On Sunday, 10 June 2018 14:09:24 MSK Stefan Agner wrote:
> On 09.06.2018 14:21, Dmitry Osipenko wrote:
> > On Saturday, 9 June 2018 00:51:01 MSK Stefan Agner wrote:
> >> On 01.06.2018 11:20, Dmitry Osipenko wrote:
> >> > On 01.06.2018 01:16, 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 | 1143
> >> >> +++++++++++++++++++++++++++++
> >> >> 4 files changed, 1157 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 <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/raw/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..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..e9664f2938a3
> >> >> --- /dev/null
> >> >> +++ b/drivers/mtd/nand/raw/tegra_nand.c
> >> >> @@ -0,0 +1,1143 @@
> >> >> +// SPDX-License-Identifier: GPL-2.0
> >> >> +/*
> >> >> + * Copyright (C) 2018 Stefan Agner <ste...@agner.ch>
> >> >> + * Copyright (C) 2014-2015 Lucas Stach <d...@lynxeye.de>
> >> >> + * 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 CMD 0x00
> >> >> +#define CMD_GO BIT(31)
> >> >> +#define CMD_CLE BIT(30)
> >> >> +#define CMD_ALE BIT(29)
> >> >> +#define CMD_PIO BIT(28)
> >> >> +#define CMD_TX BIT(27)
> >> >> +#define CMD_RX BIT(26)
> >> >> +#define CMD_SEC_CMD BIT(25)
> >> >> +#define CMD_AFT_DAT BIT(24)
> >> >> +#define CMD_TRANS_SIZE(x) (((x - 1) & 0xf) << 20)
> >> >> +#define CMD_A_VALID BIT(19)
> >> >> +#define CMD_B_VALID BIT(18)
> >> >> +#define CMD_RD_STATUS_CHK BIT(17)
> >> >> +#define CMD_RBSY_CHK BIT(16)
> >> >> +#define CMD_CE(x) BIT((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 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 CFG 0x10
> >> >> +#define CFG_HW_ECC BIT(31)
> >> >> +#define CFG_ECC_SEL BIT(30)
> >> >> +#define CFG_ERR_COR BIT(29)
> >> >> +#define CFG_PIPE_EN BIT(28)
> >> >> +#define CFG_TVAL_4 (0 << 24)
> >> >> +#define CFG_TVAL_6 (1 << 24)
> >> >> +#define CFG_TVAL_8 (2 << 24)
> >> >> +#define CFG_SKIP_SPARE BIT(23)
> >> >> +#define CFG_BUS_WIDTH_16 BIT(21)
> >> >> +#define CFG_COM_BSY BIT(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) & 0x3) <<
> >> >> 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 BIT(31)
> >> >> +#define DMA_CTRL_IN (0 << 30)
> >> >> +#define DMA_CTRL_OUT BIT(30)
> >> >> +#define DMA_CTRL_PERF_EN BIT(29)
> >> >> +#define DMA_CTRL_IE_DONE BIT(28)
> >> >> +#define DMA_CTRL_REUSE BIT(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 BIT(20)
> >> >> +#define DMA_CTRL_EN_A BIT(2)
> >> >> +#define DMA_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
> >> >> +
> >> >> +struct tegra_nand_controller {
> >> >> + struct nand_hw_control controller;
> >> >> + void __iomem *regs;
> >> >> + struct clk *clk;
> >> >> + struct device *dev;
> >> >> + struct completion command_complete;
> >> >> + struct completion dma_complete;
> >> >> + bool last_read_error;
> >> >> + int cur_chip;
> >> >> + struct nand_chip *chip;
> >> >> +};
> >> >> +
> >> >> +struct tegra_nand_chip {
> >> >> + struct nand_chip chip;
> >> >> + struct gpio_desc *wp_gpio;
> >> >> + struct mtd_oob_region tag;
> >> >> +};
> >> >> +
> >> >> +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_CTRL);
> >> >> + dev_dbg(ctrl->dev, "isr %08x\n", isr);
> >> >> +
> >> >> + if (!isr && !(dma & DMA_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_CTRL_IS_DONE) {
> >> >> + writel_relaxed(dma, ctrl->regs + DMA_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 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 |= CMD_CLE;
> >> >> + writel_relaxed(instr->ctx.cmd.opcode,
> >> >> + ctrl->regs + CMD_1);
> >> >> + } else {
> >> >> + cmd |= CMD_SEC_CMD;
> >> >> + writel_relaxed(instr->ctx.cmd.opcode,
> >> >> + ctrl->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++ << (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_1);
> >> >> + writel_relaxed(addr2, ctrl->regs + ADDR_2);
> >> >> + 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 |= CMD_TRANS_SIZE(size) | CMD_PIO | CMD_RX |
> >> >> + CMD_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 |= CMD_TRANS_SIZE(size) | CMD_PIO | CMD_TX |
> >> >> + CMD_A_VALID;
> >> >> +
> >> >> + memcpy(®, instr->ctx.data.buf.out + offset,
> >> >> size);
> >> >> + writel_relaxed(reg, ctrl->regs + RESP);
> >> >> +
> >> >> + break;
> >> >> + case NAND_OP_WAITRDY_INSTR:
> >> >> + cmd |= CMD_RBSY_CHK;
> >> >> + break;
> >> >> +
> >> >> + }
> >> >> + }
> >> >> +
> >> >> + cmd |= CMD_GO | CMD_CE(ctrl->cur_chip);
> >> >> + writel_relaxed(cmd, ctrl->regs + CMD);
> >> >> + ret = wait_for_completion_timeout(&ctrl->command_complete,
> >> >> + msecs_to_jiffies(500));
> >> >> + if (!ret) {
> >> >> + dev_err(ctrl->dev, "CMD timeout\n");
> >> >> + tegra_nand_dump_reg(ctrl);
> >> >> + return -ETIMEDOUT;
> >> >> + }
> >> >
> >> > - wait_for_completion_timeout() could fail
> >>
> >> Not according to:
> >> https://elixir.bootlin.com/linux/latest/source/kernel/sched/completion.c#
> >> L14 0 https://www.kernel.org/doc/Documentation/scheduler/completion.txt
> >>
> >> Afaik, only the _interruptible variant can fail.
> >
> > Okay.
> >
> >> Btw, maybe we should use the _io variant?
> >
> > Looks like the _io variant is something specific to block/FS subsys and
> > shouldn't be used by the drivers.
> >
> >> > - HW shall be reset
> >> > - completion shall be re-inited because IRQ could fire just after the
> >> > completion timeout
> >> >
> >> > I'd write it something like this:
> >> >
> >> > #define INT_MASK (IER_UND | IER_OVR | IER_CMD_DONE | IER_GIE)
> >> >
> >> > #define HWSTATUS_MASK (HWSTATUS_RDSTATUS_MASK(1) | \
> >> >
> >> > HWSTATUS_RDSTATUS_VALUE(0) | \
> >> > HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | \
> >> > HWSTATUS_RBSY_VALUE(NAND_STATUS_READY))
> >> >
> >> > #define HW_TIMEOUT 500
> >> >
> >> > void tegra_nand_controller_reset(struct tegra_nand_controller *ctrl)
> >> > {
> >> >
> >> > int err;
> >> >
> >> > disable_irq(ctrl->irq);
> >> >
> >> > err = reset_control_reset(ctrl->rst);
> >> > if (err) {
> >> >
> >> > dev_err(ctrl->dev, "Failed to reset HW: %d\n", err);
> >> > msleep(HW_TIMEOUT);
> >> >
> >> > }
> >> >
> >> > writel_relaxed(NAND_CMD_STATUS, ctrl->regs + HWSTATUS_CMD);
> >> > writel_relaxed(HWSTATUS_MASK, ctrl->regs + HWSTATUS_MASK);
> >> > writel_relaxed(INT_MASK, ctrl->regs + ISR);
> >>
> >> If we do a controller reset, there is much more state than that which
> >> needs to be restored. A lot of it is not readily available currently
> >> (timing, ECC settings...)
> >>
> >> That seems a lot of work for a code path I do not intend to ever use :-)
> >
> > Are you sure that resetting HW resets the timing and other registers
> > configuration? Reset implementation is HW-specific, like for example in a
> > case of a video decoder the registers state is re-intialized on HW reset,
> > but registers configuration is untouched in a case of resetting GPU. I'd
> > suggest to check whether NAND controller resetting affects the HW
> > configuration.
> It seems all registers are set back to their documented reset value:
>
> [boot loader/ROM initialized values]
> [ 1.270253] tegra-nand 70008000.nand: Tegra NAND controller register
> dump
> [ 1.277051] tegra-nand 70008000.nand: COMMAND: 0x66880104
> [ 1.282457] tegra-nand 70008000.nand: STATUS: 0x00000101
> [ 1.287763] tegra-nand 70008000.nand: ISR: 0x01000120
> [ 1.292818] tegra-nand 70008000.nand: IER: 0x00000000
> [ 1.297863] tegra-nand 70008000.nand: CONFIG: 0x00840000
> [ 1.303181] tegra-nand 70008000.nand: TIMING: 0x05040000
> [ 1.308486] tegra-nand 70008000.nand: TIMING2: 0x00000003
> [ 1.313897] tegra-nand 70008000.nand: CMD_REG1: 0x00000000
> [ 1.319377] tegra-nand 70008000.nand: CMD_REG2: 0x00000030
> [ 1.324868] tegra-nand 70008000.nand: ADDR_REG1: 0x03000000
> [ 1.330435] tegra-nand 70008000.nand: ADDR_REG2: 0x00000000
> [ 1.336011] tegra-nand 70008000.nand: DMA_MST_CTRL: 0x04100004
> [ 1.341838] tegra-nand 70008000.nand: DMA_CFG_A: 0x00000fff
> [ 1.347415] tegra-nand 70008000.nand: DMA_CFG_B: 0x0000001b
> [ 1.352991] tegra-nand 70008000.nand: FIFO_CTRL: 0x0000aa00
> [reset]
> [ 1.358559] tegra-nand 70008000.nand: Tegra NAND controller register
> dump
> [ 1.365352] tegra-nand 70008000.nand: COMMAND: 0x00800004
> [ 1.370744] tegra-nand 70008000.nand: STATUS: 0x00000101
> [ 1.376060] tegra-nand 70008000.nand: ISR: 0x00000100
> [ 1.381105] tegra-nand 70008000.nand: IER: 0x00000000
> [ 1.386161] tegra-nand 70008000.nand: CONFIG: 0x10030000
> [ 1.391466] tegra-nand 70008000.nand: TIMING: 0x00000000
> [ 1.396782] tegra-nand 70008000.nand: TIMING2: 0x00000000
> [ 1.402174] tegra-nand 70008000.nand: CMD_REG1: 0x00000000
> [ 1.407664] tegra-nand 70008000.nand: CMD_REG2: 0x00000000
> [ 1.413156] tegra-nand 70008000.nand: ADDR_REG1: 0x00000000
> [ 1.418722] tegra-nand 70008000.nand: ADDR_REG2: 0x00000000
> [ 1.424297] tegra-nand 70008000.nand: DMA_MST_CTRL: 0x24000000
> [ 1.430123] tegra-nand 70008000.nand: DMA_CFG_A: 0x00000000
> [ 1.435698] tegra-nand 70008000.nand: DMA_CFG_B: 0x00000000
> [ 1.441264] tegra-nand 70008000.nand: FIFO_CTRL: 0x0000aa00
Alright, then indeed it's not really worth to bother with HW resetting here.
Probably only a kernel module reload or a reboot will help if HW is hung.
Maybe NAND controller / chip recovering is something that NAND core should be
handling in a such case by providing a nand_controller_reset() hook?
