Subject: Re: [PATCH v12 2/8] mtd: rawnand: rockchip: NFC drivers for RK3308, RK2928 and others

From: Johan Jonker <[email-masked]>
Date: Fri, 23 Oct 2020 17:28:09 +0200

Hi,

Hope that I have the text and the brackets right now. ;)
Let us know if something is in need for improvement.

() Parentheses or round brackets
{} Braces or curly brackets
[] Brackets or square brackets
<> Chevrons or angle brackets

On 10/23/20 12:11 PM, 赵仪峰 wrote:
> Hi  Miquèl and Johan,
> 
> I've fixed some comments, but there are still a few points I can`t understand.
> 
>> Hi Yifeng, Miquèl and others,
>>
>> I've copied some comments from Miquèl from version 8 to this one here
>> and added some more. ;)
>>
>>
>> On 10/20/20 5:17 AM, Yifeng Zhao wrote:
>>> This driver supports Rockchip NFC (NAND Flash Controller) found on RK3308,
>>> RK2928, RKPX30, RV1108 and other SOCs. The driver has been tested using
>>> 8-bit NAND interface on the ARM based RK3308 platform.
>>>
>>> Support Rockchip SoCs and NFC versions:
>>> - PX30 and RK3326(NFCv900).
>>> ECC: 16/40/60/70 bits/1KB.
>>> CLOCK: ahb and nfc.
>>> - RK3308 and RV1108(NFCv800).
>>> ECC: 16 bits/1KB.
>>> CLOCK: ahb and nfc.
>>> - RK3036 and RK3128(NFCv622).
>>> ECC: 16/24/40/60 bits/1KB.
>>> CLOCK: ahb and nfc.
>>> - RK3066, RK3188 and RK2928(NFCv600).
>>> ECC: 16/24/40/60 bits/1KB.
>>> CLOCK: ahb.
>>>
>>> Supported features:
>>> - Read full page data by DMA.
>>> - Support HW ECC(one step is 1KB).
>>> - Support 2 - 32K page size.
>>> - Support 8 CS(depend on SoCs)
>>>
>>> Limitations:
>>> - No support for the ecc step size is 512.
>>> - Untested on some SoCs.
>>> - No support for subpages.
>>> - No support for the builtin randomizer.
>>> - The original bad block mask is not supported. It is recommended to use
>>>    the BBT(bad block table).
>>>
>>> Signed-off-by: Yifeng Zhao <[email-masked]>
>>> ---
>>>
>>> (no changes since v11)
>>>
>>> Changes in v11:
>>> - Fix compile error.
>>>
>>> Changes in v10:
>>> - Fix compile error on master v5.9-rc7.
>>>
>>> Changes in v9:
>>> - The nfc->buffer will realloc while the page size of the second mtd
>>>    is large than the first one
>>> - Fix coding style.
>>> - Remove struct rk_nfc_clk.
>>> - Prepend some function with rk_nfc_.
>>> - Replace function readl_poll_timeout_atomic with
>> readl_relaxed_poll_timeout.
>>> - Remove function rk_nfc_read_byte and rk_nfc_write_byte.
>>> - Don't select the die if 'check_only == true' in function rk_nfc_exec_op.
>>> - Modify function rk_nfc_write_page and rk_nfc_write_page_raw.
>>>
>>> Changes in v7:
>>> - Rebase to linux-next.
>>> - Fix coding style.
>>> - Reserved 4 bytes at the beginning of the oob area.
>>> - Page raw read and write included ecc data.
>>>
>>> Changes in v6:
>>> - The mtd->name set by NAND label property.
>>> - Add some comments.
>>> - Fix compile error.
>>>
>>> Changes in v5:
>>> - Add boot blocks support  with different ECC for bootROM.
>>> - Rename rockchip-nand.c to rockchip-nand-controller.c.
>>> - Unification of other variable names.
>>> - Remove some compatible define.
>>>
>>> Changes in v4:
>>> - Define platform data structure for the register offsets.
>>> - The compatible define with rkxx_nfc.
>>> - Use SET_SYSTEM_SLEEP_PM_OPS to define PM_OPS.
>>> - Use exec_op instead of legacy hooks.
>>>
>>> Changes in v2:
>>> - Fix compile error.
>>> - Include header files sorted by file name.
>>>
>>>   drivers/mtd/nand/raw/Kconfig                  |   12 +
>>>   drivers/mtd/nand/raw/Makefile                 |    1 +
>>>   .../mtd/nand/raw/rockchip-nand-controller.c   | 1439 +++++++++++++++++
>>>   3 files changed, 1452 insertions(+)
>>>   create mode 100644 drivers/mtd/nand/raw/rockchip-nand-controller.c
>>>
>>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>>> index 6c46f25b57e2..2cc533e4e239 100644
>>> --- a/drivers/mtd/nand/raw/Kconfig
>>> +++ b/drivers/mtd/nand/raw/Kconfig
>>> @@ -462,6 +462,18 @@ config MTD_NAND_ARASAN
>>>     Enables the driver for the Arasan NAND flash controller on
>>>     Zynq Ultrascale+ MPSoC.
>>>
>>> +config MTD_NAND_ROCKCHIP
>>> +	tristate "Rockchip NAND controller"
>>> +	depends on ARCH_ROCKCHIP && HAS_IOMEM
>>> +	help
>>> +	  Enables support for NAND controller on Rockchip SoCs.
>>> +	  There are four different versions of NAND FLASH Controllers,
>>> +	  including:
>>> +	    NFC v600: RK2928, RK3066, RK3188
>>> +	    NFC v622: RK3036, RK3128
>>> +	    NFC v800: RK3308, RV1108
>>> +	    NFC v900: PX30, RK3326
>>> +
>>>   comment "Misc"
>>>
>>>   config MTD_SM_COMMON
>>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>>> index 2930f5b9015d..960c9be25204 100644
>>> --- a/drivers/mtd/nand/raw/Makefile
>>> +++ b/drivers/mtd/nand/raw/Makefile
>>> @@ -58,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_STM32_FMC2)	+= stm32_fmc2_nand.o
>>>   obj-$(CONFIG_MTD_NAND_MESON)	+= meson_nand.o
>>>   obj-$(CONFIG_MTD_NAND_CADENCE)	+= cadence-nand-controller.o
>>>   obj-$(CONFIG_MTD_NAND_ARASAN)	+= arasan-nand-controller.o
>>> +obj-$(CONFIG_MTD_NAND_ROCKCHIP)	+= rockchip-nand-controller.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/rockchip-nand-controller.c
>> b/drivers/mtd/nand/raw/rockchip-nand-controller.c
>>> new file mode 100644
>>> index 000000000000..cf28c5936209
>>> --- /dev/null
>>> +++ b/drivers/mtd/nand/raw/rockchip-nand-controller.c
>>> @@ -0,0 +1,1439 @@
>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>>> +/*
>>> + * Rockchip NAND Flash controller driver.
>>> + * Copyright (C) 2020 Rockchip Inc.
>>> + * Author: Yifeng Zhao <[email-masked]>
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/dma-mapping.h>
>>> +#include <linux/dmaengine.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/iopoll.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mtd/mtd.h>
>>> +#include <linux/mtd/rawnand.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/slab.h>
>>> +
>>> +/*
>>> + * NFC Page Data Layout:
>>> + *	1024 Bytes Data + 4Bytes sys data + 28Bytes~124Bytes ecc +
>>> + *	1024 Bytes Data + 4Bytes sys data + 28Bytes~124Bytes ecc +
>>> + *	......
>>> + * NAND Page Data Layout:
>>> + *	1024 * n Data + m Bytes oob
>>> + * Original Bad Block Mask Location:
>>> + *	First byte of oob(spare).
>>> + * nand_chip->oob_poi data layout:
>>> + *	4Bytes sys data + .... + 4Bytes sys data + ecc data.
>>> + */
>>> +
>>> +/* NAND controller register definition */
>>> +#define NFC_READ	(0)
>>> +#define NFC_WRITE	(1)
>>> +
>>> +#define NFC_FMCTL	(0x00)
>>> +#define   FMCTL_CE_SEL_M	0xFF
>>> +#define   FMCTL_CE_SEL(x)	(1 << (x))
>>> +#define   FMCTL_WP	BIT(8)
>>> +#define   FMCTL_RDY	BIT(9)
>>> +
>>> +#define NFC_FMWAIT	(0x04)
>>> +#define   FLCTL_RST	BIT(0)
>>> +#define   FLCTL_WR	(1)	/* 0: read, 1: write */
>>> +#define   FLCTL_XFER_ST	BIT(2)
>>> +#define   FLCTL_XFER_EN	BIT(3)
>>> +#define   FLCTL_ACORRECT	BIT(10) /* Auto correct error bits. */
>>> +#define   FLCTL_XFER_READY	BIT(20)
>>> +#define   FLCTL_XFER_SECTOR	(22)
>>> +#define   FLCTL_TOG_FIX	BIT(29)
>>> +
>>> +#define   BCHCTL_BANK_M	(7 << 5)
>>> +#define   BCHCTL_BANK	(5)
>>> +
>>> +#define   DMA_ST	BIT(0)
>>> +#define   DMA_WR	(1)	/* 0: write, 1: read */
>>> +#define   DMA_EN	BIT(2)
>>> +#define   DMA_AHB_SIZE	(3)	/* 0: 1, 1: 2, 2: 4 */
>>> +#define   DMA_BURST_SIZE	(6)	/* 0: 1, 3: 4, 5: 8, 7: 16 */
>>> +#define   DMA_INC_NUM	(9)	/* 1 - 16 */
>>> +
>>> +#define ECC_ERR_CNT(x, e) ((((x) >> (e).low) & (e).low_mask) |\
>>> +	  (((x) >> (e).high) & (e).high_mask) << (e).low_bn)
>>> +#define   INT_DMA	BIT(0)
>>> +#define NFC_BANK	(0x800)
>>> +#define NFC_BANK_STEP	(0x100)
>>> +#define   BANK_DATA	(0x00)
>>> +#define   BANK_ADDR	(0x04)
>>> +#define   BANK_CMD	(0x08)
>>> +#define NFC_SRAM0	(0x1000)
>>> +#define NFC_SRAM1	(0x1400)
>>> +#define NFC_SRAM_SIZE	(0x400)
>>> +#define NFC_TIMEOUT	(500000)
>>> +#define NFC_MAX_OOB_PER_STEP	128
>>> +#define NFC_MIN_OOB_PER_STEP	64
>>> +#define MAX_DATA_SIZE	0xFFFC
>>> +#define MAX_ADDRESS_CYC	6
>>> +#define NFC_ECC_MAX_MODES	4
>>> +#define NFC_MAX_NSELS	(8) /* Some Socs only have 1 or 2 CSs. */
>>> +#define NFC_SYS_DATA_SIZE	(4) /* 4 bytes sys data in oob pre 1024
>> data.*/
>>> +#define RK_DEFAULT_CLOCK_RATE	(150 * 1000 * 1000) /* 150 Mhz */
>>> +#define ACCTIMING(csrw, rwpw, rwcs)	((csrw) << 12 | (rwpw) << 5 | (rwcs))
>>> +
>>> +enum nfc_type {
>>> +	NFC_V6,
>>> +	NFC_V8,
>>> +	NFC_V9,
>>> +};
>>> +
>>> +/**
>>> + * struct rk_ecc_cnt_status: represent a ecc status data.
>>> + * @err_flag_bit: error flag bit index at register.
>>> + * @low: ecc count low bit index at register.
>>> + * @low_mask: mask bit.
>>> + * @low_bn: ecc count low bit number.
>>> + * @high: ecc count high bit index at register.
>>> + * @high_mask: mask bit
>>> + */
>>> +struct ecc_cnt_status {
>>> +	u8 err_flag_bit;
>>> +	u8 low;
>>> +	u8 low_mask;
>>> +	u8 low_bn;
>>> +	u8 high;
>>> +	u8 high_mask;
>>> +};
>>> +
>>> +/*
>>> + * @type: nfc version
>>> + * @ecc_strengths: ecc strengths
>>> + * @ecc_cfgs: ecc config values
>>> + * @flctl_off: FLCTL register offset
>>> + * @bchctl_off: BCHCTL register offset
>>> + * @dma_data_buf_off: DMA_DATA_BUF register offset
>>> + * @dma_oob_buf_off: DMA_OOB_BUF register offset
>>> + * @dma_cfg_off: DMA_CFG register offset
>>> + * @dma_st_off: DMA_ST register offset
>>> + * @bch_st_off: BCG_ST register offset
>>> + * @randmz_off: RANDMZ register offset
>>> + * @int_en_off: interrupt enable register offset
>>> + * @int_clr_off: interrupt clean register offset
>>> + * @int_st_off: interrupt status register offset
>>> + * @oob0_off: oob0 register offset
>>> + * @oob1_off: oob1 register offset
>>> + * @ecc0: represent ECC0 status data
>>> + * @ecc1: represent ECC1 status data
>>> + */
>>> +struct nfc_cfg {
>>> +	enum nfc_type type;
>>> +	u8 ecc_strengths[NFC_ECC_MAX_MODES];
>>> +	u32 ecc_cfgs[NFC_ECC_MAX_MODES];
>>> +	u32 flctl_off;
>>> +	u32 bchctl_off;
>>> +	u32 dma_cfg_off;
>>> +	u32 dma_data_buf_off;
>>> +	u32 dma_oob_buf_off;
>>> +	u32 dma_st_off;
>>> +	u32 bch_st_off;
>>> +	u32 randmz_off;
>>> +	u32 int_en_off;
>>> +	u32 int_clr_off;
>>> +	u32 int_st_off;
>>> +	u32 oob0_off;
>>> +	u32 oob1_off;
>>> +	struct ecc_cnt_status ecc0;
>>> +	struct ecc_cnt_status ecc1;
>>> +};
>>> +
>>> +struct rk_nfc_nand_chip {
>>> +	struct list_head node;
>>> +	struct nand_chip chip;
>>> +
>>> +	u16 spare_per_sector;
>>> +	u16 oob_buf_per_sector;
>>> +	u16 boot_blks;
>>> +	u16 boot_ecc;
>>> +	u16 metadata_size;
>>> +
>>> +	u8 nsels;
>>> +	u8 sels[0];
>>> +	/* Nothing after this field. */
>>> +};
>>> +
>>> +struct rk_nfc {
>>> +	struct nand_controller controller;
>>> +	const struct nfc_cfg *cfg;
>>> +	struct device *dev;
>>> +
>>> +	struct clk *nfc_clk;
>>> +	struct clk *ahb_clk;
>>> +	void __iomem *regs;
>>> +
>>> +	u32 selected_bank;
>>> +	u32 band_offset;
>>> +	u32 cur_clk;
>>> +
>>> +	struct completion done;
>>> +	struct list_head chips;
>>> +
>>> +	u8 *buffer;
>>> +	u8 *page_buf;
>>> +	u32 *oob_buf;
>>> +	u32 buffer_size;
>>> +
>>> +	unsigned long assigned_cs;
>>> +};
>>> +
>>> +static inline struct rk_nfc_nand_chip *to_rknand(struct nand_chip *chip)
> Fixed it.，to_rknand -> rk_nfc_to_rknand
>>> +{
>>> +	return container_of(chip, struct rk_nfc_nand_chip, chip);
>>> +}
>>> +
>>> +static inline u8 *nand_data_ptr(struct nand_chip *chip, const u8 *p,
>> int i)
>>
>> rk_nfc_buf_to_data_ptr ?
>> Comment by Miquèl:
>> Please prepend all your functions with rk_nfc_
>>
>> For the ftrace filters it is needed to have all functions start with
>> the same prefix in a module.
>>
>>
>>> +{
>>> +	return (u8 *)p + i * chip->ecc.size;
>>> +}
>>> +
>>> +static inline u8 *nand_oob_ptr(struct nand_chip *chip, int i)
>>
>> same here
>>> +{
>>> +	u8 *poi;
>>> +
>>> +	poi = chip->oob_poi + i * NFC_SYS_DATA_SIZE;
>>> +
>>> +	return poi;
>>> +}
>>> +
>>> +static inline u8 *nand_oob_ecc_ptr(struct nand_chip *chip, int i)
>>
>> same here
>>> +{
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +	u8 *poi;
>>> +
>>> +	poi = chip->oob_poi + rknand->metadata_size +
>>> +	      chip->ecc.bytes * i;
>>> +
>>> +	return poi;
>>> +}
>>> +
>>> +static inline int rk_nfc_data_len(struct nand_chip *chip)
>>> +{
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +
>>> +	return chip->ecc.size + rknand->spare_per_sector;
>>> +}
>>> +
>>> +static inline u8 *rk_nfc_data_ptr(struct nand_chip *chip,  int i)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +
>>> +	return nfc->buffer + i * rk_nfc_data_len(chip);
>>> +}
>>> +
>>> +static inline u8 *rk_nfc_oob_ptr(struct nand_chip *chip, int i)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +
>>> +	return nfc->buffer + i * rk_nfc_data_len(chip) + chip->ecc.size;
>>> +}
>>> +
>>> +static void rk_nfc_select_chip(struct nand_chip *chip, int cs)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +	u32 val;
>>> +
>>> +	if (cs < 0) {
>>> +	nfc->selected_bank = -1;
>>> +	/* Deselect the currently selected target. */
>>> +	val = readl_relaxed(nfc->regs + NFC_FMCTL);
>>> +	val &= ~FMCTL_CE_SEL_M;
>>> +	writel(val, nfc->regs + NFC_FMCTL);
>>> +	return;
>>> +	}
>>> +
>>> +	nfc->selected_bank = rknand->sels[cs];
>>> +	nfc->band_offset = NFC_BANK + nfc->selected_bank * NFC_BANK_STEP;
>>> +
>>> +	val = readl_relaxed(nfc->regs + NFC_FMCTL);
>>> +	val &= ~FMCTL_CE_SEL_M;
>>> +	val |= FMCTL_CE_SEL(nfc->selected_bank);
>>> +
>>> +	writel(val, nfc->regs + NFC_FMCTL);
>>> +}
>>> +
>>> +static inline int rk_nfc_wait_ioready(struct rk_nfc *nfc)
>>> +{
>>> +	int rc;
>>> +	u32 val;
>>> +
>>> +	rc = readl_relaxed_poll_timeout(nfc->regs + NFC_FMCTL, val,
>>> +	val & FMCTL_RDY, 10, NFC_TIMEOUT);
>>> +
>>> +	return rc;
>>> +}
>>> +
>>> +static void rk_nfc_read_buf(struct rk_nfc *nfc, u8 *buf, int len)
>>> +{
>>> +	int i;
>>> +
>>> +	for (i = 0; i < len; i++)
>>> +	buf[i] = readb_relaxed(nfc->regs + nfc->band_offset +
>>> +	       BANK_DATA);
>>> +}
>>> +
>>> +static void rk_nfc_write_buf(struct rk_nfc *nfc, const u8 *buf, int len)
>>> +{
>>> +	int i;
>>> +
>>> +	for (i = 0; i < len; i++)
>>> +	writeb(buf[i], nfc->regs + nfc->band_offset + BANK_DATA);
>>> +}
>>> +
>>> +static int rk_nfc_cmd(struct nand_chip *chip,
>>> +	      const struct nand_subop *subop)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	unsigned int i, j, remaining, start;
>>> +	int reg_offset = nfc->band_offset;
>>> +	u8 *inbuf = NULL;
>>> +	const u8 *outbuf;
>>> +	u32 cnt = 0;
>>> +	int ret = 0;
>>> +
>>> +	for (i = 0; i < subop->ninstrs; i++) {
>>> +	const struct nand_op_instr *instr = &subop->instrs[i];
>>> +
>>> +	switch (instr->type) {
>>> +	case NAND_OP_CMD_INSTR:
>>> +	writeb(instr->ctx.cmd.opcode,
>>> +	       nfc->regs + reg_offset + BANK_CMD);
>>> +	break;
>>> +
>>> +	case NAND_OP_ADDR_INSTR:
>>> +	remaining = nand_subop_get_num_addr_cyc(subop, i);
>>> +	start = nand_subop_get_addr_start_off(subop, i);
>>> +
>>> +	for (j = 0; j < 8 && j + start < remaining; j++)
>>> +	writeb(instr->ctx.addr.addrs[j + start],
>>> +	       nfc->regs + reg_offset + BANK_ADDR);
>>> +	break;
>>> +
>>> +	case NAND_OP_DATA_IN_INSTR:
>>> +	case NAND_OP_DATA_OUT_INSTR:
>>> +	start = nand_subop_get_data_start_off(subop, i);
>>> +	cnt = nand_subop_get_data_len(subop, i);
>>> +
>>> +	if (instr->type == NAND_OP_DATA_OUT_INSTR) {
>>> +	outbuf = instr->ctx.data.buf.out + start;
>>> +	rk_nfc_write_buf(nfc, outbuf, cnt);
>>> +	} else {
>>> +	inbuf = instr->ctx.data.buf.in + start;
>>> +	rk_nfc_read_buf(nfc, inbuf, cnt);
>>> +	}
>>> +	break;
>>> +
>>> +	case NAND_OP_WAITRDY_INSTR:
>>> +	if (rk_nfc_wait_ioready(nfc) < 0) {
>>> +	ret = -ETIMEDOUT;
>>> +	dev_err(nfc->dev, "IO not ready\n");
>>> +	}
>>> +	break;
>>> +	}
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static const struct nand_op_parser rk_nfc_op_parser = NAND_OP_PARSER(
>>> +	NAND_OP_PARSER_PATTERN(
>>> +	rk_nfc_cmd,
>>> +	NAND_OP_PARSER_PAT_CMD_ELEM(true),
>>> +	NAND_OP_PARSER_PAT_ADDR_ELEM(true, MAX_ADDRESS_CYC),
>>> +	NAND_OP_PARSER_PAT_CMD_ELEM(true),
>>> +	NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
>>> +	NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, MAX_DATA_SIZE)),
>>> +	NAND_OP_PARSER_PATTERN(
>>> +	rk_nfc_cmd,
>>> +	NAND_OP_PARSER_PAT_CMD_ELEM(true),
>>> +	NAND_OP_PARSER_PAT_ADDR_ELEM(true, MAX_ADDRESS_CYC),
>>> +	NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, MAX_DATA_SIZE),
>>> +	NAND_OP_PARSER_PAT_CMD_ELEM(true),
>>> +	NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
>>> +);
>>> +
>>> +static int rk_nfc_exec_op(struct nand_chip *chip,
>>> +	  const struct nand_operation *op,
>>> +	  bool check_only)
>>> +{
>>> +	if (!check_only)
>>> +	rk_nfc_select_chip(chip, op->cs);
>>> +
>>> +	return nand_op_parser_exec_op(chip, &rk_nfc_op_parser, op,
>>> +	      check_only);
>>> +}
>>> +
>>> +static int rk_nfc_setup_data_interface(struct nand_chip *chip, int
>> csline,
>>> +	       const struct nand_interface_config *conf)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	const struct nand_sdr_timings *timings;
>>> +	u32 rate, tc2rw, trwpw, trw2c;
>>> +	u32 temp;
>>> +
>>> +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
>>> +	return 0;
>>> +
>>> +	timings = nand_get_sdr_timings(conf);
>>> +	if (IS_ERR(timings))
>>> +	return -EOPNOTSUPP;
>>> +
>>> +	if (IS_ERR(nfc->nfc_clk))
>>> +	rate = clk_get_rate(nfc->ahb_clk);
>>> +	else
>>> +	rate = clk_get_rate(nfc->nfc_clk);
>>> +
>>> +	/* Turn clock rate into kHz. */
>>> +	rate /= 1000;
>>> +
>>> +	tc2rw = 1;
>>> +	trw2c = 1;
>>> +
>>> +	trwpw = max(timings->tWC_min, timings->tRC_min) / 1000;
>>> +	trwpw = DIV_ROUND_UP(trwpw * rate, 1000000);
>>> +
>>> +	temp = timings->tREA_max / 1000;
>>> +	temp = DIV_ROUND_UP(temp * rate, 1000000);
>>> +
>>> +	if (trwpw < temp)
>>> +	trwpw = temp;
>>> +
>>> +	/*
>>> +	* ACCON: access timing control register
>>> +	* -------------------------------------
>>> +	* 31:18: reserved
>>> +	* 17:12: csrw, clock cycles from the falling edge of CSn to the
>>> +	*   falling edge of RDn or WRn
>>> +	* 11:11: reserved
>>> +	* 10:05: rwpw, the width of RDn or WRn in processor clock cycles
>>> +	* 04:00: rwcs, clock cycles from the rising edge of RDn or WRn to the
>>> +	*   rising edge of CSn
>>> +	*/
>>> +	temp = ACCTIMING(tc2rw, trwpw, trw2c);
>>> +	writel(temp, nfc->regs + NFC_FMWAIT);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int rk_nfc_hw_ecc_setup(struct nand_chip *chip,
>>> +	       struct nand_ecc_ctrl *ecc,
>>> +	       uint32_t strength)
>>> +{
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	u32 reg, i;
>>> +
>>> +	for (i = 0; i < NFC_ECC_MAX_MODES; i++) {
>>> +	if (ecc->strength == nfc->cfg->ecc_strengths[i]) {
>>> +	reg = nfc->cfg->ecc_cfgs[i];
>>> +	break;
>>> +	}
>>> +	}
>>> +
>>> +	if (i >= NFC_ECC_MAX_MODES)
>>> +	return -EINVAL;
>>> +
>>> +	writel(reg, nfc->regs + nfc->cfg->bchctl_off);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void rk_nfc_xfer_start(struct rk_nfc *nfc, u8 rw, u8 n_KB,
>>> +	      dma_addr_t dma_data, dma_addr_t dma_oob)
>>> +{
>>> +	u32 dma_reg, fl_reg, bch_reg;
>>> +
>>> +	dma_reg = DMA_ST | ((!rw) << DMA_WR) | DMA_EN | (2 << DMA_AHB_SIZE) |
>>> +	      (7 << DMA_BURST_SIZE) | (16 << DMA_INC_NUM);
>>> +
>>> +	fl_reg = (rw << FLCTL_WR) | FLCTL_XFER_EN | FLCTL_ACORRECT |
>>> +	(n_KB << FLCTL_XFER_SECTOR) | FLCTL_TOG_FIX;
>>> +
>>> +	if (nfc->cfg->type == NFC_V6 || nfc->cfg->type == NFC_V8) {
>>> +	bch_reg = readl_relaxed(nfc->regs + nfc->cfg->bchctl_off);
>>> +	bch_reg = (bch_reg & (~BCHCTL_BANK_M)) |
>>> +	  (nfc->selected_bank << BCHCTL_BANK);
>>> +	writel(bch_reg, nfc->regs + nfc->cfg->bchctl_off);
>>> +	}
>>> +
>>> +	writel(dma_reg, nfc->regs + nfc->cfg->dma_cfg_off);
>>> +	writel((u32)dma_data, nfc->regs + nfc->cfg->dma_data_buf_off);
>>> +	writel((u32)dma_oob, nfc->regs + nfc->cfg->dma_oob_buf_off);
>>> +	writel(fl_reg, nfc->regs + nfc->cfg->flctl_off);
>>> +	fl_reg |= FLCTL_XFER_ST;
>>> +	writel(fl_reg, nfc->regs + nfc->cfg->flctl_off);
>>> +}
>>> +
>>> +static int rk_nfc_wait_for_xfer_done(struct rk_nfc *nfc)
>>> +{
>>> +	void __iomem *ptr;
>>> +	int ret = 0;
>>> +	u32 reg;
>>> +
>>> +	ptr = nfc->regs + nfc->cfg->flctl_off;
>>> +
>>> +	ret = readl_relaxed_poll_timeout(ptr, reg,
>>> +	reg & FLCTL_XFER_READY,
>>> +	10, NFC_TIMEOUT);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int rk_nfc_write_page_raw(struct nand_chip *chip, const u8 *buf,
>>> +	int oob_on, int page)
>>> +{
>>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	int ret = 0;
>>> +	u32 i;
>>> +
>>> +	if (!buf)
>>> +	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
>>> +
>>> +	for (i = 0; i < chip->ecc.steps; i++) {
>>> +	/* Copy data to nfc buffer. */
>>> +	if (buf)
>>> +	memcpy(rk_nfc_data_ptr(chip, i),
>>> +	       nand_data_ptr(chip, buf, i),
>>> +	       chip->ecc.size);
>>
>>> +	/*
>>> +	* The first four bytes of OOB are reserved for the
>>> +	* boot ROM. In some debugging cases, sush as dump
>>
>> such as
>>
>>> +	* data and write back, the last four bytes stored
>>> +	* in OOB need to be write back.
>>
>> such as with a read, erase and write back test
>> these 4 bytes stored in OOB also need to be written back.>>> +	*/
>>> +	if (!i)
>>> +	memcpy(rk_nfc_oob_ptr(chip, i),
>>> +	       nand_oob_ptr(chip, chip->ecc.steps - 1),
>>> +	       NFC_SYS_DATA_SIZE);
>>> +	else
>>> +	memcpy(rk_nfc_oob_ptr(chip, i),
>>> +	       nand_oob_ptr(chip, i - 1),
>>> +	       NFC_SYS_DATA_SIZE);
>>> +	/* Copy ecc data to nfc buffer. */
>>
>> Copy ECC data to the NFC buffer.
>>> +	memcpy(rk_nfc_oob_ptr(chip, i) + NFC_SYS_DATA_SIZE,
>>> +	       nand_oob_ecc_ptr(chip, i),
>>> +	       chip->ecc.bytes);
>>> +	}
>>> +
>>> +	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
>>> +	rk_nfc_write_buf(nfc, buf, mtd->writesize + mtd->oobsize);
>>> +	ret = nand_prog_page_end_op(chip);
>>> +
>>> +	/*
>>> +	* Deselect the currently selected target after ops done,
>>> +	* otherwise the NAND flash will has extra power consumption.
>>
>> will have
>>
>> or use for example:
>>
>> Deselect the currently selected target after the ops is done
>> to reduce the power consumption.
>>
>>> +	*/
>>> +	rk_nfc_select_chip(chip, -1);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int rk_nfc_write_oob(struct nand_chip *chip, int page)
>>> +{
>>> +	return rk_nfc_write_page_raw(chip, NULL, 1, page);
>>> +}
>>> +
>>> +static int rk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
>>> +	   int oob_on, int page)
>>> +{
>>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +	struct nand_ecc_ctrl *ecc = &chip->ecc;
>>> +	int oob_step = (ecc->bytes > 60) ? NFC_MAX_OOB_PER_STEP :
>>> +	NFC_MIN_OOB_PER_STEP;
>>> +	int pages_per_blk = mtd->erasesize / mtd->writesize;
>>> +	int ret = 0, i, boot_rom_mode = 0;
>>> +	dma_addr_t dma_data, dma_oob;
>>> +	u32 reg;
>>> +	u8 *oob;
>>> +
>>> +	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
>>> +
>>> +	memcpy(nfc->page_buf, buf, mtd->writesize);
>>> +
>>> +	/*
>>> +	* The first blocks (4, 8 or 16 depending on the device) are used
>>> +	* by the boot ROM and the first 32 bits of oob need to link to
>>
>> OOB
>>
>>> +	* the next page address in the same block.
>>
>> Add more explanation why:
>>
>> We can't copy OOB directly,
>> because this page address conflicts with the bad block marker (BBM),
>> so we shift all OOB including the BBM with 4 byte positions.
>> As consequence the OOB size then is also reduced with 4 bytes.
>>
>> PA0  PA1  PA2  PA3  | BBM OOB1 OOB2 OOB3 | ...
>>
>> If a NAND is not a boot medium the first 4 bytes are left untouched
>> by writing 0xFF to them.
>>
>> 0xFF 0xFF 0xFF 0xFF | BBM OOB1 OOB2 OOB3 | ...
>>
>>
>> Could you include the above layout to make things more clear?
>>
>>> +	* Config the ECC algorithm supported by the boot ROM.
>>
>> comment by Miquèl:
>>
>> s/Config/Configure/
> 
> modified, please check again...
> /*
>  * The first blocks (4, 8 or 16 depending on the device) are used
>  * by the boot ROM and the first 32 bits of OOB need to link to
>  * the next page address in the same block. We can't copy OOB
>  * directly, because this page address conflicts with the bad block
>  * marker (BBM), so we shift all OOB including the BBM with 4 byte
>  * positions. As consequence the OOB size then is also reduced with
>  * 4 bytes.
>  *   PA0 PA1 PA2 PA3 | BBM OOB1 OOB2 OOB3 | ...
>  * If a NAND is not a boot medium, the first 4 bytes are left untouched
>  * by writing 0xFF to them.
>  *   0xFF 0xFF 0xFF 0xFF | BBM OOB1 OOB2 OOB3 | ...
>  */

/*
 * The first blocks (4, 8 or 16 depending on the device)
 * are used by the boot ROM and the first 32 bits of OOB need to link to
 * the next page address in the same block. We can't directly copy
 * OOB data from the MTD framework, because this page address
 * conflicts for example with the bad block marker (BBM),
 * so we shift all OOB data including the BBM with 4 byte positions.
 * As a consequence the OOB size available to the MTD framework is
 * also reduced with 4 bytes.
 *
 *    PA0  PA1  PA2  PA3 | BBM OOB1 OOB2 OOB3 | ...
 *
 * If a NAND is not a boot medium or the page is not a boot block,
 * the first 4 bytes are left untouched by writing 0xFF to them.
 *
 *   0xFF 0xFF 0xFF 0xFF | BBM OOB1 OOB2 OOB3 | ...
 *
 * Configure the ECC algorithm supported by the boot ROM.
 */

> 
>>
>>> +	*/
>>> +	if ((page < pages_per_blk * rknand->boot_blks) &&
>>> +	    (chip->options & NAND_IS_BOOT_MEDIUM)) {
>>> +	boot_rom_mode = 1;
>>> +	if (rknand->boot_ecc != ecc->strength)
>>> +	rk_nfc_hw_ecc_setup(chip, ecc,
>>> +	    rknand->boot_ecc);
>>> +	}
>>> +
>>> +	for (i = 0; i < ecc->steps; i++) {
>>> +	if (!i) {
>>> +	reg = 0xFFFFFFFF;
>>> +	} else {
>>> +	oob = chip->oob_poi + (i - 1) * NFC_SYS_DATA_SIZE;
>>> +	reg = oob[0] | oob[1] << 8 | oob[2] << 16 |
>>> +	      oob[3] << 24;
>>> +	}
>>> +	if (!i && boot_rom_mode)
>>> +	reg = (page & (pages_per_blk - 1)) * 4;
>>> +
>>> +	if (nfc->cfg->type == NFC_V9)
>>> +	nfc->oob_buf[i] = reg;
>>> +	else

>>> +	nfc->oob_buf[i * oob_step / 4] = reg;

	nfc->oob_buf[i * (oob_step / 4)] = reg;

>>
>> Please use brackets.
> 
> I don't understand this. Can you give an example of how to modify it?
> 
>>> +	}
>>> +
>>> +	dma_data = dma_map_single(nfc->dev, (void *)nfc->page_buf,
>>
>> Do you need this cast?
> 
> Yes, need dma_map_single to get phy_addr and do cache ops.
> 
>>> +	  mtd->writesize, DMA_TO_DEVICE);
>>> +	dma_oob = dma_map_single(nfc->dev, nfc->oob_buf,
>>> +	ecc->steps * oob_step,
>>> +	DMA_TO_DEVICE);
>>> +
>>> +	reinit_completion(&nfc->done);
>>> +	writel(INT_DMA, nfc->regs + nfc->cfg->int_en_off);
>>> +
>>> +	rk_nfc_xfer_start(nfc, NFC_WRITE, ecc->steps, dma_data,
>>> +	  dma_oob);
>>> +	ret = wait_for_completion_timeout(&nfc->done,
>>> +	  msecs_to_jiffies(100));
>>> +	if (!ret)
>>> +	dev_warn(nfc->dev, "write: wait dma done timeout.\n");
>>> +	/*
>>> +	* Whether the DMA transfer is completed or not. The driver
>>> +	* needs to check the NFC`s status register to see if the data
>>> +	* transfer was completed.
>>> +	*/
>>> +	ret = rk_nfc_wait_for_xfer_done(nfc);
>>> +
>>> +	dma_unmap_single(nfc->dev, dma_data, mtd->writesize,
>>> +	DMA_TO_DEVICE);
>>> +	dma_unmap_single(nfc->dev, dma_oob, ecc->steps * oob_step,
>>> +	DMA_TO_DEVICE);
>>> +
>>> +	if (boot_rom_mode && rknand->boot_ecc != ecc->strength)
>>> +	rk_nfc_hw_ecc_setup(chip, ecc, ecc->strength);
>>> +
>>> +	if (ret) {
>>> +	ret = -EIO;
>>> +	dev_err(nfc->dev,
>>> +	"write: wait transfer done timeout.\n");
>>> +	}
>>> +
>>> +	if (ret)
>>> +	return ret;
>>> +
>>> +	ret = nand_prog_page_end_op(chip);
>>> +
>>> +	/*
>>> +	* Deselect the currently selected target after ops done,
>>
>>> +	* otherwise the NAND flash will has extra power consumption.
>>
>> will have
>>
>> or use for example:
>>
>> Deselect the currently selected target after the ops is done
>> to reduce the power consumption.
>>> +	*/
>>> +	rk_nfc_select_chip(chip, -1);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int rk_nfc_read_page_raw(struct nand_chip *chip, u8 *buf, int
>> oob_on,
>>> +	int page)
>>> +{
>>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	int i;
>>> +
>>> +	nand_read_page_op(chip, page, 0, NULL, 0);
>>> +	rk_nfc_read_buf(nfc, nfc->buffer, mtd->writesize + mtd->oobsize);
>>> +
>>> +	/*
>>> +	* Deselect the currently selected target after ops done,
>>
>>> +	* otherwise the NAND flash will has extra power consumption.
>>
>> will have
>>
>> or use for example:
>>
>> Deselect the currently selected target after the ops is done
>> to reduce the power consumption.
>>> +	*/
>>> +	rk_nfc_select_chip(chip, -1);
>>> +
>>> +	for (i = 0; i < chip->ecc.steps; i++) {
>>
>>> +	/*
>>> +	* The first four bytes of OOB are reserved for the
>>> +	* boot ROM. In some debugging cases, sush as dump data
>>
>> such as
>>
>>> +	* and write back, it`s need to read out this four bytes,
>>
>> such as with a read, erase and write back test
>> these 4 bytes also must be saved somewhere,
>>
>>> +	* otherwise this information will be lost during write back.
>>
>> otherwise this information will be lost during a write back.
>>> +	*/
>>> +	if (!i)
>>> +	memcpy(nand_oob_ptr(chip, chip->ecc.steps - 1),
>>> +	       rk_nfc_oob_ptr(chip, i),
>>> +	       NFC_SYS_DATA_SIZE);
>>> +	else
>>> +	memcpy(nand_oob_ptr(chip, i - 1),
>>> +	       rk_nfc_oob_ptr(chip, i),
>>> +	       NFC_SYS_DATA_SIZE);
>>
>>> +	/* Copy ecc data form nfc buffer. */
>>
>> Copy ECC data from the NFC buffer.
>>> +	memcpy(nand_oob_ecc_ptr(chip, i),
>>> +	       rk_nfc_oob_ptr(chip, i) + NFC_SYS_DATA_SIZE,
>>> +	       chip->ecc.bytes);
>>
>>> +	/* Copy data form nfc buffer. */
>>
>> Copy data from the NFC buffer.
>>> +	if (buf)
>>> +	memcpy(nand_data_ptr(chip, buf, i),
>>> +	       rk_nfc_data_ptr(chip, i),
>>> +	       chip->ecc.size);
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int rk_nfc_read_oob(struct nand_chip *chip, int page)
>>> +{
>>> +	return rk_nfc_read_page_raw(chip, NULL, 1, page);
>>> +}
>>> +
>>> +static int rk_nfc_read_page_hwecc(struct nand_chip *chip, u8 *buf,
>> int oob_on,
>>> +	  int page)
>>> +{
>>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +	struct nand_ecc_ctrl *ecc = &chip->ecc;
>>> +	int oob_step = (ecc->bytes > 60) ? NFC_MAX_OOB_PER_STEP :
>>> +	NFC_MIN_OOB_PER_STEP;
>>> +	int pages_per_blk = mtd->erasesize / mtd->writesize;
>>> +	dma_addr_t dma_data, dma_oob;
>>> +	int ret = 0, i, boot_rom_mode = 0;
>>> +	int bitflips = 0, bch_st;
>>> +	u8 *oob;
>>> +	u32 tmp;
>>> +
>>> +	nand_read_page_op(chip, page, 0, NULL, 0);
>>> +
>>> +	dma_data = dma_map_single(nfc->dev, nfc->page_buf,
>>> +	  mtd->writesize,
>>> +	  DMA_FROM_DEVICE);
>>> +	dma_oob = dma_map_single(nfc->dev, nfc->oob_buf,
>>> +	ecc->steps * oob_step,
>>> +	DMA_FROM_DEVICE);
>>> +
>>> +	/*
>>> +	* The first blocks (4, 8 or 16 depending on the device)
>>> +	* are used by the boot ROM.

>>> +	* Config the ECC algorithm supported by the boot ROM.

s/Config/Configure/

Configure the ECC algorithm supported by the boot ROM.

>>> +	*/
>>> +	if ((page < pages_per_blk * rknand->boot_blks) &&
>>> +	    (chip->options & NAND_IS_BOOT_MEDIUM)) {
>>> +	boot_rom_mode = 1;
>>> +	if (rknand->boot_ecc != ecc->strength)
>>> +	rk_nfc_hw_ecc_setup(chip, ecc,
>>> +	    rknand->boot_ecc);
>>> +	}
>>> +
>>> +	reinit_completion(&nfc->done);
>>> +	writel(INT_DMA, nfc->regs + nfc->cfg->int_en_off);
>>> +	rk_nfc_xfer_start(nfc, NFC_READ, ecc->steps, dma_data,
>>> +	  dma_oob);
>>> +	ret = wait_for_completion_timeout(&nfc->done,
>>> +	  msecs_to_jiffies(100));
>>> +	if (!ret)
>>> +	dev_warn(nfc->dev, "read: wait dma done timeout.\n");
>>> +	/*
>>> +	* Whether the DMA transfer is completed or not. The driver
>>> +	* needs to check the NFC`s status register to see if the data
>>> +	* transfer was completed.
>>> +	*/
>>> +	ret = rk_nfc_wait_for_xfer_done(nfc);
>>> +	dma_unmap_single(nfc->dev, dma_data, mtd->writesize,
>>> +	DMA_FROM_DEVICE);
>>> +	dma_unmap_single(nfc->dev, dma_oob, ecc->steps * oob_step,
>>> +	DMA_FROM_DEVICE);
>>> +
>>> +	if (ret) {
>>> +	bitflips = -EIO;
>>> +	dev_err(nfc->dev,
>>> +	"read: wait transfer done timeout.\n");
>>> +	goto out;
>>> +	}
>>> +
>>> +	for (i = 1; i < ecc->steps; i++) {
>>> +	oob = chip->oob_poi + (i - 1) * NFC_SYS_DATA_SIZE;
>>> +	if (nfc->cfg->type == NFC_V9)
>>> +	tmp = nfc->oob_buf[i];
>>> +	else

>>> +	tmp = nfc->oob_buf[i * oob_step / 4];

	tmp = nfc->oob_buf[i * (oob_step / 4)];

>>> +	*oob++ = (u8)tmp;
>>> +	*oob++ = (u8)(tmp >> 8);
>>> +	*oob++ = (u8)(tmp >> 16);
>>> +	*oob++ = (u8)(tmp >> 24);
>>> +	}
>>> +

>>> +	for (i = 0; i < ecc->steps / 2; i++) {
	for (i = 0; i < (ecc->steps / 2); i++) {
>>
>> Brackets here as well please
> 
> I don't understand this. Can you give an example of how to modify it?
> 
>>> +	bch_st = readl_relaxed(nfc->regs +
>>> +	       nfc->cfg->bch_st_off + i * 4);
>>> +	if (bch_st & BIT(nfc->cfg->ecc0.err_flag_bit) ||
>>> +	    bch_st & BIT(nfc->cfg->ecc1.err_flag_bit)) {
>>> +	mtd->ecc_stats.failed++;
>>> +	/* ECC failed, return the minimum number of error bits */
>>> +	bitflips = ecc->strength + 1;
>>
>> Could you explain why:
>>
>> bitflips = -1;
>>
>> changed to:
>>
>> bitflips = ecc->strength + 1;
>>
>>
>> Comment by Miquèl:
>>
>> I think you should return 0.
>>
>> Then the upper layer will check for failures.
>>
>>> +	} else {
>>> +	ret = ECC_ERR_CNT(bch_st, nfc->cfg->ecc0);
>>> +	mtd->ecc_stats.corrected += ret;
>>> +	bitflips = max_t(u32, bitflips, ret);
>>> +
>>> +	ret = ECC_ERR_CNT(bch_st, nfc->cfg->ecc1);
>>> +	mtd->ecc_stats.corrected += ret;
>>> +	bitflips = max_t(u32, bitflips, ret);
>>> +	}
>>> +	}
>>> +out:
>>> +	memcpy(buf, nfc->page_buf, mtd->writesize);
>>> +
>>> +	if (boot_rom_mode && rknand->boot_ecc != ecc->strength)
>>> +	rk_nfc_hw_ecc_setup(chip, ecc, ecc->strength);
>>> +
>>> +	if (bitflips > ecc->strength)
>>> +	dev_err(nfc->dev, "read page: %x ecc error!\n", page);
>>> +
>>> +	/*
>>> +	* Deselect the currently selected target after ops done,
>>
>>> +	* otherwise the NAND flash will has extra power consumption.
>>
>> will have
>>
>> or use for example:
>>
>> Deselect the currently selected target after the ops is done
>> to reduce the power consumption.
>>
>>> +	*/
>>> +	rk_nfc_select_chip(chip, -1);
>>> +
>>> +	return bitflips;
>>> +}
>>> +
>>> +static inline void rk_nfc_hw_init(struct rk_nfc *nfc)
>>> +{
>>> +	/* Disable flash wp. */
>>> +	writel(FMCTL_WP, nfc->regs + NFC_FMCTL);
>>> +	/* Config default timing 40ns at 150 Mhz nfc clock. */
>>> +	writel(0x1081, nfc->regs + NFC_FMWAIT);
>>> +	/* Disable randomizer and DMA. */
>>> +	writel(0, nfc->regs + nfc->cfg->randmz_off);
>>> +	writel(0, nfc->regs + nfc->cfg->dma_cfg_off);
>>> +	writel(FLCTL_RST, nfc->regs + nfc->cfg->flctl_off);
>>> +}
>>> +
>>> +static irqreturn_t rk_nfc_irq(int irq, void *id)
>>> +{
>>> +	struct rk_nfc *nfc = id;
>>> +	u32 sta, ien;
>>> +
>>> +	sta = readl_relaxed(nfc->regs + nfc->cfg->int_st_off);
>>> +	ien = readl_relaxed(nfc->regs + nfc->cfg->int_en_off);
>>> +
>>> +	if (!(sta & ien))
>>> +	return IRQ_NONE;
>>> +
>>> +	writel(sta, nfc->regs + nfc->cfg->int_clr_off);
>>> +	writel(~sta & ien, nfc->regs + nfc->cfg->int_en_off);
>>> +
>>> +	complete(&nfc->done);
>>> +
>>> +	return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int rk_nfc_enable_clk(struct device *dev, struct rk_nfc *nfc)
>>
>> Change function name, because there are 2 clocks.
>>
>> _clks with an s to inform that there are several of them.
>>
>> _clk ==>> _clks
>>
>>> +{
>>> +	int ret;
>>> +
>>> +	if (!IS_ERR(nfc->nfc_clk)) {
>>> +	ret = clk_prepare_enable(nfc->nfc_clk);
>>> +	if (ret) {
>>> +	dev_err(dev, "failed to enable nfc clk\n");
>>> +	return ret;
>>> +	}
>>> +	}
>>> +
>>> +	ret = clk_prepare_enable(nfc->ahb_clk);
>>> +	if (ret) {
>>> +	dev_err(dev, "failed to enable ahb clk\n");
>>> +	if (!IS_ERR(nfc->nfc_clk))
>>> +	clk_disable_unprepare(nfc->nfc_clk);
>>> +	return ret;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void rk_nfc_disable_clk(struct rk_nfc *nfc)
>>
>> Change function name, because there are 2 clocks.
>>
>> ditto
>>
>> _clk ==>> _clks
>>
>>> +{
>>> +	if (!IS_ERR(nfc->nfc_clk))
>>> +	clk_disable_unprepare(nfc->nfc_clk);
>>> +	clk_disable_unprepare(nfc->ahb_clk);
>>> +}
>>> +
>>> +static int rk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
>>> +	struct mtd_oob_region *oob_region)
>>> +{
>>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +
>>> +	if (section)
>>> +	return -ERANGE;
>>> +
>>> +	/*
>>> +	* The beginning of the oob area stores the reserved data for the NFC,
>>
>> OOB area
>>
>>> +	* the size of the reserved data is NFC_SYS_DATA_SIZE bytes.
>>> +	*/
>>> +	oob_region->length = rknand->metadata_size - NFC_SYS_DATA_SIZE - 2;
>>> +	oob_region->offset = NFC_SYS_DATA_SIZE + 2;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int rk_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
>>> +	struct mtd_oob_region *oob_region)
>>> +{
>>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +
>>> +	if (section)
>>> +	return -ERANGE;
>>> +
>>
>>> +	oob_region->offset = rknand->metadata_size;
>>> +	oob_region->length = mtd->oobsize - oob_region->offset;
>>
>> 	oob_region->length = mtd->oobsize - oob_region->offset;
>> 	oob_region->offset = rknand->metadata_size;
>>
>> Keep length and offset in the same sort order as in rk_nfc_ooblayout_free().
> 
> modified:
> oob_region->length = mtd->oobsize - rknand->metadata_size;
> oob_region->offset = rknand->metadata_size;
> 
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct mtd_ooblayout_ops rk_nfc_ooblayout_ops = {
>>> +	.free = rk_nfc_ooblayout_free,
>>> +	.ecc = rk_nfc_ooblayout_ecc,
>>> +};
>>> +
>>> +static int rk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
>>> +{
>>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	struct nand_ecc_ctrl *ecc = &chip->ecc;
>>> +	const u8 *strengths = nfc->cfg->ecc_strengths;
>>> +	u8 max_strength, nfc_max_strength;
>>> +	int i;
>>> +
>>> +	nfc_max_strength = nfc->cfg->ecc_strengths[0];
>>> +	/* If optional dt settings not present. */
>>> +	if (!ecc->size || !ecc->strength ||
>>> +	    ecc->strength > nfc_max_strength) {
>>> +	chip->ecc.size = 1024;
>>> +	ecc->steps = mtd->writesize / ecc->size;
>>> +
>>> +	/*
>>> +	* HW ECC always requests the number of ECC bytes per 1024 byte
>>
>>> +	* blocks. 4 Bytes is oob for sys data.
>>
>> The first 4 OOB bytes are reserved for sys data.
>>> +	*/
>>> +	max_strength = ((mtd->oobsize / ecc->steps) - 4) * 8 /
>>> +	fls(8 * 1024);
>>> +	if (max_strength > nfc_max_strength)
>>> +	max_strength = nfc_max_strength;
>>> +
>>> +	for (i = 0; i < 4; i++) {
>>> +	if (max_strength >= strengths[i])
>>> +	break;
>>> +	}
>>> +
>>> +	if (i >= 4) {
>>> +	dev_err(nfc->dev, "Unsupported ECC strength\n");
>>> +	return -EOPNOTSUPP;
>>> +	}
>>> +
>>> +	ecc->strength = strengths[i];
>>> +	}
>>> +	ecc->steps = mtd->writesize / ecc->size;
>>> +	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
>>> +	/* HW ECC always work with even numbers of ECC bytes. */
>>> +	ecc->bytes = ALIGN(ecc->bytes, 2);
>>> +
>>> +	rk_nfc_hw_ecc_setup(chip, ecc, ecc->strength);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int rk_nfc_attach_chip(struct nand_chip *chip)
>>> +{
>>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>>> +	struct device *dev = mtd->dev.parent;
>>> +	struct rk_nfc *nfc = nand_get_controller_data(chip);
>>> +	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
>>> +	struct nand_ecc_ctrl *ecc = &chip->ecc;
>>> +	u8 *temp_buf;
>>> +	int len, oob_len;
>>> +	int ret;
>>> +
>>> +	if (chip->options & NAND_BUSWIDTH_16) {
>>> +	dev_err(dev, "16 bits bus width not supported");
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	if (ecc->engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
>>> +	return 0;
>>> +
>>> +	ret = rk_nfc_ecc_init(dev, mtd);
>>> +	if (ret)
>>> +	return ret;
>>> +	rknand->spare_per_sector = ecc->bytes + NFC_SYS_DATA_SIZE;
>>> +	rknand->metadata_size = NFC_SYS_DATA_SIZE * ecc->steps;
>>> +
>>> +	if (rknand->metadata_size < NFC_SYS_DATA_SIZE + 2) {
>>> +	dev_err(dev,
>>> +	"Driver needs at least %d bytes of meta data\n",
>>> +	NFC_SYS_DATA_SIZE + 2);
>>> +	return -EIO;
>>> +	}
>>
>>> +	len = mtd->writesize + mtd->oobsize;
>>
>>> +
>>> +	/* Check buffer first, avoid duplicate alloc buffer. */
>>> +	if (nfc->buffer) {
>>> +	if (len > nfc->buffer_size) {
>>
>> Check only for buffer_size.
>> Maybe split in 2. One size variable per buffer.
>> Reorder flow, see example?
>>
>>> +	temp_buf = kzalloc(len, GFP_KERNEL | GFP_DMA);
>>> +	if (!temp_buf)
>>> +	return -ENOMEM;
>>> +	kfree(nfc->buffer);
>>
>> Is there a realloc for kernels or use helper?
>>
>>> +	nfc->buffer = temp_buf;
>>> +	nfc->buffer_size = len;
>>> +
>>> +	oob_len = ecc->steps * NFC_MAX_OOB_PER_STEP;
>>> +	temp_buf = kzalloc(oob_len, GFP_KERNEL | GFP_DMA);
>>> +	if (!temp_buf)
>>> +	return -ENOMEM;
>>> +	kfree(nfc->oob_buf);
>>> +	nfc->oob_buf = (u32 *)temp_buf;
>>> +	}
>>> +	return 0;
>>> +	}
>>> +
>>
>> Example:
>>
>> // Check and resize existing buffer sizes.
>>
>> new_len = mtd->writesize + mtd->oobsize;
>>
>> if (nfc->buffer && new_len > nfc->buffer_size) {
>>   ret = resize(...);
>>   if (!ret)
>>     return -ENOMEM;
>>   nfc->buffer_size = new_len;
>> }
>>
>> new_oob_len = ecc->steps * NFC_MAX_OOB_PER_STEP;
>>
>> if (nfc->oob_buf && new_oob_len > nfc->oob_buffer_size) {
>>   ret = resize(...);
>>   if (!ret) {
>>     free(nfc->buffer);
>>     return -ENOMEM;
>>   }
>>   nfc->oob_buffer_size = new_oob_len;
>> }
>>
>> // If no buffers exists then create new buffers.
>>
>> if (!nfc->buffer) {
>>   ret = kzalloc(...);
>>   if (!ret)
>>     return -ENOMEM;
>>   nfc->buffer_size = new_len;
>> }
>>
>> if (!nfc->oob_buf) {
>>   ret = kzalloc(...);
>>   if (!ret) {
>>     free(nfc->buffer);
>>     return -ENOMEM;
>>   }
>>   nfc->oob_buffer_size = new_oob_len;
>> }
>>
>>
>>> +	nfc->buffer = kzalloc(len, GFP_KERNEL | GFP_DMA);
>>> +	if (!nfc->buffer)
>>> +	return -ENOMEM;
>>
>>
>>> +
>>> +	oob_len = ecc->steps * NFC_MAX_OOB_PER_STEP;
>>> +	nfc->oob_buf = kzalloc(oob_len, GFP_KERNEL | GFP_DMA);
>>> +	if (!nfc->oob_buf) {
>>> +	kfree(nfc->buffer);
>>> +	nfc->buffer = NULL;
>>
>>> +	nfc->oob_buf = NULL;
>>
>> !nfc->oob_buf == (nfc->oob_buf = NULL)
>>
>> Comment from Miquèl:
>> I don't think this is needed
>>
>> If something is NULL then there's no need to set it to NULL again.
>>
>>> +	return -ENOMEM;
>>> +	}
>>> +
>>> +	nfc->buffer_size = len;
>>> +	nfc->page_buf = nfc->buffer;
>>> +
>>> +	chip->ecc.write_page_raw = rk_nfc_write_page_raw;
>>> +	chip->ecc.write_page = rk_nfc_write_page_hwecc;
>>> +	chip->ecc.write_oob_raw = rk_nfc_write_oob;
>>> +	chip->ecc.write_oob = rk_nfc_write_oob;
>>> +
>>> +	chip->ecc.read_page_raw = rk_nfc_read_page_raw;
>>> +	chip->ecc.read_page = rk_nfc_read_page_hwecc;
>>> +	chip->ecc.read_oob_raw = rk_nfc_read_oob;
>>> +	chip->ecc.read_oob = rk_nfc_read_oob;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct nand_controller_ops rk_nfc_controller_ops = {
>>> +	.attach_chip = rk_nfc_attach_chip,
>>> +	.exec_op = rk_nfc_exec_op,
>>> +	.setup_interface = rk_nfc_setup_data_interface,
>>> +};
>>> +
>>> +static int rk_nfc_nand_chip_init(struct device *dev, struct rk_nfc *nfc,
>>> +	struct device_node *np)
>>> +{
>>> +	struct rk_nfc_nand_chip *rknand;
>>> +	struct nand_chip *chip;
>>> +	struct mtd_info *mtd;
>>> +	int nsels;
>>> +	u32 tmp;
>>> +	int ret;
>>> +	int i;
>>> +
>>> +	if (!of_get_property(np, "reg", &nsels))
>>> +	return -ENODEV;
>>> +	nsels /= sizeof(u32);
>>> +	if (!nsels || nsels > NFC_MAX_NSELS) {
>>> +	dev_err(dev, "invalid reg property size %d\n", nsels);
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	rknand = devm_kzalloc(dev, sizeof(*rknand) + nsels * sizeof(u8),
>>> +	      GFP_KERNEL);
>>> +	if (!rknand)
>>> +	return -ENOMEM;
>>> +
>>> +	rknand->nsels = nsels;
>>> +	for (i = 0; i < nsels; i++) {
>>> +	ret = of_property_read_u32_index(np, "reg", i, &tmp);
>>> +	if (ret) {
>>> +	dev_err(dev, "reg property failure : %d\n", ret);
>>> +	return ret;
>>> +	}
>>> +
>>> +	if (tmp >= NFC_MAX_NSELS) {
>>> +	dev_err(dev, "invalid CS: %u\n", tmp);
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
>>> +	dev_err(dev, "CS %u already assigned\n", tmp);
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	rknand->sels[i] = tmp;
>>> +	}
>>> +
>>> +	chip = &rknand->chip;
>>> +	chip->controller = &nfc->controller;
>>> +
>>> +	nand_set_flash_node(chip, np);
>>> +
>>> +	nand_set_controller_data(chip, nfc);
>>> +
>>> +	chip->options |= NAND_USES_DMA | NAND_NO_SUBPAGE_WRITE;
>>> +	chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
>>> +
>>> +	/* Set default mode in case dt entry is missing. */
>>> +	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
>>> +
>>> +	mtd = nand_to_mtd(chip);
>>> +	mtd->owner = THIS_MODULE;
>>> +	mtd->dev.parent = dev;
>>> +
>>> +	if (!mtd->name) {
>>> +	dev_err(nfc->dev, "NAND label property is mandatory\n");
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	mtd_set_ooblayout(mtd, &rk_nfc_ooblayout_ops);
>>> +	rk_nfc_hw_init(nfc);
>>> +	ret = nand_scan(chip, nsels);
>>> +	if (ret)
>>> +	return ret;
>>> +
>>> +	if (chip->options & NAND_IS_BOOT_MEDIUM) {
>>> +	ret = of_property_read_u32(np, "rockchip,boot-blks", &tmp);
>>> +	rknand->boot_blks = ret ? 0 : tmp;
>>
>> Comment by Miquèl:
>> Can't you guess this entry knowing the IP version/SoC version?
>>
>> No, "rockchip,boot-blks" depends on the size of multiple partitions
>> and is user layout dependent.
> 
> The "rockchip,boot-blks" is not a fixed number, can be configured with different number of blocks to store the pre loader
> for the same SoC.
> 
>>> +
>>> +	ret = of_property_read_u32(np, "rockchip,boot-ecc-strength",
>>> +	   &tmp);
>>> +	rknand->boot_ecc = ret ? chip->ecc.strength : tmp;
>>> +	}
>>> +
>>> +	ret = mtd_device_register(mtd, NULL, 0);
>>> +	if (ret) {
>>> +	dev_err(dev, "mtd parse partition error\n");
>>> +	nand_cleanup(chip);
>>> +	return ret;
>>> +	}
>>> +
>>> +	list_add_tail(&rknand->node, &nfc->chips);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void rk_nfc_chips_cleanup(struct rk_nfc *nfc)
>>> +{
>>> +	struct rk_nfc_nand_chip *rknand, *tmp;
>>> +	struct nand_chip *chip;
>>> +	int ret;
>>> +
>>> +	list_for_each_entry_safe(rknand, tmp, &nfc->chips, node) {
>>> +	chip = &rknand->chip;
>>> +	ret = mtd_device_unregister(nand_to_mtd(chip));
>>> +	WARN_ON(ret);
>>> +	nand_cleanup(chip);
>>> +	list_del(&rknand->node);
>>> +	}
>>> +}
>>> +
>>> +static int rk_nfc_nand_chips_init(struct device *dev, struct rk_nfc *nfc)
>>> +{
>>> +	struct device_node *np = dev->of_node, *nand_np;
>>> +	int nchips = of_get_child_count(np);
>>> +	int ret;
>>> +
>>> +	if (!nchips || nchips > NFC_MAX_NSELS) {
>>> +	dev_err(nfc->dev, "Incorrect number of NAND chips (%d)\n",
>>> +	nchips);
>>> +	return -EINVAL;
>>> +	}
>>> +
>>> +	for_each_child_of_node(np, nand_np) {
>>> +	ret = rk_nfc_nand_chip_init(dev, nfc, nand_np);
>>> +	if (ret) {
>>> +	of_node_put(nand_np);
>>> +	rk_nfc_chips_cleanup(nfc);
>>> +	return ret;
>>> +	}
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static struct nfc_cfg nfc_v6_cfg = {
>>> +	.type	= NFC_V6,
>>> +	.ecc_strengths	= {60, 40, 24, 16},
>>> +	.ecc_cfgs	= {
>>> +	0x00040011, 0x00040001, 0x00000011, 0x00000001,
>>> +	},
>>> +	.flctl_off	= 0x08,
>>> +	.bchctl_off	= 0x0C,
>>> +	.dma_cfg_off	= 0x10,
>>> +	.dma_data_buf_off	= 0x14,
>>> +	.dma_oob_buf_off	= 0x18,
>>> +	.dma_st_off	= 0x1C,
>>> +	.bch_st_off	= 0x20,
>>> +	.randmz_off	= 0x150,
>>> +	.int_en_off	= 0x16C,
>>> +	.int_clr_off	= 0x170,
>>> +	.int_st_off	= 0x174,
>>> +	.oob0_off	= 0x200,
>>> +	.oob1_off	= 0x230,
>>> +	.ecc0	= {
>>> +	.err_flag_bit	= 2,
>>> +	.low	= 3,
>>> +	.low_mask	= 0x1F,
>>> +	.low_bn	= 5,
>>> +	.high	= 27,
>>> +	.high_mask	= 0x1,
>>> +	},
>>> +	.ecc1	= {
>>> +	.err_flag_bit	= 15,
>>> +	.low	= 16,
>>> +	.low_mask	= 0x1F,
>>> +	.low_bn	= 5,
>>> +	.high	= 29,
>>> +	.high_mask	= 0x1,
>>> +	},
>>> +};
>>> +
>>> +static struct nfc_cfg nfc_v8_cfg = {
>>> +	.type	= NFC_V8,
>>> +	.ecc_strengths	= {16, 16, 16, 16},
>>> +	.ecc_cfgs	= {
>>> +	0x00000001, 0x00000001, 0x00000001, 0x00000001,
>>> +	},
>>> +	.flctl_off	= 0x08,
>>> +	.bchctl_off	= 0x0C,
>>> +	.dma_cfg_off	= 0x10,
>>> +	.dma_data_buf_off	= 0x14,
>>> +	.dma_oob_buf_off	= 0x18,
>>> +	.dma_st_off	= 0x1C,
>>> +	.bch_st_off	= 0x20,
>>> +	.randmz_off	= 0x150,
>>> +	.int_en_off	= 0x16C,
>>> +	.int_clr_off	= 0x170,
>>> +	.int_st_off	= 0x174,
>>> +	.oob0_off	= 0x200,
>>> +	.oob1_off	= 0x230,
>>> +	.ecc0	= {
>>> +	.err_flag_bit	= 2,
>>> +	.low	= 3,
>>> +	.low_mask	= 0x1F,
>>> +	.low_bn	= 5,
>>> +	.high	= 27,
>>> +	.high_mask	= 0x1,
>>> +	},
>>> +	.ecc1	= {
>>> +	.err_flag_bit	= 15,
>>> +	.low	= 16,
>>> +	.low_mask	= 0x1F,
>>> +	.low_bn	= 5,
>>> +	.high	= 29,
>>> +	.high_mask	= 0x1,
>>> +	},
>>> +};
>>> +
>>> +static struct nfc_cfg nfc_v9_cfg = {
>>> +	.type	= NFC_V9,
>>> +	.ecc_strengths	= {70, 60, 40, 16},
>>> +	.ecc_cfgs	= {
>>> +	0x00000001, 0x06000001, 0x04000001, 0x02000001,
>>> +	},
>>> +	.flctl_off	= 0x10,
>>> +	.bchctl_off	= 0x20,
>>> +	.dma_cfg_off	= 0x30,
>>> +	.dma_data_buf_off	= 0x34,
>>> +	.dma_oob_buf_off	= 0x38,
>>> +	.dma_st_off	= 0x3C,
>>> +	.bch_st_off	= 0x150,
>>> +	.randmz_off	= 0x208,
>>> +	.int_en_off	= 0x120,
>>> +	.int_clr_off	= 0x124,
>>> +	.int_st_off	= 0x128,
>>> +	.oob0_off	= 0x200,
>>> +	.oob1_off	= 0x204,
>>> +	.ecc0	= {
>>> +	.err_flag_bit	= 2,
>>> +	.low	= 3,
>>> +	.low_mask	= 0x7F,
>>> +	.low_bn	= 7,
>>> +	.high	= 0,
>>> +	.high_mask	= 0x0,
>>> +	},
>>> +	.ecc1	= {
>>> +	.err_flag_bit	= 18,
>>> +	.low	= 19,
>>> +	.low_mask	= 0x7F,
>>> +	.low_bn	= 7,
>>> +	.high	= 0,
>>> +	.high_mask	= 0x0,
>>> +	},
>>> +};
>>> +
>>> +static const struct of_device_id rk_nfc_id_table[] = {
>>> +	{
>>> +	.compatible = "rockchip,px30-nfc",
>>> +	.data = &nfc_v9_cfg
>>> +	},
>>> +	{
>>> +	.compatible = "rockchip,rk2928-nfc",
>>> +	.data = &nfc_v6_cfg
>>> +	},
>>> +	{
>>> +	.compatible = "rockchip,rv1108-nfc",
>>> +	.data = &nfc_v8_cfg
>>> +	},
>>> +	{ /* sentinel */ }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, rk_nfc_id_table);
>>> +
>>> +static int rk_nfc_probe(struct platform_device *pdev)
>>> +{
>>> +	struct device *dev = &pdev->dev;
>>> +	struct rk_nfc *nfc;
>>> +	int ret, irq;
>>> +
>>> +	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
>>> +	if (!nfc)
>>> +	return -ENOMEM;
>>> +
>>> +	nand_controller_init(&nfc->controller);
>>> +	INIT_LIST_HEAD(&nfc->chips);
>>> +	nfc->controller.ops = &rk_nfc_controller_ops;
>>> +
>>> +	nfc->cfg = of_device_get_match_data(dev);
>>> +	nfc->dev = dev;
>>> +
>>> +	init_completion(&nfc->done);
>>> +
>>> +	nfc->regs = devm_platform_ioremap_resource(pdev, 0);
>>> +	if (IS_ERR(nfc->regs)) {
>>> +	ret = PTR_ERR(nfc->regs);
>>> +	goto release_nfc;
>>> +	}
>>> +
>>> +	nfc->nfc_clk = devm_clk_get(dev, "nfc");
>>> +	if (IS_ERR(nfc->nfc_clk)) {
>>> +	dev_dbg(dev, "no nfc clk\n");
>>> +	/* Some earlier models, such as rk3066, have no nfc clk. */
>>> +	}
>>> +
>>> +	nfc->ahb_clk = devm_clk_get(dev, "ahb");
>>> +	if (IS_ERR(nfc->ahb_clk)) {
>>> +	dev_err(dev, "no ahb clk\n");
>>> +	ret = PTR_ERR(nfc->ahb_clk);
>>> +	goto release_nfc;
>>> +	}
>>> +
>>> +	ret = rk_nfc_enable_clk(dev, nfc);
>>> +	if (ret)
>>> +	goto release_nfc;
>>> +
>>> +	irq = platform_get_irq(pdev, 0);
>>> +	if (irq < 0) {
>>> +	dev_err(dev, "no nfc irq resource\n");
>>> +	ret = -EINVAL;
>>> +	goto clk_disable;
>>> +	}
>>> +
>>> +	writel(0, nfc->regs + nfc->cfg->int_en_off);
>>> +	ret = devm_request_irq(dev, irq, rk_nfc_irq, 0x0, "rk-nand", nfc);
>>> +	if (ret) {
>>> +	dev_err(dev, "failed to request nfc irq\n");
>>> +	goto clk_disable;
>>> +	}
>>> +
>>> +	platform_set_drvdata(pdev, nfc);
>>> +
>>> +	ret = rk_nfc_nand_chips_init(dev, nfc);
>>> +	if (ret) {
>>> +	dev_err(dev, "failed to init NAND chips\n");
>>> +	goto clk_disable;
>>> +	}
>>> +	return 0;
>>> +
>>> +clk_disable:
>>> +	rk_nfc_disable_clk(nfc);
>>> +release_nfc:
>>> +	return ret;
>>> +}
>>> +
>>> +static int rk_nfc_remove(struct platform_device *pdev)
>>> +{
>>> +	struct rk_nfc *nfc = platform_get_drvdata(pdev);
>>> +
>>> +	kfree(nfc->buffer);
>>> +	kfree(nfc->oob_buf);
>>> +	rk_nfc_chips_cleanup(nfc);
>>> +	rk_nfc_disable_clk(nfc);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int __maybe_unused rk_nfc_suspend(struct device *dev)
>>> +{
>>> +	struct rk_nfc *nfc = dev_get_drvdata(dev);
>>> +
>>> +	rk_nfc_disable_clk(nfc);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int __maybe_unused rk_nfc_resume(struct device *dev)
>>> +{
>>> +	struct rk_nfc *nfc = dev_get_drvdata(dev);
>>> +	struct rk_nfc_nand_chip *rknand;
>>> +	struct nand_chip *chip;
>>> +	int ret;
>>> +	u32 i;
>>> +
>>> +	ret = rk_nfc_enable_clk(dev, nfc);
>>> +	if (ret)
>>> +	return ret;
>>> +
>>> +	/* Reset NAND chip if VCC was powered off. */
>>> +	list_for_each_entry(rknand, &nfc->chips, node) {
>>> +	chip = &rknand->chip;
>>> +	for (i = 0; i < rknand->nsels; i++)
>>> +	nand_reset(chip, i);
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct dev_pm_ops rk_nfc_pm_ops = {
>>> +	SET_SYSTEM_SLEEP_PM_OPS(rk_nfc_suspend, rk_nfc_resume)
>>> +};
>>> +
>>> +static struct platform_driver rk_nfc_driver = {
>>> +	.probe = rk_nfc_probe,
>>> +	.remove = rk_nfc_remove,
>>> +	.driver = {
>>> +	.name = "rockchip-nfc",
>>> +	.of_match_table = rk_nfc_id_table,
>>> +	.pm = &rk_nfc_pm_ops,
>>> +	},
>>> +};
>>> +
>>> +module_platform_driver(rk_nfc_driver);
>>> +
>>> +MODULE_LICENSE("Dual MIT/GPL");
>>> +MODULE_AUTHOR("Yifeng Zhao <[email-masked]>");
>>> +MODULE_DESCRIPTION("Rockchip Nand Flash Controller Driver");
>>> +MODULE_ALIAS("platform:rockchip-nand-controller");
>>>
>>
>>
>>
> 

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