tegra_nand_ooblayout_16_ecc(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 4; > + oobregion->length = 4; > + > + return 0; > +} > + > +static int tegra_nand_ooblayout_16_free(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 8; > + oobregion->length = 8; > + > + return 0; > +} > + > +static const struct mtd_ooblayout_ops tegra_nand_oob_16_ops = { > + .ecc = tegra_nand_ooblayout_16_ecc, > + .free = tegra_nand_ooblayout_16_free, > +}; > + > +static int tegra_nand_ooblayout_64_ecc(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 4; > + oobregion->length = 36; > + > + return 0; > +} > + > +static int tegra_nand_ooblayout_64_free(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 40; > + oobregion->length = 24; > + > + return 0; > +} > + > +static const struct mtd_ooblayout_ops tegra_nand_oob_64_ops = { > + .ecc = tegra_nand_ooblayout_64_ecc, > + .free = tegra_nand_ooblayout_64_free, > +}; > + > +static int tegra_nand_ooblayout_128_ecc(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 4; > + oobregion->length = 72; > + > + return 0; > +} > + > +static int tegra_nand_ooblayout_128_free(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 76; > + oobregion->length = 52; > + > + return 0; > +} > + > +static const struct mtd_ooblayout_ops tegra_nand_oob_128_ops = { > + .ecc = tegra_nand_ooblayout_128_ecc, > + .free = tegra_nand_ooblayout_128_free, > +}; > + > +static int tegra_nand_ooblayout_224_ecc(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 4; > + oobregion->length = 144; > + > + return 0; > +} > + > +static int tegra_nand_ooblayout_224_free(struct mtd_info *mtd, int section, > + struct mtd_oob_region *oobregion) > +{ > + if (section > 0) > + return -ERANGE; > + > + oobregion->offset = 148; > + oobregion->length = 76; > + > + return 0; > +} > + > +static const struct mtd_ooblayout_ops tegra_nand_oob_224_ops = { > + .ecc = tegra_nand_ooblayout_224_ecc, > + .free = tegra_nand_ooblayout_224_free, > +}; The layout mostly depends on algorithm used. So for Reed-Solomon with maximum symbol error of 8 it is probably better to create something like: static const struct mtd_ooblayout_ops tegra_nand_oob_rs_8_ops = { .ecc = tegra_nand_ooblayout_rs_8_ecc, .free = tegra_nand_ooblayout_rs_8_free, }; And then use mtd->writesize/mtd->oobsize to calculate offset/length? > + > +static irqreturn_t tegra_nand_irq(int irq, void *data) > +{ > + struct tegra_nand *nand = data; > + u32 isr, dma; > + > + isr = readl(nand->regs + ISR); > + dma = readl(nand->regs + DMA_CTRL); > + dev_dbg(nand->dev, "isr %08x\n", isr); > + > + if (!isr && !(dma & DMA_CTRL_IS_DONE)) > + return IRQ_NONE; > + > + if (isr & ISR_CORRFAIL_ERR) > + nand->last_read_error = true; > + > + if (isr & ISR_CMD_DONE) > + complete(&nand->command_complete); > + > + if (isr & ISR_UND) > + dev_dbg(nand->dev, "FIFO underrun\n"); > + > + if (isr & ISR_OVR) > + dev_dbg(nand->dev, "FIFO overrun\n"); > + > + /* handle DMA interrupts */ > + if (dma & DMA_CTRL_IS_DONE) { > + writel(dma, nand->regs + DMA_CTRL); > + complete(&nand->dma_complete); > + } > + > + /* clear interrupts */ > + writel(isr, nand->regs + ISR); > + > + return IRQ_HANDLED; > +} > + > +static int tegra_nand_cmd(struct nand_chip *chip, > + const struct nand_subop *subop) > +{ > + const struct nand_op_instr *instr; > + const struct nand_op_instr *instr_data_in = NULL; > + struct mtd_info *mtd = nand_to_mtd(chip); > + struct tegra_nand *nand = to_tegra_nand(mtd); > + unsigned int op_id = -1, trfr_in_sz = 0, trfr_out_sz = 0, offset = 0; > + bool first_cmd = true; > + bool force8bit; > + u32 cmd = 0; > + u32 value; > + > + for (op_id = 0; op_id < subop->ninstrs; op_id++) { > + unsigned int naddrs, i; > + const u8 *addrs; > + u32 addr1 = 0, addr2 = 0; > + > + instr = &subop->instrs[op_id]; > + > + switch (instr->type) { > + case NAND_OP_CMD_INSTR: > + if (first_cmd) { > + cmd |= CMD_CLE; > + writel(instr->ctx.cmd.opcode, nand->regs + CMD_1); > + } else { > + cmd |= CMD_SEC_CMD; > + writel(instr->ctx.cmd.opcode, nand->regs + CMD_2); > + } > + first_cmd = false; > + break; > + case NAND_OP_ADDR_INSTR: > + offset = nand_subop_get_addr_start_off(subop, op_id); > + naddrs = nand_subop_get_num_addr_cyc(subop, op_id); > + addrs = &instr->ctx.addr.addrs[offset]; > + > + cmd |= CMD_ALE | CMD_ALE_SIZE(naddrs); > + for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) > + addr1 |= *addrs++ << (8 * i); > + naddrs -= i; > + for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) > + addr2 |= *addrs++ << (8 * i); > + writel(addr1, nand->regs + ADDR_1); > + writel(addr2, nand->regs + ADDR_2); > + break; > + > + case NAND_OP_DATA_IN_INSTR: > + trfr_in_sz = nand_subop_get_data_len(subop, op_id); > + offset = nand_subop_get_data_start_off(subop, op_id); > + > + cmd |= CMD_TRANS_SIZE(trfr_in_sz) | CMD_PIO | CMD_RX | CMD_A_VALID; > + > + instr_data_in = instr; > + break; > + > + case NAND_OP_DATA_OUT_INSTR: > + trfr_out_sz = nand_subop_get_data_len(subop, op_id); > + offset = nand_subop_get_data_start_off(subop, op_id); > + trfr_out_sz = min_t(size_t, trfr_out_sz, 4); > + > + cmd |= CMD_TRANS_SIZE(trfr_out_sz) | CMD_PIO | CMD_TX | CMD_A_VALID; > + > + memcpy(&value, instr->ctx.data.buf.out + offset, trfr_out_sz); > + writel(value, nand->regs + RESP); > + > + break; > + case NAND_OP_WAITRDY_INSTR: > + cmd |= CMD_RBSY_CHK; > + break; > + > + } > + } > + > + > + cmd |= CMD_GO | CMD_CE(nand->cur_chip); > + writel(cmd, nand->regs + CMD); > + wait_for_completion(&nand->command_complete); > + > + if (instr_data_in) { > + u32 value; > + size_t n = min_t(size_t, trfr_in_sz, 4); > + > + value = readl(nand->regs + RESP); > + memcpy(instr_data_in->ctx.data.buf.in + offset, &value, n); > + } > + > + return 0; > +} > + > +static const struct nand_op_parser tegra_nand_op_parser = NAND_OP_PARSER( > + NAND_OP_PARSER_PATTERN(tegra_nand_cmd, > + NAND_OP_PARSER_PAT_CMD_ELEM(true), > + NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8), > + NAND_OP_PARSER_PAT_CMD_ELEM(true), > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)), > + NAND_OP_PARSER_PATTERN(tegra_nand_cmd, > + NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 4)), > + NAND_OP_PARSER_PATTERN(tegra_nand_cmd, > + NAND_OP_PARSER_PAT_CMD_ELEM(true), > + NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8), > + NAND_OP_PARSER_PAT_CMD_ELEM(true), > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true), > + NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 4)), > + ); > + > +static int tegra_nand_exec_op(struct nand_chip *chip, > + const struct nand_operation *op, > + bool check_only) > +{ > + return nand_op_parser_exec_op(chip, &tegra_nand_op_parser, op, > + check_only); > +} > +static void tegra_nand_select_chip(struct mtd_info *mtd, int chip) > +{ > + struct tegra_nand *nand = to_tegra_nand(mtd); > + > + nand->cur_chip = chip; > +} > + > +static u32 tegra_nand_fill_address(struct mtd_info *mtd, struct > nand_chip *chip, > + int page) > +{ > + struct tegra_nand *nand = to_tegra_nand(mtd); > + > + /* Lower 16-bits are column, always 0 */ > + writel(page << 16, nand->regs + ADDR_1); > + > + if (chip->options & NAND_ROW_ADDR_3) { > + writel(page >> 16, nand->regs + ADDR_2); > + return 5; > + } > + > + return 4; > +} > + > +static int tegra_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip, > + uint8_t *buf, int oob_required, int page) > +{ > + struct tegra_nand *nand = to_tegra_nand(mtd); > + u32 value, addrs; > + > + writel(NAND_CMD_READ0, nand->regs + CMD_1); > + writel(NAND_CMD_READSTART, nand->regs + CMD_2); > + > + addrs = tegra_nand_fill_address(mtd, chip, page); > + > + value = readl(nand->regs + CFG); > + value |= CFG_HW_ECC | CFG_ERR_COR; > + writel(value, nand->regs + CFG); > + > + writel(mtd->writesize - 1, nand->regs + DMA_CFG_A); > + writel(nand->data_dma, nand->regs + DATA_PTR); > + > + if (oob_required) { > + writel(mtd_ooblayout_count_freebytes(mtd) - 1, > + nand->regs + DMA_CFG_B); > + writel(nand->oob_dma, nand->regs + TAG_PTR); > + } else { > + writel(0, nand->regs + DMA_CFG_B); > + writel(0, nand->regs + TAG_PTR); > + } > + > + value = DMA_CTRL_GO | DMA_CTRL_IN | DMA_CTRL_PERF_EN | > + DMA_CTRL_REUSE | DMA_CTRL_IE_DONE | DMA_CTRL_IS_DONE | > + DMA_CTRL_BURST_8 | DMA_CTRL_EN_A; > + if (oob_required) > + value |= DMA_CTRL_EN_B; > + writel(value, nand->regs + DMA_CTRL); > + > + value = CMD_CLE | CMD_ALE | CMD_ALE_SIZE(addrs) | CMD_SEC_CMD | > + CMD_RBSY_CHK | CMD_GO | CMD_RX | CMD_TRANS_SIZE(9) | > + CMD_A_VALID | CMD_CE(nand->cur_chip); > + if (oob_required) > + value |= CMD_B_VALID; > + writel(value, nand->regs + CMD); > + > + wait_for_completion(&nand->command_complete); > + wait_for_completion(&nand->dma_complete); > + > + if (oob_required) { > + struct mtd_oob_region oobregion; > + > + mtd_ooblayout_free(mtd, 0, &oobregion); > + memcpy(chip->oob_poi, nand->oob_buf + oobregion.offset, > + mtd_ooblayout_count_freebytes(mtd)); > + } > + memcpy(buf, nand->data_buf, mtd->writesize); > + > + value = readl(nand->regs + CFG); > + value &= ~(CFG_HW_ECC | CFG_ERR_COR); > + writel(value, nand->regs + CFG); > + > + value = readl(nand->regs + DEC_STATUS); > + if (value & DEC_STATUS_A_ECC_FAIL) { > + /* > + * The ECC isn't smart enough to figure out if a page is > + * completely erased and flags an error in this case. So we > + * check the read data here to figure out if it's a legitimate > + * error or a false positive. > + */ > + int i, err; > + int flips_threshold = chip->ecc.strength / 2; > + int max_bitflips = 0; > + > + for (i = 0; i < chip->ecc.steps; i++) { > + u8 *data = buf + (chip->ecc.size * i); > + err = nand_check_erased_ecc_chunk(data, chip->ecc.size, > + NULL, 0, > + NULL, 0, > + flips_threshold); > + if (err < 0) > + return err; > + > + max_bitflips += max_bitflips; > + } > + > + return max_bitflips; > + } > + > + if (nand->last_read_error) { > + int max_corr_cnt, corr_sec_flag; > + > + value = readl(nand->regs + DEC_STAT_BUF); > + corr_sec_flag = (value & DEC_STAT_BUF_CORR_SEC_FLAG_MASK) >> > + DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT; > + max_corr_cnt = (value & DEC_STAT_BUF_MAX_CORR_CNT_MASK) >> > + DEC_STAT_BUF_MAX_CORR_CNT_SHIFT; > + > + /* > + * The value returned in the register is the maximum of > + * bitflips encountered in any of the ECC regions. As there is > + * no way to get the number of bitflips in a specific regions > + * we are not able to deliver correct stats but instead > + * overestimate the number of corrected bitflips by assuming > + * that all regions where errors have been corrected > + * encountered the maximum number of bitflips. > + */ > + mtd->ecc_stats.corrected += max_corr_cnt * hweight8(corr_sec_flag); > + nand->last_read_error = false; > + return value; > + } > + > + return 0; > +} > + > +static int tegra_nand_write_page(struct mtd_info *mtd, struct nand_chip *chip, > + const uint8_t *buf, int oob_required, int page) > +{ > + struct tegra_nand *nand = to_tegra_nand(mtd); > + u32 value, addrs; > + > + writel(NAND_CMD_SEQIN, nand->regs + CMD_1); > + writel(NAND_CMD_PAGEPROG, nand->regs + CMD_2); > + > + addrs = tegra_nand_fill_address(mtd, chip, page); > + > + value = readl(nand->regs + CFG); > + value |= CFG_HW_ECC | CFG_ERR_COR; > + writel(value, nand->regs + CFG); > + > + memcpy(nand->data_buf, buf, mtd->writesize); > + > + writel(mtd->writesize - 1, nand->regs + DMA_CFG_A); > + writel(nand->data_dma, nand->regs + DATA_PTR); > + > + if (oob_required) { > + struct mtd_oob_region oobregion; > + > + mtd_ooblayout_free(mtd, 0, &oobregion); > + memcpy(nand->oob_buf, chip->oob_poi + oobregion.offset, > + mtd_ooblayout_count_freebytes(mtd)); > + writel(mtd_ooblayout_count_freebytes(mtd) - 1, > + nand->regs + DMA_CFG_B); > + writel(nand->oob_dma, nand->regs + TAG_PTR); > + } else { > + writel(0, nand->regs + DMA_CFG_B); > + writel(0, nand->regs + TAG_PTR); > + } > + > + value = DMA_CTRL_GO | DMA_CTRL_OUT | DMA_CTRL_PERF_EN | > + DMA_CTRL_IE_DONE | DMA_CTRL_IS_DONE | > + DMA_CTRL_BURST_8 | DMA_CTRL_EN_A; > + if (oob_required) > + value |= DMA_CTRL_EN_B; > + writel(value, nand->regs + DMA_CTRL); > + > + value = CMD_CLE | CMD_ALE | CMD_ALE_SIZE(addrs) | CMD_SEC_CMD | > + CMD_AFT_DAT | CMD_RBSY_CHK | CMD_GO | CMD_TX | CMD_A_VALID | > + CMD_TRANS_SIZE(9) | CMD_CE(nand->cur_chip); > + if (oob_required) > + value |= CMD_B_VALID; > + writel(value, nand->regs + CMD); > + > + wait_for_completion(&nand->command_complete); > + wait_for_completion(&nand->dma_complete); > + > + value = readl(nand->regs + CFG); > + value &= ~(CFG_HW_ECC | CFG_ERR_COR); > + writel(value, nand->regs + CFG); > + > + return 0; > +} > + > +static void tegra_nand_setup_timing(struct tegra_nand *nand, int mode) > +{ > + /* > + * The period (and all other timings in this function) is in ps, > + * so need to take care here to avoid integer overflows. > + */ > + unsigned int rate = clk_get_rate(nand->clk) / 1000000; > + unsigned int period = DIV_ROUND_UP(1000000, rate); > + const struct nand_sdr_timings *timings; > + u32 val, reg = 0; > + > + timings = onfi_async_timing_mode_to_sdr_timings(mode); > + > + val = DIV_ROUND_UP(max3(timings->tAR_min, timings->tRR_min, > + timings->tRC_min), period); > + if (val > 2) > + val -= 3; > + reg |= TIMING_TCR_TAR_TRR(val); > + > + val = DIV_ROUND_UP(max(max(timings->tCS_min, timings->tCH_min), > + max(timings->tALS_min, timings->tALH_min)), > + period); > + if (val > 1) > + val -= 2; > + reg |= TIMING_TCS(val); > + > + val = DIV_ROUND_UP(max(timings->tRP_min, timings->tREA_max) + 6000, > + period); > + reg |= TIMING_TRP(val) | TIMING_TRP_RESP(val); > + > + reg |= TIMING_TWB(DIV_ROUND_UP(timings->tWB_max, period)); > + reg |= TIMING_TWHR(DIV_ROUND_UP(timings->tWHR_min, period)); > + reg |= TIMING_TWH(DIV_ROUND_UP(timings->tWH_min, period)); > + reg |= TIMING_TWP(DIV_ROUND_UP(timings->tWP_min, period)); > + reg |= TIMING_TRH(DIV_ROUND_UP(timings->tRHW_min, period)); > + > + writel(reg, nand->regs + TIMING_1); > + > + val = DIV_ROUND_UP(timings->tADL_min, period); > + if (val > 2) > + val -= 3; > + reg = TIMING_TADL(val); > + > + writel(reg, nand->regs + TIMING_2); > +} > + > +static void tegra_nand_setup_chiptiming(struct tegra_nand *nand) > +{ > + struct nand_chip *chip = &nand->chip; > + int mode; > + > + mode = onfi_get_async_timing_mode(chip); > + if (mode == ONFI_TIMING_MODE_UNKNOWN) > + mode = chip->onfi_timing_mode_default; > + else > + mode = fls(mode); > + > + tegra_nand_setup_timing(nand, mode); > +} > + > +static int tegra_nand_probe(struct platform_device *pdev) > +{ > + struct reset_control *rst; > + struct tegra_nand *nand; > + struct nand_chip *chip; > + struct mtd_info *mtd; > + struct resource *res; > + unsigned long value; > + int irq, err = 0; > + > + nand = devm_kzalloc(&pdev->dev, sizeof(*nand), GFP_KERNEL); > + if (!nand) > + return -ENOMEM; > + > + nand->dev = &pdev->dev; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + nand->regs = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(nand->regs)) > + return PTR_ERR(nand->regs); > + > + irq = platform_get_irq(pdev, 0); > + err = devm_request_irq(&pdev->dev, irq, tegra_nand_irq, 0, > + dev_name(&pdev->dev), nand); > + if (err) > + return err; > + > + rst = devm_reset_control_get(&pdev->dev, "nand"); > + if (IS_ERR(rst)) > + return PTR_ERR(rst); > + > + nand->clk = devm_clk_get(&pdev->dev, "nand"); > + if (IS_ERR(nand->clk)) > + return PTR_ERR(nand->clk); > + > + nand->wp_gpio = gpiod_get_optional(&pdev->dev, "wp-gpios", > + GPIOD_OUT_HIGH); > + if (IS_ERR(nand->wp_gpio)) > + return PTR_ERR(nand->wp_gpio); > + > + err = clk_prepare_enable(nand->clk); > + if (err) > + return err; > + > + reset_control_assert(rst); > + udelay(2); > + reset_control_deassert(rst); > + > + value = HWSTATUS_RDSTATUS_MASK(1) | HWSTATUS_RDSTATUS_VALUE(0) | > + HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | > + HWSTATUS_RBSY_VALUE(NAND_STATUS_READY); > + writel(NAND_CMD_STATUS, nand->regs + HWSTATUS_CMD); > + writel(value, nand->regs + HWSTATUS_MASK); > + > + init_completion(&nand->command_complete); > + init_completion(&nand->dma_complete); > + > + /* clear interrupts */ > + value = readl(nand->regs + ISR); > + writel(value, nand->regs + ISR); > + > + writel(DMA_CTRL_IS_DONE, nand->regs + DMA_CTRL); > + > + /* enable interrupts */ > + value = IER_UND | IER_OVR | IER_CMD_DONE | IER_ECC_ERR | IER_GIE; > + writel(value, nand->regs + IER); > + > + /* reset config */ > + writel(0, nand->regs + CFG); > + > + chip = &nand->chip; > + mtd = nand_to_mtd(chip); > + > + mtd->dev.parent = &pdev->dev; > + mtd->name = "tegra_nand"; > + mtd->owner = THIS_MODULE; > + > + nand_set_flash_node(chip, pdev->dev.of_node); > + nand_set_controller_data(chip, nand); > + > + chip->options = NAND_NO_SUBPAGE_WRITE; > + chip->exec_op = tegra_nand_exec_op; > + chip->select_chip = tegra_nand_select_chip; > + tegra_nand_setup_timing(nand, 0); > + > + err = nand_scan_ident(mtd, 1, NULL); > + if (err) > + goto err_disable_clk; > + > + if (chip->bbt_options & NAND_BBT_USE_FLASH) > + chip->bbt_options |= NAND_BBT_NO_OOB; > + > + nand->data_buf = dmam_alloc_coherent(&pdev->dev, mtd->writesize, > + &nand->data_dma, GFP_KERNEL); > + if (!nand->data_buf) { > + err = -ENOMEM; > + goto err_disable_clk; > + } > + > + nand->oob_buf = dmam_alloc_coherent(&pdev->dev, mtd->oobsize, > + &nand->oob_dma, GFP_KERNEL); > + if (!nand->oob_buf) { > + err = -ENOMEM; > + goto err_disable_clk; > + } > + > + chip->ecc.mode = NAND_ECC_HW; > + chip->ecc.size = 512; > + chip->ecc.read_page = tegra_nand_read_page; > + chip->ecc.write_page = tegra_nand_write_page; > + > + value = readl(nand->regs + CFG); > + value |= CFG_PIPE_EN | CFG_SKIP_SPARE | CFG_SKIP_SPARE_SIZE_4 | > + CFG_TAG_BYTE_SIZE(mtd_ooblayout_count_freebytes(mtd) - 1); > + > + if (chip->options & NAND_BUSWIDTH_16) > + value |= CFG_BUS_WIDTH_16; > + > + switch (mtd->oobsize) { > + case 16: > + mtd_set_ooblayout(mtd, &tegra_nand_oob_16_ops); > + chip->ecc.strength = 1; > + chip->ecc.bytes = 4; > + break; > + case 64: > + mtd_set_ooblayout(mtd, &tegra_nand_oob_64_ops); > + chip->ecc.strength = 8; > + chip->ecc.bytes = 18; > + value |= CFG_ECC_SEL | CFG_TVAL_8; > + break; > + case 128: > + mtd_set_ooblayout(mtd, &tegra_nand_oob_128_ops); > + chip->ecc.strength = 8; > + chip->ecc.bytes = 18; > + value |= CFG_ECC_SEL | CFG_TVAL_8; > + break; > + case 224: > + mtd_set_ooblayout(mtd, &tegra_nand_oob_224_ops); > + chip->ecc.strength = 8; > + chip->ecc.bytes = 18; > + value |= CFG_ECC_SEL | CFG_TVAL_8; > + break; > + default: > + dev_err(&pdev->dev, "unhandled OOB size %d\n", mtd->oobsize); > + err = -ENODEV; > + goto err_disable_clk; > + } This selects the algorithm used somewhat ad-hoc. The controller supports Hamming/Reed-Solomon and BCH. I was thinking to use the device tree property nand-ecc-algo for manual algorithm selection (need to add rs...). Then use ONFI/JEDEC/parameter page/driver information from ecc_strength_ds/ecc_step_ds to select an appropriate ECC strength. Or in case device tree nand-ecc-maximize just use the maximum possible with given algorithm/OOB size. Does that sound reasonable? -- Stefan > + > + switch (mtd->writesize) { > + case 256: > + value |= CFG_PS_256; > + break; > + case 512: > + value |= CFG_PS_512; > + break; > + case 1024: > + value |= CFG_PS_1024; > + break; > + case 2048: > + value |= CFG_PS_2048; > + break; > + case 4096: > + value |= CFG_PS_4096; > + break; > + default: > + dev_err(&pdev->dev, "unhandled writesize %d\n", mtd->writesize); > + err = -ENODEV; > + goto err_disable_clk; > + } > + > + writel(value, nand->regs + CFG); > + > + tegra_nand_setup_chiptiming(nand); > + > + err = nand_scan_tail(mtd); > + if (err) > + goto err_disable_clk; > + > + err = mtd_device_register(mtd, NULL, 0); > + if (err) > + goto err_cleanup_nand; > + > + platform_set_drvdata(pdev, nand); > + > + return 0; > + > +err_cleanup_nand: > + nand_cleanup(chip); > +err_disable_clk: > + clk_disable_unprepare(nand->clk); > + return err; > +} > + > +static int tegra_nand_remove(struct platform_device *pdev) > +{ > + struct tegra_nand *nand = platform_get_drvdata(pdev); > + > + nand_release(nand_to_mtd(&nand->chip)); > + > + clk_disable_unprepare(nand->clk); > + > + return 0; > +} > + > +static const struct of_device_id tegra_nand_of_match[] = { > + { .compatible = "nvidia,tegra20-nand" }, > + { /* sentinel */ } > +}; > + > +static struct platform_driver tegra_nand_driver = { > + .driver = { > + .name = "tegra-nand", > + .of_match_table = tegra_nand_of_match, > + }, > + .probe = tegra_nand_probe, > + .remove = tegra_nand_remove, > +}; > +module_platform_driver(tegra_nand_driver); > + > +MODULE_DESCRIPTION("NVIDIA Tegra NAND driver"); > +MODULE_AUTHOR("Thierry Reding "); > +MODULE_AUTHOR("Lucas Stach "); > +MODULE_AUTHOR("Stefan Agner "); > +MODULE_LICENSE("GPL v2"); > +MODULE_DEVICE_TABLE(of, tegra_nand_of_match);