Re: [PATCH v4 4/6] mtd: rawnand: add NVIDIA Tegra NAND Flash controller driver
From: Dmitry Osipenko
Date: Mon Jun 11 2018 - 20:03:29 EST
On Monday, 11 June 2018 23:52:22 MSK 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 <dev@xxxxxxxxxx>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> ---
> MAINTAINERS | 7 +
> drivers/mtd/nand/raw/Kconfig | 6 +
> drivers/mtd/nand/raw/Makefile | 1 +
> drivers/mtd/nand/raw/tegra_nand.c | 1248 +++++++++++++++++++++++++++++
> 4 files changed, 1262 insertions(+)
> create mode 100644 drivers/mtd/nand/raw/tegra_nand.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 58b9861ccf99..c2e5571c85d4 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13844,6 +13844,13 @@ M: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> S: Supported
> F: drivers/input/keyboard/tegra-kbc.c
>
> +TEGRA NAND DRIVER
> +M: Stefan Agner <stefan@xxxxxxxx>
> +M: Lucas Stach <dev@xxxxxxxxxx>
> +S: Maintained
> +F: Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
> +F: drivers/mtd/nand/raw/tegra_nand.c
> +
> TEGRA PWM DRIVER
> M: Thierry Reding <thierry.reding@xxxxxxxxx>
> S: Supported
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index 19a2b283fbbe..e9093f52371e 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 controller on NVIDIA Tegra"
> + depends on ARCH_TEGRA || COMPILE_TEST
> + help
> + Enables support for NAND flash controller on NVIDIA Tegra SoC.
> +
> 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..dd23a5eb6af3
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/tegra_nand.c
> @@ -0,0 +1,1248 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2018 Stefan Agner <stefan@xxxxxxxx>
> + * Copyright (C) 2014-2015 Lucas Stach <dev@xxxxxxxxxx>
> + * Copyright (C) 2012 Avionic Design GmbH
> + */
> +
> +#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 COMMAND 0x00
> +#define COMMAND_GO BIT(31)
> +#define COMMAND_CLE BIT(30)
> +#define COMMAND_ALE BIT(29)
> +#define COMMAND_PIO BIT(28)
> +#define COMMAND_TX BIT(27)
> +#define COMMAND_RX BIT(26)
> +#define COMMAND_SEC_CMD BIT(25)
> +#define COMMAND_AFT_DAT BIT(24)
> +#define COMMAND_TRANS_SIZE(x) (((x - 1) & 0xf) << 20)
> +#define COMMAND_A_VALID BIT(19)
> +#define COMMAND_B_VALID BIT(18)
> +#define COMMAND_RD_STATUS_CHK BIT(17)
> +#define COMMAND_RBSY_CHK BIT(16)
> +#define COMMAND_CE(x) BIT(8 + ((x) & 0x7))
> +#define COMMAND_CLE_SIZE(x) (((x - 1) & 0x3) << 4)
> +#define COMMAND_ALE_SIZE(x) (((x - 1) & 0xf) << 0)
> +
> +#define STATUS 0x04
> +
> +#define ISR 0x08
> +#define ISR_CORRFAIL_ERR BIT(24)
> +#define ISR_UND BIT(7)
> +#define ISR_OVR BIT(6)
> +#define ISR_CMD_DONE BIT(5)
> +#define ISR_ECC_ERR BIT(4)
> +
> +#define IER 0x0c
> +#define IER_ERR_TRIG_VAL(x) (((x) & 0xf) << 16)
> +#define IER_UND BIT(7)
> +#define IER_OVR BIT(6)
> +#define IER_CMD_DONE BIT(5)
> +#define IER_ECC_ERR BIT(4)
> +#define IER_GIE BIT(0)
> +
> +#define CONFIG 0x10
> +#define CONFIG_HW_ECC BIT(31)
> +#define CONFIG_ECC_SEL BIT(30)
> +#define CONFIG_ERR_COR BIT(29)
> +#define CONFIG_PIPE_EN BIT(28)
> +#define CONFIG_TVAL_4 (0 << 24)
> +#define CONFIG_TVAL_6 (1 << 24)
> +#define CONFIG_TVAL_8 (2 << 24)
> +#define CONFIG_SKIP_SPARE BIT(23)
> +#define CONFIG_BUS_WIDTH_16 BIT(21)
> +#define CONFIG_COM_BSY BIT(20)
> +#define CONFIG_PS_256 (0 << 16)
> +#define CONFIG_PS_512 (1 << 16)
> +#define CONFIG_PS_1024 (2 << 16)
> +#define CONFIG_PS_2048 (3 << 16)
> +#define CONFIG_PS_4096 (4 << 16)
> +#define CONFIG_SKIP_SPARE_SIZE_4 (0 << 14)
> +#define CONFIG_SKIP_SPARE_SIZE_8 (1 << 14)
> +#define CONFIG_SKIP_SPARE_SIZE_12 (2 << 14)
> +#define CONFIG_SKIP_SPARE_SIZE_16 (3 << 14)
> +#define CONFIG_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) & 0x3) << 4)
> +#define TIMING_TRP(x) (((x) & 0xf) << 0)
> +
> +#define RESP 0x18
> +
> +#define TIMING_2 0x1c
> +#define TIMING_TADL(x) ((x) & 0xf)
> +
> +#define CMD_REG1 0x20
> +#define CMD_REG2 0x24
> +#define ADDR_REG1 0x28
> +#define ADDR_REG2 0x2c
> +
> +#define DMA_MST_CTRL 0x30
> +#define DMA_MST_CTRL_GO BIT(31)
> +#define DMA_MST_CTRL_IN (0 << 30)
> +#define DMA_MST_CTRL_OUT BIT(30)
> +#define DMA_MST_CTRL_PERF_EN BIT(29)
> +#define DMA_MST_CTRL_IE_DONE BIT(28)
> +#define DMA_MST_CTRL_REUSE BIT(27)
> +#define DMA_MST_CTRL_BURST_1 (2 << 24)
> +#define DMA_MST_CTRL_BURST_4 (3 << 24)
> +#define DMA_MST_CTRL_BURST_8 (4 << 24)
> +#define DMA_MST_CTRL_BURST_16 (5 << 24)
> +#define DMA_MST_CTRL_IS_DONE BIT(20)
> +#define DMA_MST_CTRL_EN_A BIT(2)
> +#define DMA_MST_CTRL_EN_B BIT(1)
> +
> +#define DMA_CFG_A 0x34
> +#define DMA_CFG_B 0x38
> +
> +#define FIFO_CTRL 0x3c
> +#define FIFO_CTRL_CLR_ALL BIT(3)
> +
> +#define DATA_PTR 0x40
> +#define TAG_PTR 0x44
> +#define ECC_PTR 0x48
> +
> +#define DEC_STATUS 0x4c
> +#define DEC_STATUS_A_ECC_FAIL BIT(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 BCH_CONFIG 0xcc
> +#define BCH_ENABLE BIT(0)
> +#define BCH_TVAL_4 (0 << 4)
> +#define BCH_TVAL_8 (1 << 4)
> +#define BCH_TVAL_14 (2 << 4)
> +#define BCH_TVAL_16 (3 << 4)
> +
> +#define DEC_STAT_RESULT 0xd0
> +#define DEC_STAT_BUF 0xd4
> +#define DEC_STAT_BUF_FAIL_SEC_FLAG_MASK 0xff000000
> +#define DEC_STAT_BUF_FAIL_SEC_FLAG_SHIFT 24
> +#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
> +
> +#define OFFSET(val, off) ((val) < (off) ? 0 : (val) - (off))
> +
> +#define SKIP_SPARE_BYTES 4
> +#define BITS_PER_STEP_RS 18
> +#define BITS_PER_STEP_BCH 13
> +
> +#define INT_MASK (IER_UND | IER_OVR | IER_CMD_DONE | IER_GIE)
> +#define HWSTATUS_CMD_DEFAULT NAND_STATUS_READY
> +#define HWSTATUS_MASK_DEFAULT (HWSTATUS_RDSTATUS_MASK(1) | \
> + HWSTATUS_RDSTATUS_VALUE(0) | \
> + HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | \
> + HWSTATUS_RBSY_VALUE(NAND_STATUS_READY))
> +
> +struct tegra_nand_controller {
> + struct nand_hw_control controller;
> + struct device *dev;
> + void __iomem *regs;
> + int irq;
> + struct clk *clk;
> + struct completion command_complete;
> + struct completion dma_complete;
> + bool last_read_error;
> + int cur_cs;
> + struct nand_chip *chip;
> +};
> +
> +struct tegra_nand_chip {
> + struct nand_chip chip;
> + struct gpio_desc *wp_gpio;
> + struct mtd_oob_region tag;
> + u32 config;
> + u32 config_ecc;
> + u32 bch_config;
> + int cs[1];
> +};
> +
> +static inline struct tegra_nand_controller *to_tegra_ctrl(
> + struct nand_hw_control *hw_ctrl)
> +{
> + return container_of(hw_ctrl, struct tegra_nand_controller, controller);
> +}
> +
> +static inline struct tegra_nand_chip *to_tegra_chip(struct nand_chip *chip)
> +{
> + return container_of(chip, struct tegra_nand_chip, chip);
> +}
> +
> +static int tegra_nand_ooblayout_rs_ecc(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_RS * chip->ecc.strength,
> + BITS_PER_BYTE);
> +
> + if (section > 0)
> + return -ERANGE;
> +
> + oobregion->offset = SKIP_SPARE_BYTES;
> + oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
> +
> + return 0;
> +}
> +
> +static int tegra_nand_ooblayout_rs_free(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_RS * chip->ecc.strength,
> + BITS_PER_BYTE);
> +
> + if (section > 0)
> + return -ERANGE;
> +
> + oobregion->offset = SKIP_SPARE_BYTES +
> + round_up(bytes_per_step * chip->ecc.steps, 4);
> + oobregion->length = mtd->oobsize - oobregion->offset;
> +
> + return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops tegra_nand_oob_rs_ops = {
> + .ecc = tegra_nand_ooblayout_rs_ecc,
> + .free = tegra_nand_ooblayout_rs_free,
> +};
> +
> +static int tegra_nand_ooblayout_bch_ecc(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_BCH * chip->ecc.strength,
> + BITS_PER_BYTE);
> +
> + if (section > 0)
> + return -ERANGE;
> +
> + oobregion->offset = SKIP_SPARE_BYTES;
> + oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
> +
> + return 0;
> +}
> +
> +static int tegra_nand_ooblayout_bch_free(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_BCH * chip->ecc.strength,
> + BITS_PER_BYTE);
> +
> + if (section > 0)
> + return -ERANGE;
> +
> + oobregion->offset = SKIP_SPARE_BYTES +
> + round_up(bytes_per_step * chip->ecc.steps, 4);
> + oobregion->length = mtd->oobsize - oobregion->offset;
> +
> + return 0;
> +}
> +
> +/*
> + * Layout with tag bytes is
> + *
> + *
> --------------------------------------------------------------------------
> + * | main area | skip bytes | tag bytes | parity |
> .. | + *
> --------------------------------------------------------------------------
> + *
> + * If not tag bytes are written, parity moves right after skip bytes!
> + */
> +static const struct mtd_ooblayout_ops tegra_nand_oob_bch_ops = {
> + .ecc = tegra_nand_ooblayout_bch_ecc,
> + .free = tegra_nand_ooblayout_bch_free,
> +};
> +
> +static irqreturn_t tegra_nand_irq(int irq, void *data)
> +{
> + struct tegra_nand_controller *ctrl = data;
> + u32 isr, dma;
> +
> + isr = readl_relaxed(ctrl->regs + ISR);
> + dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
> + dev_dbg(ctrl->dev, "isr %08x\n", isr);
> +
> + if (!isr && !(dma & DMA_MST_CTRL_IS_DONE))
> + return IRQ_NONE;
> +
> + /*
> + * The bit name is somewhat missleading: This is also set when
> + * HW ECC was successful. The data sheet states:
> + * Correctable OR Un-correctable errors occurred in the DMA transfer...
> + */
> + if (isr & ISR_CORRFAIL_ERR)
> + ctrl->last_read_error = true;
> +
> + if (isr & ISR_CMD_DONE)
> + complete(&ctrl->command_complete);
> +
> + if (isr & ISR_UND)
> + dev_err(ctrl->dev, "FIFO underrun\n");
> +
> + if (isr & ISR_OVR)
> + dev_err(ctrl->dev, "FIFO overrun\n");
> +
> + /* handle DMA interrupts */
> + if (dma & DMA_MST_CTRL_IS_DONE) {
> + writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
> + complete(&ctrl->dma_complete);
> + }
> +
> + /* clear interrupts */
> + writel_relaxed(isr, ctrl->regs + ISR);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static const char * const tegra_nand_reg_names[] = {
> + "COMMAND",
> + "STATUS",
> + "ISR",
> + "IER",
> + "CONFIG",
> + "TIMING",
> + NULL,
> + "TIMING2",
> + "CMD_REG1",
> + "CMD_REG2",
> + "ADDR_REG1",
> + "ADDR_REG2",
> + "DMA_MST_CTRL",
> + "DMA_CFG_A",
> + "DMA_CFG_B",
> + "FIFO_CTRL",
> +};
> +
> +static void tegra_nand_dump_reg(struct tegra_nand_controller *ctrl)
> +{
> + u32 reg;
> + int i;
> +
> + dev_err(ctrl->dev, "Tegra NAND controller register dump\n");
> + for (i = 0; i < ARRAY_SIZE(tegra_nand_reg_names); i++) {
> + const char *reg_name = tegra_nand_reg_names[i];
> +
> + if (!reg_name)
> + continue;
> +
> + reg = readl_relaxed(ctrl->regs + (i * 4));
> + dev_err(ctrl->dev, "%s: 0x%08x\n", reg_name, reg);
> + }
> +}
> +
> +static void tegra_nand_controller_abort(struct tegra_nand_controller *ctrl)
> +{
> + u32 isr, dma;
> +
> + disable_irq(ctrl->irq);
> +
> + /* Abort current command/DMA operation */
> + writel_relaxed(0, ctrl->regs + DMA_MST_CTRL);
> + writel_relaxed(0, ctrl->regs + COMMAND);
> +
> + /* clear interrupts */
> + isr = readl_relaxed(ctrl->regs + ISR);
> + writel_relaxed(isr, ctrl->regs + ISR);
> + dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
> + writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
> +
> + reinit_completion(&ctrl->command_complete);
> + reinit_completion(&ctrl->dma_complete);
> +
> + enable_irq(ctrl->irq);
> +}
> +
> +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 tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
> + unsigned int op_id, size = 0, offset = 0;
> + bool first_cmd = true;
> + u32 reg, cmd = 0;
> + int ret;
> +
> + 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 |= COMMAND_CLE;
> + writel_relaxed(instr->ctx.cmd.opcode,
> + ctrl->regs + CMD_REG1);
> + } else {
> + cmd |= COMMAND_SEC_CMD;
> + writel_relaxed(instr->ctx.cmd.opcode,
> + ctrl->regs + CMD_REG2);
> + }
> + 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 |= COMMAND_ALE | COMMAND_ALE_SIZE(naddrs);
> + for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
> + addr1 |= *addrs++ << (BITS_PER_BYTE * i);
> + naddrs -= i;
> + for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
> + addr2 |= *addrs++ << (BITS_PER_BYTE * i);
> + writel_relaxed(addr1, ctrl->regs + ADDR_REG1);
> + writel_relaxed(addr2, ctrl->regs + ADDR_REG2);
> + break;
> +
> + case NAND_OP_DATA_IN_INSTR:
> + size = nand_subop_get_data_len(subop, op_id);
> + offset = nand_subop_get_data_start_off(subop, op_id);
> +
> + cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
> + COMMAND_RX | COMMAND_A_VALID;
> +
> + instr_data_in = instr;
> + break;
> +
> + case NAND_OP_DATA_OUT_INSTR:
> + size = nand_subop_get_data_len(subop, op_id);
> + offset = nand_subop_get_data_start_off(subop, op_id);
> +
> + cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
> + COMMAND_TX | COMMAND_A_VALID;
> +
> + memcpy(®, instr->ctx.data.buf.out + offset, size);
> + writel_relaxed(reg, ctrl->regs + RESP);
> +
> + break;
> + case NAND_OP_WAITRDY_INSTR:
> + cmd |= COMMAND_RBSY_CHK;
> + break;
> +
> + }
> + }
> +
> + cmd |= COMMAND_GO | COMMAND_CE(ctrl->cur_cs);
> + writel_relaxed(cmd, ctrl->regs + COMMAND);
> + ret = wait_for_completion_io_timeout(&ctrl->command_complete,
> + msecs_to_jiffies(500));
It's not obvious to me whether _io_ variant is appropriate to use here, would
be nice if somebody could clarify that. Maybe block/ already does the IO
accounting itself and hence the IO time would be counted twice in that case.