[PATCH v7 3/3] mtd: rawnand: Add Loongson-1 NAND Controller driver

Keguang Zhang keguang.zhang at gmail.com
Thu Aug 1 03:53:37 PDT 2024


On Mon, May 6, 2024 at 3:59 PM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
>
> Hi,
>
> devnull+keguang.zhang.gmail.com at kernel.org wrote on Tue, 30 Apr 2024
> 19:11:12 +0800:
>
> > From: Keguang Zhang <keguang.zhang at gmail.com>
> >
> > This patch adds NAND Controller driver for Loongson-1 SoCs.
> >
> > Signed-off-by: Keguang Zhang <keguang.zhang at gmail.com>
> > ---
> > Changes in v7:
> > - Rename the dependency to LOONGSON1_APB_DMA
> >
> > Changes in v6:
> > - Amend Kconfig
> > - Add DT support
> > - Use DT data instead of platform data
> > - Remove MAX_ID_SIZE
> > - Remove case NAND_OP_CMD_INSTR in ls1x_nand_set_controller()
> > - Move ECC configuration to ls1x_nand_attach_chip()
> > - Rename variable "nand" to "ls1x"
> > - Rename variable "nc" to "nfc"
> > - Some minor fixes
> > - Link to v5: https://lore.kernel.org/all/20210520224213.7907-1-keguang.zhang@gmail.com
> >
> > Changes in v5:
> > - Update the driver to fit the raw NAND framework.
> > - Implement exec_op() instead of legacy cmdfunc().
> > - Use dma_request_chan() instead of dma_request_channel().
> > - Some minor fixes and cleanups.
> >
> > Changes in v4:
> > - Retrieve the controller from nand_hw_control.
> >
> > Changes in v3:
> > - Replace __raw_readl/__raw_writel with readl/writel.
> > - Split ls1x_nand into two structures:
> > ls1x_nand_chip and ls1x_nand_controller.
> >
> > Changes in v2:
> > - Modify the dependency in Kconfig due to the changes of DMA module.
> > ---
> >  drivers/mtd/nand/raw/Kconfig          |   7 +
> >  drivers/mtd/nand/raw/Makefile         |   1 +
> >  drivers/mtd/nand/raw/loongson1_nand.c | 748 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 756 insertions(+)
> >
> > diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> > index cbf8ae85e1ae..822bb7a2cea9 100644
> > --- a/drivers/mtd/nand/raw/Kconfig
> > +++ b/drivers/mtd/nand/raw/Kconfig
> > @@ -449,6 +449,13 @@ config MTD_NAND_RENESAS
> >         Enables support for the NAND controller found on Renesas R-Car
> >         Gen3 and RZ/N1 SoC families.
> >
> > +config MTD_NAND_LOONGSON1
> > +     tristate "Loongson1 NAND controller"
> > +     depends on LOONGSON1_APB_DMA || COMPILE_TEST
> > +     select REGMAP_MMIO
> > +     help
> > +       Enables support for NAND controller on Loongson1 SoCs.
> > +
> >  comment "Misc"
> >
> >  config MTD_SM_COMMON
> > diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> > index 25120a4afada..b3c65cab819c 100644
> > --- a/drivers/mtd/nand/raw/Makefile
> > +++ b/drivers/mtd/nand/raw/Makefile
> > @@ -57,6 +57,7 @@ obj-$(CONFIG_MTD_NAND_INTEL_LGM)    += intel-nand-controller.o
> >  obj-$(CONFIG_MTD_NAND_ROCKCHIP)              += rockchip-nand-controller.o
> >  obj-$(CONFIG_MTD_NAND_PL35X)         += pl35x-nand-controller.o
> >  obj-$(CONFIG_MTD_NAND_RENESAS)               += renesas-nand-controller.o
> > +obj-$(CONFIG_MTD_NAND_LOONGSON1)     += loongson1_nand.o
> >
> >  nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
> >  nand-objs += nand_onfi.o
> > diff --git a/drivers/mtd/nand/raw/loongson1_nand.c b/drivers/mtd/nand/raw/loongson1_nand.c
> > new file mode 100644
> > index 000000000000..d0f66a81ba0b
> > --- /dev/null
> > +++ b/drivers/mtd/nand/raw/loongson1_nand.c
> > @@ -0,0 +1,748 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * NAND Controller Driver for Loongson-1 SoC
> > + *
> > + * Copyright (C) 2015-2024 Keguang Zhang <keguang.zhang at gmail.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/dmaengine.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/mtd/mtd.h>
> > +#include <linux/mtd/rawnand.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/sizes.h>
> > +
> > +/* Loongson-1 NAND Controller Registers */
> > +#define NAND_CMD             0x0
> > +#define NAND_ADDR1           0x4
> > +#define NAND_ADDR2           0x8
> > +#define NAND_TIMING          0xc
> > +#define NAND_IDL             0x10
> > +#define NAND_IDH_STATUS              0x14
> > +#define NAND_PARAM           0x18
> > +#define NAND_OP_NUM          0x1c
> > +#define MAX_DUMP_REGS                0x20
> > +
> > +#define NAND_DMA_ADDR                0x40
> > +
> > +/* NAND Command Register Bits */
> > +#define OP_DONE                      BIT(10)
> > +#define OP_SPARE             BIT(9)
> > +#define OP_MAIN                      BIT(8)
> > +#define CMD_STATUS           BIT(7)
> > +#define CMD_RESET            BIT(6)
> > +#define CMD_READID           BIT(5)
> > +#define BLOCKS_ERASE         BIT(4)
> > +#define CMD_ERASE            BIT(3)
> > +#define CMD_WRITE            BIT(2)
> > +#define CMD_READ             BIT(1)
> > +#define CMD_VALID            BIT(0)
>
> Please add a common suffix to all your definitions and functions (LSN_,
> LSN1_, LOONGSON_, whatever)
>
Will do.

> > +
> > +#define MAX_ADDR_CYC         5U
> > +
> > +#define WAIT_CYCLE_MASK              GENMASK(7, 0)
> > +#define HOLD_CYCLE_MASK              GENMASK(15, 8)
> > +#define CELL_SIZE_MASK               GENMASK(11, 8)
> > +
> > +#define BITS_PER_WORD                (4 * BITS_PER_BYTE)
> > +
> > +/* macros for registers read/write */
> > +#define nand_readl(nfc, off)         \
> > +     readl((nfc)->reg_base + (off))
> > +
> > +#define nand_writel(nfc, off, val)   \
> > +     writel((val), (nfc)->reg_base + (off))
> > +
> > +struct ls1x_nfc_data {
> > +     unsigned int status_field;
> > +     unsigned int op_scope_field;
> > +     unsigned int hold_cycle;
> > +     unsigned int wait_cycle;
> > +     void (*parse_address)(struct nand_chip *chip, const u8 *addrs,
> > +                           unsigned int naddrs, int cmd);
> > +};
> > +
> > +struct ls1x_nfc {
> > +     void __iomem *reg_base;
> > +     struct regmap *regmap;
> > +     const struct ls1x_nfc_data *data;
> > +     __le32 addr1_reg;
> > +     __le32 addr2_reg;
> > +
> > +     char *buf;
> > +     unsigned int len;
> > +     unsigned int rdy_timeout;
> > +
> > +     /* DMA Engine stuff */
> > +     struct dma_chan *dma_chan;
> > +     dma_cookie_t dma_cookie;
> > +     struct completion dma_complete;
> > +};
> > +
> > +struct ls1x_nand {
> > +     struct device *dev;
> > +     struct nand_chip chip;
> > +     struct nand_controller controller;
> > +     struct ls1x_nfc nfc;
> > +};
> > +
> > +static const struct regmap_config ls1x_nand_regmap_config = {
> > +     .reg_bits = 32,
> > +     .val_bits = 32,
> > +     .reg_stride = 4,
> > +};
> > +
> > +static inline void ls1b_nand_parse_address(struct nand_chip *chip,
> > +                                        const u8 *addrs,
> > +                                        unsigned int naddrs, int cmd)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     unsigned int page_shift = chip->page_shift + 1;
> > +     int i;
> > +
> > +     nfc->addr1_reg = 0;
> > +     nfc->addr2_reg = 0;
> > +
> > +     if (cmd == CMD_ERASE) {
> > +             page_shift = chip->page_shift;
> > +
> > +             for (i = 0; i < min(MAX_ADDR_CYC - 2, naddrs); i++)
> > +                     nfc->addr1_reg |=
> > +                         (u32)addrs[i] << (page_shift + BITS_PER_BYTE * i);
> > +             if (i == MAX_ADDR_CYC - 2)
> > +                     nfc->addr2_reg |=
> > +                         (u32)addrs[i] >> (BITS_PER_WORD - page_shift -
> > +                                           BITS_PER_BYTE * (i - 1));
> > +
> > +             return;
> > +     }
>
> I don't see the point in having this if, can you try to make it a
> single generic logic? Same below.
>
Will improve the logic.

> > +
> > +     for (i = 0; i < min(2U, naddrs); i++)
> > +             nfc->addr1_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
> > +     for (i = 2; i < min(MAX_ADDR_CYC, naddrs); i++)
> > +             nfc->addr1_reg |=
> > +                 (u32)addrs[i] << (page_shift + BITS_PER_BYTE * (i - 2));
> > +     if (i == MAX_ADDR_CYC)
> > +             nfc->addr2_reg |=
> > +                 (u32)addrs[i] >> (BITS_PER_WORD - page_shift -
> > +                                   BITS_PER_BYTE * (i - 1));
> > +}
> > +
> > +static inline void ls1c_nand_parse_address(struct nand_chip *chip,
> > +                                        const u8 *addrs,
> > +                                        unsigned int naddrs, int cmd)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     int i;
> > +
> > +     nfc->addr1_reg = 0;
> > +     nfc->addr2_reg = 0;
> > +
> > +     if (cmd == CMD_ERASE) {
> > +             for (i = 0; i < min(MAX_ADDR_CYC, naddrs); i++)
> > +                     nfc->addr2_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
> > +
> > +             return;
> > +     }
> > +
> > +     for (i = 0; i < min(MAX_ADDR_CYC, naddrs); i++) {
> > +             if (i < 2)
> > +                     nfc->addr1_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
> > +             else
> > +                     nfc->addr2_reg |=
> > +                         (u32)addrs[i] << BITS_PER_BYTE * (i - 2);
> > +     }
> > +}
> > +
> > +static int ls1x_nand_set_controller(struct nand_chip *chip,
>
> The function name is misleading
>
Will improve the naming.

> > +                                 const struct nand_subop *subop, int cmd)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     unsigned int op_id;
> > +
> > +     nfc->buf = NULL;
> > +     nfc->len = 0;
> > +     nfc->rdy_timeout = 0;
> > +
> > +     for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> > +             const struct nand_op_instr *instr = &subop->instrs[op_id];
> > +             unsigned int offset, naddrs;
> > +             const u8 *addrs;
> > +
> > +             switch (instr->type) {
> > +             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];

> > +
> > +                     nfc->data->parse_address(chip, addrs, naddrs, cmd);
> > +                     /* set NAND address */
> > +                     nand_writel(nfc, NAND_ADDR1, nfc->addr1_reg);
> > +                     nand_writel(nfc, NAND_ADDR2, nfc->addr2_reg);
> > +                     break;
> > +             case NAND_OP_DATA_IN_INSTR:
> > +             case NAND_OP_DATA_OUT_INSTR:
> > +                     offset = nand_subop_get_data_start_off(subop, op_id);
> > +                     nfc->len = nand_subop_get_data_len(subop, op_id);
> > +                     if (instr->type == NAND_OP_DATA_IN_INSTR)
> > +                             nfc->buf =
> > +                                 (void *)instr->ctx.data.buf.in + offset;
> > +                     else if (instr->type == NAND_OP_DATA_OUT_INSTR)
> > +                             nfc->buf =
> > +                                 (void *)instr->ctx.data.buf.out + offset;
>
> The buf pointer feels clunky. You don't know for how long the buffer
> you point to will be valid, please don't do that.
>
The buf pointer is used for DMA transfer afterwards.
I referred to other drivers, and they used the same approach.
https://elixir.bootlin.com/linux/v6.8.9/source/drivers/mtd/nand/raw/arasan-nand-controller.c#L647
https://elixir.bootlin.com/linux/v6.8.9/source/drivers/mtd/nand/raw/rockchip-nand-controller.c#L366

> > +
> > +                     if (cmd & (CMD_READID | CMD_STATUS))
> > +                             break;
> > +
> > +                     if (!IS_ALIGNED((u32)nfc->buf, chip->buf_align)) {
> > +                             dev_err(ls1x->dev,
> > +                                     "nfc->buf %px is not aligned!\n",
> > +                                     nfc->buf);
> > +                             return -EOPNOTSUPP;
> > +                     } else if (!IS_ALIGNED(nfc->len, chip->buf_align)) {
> > +                             dev_err(ls1x->dev,
> > +                                     "nfc->len %u is not aligned!\n",
> > +                                     nfc->len);
> > +                             return -EOPNOTSUPP;
> > +                     }
> > +
> > +                     /* set NAND data length */
> > +                     nand_writel(nfc, NAND_OP_NUM, nfc->len);
> > +
> > +                     if (nfc->data->op_scope_field) {
> > +                             int op_scope = nfc->len << ffs(nfc->data->op_scope_field);
> > +
> > +                             regmap_update_bits(nfc->regmap, NAND_PARAM,
> > +                                                nfc->data->op_scope_field,
> > +                                                op_scope);
> > +                     }
> > +
> > +                     break;
> > +             case NAND_OP_WAITRDY_INSTR:
> > +                     nfc->rdy_timeout = instr->ctx.waitrdy.timeout_ms;
> > +                     break;
> > +             default:
> > +                     break;
> > +             }
> > +     }
> > +
> > +     /* set NAND erase block count */
> > +     if (cmd & CMD_ERASE)
> > +             nand_writel(nfc, NAND_OP_NUM, 1);
> > +     /* set NAND operation region */
> > +     if (nfc->buf && nfc->len)
> > +             cmd |= OP_SPARE | OP_MAIN;
> > +
> > +     /* set NAND command */
> > +     nand_writel(nfc, NAND_CMD, cmd);
> > +     /* Trigger operation */
> > +     regmap_write_bits(nfc->regmap, NAND_CMD, CMD_VALID, CMD_VALID);
> > +
> > +     return 0;
> > +}
> > +
> > +static void ls1x_nand_dma_callback(void *data)
> > +{
> > +     struct ls1x_nand *ls1x = (struct ls1x_nand *)data;
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     enum dma_status status;
> > +
> > +     status = dmaengine_tx_status(nfc->dma_chan, nfc->dma_cookie, NULL);
> > +     if (likely(status == DMA_COMPLETE))
> > +             dev_dbg(ls1x->dev, "DMA complete with cookie=%d\n",
> > +                     nfc->dma_cookie);
> > +     else
> > +             dev_err(ls1x->dev, "DMA error with cookie=%d\n",
> > +                     nfc->dma_cookie);
> > +
> > +     complete(&nfc->dma_complete);
> > +}
> > +
> > +static int ls1x_nand_dma_transfer(struct ls1x_nand *ls1x, bool is_write)
> > +{
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     struct dma_chan *chan = nfc->dma_chan;
> > +     struct dma_async_tx_descriptor *desc;
> > +     enum dma_data_direction data_dir =
> > +         is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
> > +     enum dma_transfer_direction xfer_dir =
> > +         is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
> > +     dma_addr_t dma_addr;
> > +     int ret;
> > +
> > +     dma_addr = dma_map_single(chan->device->dev, nfc->buf, nfc->len,
> > +                               data_dir);
> > +     if (dma_mapping_error(chan->device->dev, dma_addr)) {
> > +             dev_err(ls1x->dev, "failed to map DMA buffer!\n");
> > +             return -ENXIO;
> > +     }
> > +
> > +     desc = dmaengine_prep_slave_single(chan, dma_addr, nfc->len, xfer_dir,
> > +                                        DMA_PREP_INTERRUPT);
> > +     if (!desc) {
> > +             dev_err(ls1x->dev, "failed to prepare DMA descriptor!\n");
> > +             ret = PTR_ERR(desc);
> > +             goto err;
> > +     }
> > +     desc->callback = ls1x_nand_dma_callback;
> > +     desc->callback_param = ls1x;
> > +
> > +     nfc->dma_cookie = dmaengine_submit(desc);
> > +     ret = dma_submit_error(nfc->dma_cookie);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "failed to submit DMA descriptor!\n");
> > +             goto err;
> > +     }
> > +
> > +     dev_dbg(ls1x->dev, "issue DMA with cookie=%d\n", nfc->dma_cookie);
> > +     dma_async_issue_pending(chan);
> > +
> > +     ret = wait_for_completion_timeout(&nfc->dma_complete,
> > +                                       msecs_to_jiffies(nfc->rdy_timeout));
> > +     if (ret <= 0) {
> > +             dev_err(ls1x->dev, "DMA timeout!%u\n", nfc->rdy_timeout);
> > +             dmaengine_terminate_all(chan);
> > +             ret = -EIO;
> > +     }
> > +     ret = 0;
> > +err:
> > +     dma_unmap_single(chan->device->dev, dma_addr, nfc->len, data_dir);
> > +
> > +     return ret;
> > +}
> > +
> > +static inline int ls1x_nand_wait_for_op_done(struct ls1x_nfc *nfc)
> > +{
> > +     unsigned int val;
> > +     int ret = 0;
> > +
> > +     /* Wait for operation done */
> > +     if (nfc->rdy_timeout)
> > +             ret = regmap_read_poll_timeout(nfc->regmap, NAND_CMD, val,
> > +                                            val & OP_DONE, 0,
> > +                                            nfc->rdy_timeout * 1000);
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_reset_exec(struct nand_chip *chip,
> > +                             const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     int ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_RESET);
> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret)
> > +             dev_err(ls1x->dev, "CMD_RESET failed! %d\n", ret);
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_read_id_exec(struct nand_chip *chip,
> > +                               const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     long long idl = 0;
> > +     int i, ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_READID);
> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "CMD_READID failed! %d\n", ret);
> > +             print_hex_dump_debug("REG: ", DUMP_PREFIX_OFFSET, 16, 4,
> > +                                  nfc->reg_base, MAX_DUMP_REGS, false);
> > +             return ret;
> > +     }
> > +
> > +     idl = __be32_to_cpu(nand_readl(nfc, NAND_IDL));
> > +     memset(nfc->buf, 0x0, nfc->len);
> > +
> > +     for (i = 0; i < nfc->len; i++) {
> > +             if (i > 0)
> > +                     nfc->buf[i] = (char)(idl >> (i - 1) * BITS_PER_BYTE);
> > +             else
> > +                     nfc->buf[i] = (char)nand_readl(nfc, NAND_IDH_STATUS);
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_erase_exec(struct nand_chip *chip,
> > +                             const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     int ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_ERASE);
>
> No, you don't know what the command is gonna be, so if your controller
> forces the command opcodes, you need to go through this:
>
> https://elixir.bootlin.com/linux/v6.8.9/source/drivers/mtd/nand/raw/arasan-nand-controller.c#L819
> and
> https://elixir.bootlin.com/linux/v6.8.9/source/drivers/mtd/nand/raw/arasan-nand-controller.c#L940
>
Will change the command forcing to op cmd mapping and add check_op()
accordingly.

> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "CMD_ERASE failed! %d\n", ret);
> > +             print_hex_dump_debug("REG: ", DUMP_PREFIX_OFFSET, 16, 4,
> > +                                  nfc->reg_base, MAX_DUMP_REGS, false);
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_read_exec(struct nand_chip *chip,
> > +                            const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     bool is_write = false;
> > +     int ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_READ);
> > +
> > +     ret = ls1x_nand_dma_transfer(ls1x, is_write);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "CMD_READ failed! %d\n", ret);
> > +             print_hex_dump_debug("REG: ", DUMP_PREFIX_OFFSET, 16, 4,
> > +                                  nfc->reg_base, MAX_DUMP_REGS, false);
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_write_exec(struct nand_chip *chip,
> > +                             const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     bool is_write = true;
> > +     int ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_WRITE);
> > +
> > +     ret = ls1x_nand_dma_transfer(ls1x, is_write);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "CMD_WRITE failed! %d\n", ret);
> > +             print_hex_dump_debug("REG: ", DUMP_PREFIX_OFFSET, 16, 4,
> > +                                  nfc->reg_base, MAX_DUMP_REGS, false);
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_read_status_exec(struct nand_chip *chip,
> > +                                   const struct nand_subop *subop)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     int val, ret;
> > +
> > +     ls1x_nand_set_controller(chip, subop, CMD_STATUS);
> > +
> > +     ret = ls1x_nand_wait_for_op_done(nfc);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "CMD_STATUS failed! %d\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     val = nand_readl(nfc, NAND_IDH_STATUS) & ~nfc->data->status_field;
> > +     nfc->buf[0] = val << ffs(nfc->data->status_field);
> > +
> > +     return ret;
> > +}
> > +
> > +static const struct nand_op_parser ls1x_nand_op_parser = NAND_OP_PARSER(
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_reset_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_read_id_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
> > +             NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 8)),
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_erase_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_read_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> > +             NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 0)),
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_write_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
> > +             NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 0),
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> > +     NAND_OP_PARSER_PATTERN(
> > +             ls1x_nand_read_status_exec,
> > +             NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +             NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 1)),
> > +     );
> > +
> > +static int ls1x_nand_exec_op(struct nand_chip *chip,
> > +                          const struct nand_operation *op, bool check_only)
> > +{
> > +     return nand_op_parser_exec_op(chip, &ls1x_nand_op_parser, op,
> > +                                   check_only);
> > +}
> > +
> > +static int ls1x_nand_attach_chip(struct nand_chip *chip)
> > +{
> > +     struct ls1x_nand *ls1x = nand_get_controller_data(chip);
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     u64 chipsize = nanddev_target_size(&chip->base);
> > +     int cell_size = 0;
> > +
> > +     switch (chipsize) {
> > +     case SZ_128M:
> > +             cell_size = 0x0;
> > +             break;
> > +     case SZ_256M:
> > +             cell_size = 0x1;
> > +             break;
> > +     case SZ_512M:
> > +             cell_size = 0x2;
> > +             break;
> > +     case SZ_1G:
> > +             cell_size = 0x3;
> > +             break;
> > +     case SZ_2G:
> > +             cell_size = 0x4;
> > +             break;
> > +     case SZ_4G:
> > +             cell_size = 0x5;
> > +             break;
> > +     case (SZ_2G * SZ_4G):   /* 8G */
> > +             cell_size = 0x6;
> > +             break;
> > +     case (SZ_4G * SZ_4G):   /* 16G */
>
> Why not SZ_8G and SZ_16G?
>
Will do.

> > +             cell_size = 0x7;
> > +             break;
> > +     default:
> > +             dev_err(ls1x->dev, "unsupported chip size: %llu MB\n",
> > +                     chipsize);
>
> You should error out.
>
Will do.

> > +             break;
> > +     }
> > +
> > +     /* Set cell size */
> > +     regmap_update_bits(nfc->regmap, NAND_PARAM, CELL_SIZE_MASK,
> > +                        FIELD_PREP(CELL_SIZE_MASK, cell_size));
> > +
> > +     regmap_update_bits(nfc->regmap, NAND_TIMING, HOLD_CYCLE_MASK,
> > +                        FIELD_PREP(HOLD_CYCLE_MASK, nfc->data->hold_cycle));
> > +     regmap_update_bits(nfc->regmap, NAND_TIMING, WAIT_CYCLE_MASK,
> > +                        FIELD_PREP(WAIT_CYCLE_MASK, nfc->data->wait_cycle));
> > +
> > +     chip->ecc.read_page_raw = nand_monolithic_read_page_raw;
> > +     chip->ecc.write_page_raw = nand_monolithic_write_page_raw;
>
> I need to further understand this, see other thread.
>
Will drop NAND_MONOLITHIC_READ and implement subpage read instead.

> > +     chip->options |= NAND_MONOLITHIC_READ;
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct nand_controller_ops ls1x_nfc_ops = {
> > +     .exec_op = ls1x_nand_exec_op,
> > +     .attach_chip = ls1x_nand_attach_chip,
> > +};
> > +
> > +static void ls1x_nand_controller_cleanup(struct ls1x_nand *ls1x)
> > +{
> > +     if (ls1x->nfc.dma_chan)
> > +             dma_release_channel(ls1x->nfc.dma_chan);
> > +}
> > +
> > +static int ls1x_nand_controller_init(struct ls1x_nand *ls1x,
> > +                                  struct platform_device *pdev)
> > +{
> > +     struct ls1x_nfc *nfc = &ls1x->nfc;
> > +     struct dma_slave_config cfg;
> > +     int ret;
> > +
> > +     nfc->reg_base = devm_platform_ioremap_resource(pdev, 0);
> > +     if (IS_ERR(nfc->reg_base))
> > +             return PTR_ERR(nfc->reg_base);

> > +
> > +     nfc->regmap = devm_regmap_init_mmio(ls1x->dev, nfc->reg_base,
> > +                                         &ls1x_nand_regmap_config);
> > +     if (IS_ERR(nfc->regmap))
> > +             return dev_err_probe(ls1x->dev, PTR_ERR(nfc->regmap),
> > +                                  "failed to init regmap\n");
> > +
> > +     nfc->dma_chan = dma_request_chan(ls1x->dev, "rxtx");
> > +     if (IS_ERR(nfc->dma_chan))
> > +             return dev_err_probe(ls1x->dev, PTR_ERR(nfc->dma_chan),
> > +                                  "failed to request DMA channel\n");
> > +     dev_info(ls1x->dev, "got %s for %s access\n",
> > +              dma_chan_name(nfc->dma_chan), dev_name(ls1x->dev));
>
> Might be lowered to debug maybe?
>
Will do.

> > +
> > +     cfg.src_addr = CPHYSADDR(nfc->reg_base + NAND_DMA_ADDR);
> > +     cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > +     cfg.dst_addr = CPHYSADDR(nfc->reg_base + NAND_DMA_ADDR);
>
> Doesn't feel right. That shall be a dma_addr_t, not a virtual pointer.
>
Will define a macro for the DMA_ADDR.

> > +     cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > +
> > +     ret = dmaengine_slave_config(nfc->dma_chan, &cfg);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "failed to config DMA channel\n");
> > +             dma_release_channel(nfc->dma_chan);
> > +             return ret;
> > +     }
> > +
> > +     init_completion(&nfc->dma_complete);
> > +
> > +     return 0;
> > +}
> > +
> > +static int ls1x_nand_chip_init(struct ls1x_nand *ls1x)
> > +{
> > +     int nchips = of_get_child_count(ls1x->dev->of_node);
> > +     struct device_node *chip_np;
> > +     struct nand_chip *chip = &ls1x->chip;
> > +     struct mtd_info *mtd = nand_to_mtd(chip);
> > +     int ret = 0;
> > +
> > +     if (nchips != 1)
> > +             return dev_err_probe(ls1x->dev, -EINVAL,
> > +                                  "Currently one NAND chip supported\n");
> > +
> > +     chip_np = of_get_next_child(ls1x->dev->of_node, NULL);
> > +     if (!chip_np)
> > +             return dev_err_probe(ls1x->dev, -ENODEV,
> > +                                  "failed to get child node for NAND chip\n");
> > +
> > +     chip->controller = &ls1x->controller;
> > +     chip->options = NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA | NAND_BROKEN_XD;
> > +     chip->buf_align = 4;
> > +     nand_set_controller_data(chip, ls1x);
> > +     nand_set_flash_node(chip, chip_np);
> > +
> > +     mtd->dev.parent = ls1x->dev;
> > +     mtd->name = "ls1x-nand";
> > +     mtd->owner = THIS_MODULE;
> > +
> > +     ret = nand_scan(chip, 1);
> > +     if (ret) {
> > +             of_node_put(chip_np);
> > +             return ret;
> > +     }
> > +
> > +     ret = mtd_device_register(mtd, NULL, 0);
> > +     if (ret) {
> > +             dev_err(ls1x->dev, "failed to register MTD device! %d\n", ret);
> > +             nand_cleanup(chip);
> > +             of_node_put(chip_np);
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     const struct ls1x_nfc_data *data;
> > +     struct ls1x_nand *ls1x;
> > +     int ret;
> > +
> > +     data = of_device_get_match_data(&pdev->dev);
> > +     if (!data)
> > +             return -ENODEV;
> > +
> > +     ls1x = devm_kzalloc(dev, sizeof(*ls1x), GFP_KERNEL);
> > +     if (!ls1x)
> > +             return -ENOMEM;
> > +
> > +     ls1x->nfc.data = data;
> > +     ls1x->dev = dev;
> > +     ls1x->controller.ops = &ls1x_nfc_ops;
> > +     nand_controller_init(&ls1x->controller);
>
> It would feel more natural to perform the init and then add the ops.
>
Will do.

> > +
> > +     ret = ls1x_nand_controller_init(ls1x, pdev);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = ls1x_nand_chip_init(ls1x);
> > +     if (ret)
> > +             goto err;
> > +
> > +     platform_set_drvdata(pdev, ls1x);
> > +
> > +     return 0;
> > +err:
> > +     ls1x_nand_controller_cleanup(ls1x);
> > +     return ret;
> > +}
> > +
> > +static int ls1x_nand_remove(struct platform_device *pdev)
> > +{
> > +     struct ls1x_nand *ls1x = platform_get_drvdata(pdev);
> > +     struct nand_chip *chip = &ls1x->chip;
> > +     int ret;
> > +
> > +     ret = mtd_device_unregister(nand_to_mtd(chip));
> > +     WARN_ON(ret);
> > +     nand_cleanup(chip);
> > +     ls1x_nand_controller_cleanup(ls1x);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct ls1x_nfc_data ls1b_nfc_data = {
> > +     .status_field = GENMASK(15, 8),
> > +     .hold_cycle = 0x2,
> > +     .wait_cycle = 0xc,
> > +     .parse_address = ls1b_nand_parse_address,
> > +};
> > +
> > +static const struct ls1x_nfc_data ls1c_nfc_data = {
> > +     .status_field = GENMASK(23, 16),
> > +     .op_scope_field = GENMASK(29, 16),
> > +     .hold_cycle = 0x2,
> > +     .wait_cycle = 0xc,
> > +     .parse_address = ls1c_nand_parse_address,
> > +};
> > +
> > +static const struct of_device_id ls1x_nfc_match[] = {
> > +     { .compatible = "loongson,ls1b-nfc", .data = &ls1b_nfc_data },
> > +     { .compatible = "loongson,ls1c-nfc", .data = &ls1c_nfc_data },
> > +     { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, ls1x_nfc_match);
> > +
> > +static struct platform_driver ls1x_nand_driver = {
> > +     .probe  = ls1x_nand_probe,
> > +     .remove = ls1x_nand_remove,
> > +     .driver = {
> > +             .name   = KBUILD_MODNAME,
> > +             .of_match_table = ls1x_nfc_match,
> > +     },
> > +};
> > +
> > +module_platform_driver(ls1x_nand_driver);
> > +
> > +MODULE_AUTHOR("Keguang Zhang <keguang.zhang at gmail.com>");
> > +MODULE_DESCRIPTION("Loongson-1 NAND Controller driver");
> > +MODULE_LICENSE("GPL");
> >
>
>
> Thanks,
> Miquèl

Thanks for your review!

--
Best regards,

Keguang Zhang



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