[Re-sending the review I made before of the series RESEND]
> Hello Stefan, > > I don't have expertise to review the actual NAND-related driver logic, so I > only > reviewed the basics. The driver code looks good to me, though I've couple > minor > comments. > > On 21.05.2018 03:16, 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 <d...@lynxeye.de> >> Signed-off-by: Stefan Agner <ste...@agner.ch> >> --- >> 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 <ldewan...@nvidia.com> >> S: Supported >> F: drivers/input/keyboard/tegra-kbc.c >> >> +TEGRA NAND DRIVER >> +M: Stefan Agner <ste...@agner.ch> >> +M: Lucas Stach <d...@lynxeye.de> >> +S: Maintained >> +F: Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt >> +F: drivers/mtd/nand/tegra_nand.c >> + >> TEGRA PWM DRIVER >> M: Thierry Reding <thierry.red...@gmail.com> >> 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 <ste...@agner.ch> >> + * Copyright (C) 2014-2015 Lucas Stach <d...@lynxeye.de> >> + * 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 <linux/clk.h> >> +#include <linux/completion.h> >> +#include <linux/delay.h> >> +#include <linux/dma-mapping.h> >> +#include <linux/err.h> >> +#include <linux/gpio/consumer.h> >> +#include <linux/interrupt.h> >> +#include <linux/io.h> >> +#include <linux/module.h> >> +#include <linux/mtd/partitions.h> >> +#include <linux/mtd/rawnand.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h>> +#include <linux/reset.h> >> + >> +#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, >> +}; >> + >> +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); > > You could use readl_relaxed() here. > >> + 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; > > The force8bit variable isn't used anywhere in the code, so compiler should > warn > you about the "unused variable", is it the case? > >> + u32 cmd = 0; >> + u32 value; >> + > > The op_id=-1 above is probably because the loop below was: > > while (++op_id < subop->ninstrs) {} > > Both variants are fine, but the for-loop is a bit more explicit. You could > omit > the above op_id variable initialization for consistency. > >> + 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); > > Note: > > The memcpy + readl / writel won't work with a big-endian kernel, > cpu_to_[bl]e32() should be applied in a such cases. > > Tegra's I2C driver had a similar memcpy-case issue, it was corrected during > the > attempt to get BE kernel support for Tegra. But that attempt was quite long > time > ago and Tegra maintainers were not very excited to have to do more testing > work > for each kernel release and hence Tegra is LE-only as of today. > >> + >> + 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; > > Wouldn't be more efficient to set DMA burst to 16 words? The writesize seems > always aligned to at least 64 words. > >> + 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); > > You could use the reset_control_reset() here, though it uses the 1 usec delay > instead of 2, but I think it shouldn't really matter. > >> + >> + 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); > > Isn't a set ISR bit means that NAND HW asserts interrupt line? If yes, then > you > may want to move devm_request_irq() after resetting the HW state, to be on a > safe side. > >> + >> + 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); > > Is this "reset config" really needed? It is overwritten below in the code. > > > Also, maybe you could factor out the HW reset/init stuff into a respective > tegra_nand_hw_reset() / tegra_nand_hw_init(), just for consistency. > >> + >> + 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; >> + } >> + >> + 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 <thierry.red...@nvidia.com>"); >> +MODULE_AUTHOR("Lucas Stach <d...@lynxeye.de>"); >> +MODULE_AUTHOR("Stefan Agner <ste...@agner.ch>"); >> +MODULE_LICENSE("GPL v2"); >> +MODULE_DEVICE_TABLE(of, tegra_nand_of_match); >>