Re: [PATCH v5 2/2] mtd: rawnand: meson: add support for Amlogic NAND flash controller
From: Boris Brezillon
Date: Thu Oct 18 2018 - 15:33:19 EST
On Thu, 18 Oct 2018 13:09:05 +0800
Jianxin Pan <jianxin.pan@xxxxxxxxxxx> wrote:
> From: Liang Yang <liang.yang@xxxxxxxxxxx>
>
> Add initial support for the Amlogic NAND flash controller which found
> in the Meson-GXBB/GXL/AXG SoCs.
>
> Signed-off-by: Liang Yang <liang.yang@xxxxxxxxxxx>
> Signed-off-by: Yixun Lan <yixun.lan@xxxxxxxxxxx>
> Signed-off-by: Jianxin Pan <jianxin.pan@xxxxxxxxxxx>
> ---
> drivers/mtd/nand/raw/Kconfig | 10 +
> drivers/mtd/nand/raw/Makefile | 1 +
> drivers/mtd/nand/raw/meson_nand.c | 1370 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 1381 insertions(+)
> create mode 100644 drivers/mtd/nand/raw/meson_nand.c
>
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index c7efc31..223b041 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -541,4 +541,14 @@ config MTD_NAND_TEGRA
> is supported. Extra OOB bytes when using HW ECC are currently
> not supported.
>
> +config MTD_NAND_MESON
> + tristate "Support for NAND controller on Amlogic's Meson SoCs"
> + depends on ARCH_MESON || COMPILE_TEST
> + depends on COMMON_CLK_AMLOGIC
> + select COMMON_CLK_REGMAP_MESON
> + select MFD_SYSCON
> + help
> + Enables support for NAND controller on Amlogic's Meson SoCs.
> + This controller is found on Meson GXBB, GXL, AXG SoCs.
> +
> endif # MTD_NAND
> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> index 57159b3..a2cc2fe 100644
> --- a/drivers/mtd/nand/raw/Makefile
> +++ b/drivers/mtd/nand/raw/Makefile
> @@ -56,6 +56,7 @@ 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
> +obj-$(CONFIG_MTD_NAND_MESON) += meson_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/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> new file mode 100644
> index 0000000..bcaac53
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -0,0 +1,1370 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson Nand Flash Controller Driver
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Liang Yang <liang.yang@xxxxxxxxxxx>
> + */
> +
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/iopoll.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +
> +#define NFC_REG_CMD 0x00
> +#define NFC_CMD_DRD (0x8 << 14)
> +#define NFC_CMD_IDLE (0xc << 14)
> +#define NFC_CMD_DWR (0x4 << 14)
> +#define NFC_CMD_CLE (0x5 << 14)
> +#define NFC_CMD_ALE (0x6 << 14)
> +#define NFC_CMD_ADL ((0 << 16) | (3 << 20))
> +#define NFC_CMD_ADH ((1 << 16) | (3 << 20))
> +#define NFC_CMD_AIL ((2 << 16) | (3 << 20))
> +#define NFC_CMD_AIH ((3 << 16) | (3 << 20))
> +#define NFC_CMD_SEED ((8 << 16) | (3 << 20))
> +#define NFC_CMD_M2N ((0 << 17) | (2 << 20))
> +#define NFC_CMD_N2M ((1 << 17) | (2 << 20))
> +#define NFC_CMD_RB BIT(20)
> +#define NFC_CMD_IO6 ((0xb << 10) | (1 << 18))
> +
> +#define NFC_REG_CFG 0x04
> +#define NFC_REG_DADR 0x08
> +#define NFC_REG_IADR 0x0c
> +#define NFC_REG_BUF 0x10
> +#define NFC_REG_INFO 0x14
> +#define NFC_REG_DC 0x18
> +#define NFC_REG_ADR 0x1c
> +#define NFC_REG_DL 0x20
> +#define NFC_REG_DH 0x24
> +#define NFC_REG_CADR 0x28
> +#define NFC_REG_SADR 0x2c
> +#define NFC_REG_PINS 0x30
> +#define NFC_REG_VER 0x38
> +
> +#define NFC_RB_IRQ_EN BIT(21)
> +#define NFC_INT_MASK (3 << 20)
> +
> +#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages) \
> + ( \
> + (cmd_dir) | \
> + ((ran) << 19) | \
> + ((bch) << 14) | \
> + ((short_mode) << 13) | \
> + (((page_size) & 0x7f) << 6) | \
> + ((pages) & 0x3f) \
> + )
> +
> +#define GENCMDDADDRL(adl, addr) ((adl) | ((addr) & 0xffff))
> +#define GENCMDDADDRH(adh, addr) ((adh) | (((addr) >> 16) & 0xffff))
> +#define GENCMDIADDRL(ail, addr) ((ail) | ((addr) & 0xffff))
> +#define GENCMDIADDRH(aih, addr) ((aih) | (((addr) >> 16) & 0xffff))
> +
> +#define RB_STA(x) (1 << (26 + (x)))
> +#define DMA_DIR(dir) ((dir) ? NFC_CMD_N2M : NFC_CMD_M2N)
> +
> +#define ECC_CHECK_RETURN_FF (-1)
> +
> +#define NAND_CE0 (0xe << 10)
> +#define NAND_CE1 (0xd << 10)
> +
> +#define DMA_BUSY_TIMEOUT 0x100000
> +#define CMD_FIFO_EMPTY_TIMEOUT 1000
> +
> +#define MAX_CE_NUM 2
> +
> +/* eMMC clock register, misc control */
> +#define SD_EMMC_CLOCK 0x00
> +#define CLK_ALWAYS_ON BIT(28)
> +#define CLK_SELECT_NAND BIT(31)
> +#define CLK_DIV_MASK GENMASK(5, 0)
> +
> +#define NFC_CLK_CYCLE 6
> +
> +/* nand flash controller delay 3 ns */
> +#define NFC_DEFAULT_DELAY 3000
> +
> +#define MAX_ECC_INDEX 10
> +
> +#define MUX_CLK_NUM_PARENTS 2
> +
> +#define ROW_ADDER(page, index) (((page) >> (8 * (index))) & 0xff)
> +#define MAX_CYCLE_ROW_ADDRS 3
> +#define MAX_CYCLE_COLUMN_ADDRS 2
> +#define DIRREAD 1
> +#define DIRWRITE 0
> +
> +#define ECC_PARITY_BCH8_512B 14
> +
> +struct meson_nfc_info_format {
> + u16 info_bytes;
> +
> + /* bit[5:0] are valid */
> + u8 zero_cnt;
> + struct ecc_sta {
> + u8 eccerr_cnt : 6;
> + u8 notused : 1;
> + u8 completed : 1;
> + } ecc;
It's usually a bad idea to use bitfields for things like HW
regs/descriptors fields because it's hard to tell where the bits are
actually placed (not even sure the C standard defines how this should be
done).
> + u32 reserved;
> +};
How about defining that the HW returns an array of __le64 instead and then
define the following macros which you can use after converting in the
CPU endianness
#define ECC_GET_PROTECTED_OOB_BYTE(x, y) (((x) >> (8 * (1 + y)) & GENMASK(7, 0))
#define ECC_COMPLETE BIT(31)
#define ECC_ERR_CNT(x) (((x) >> 24) & GENMASK(5, 0))
(I'm not entirely sure the field positions are correct, but I'll let you
check that).
> +
> +#define PER_INFO_BYTE (sizeof(struct meson_nfc_info_format))
> +
> +struct meson_nfc_nand_chip {
> + struct list_head node;
> + struct nand_chip nand;
> + bool is_scramble;
I think I already mentioned the NAND_NEED_SCRAMBLING flag []. Please
drop this field and test (chip->flags & NAND_NEED_SCRAMBLING) instead.
> + int bch_mode;
> + int nsels;
> + u8 sels[0];
> +};
> +
> +struct meson_nand_ecc {
> + int bch;
> + int strength;
> +};
> +
> +struct meson_nfc_data {
> + const struct nand_ecc_caps *ecc_caps;
> +};
> +
> +struct meson_nfc_param {
> + int chip_select;
> + int rb_select;
> +};
> +
> +struct nand_rw_cmd {
> + int cmd0;
> + int col[MAX_CYCLE_COLUMN_ADDRS];
> + int row[MAX_CYCLE_ROW_ADDRS];
> + int cmd1;
> +};
> +
> +struct nand_timing {
> + int twb;
> + int tadl;
> + int twhr;
> +};
> +
> +struct meson_nfc {
> + struct nand_controller controller;
> + struct clk *core_clk;
> + struct clk *device_clk;
> + struct clk *phase_tx;
> + struct clk *phase_rx;
> +
> + struct device *dev;
> + void __iomem *reg_base;
> + struct regmap *reg_clk;
> + struct completion completion;
> + struct list_head chips;
> + const struct meson_nfc_data *data;
> + struct meson_nfc_param param;
> + struct nand_timing timing;
> + union {
> + int cmd[32];
> + struct nand_rw_cmd rw;
> + } cmdfifo;
> +
> + dma_addr_t data_dma;
> + dma_addr_t info_dma;
> +
> + unsigned long assigned_cs;
> +
> + u8 *data_buf;
> + u8 *info_buf;
> +};
> +
> +enum {
> + NFC_ECC_BCH8_1K = 2,
> + NFC_ECC_BCH24_1K,
> + NFC_ECC_BCH30_1K,
> + NFC_ECC_BCH40_1K,
> + NFC_ECC_BCH50_1K,
> + NFC_ECC_BCH60_1K,
> +};
> +
> +#define MESON_ECC_DATA(b, s) { .bch = (b), .strength = (s)}
> +
> +static int meson_nand_calc_ecc_bytes(int step_size, int strength)
> +{
> + int ecc_bytes;
> +
> + if (step_size == 512 && strength == 8)
> + return ECC_PARITY_BCH8_512B;
> +
> + ecc_bytes = DIV_ROUND_UP(strength * fls(step_size * 8), 8);
> + if (ecc_bytes % 2)
> + ecc_bytes++;
Just a tiny detail, but this can be replaced by ALIGN(ecc_bytes, 2).
> +
> + return ecc_bytes;
> +}
> +
> +NAND_ECC_CAPS_SINGLE(meson_gxl_ecc_caps,
> + meson_nand_calc_ecc_bytes, 1024, 8, 24, 30, 40, 50, 60);
> +NAND_ECC_CAPS_SINGLE(meson_axg_ecc_caps,
> + meson_nand_calc_ecc_bytes, 1024, 8);
> +
> +static inline
> +struct meson_nfc_nand_chip *to_meson_nand(struct nand_chip *nand)
> +{
> + return container_of(nand, struct meson_nfc_nand_chip, nand);
> +}
> +
> +static void meson_nfc_select_chip(struct nand_chip *nand, int chip)
> +{
> + struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> + struct meson_nfc *nfc = nand_get_controller_data(nand);
> +
> + if (chip < 0 || chip > MAX_CE_NUM)
You can add a WARN_ON_ONCE() around chip > MAX_CE_NUM, because this should
never happen.
> + return;
> +
> + nfc->param.chip_select = meson_chip->sels[chip] ? NAND_CE1 : NAND_CE0;
> + nfc->param.rb_select = nfc->param.chip_select;
> +}
> +
> +static inline void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
> +{
> + writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
> + nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static inline void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
> +{
> + writel(NFC_CMD_SEED | (0xc2 + (seed & 0x7fff)),
> + nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static void meson_nfc_cmd_access(struct meson_nfc *nfc,
> + struct mtd_info *mtd, int raw, bool dir)
Just pass a nand_chip or a meson_nfc_nand_chip object here, nfc and mtd
can be extracted from there.
> +{
> + struct nand_chip *nand = mtd_to_nand(mtd);
> + struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> + u32 cmd, pagesize, pages;
> + int bch = meson_chip->bch_mode;
> + int len = mtd->writesize;
> + int scramble = meson_chip->is_scramble ? 1 : 0;
> +
> + pagesize = nand->ecc.size;
> +
> + if (raw) {
> + bch = NAND_ECC_NONE;
You set bch to NAND_ECC_NONE but never use the variable afterwards, is
that normal?
> + len = mtd->writesize + mtd->oobsize;
> + cmd = (len & 0x3fff) | (scramble << 19) | DMA_DIR(dir);
Please use a macro to describe bit 19:
#define NFC_CMD_SCRAMBLER_ENABLE BIT(19)
> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> + return;
> + }
> +
> + pages = len / nand->ecc.size;
> +
> + cmd = CMDRWGEN(DMA_DIR(dir), scramble, bch, 0, pagesize, pages);
> +
> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static inline void meson_nfc_drain_cmd(struct meson_nfc *nfc)
> +{
> + /*
> + * Insert two commands to make sure all valid commands are finished.
> + *
> + * The Nand flash controller is designed as two stages pipleline -
> + * a) fetch and b) excute.
> + * There might be cases when the driver see command queue is empty,
> + * but the Nand flash controller still has two commands buffered,
> + * one is fetched into NFC request queue (ready to run), and another
> + * is actively executing. So pushing 2 "IDLE" commands guarantees that
> + * the pipeline is emptied.
> + */
> + meson_nfc_cmd_idle(nfc, 0);
> + meson_nfc_cmd_idle(nfc, 0);
> +}
> +
> +static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
> + unsigned int timeout_ms)
> +{
> + u32 cmd_size = 0;
> + int ret;
> +
> + /* wait cmd fifo is empty */
> + ret = readl_poll_timeout(nfc->reg_base + NFC_REG_CMD, cmd_size,
> + !((cmd_size >> 22) & 0x1f),
Define a macro to extract the cmd_size:
#define NFC_CMD_GET_SIZE(x) (((x) >> 22) & GENMASK(4, 0))
> + 10, timeout_ms * 1000);
> + if (ret)
> + dev_err(nfc->dev, "wait for empty cmd FIFO time out\n");
> +
> + return ret;
> +}
> +
> +static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
> +{
> + meson_nfc_drain_cmd(nfc);
> +
> + return meson_nfc_wait_cmd_finish(nfc, DMA_BUSY_TIMEOUT);
> +}
> +
> +static inline
> +struct meson_nfc_info_format *nfc_info_ptr(struct meson_nfc *nfc,
> + int index)
> +{
> + return (struct meson_nfc_info_format *)&nfc->info_buf[index * 8];
As said previously, I think ->info_buf should be an array of __le64, and
all you should do here is
return le64_to_cpu(nfc->info_buf[index]);
Then you can use the macros defined above to extract the results you
need.
> +}
> +
> +static u8 *meson_nfc_oob_ptr(struct meson_nfc *nfc,
> + struct mtd_info *mtd, int i)
> +{
> + struct nand_chip *nand = mtd_to_nand(mtd);
> + int len;
> +
> + len = nand->ecc.size * (i + 1) + (nand->ecc.bytes + 2) * i;
> +
> + return nfc->data_buf + len;
> +}
> +
> +static u8 *meson_nfc_data_ptr(struct meson_nfc *nfc,
> + struct mtd_info *mtd, int i)
> +{
> + struct nand_chip *nand = mtd_to_nand(mtd);
> + int len;
> + int temp;
> +
> + temp = nand->ecc.size + nand->ecc.bytes;
> + len = (temp + 2) * i;
> +
> + return nfc->data_buf + len;
> +}
> +
> +static void meson_nfc_prase_data_oob(struct meson_nfc *nfc,
What does prase mean? Maybe _set_ and _get_ would be better that _prase_
and _format_.
> + struct mtd_info *mtd, u8 *buf, u8 *oobbuf)
As said previously, please stop passing mtd objects around. Same goes
for nfc if you already have to pass a nand_chip object.
> +{
> + struct nand_chip *nand = mtd_to_nand(mtd);
> + int i, oob_len = 0;
> + u8 *dsrc, *osrc;
> +
> + for (i = 0; i < mtd->writesize / nand->ecc.size; i++) {
You have ecc->steps for that, no need to do the division everytime.
> + if (buf) {
> + dsrc = meson_nfc_data_ptr(nfc, mtd, i);
> + memcpy(buf, dsrc, nand->ecc.size);
> + buf += nand->ecc.size;
> + }
> + oob_len = nand->ecc.bytes + 2;
Looks like oob_len does not change, so you can move the oob_len
assignment outside of this loop.
> + osrc = meson_nfc_oob_ptr(nfc, mtd, i);
> + memcpy(oobbuf, osrc, oob_len);
> + oobbuf += oob_len;
> + }
> +}
> +
> +static void meson_nfc_format_data_oob(struct meson_nfc *nfc,
> + struct mtd_info *mtd,
> + const u8 *buf, u8 *oobbuf)
> +{
> + struct nand_chip *nand = mtd_to_nand(mtd);
> + int i, oob_len = 0;
> + u8 *dsrc, *osrc;
> +
> + for (i = 0; i < mtd->writesize / nand->ecc.size; i++) {
> + if (buf) {
> + dsrc = meson_nfc_data_ptr(nfc, mtd, i);
> + memcpy(dsrc, buf, nand->ecc.size);
> + buf += nand->ecc.size;
> + }
> + oob_len = nand->ecc.bytes + 2;
> + osrc = meson_nfc_oob_ptr(nfc, mtd, i);
> + memcpy(osrc, oobbuf, oob_len);
> + oobbuf += oob_len;
> + }
> +}
> +
> +static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
> +{
> + u32 cmd, cfg;
> + int ret = 0;
> +
> + meson_nfc_cmd_idle(nfc, nfc->timing.twb);
> + meson_nfc_drain_cmd(nfc);
> + meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
> +
> + cfg = readl(nfc->reg_base + NFC_REG_CFG);
> + cfg |= (1 << 21);
> + writel(cfg, nfc->reg_base + NFC_REG_CFG);
> +
> + init_completion(&nfc->completion);
> +
> + cmd = NFC_CMD_RB | (0x1 << 14) | nfc->param.chip_select | 0x18;
Please define macros for all those magic values (0x18 and 1 << 14)
> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> + ret = wait_for_completion_timeout(&nfc->completion,
> + msecs_to_jiffies(timeout_ms));
> + if (ret == 0) {
> + dev_err(nfc->dev, "wait nand irq timeout\n");
> + ret = -1;
-ETIMEDOUT;
> + }
> + return ret;
> +}
> +
> +static void meson_nfc_set_user_byte(struct mtd_info *mtd,
> + struct nand_chip *chip, u8 *oob_buf)
> +{
> + struct meson_nfc *nfc = nand_get_controller_data(chip);
> + struct meson_nfc_info_format *info;
> + int i, count;
> +
> + for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
> + info = nfc_info_ptr(nfc, i);
> + info->info_bytes =
> + oob_buf[count] | (oob_buf[count + 1] << 8);
Use a macro to set/get protected OOB bytes.
> + }
> +}
> +