Re: [PATCH 2/2] mtd: rawnand: nuvoton: add new driver for the Nuvoton MA35 SoC

[Hui-Ping Chen <hpchen0nvt@gmail.com>]

Dear Krzysztof,

Thank you for your reply.



On 2024/8/12 下午 02:30, Krzysztof Kozlowski wrote:
> On 12/08/2024 05:00, Hui-Ping Chen wrote:
>> Nuvoton MA35 SoCs NAND Flash Interface Controller
>> supports 2KB, 4KB and 8KB page size, and up to 8-bit,
>> 12-bit, and 24-bit hardware ECC calculation circuit
>> to protect data communication.
>>
>> Signed-off-by: Hui-Ping Chen <hpchen0nvt@gmail.com>
>> ---
>>   drivers/mtd/nand/raw/Kconfig               |    8 +
>>   drivers/mtd/nand/raw/Makefile              |    1 +
>>   drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c | 1109 ++++++++++++++++++++
>>   3 files changed, 1118 insertions(+)
>>   create mode 100644 drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c
>>
>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>> index 614257308516..932bf2215470 100644
>> --- a/drivers/mtd/nand/raw/Kconfig
>> +++ b/drivers/mtd/nand/raw/Kconfig
>> @@ -448,6 +448,14 @@ config MTD_NAND_RENESAS
>>   	  Enables support for the NAND controller found on Renesas R-Car
>>   	  Gen3 and RZ/N1 SoC families.
>>   
>> +config MTD_NAND_NVT_MA35
>> +	tristate "Nuvoton MA35 SoC NAND controller"
>> +	depends on ARCH_MA35 || COMPILE_TEST
>> +	depends on OF
>> +	help
>> +	  Enables support for the NAND controller found on
>> +	  the Nuvoton MA35 series SoCs.
>> +
>>   comment "Misc"
>>   
>>   config MTD_SM_COMMON
>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>> index 25120a4afada..cdfdfee3f5f3 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_NVT_MA35)	+= nuvoton_ma35d1_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/nuvoton_ma35d1_nand.c b/drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c
>> new file mode 100644
>> index 000000000000..7445eb489c38
>> --- /dev/null
>> +++ b/drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c
>> @@ -0,0 +1,1109 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2024 Nuvoton Technology Corp.
>> + */
>> +#include <linux/slab.h>
>> +#include <linux/init.h>
>> +#include <linux/module.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/delay.h>
>> +#include <linux/clk.h>
>> +#include <linux/err.h>
>> +#include <linux/of.h>
>> +
>> +#include <linux/mtd/mtd.h>
>> +#include <linux/mtd/partitions.h>
>> +#include <linux/mtd/rawnand.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/dmaengine.h>
>> +
>> +/* NFI DMA Registers */
>> +#define MA35_NFI_REG_BUFFER0		(0x000)
>> +#define MA35_NFI_REG_DMACTL		(0x400)
>> +#define   DMA_EN				BIT(0)
>> +#define   DMA_RST				BIT(1)
>> +#define   DMA_BUSY				BIT(9)
>> +
>> +#define MA35_NFI_REG_DMASA		(0x408)
>> +#define MA35_NFI_REG_DMABCNT		(0x40C)
>> +#define MA35_NFI_REG_DMAINTEN		(0x410)
>> +#define MA35_NFI_REG_DMAINTSTS	(0x414)
>> +
>> +/* NFI Global Registers */
>> +#define MA35_NFI_REG_GCTL		(0x800)
>> +#define   NAND_EN				BIT(3)
>> +#define MA35_NFI_REG_GINTEN		(0x804)
>> +#define MA35_NFI_REG_GINTSTS		(0x808)
>> +
>> +/* NAND-type Flash Registers */
>> +#define MA35_NFI_REG_NANDCTL		(0x8A0)
>> +#define   SWRST				BIT(0)
>> +#define   DMA_W_EN				BIT(1)
>> +#define   DMA_R_EN				BIT(2)
>> +#define   ECC_CHK				BIT(7)
>> +#define   PROT3BEN				BIT(8)
>> +#define   PSIZE_2K				(1 << 16)
>> +#define   PSIZE_4K				(2 << 16)
>> +#define   PSIZE_8K				(3 << 16)
>> +#define   PSIZE_MASK				(3 << 16)
>> +#define   BCH_T24				BIT(18)
>> +#define   BCH_T8				BIT(20)
>> +#define   BCH_T12				BIT(21)
>> +#define   BCH_MASK				(0x1f << 18)
>> +#define   ECC_EN				BIT(23)
>> +#define   DISABLE_CS0				BIT(25)
>> +
>> +#define MA35_NFI_REG_NANDTMCTL	(0x8A4)
>> +#define MA35_NFI_REG_NANDINTEN	(0x8A8)
>> +#define MA35_NFI_REG_NANDINTSTS	(0x8AC)
>> +#define   INT_DMA				BIT(0)
>> +#define   INT_ECC				BIT(2)
>> +#define   INT_RB0				BIT(10)
>> +#define   INT_RB0_STS				BIT(18)
>> +
>> +#define MA35_NFI_REG_NANDCMD		(0x8B0)
>> +#define MA35_NFI_REG_NANDADDR		(0x8B4)
>> +#define   ENDADDR				BIT(31)
>> +
>> +#define MA35_NFI_REG_NANDDATA		(0x8B8)
>> +#define MA35_NFI_REG_NANDRACTL	(0x8BC)
>> +#define MA35_NFI_REG_NANDECTL		(0x8C0)
>> +#define   ENABLE_WP				(0x0)
>> +#define   DISABLE_WP				BIT(0)
>> +
>> +#define MA35_NFI_REG_NANDECCES0	(0x8D0)
>> +#define   ECC_STATUS_MASK			(0x3)
>> +#define   ECC_ERR_CNT_MASK			(0x1f)
>> +
>> +#define MA35_NFI_REG_NANDECCES1	(0x8D4)
>> +#define MA35_NFI_REG_NANDECCES2	(0x8D8)
>> +#define MA35_NFI_REG_NANDECCES3	(0x8DC)
>> +
>> +/* NAND-type Flash BCH Error Address Registers */
>> +#define MA35_NFI_REG_NANDECCEA0	(0x900)
>> +#define MA35_NFI_REG_NANDECCEA1	(0x904)
>> +#define MA35_NFI_REG_NANDECCEA2	(0x908)
>> +#define MA35_NFI_REG_NANDECCEA3	(0x90C)
>> +#define MA35_NFI_REG_NANDECCEA4	(0x910)
>> +#define MA35_NFI_REG_NANDECCEA5	(0x914)
>> +#define MA35_NFI_REG_NANDECCEA6	(0x918)
>> +#define MA35_NFI_REG_NANDECCEA7	(0x91C)
>> +#define MA35_NFI_REG_NANDECCEA8	(0x920)
>> +#define MA35_NFI_REG_NANDECCEA9	(0x924)
>> +#define MA35_NFI_REG_NANDECCEA10	(0x928)
>> +#define MA35_NFI_REG_NANDECCEA11	(0x92C)
>> +
>> +/* NAND-type Flash BCH Error Data Registers */
>> +#define MA35_NFI_REG_NANDECCED0	(0x960)
>> +#define MA35_NFI_REG_NANDECCED1	(0x964)
>> +#define MA35_NFI_REG_NANDECCED2	(0x968)
>> +#define MA35_NFI_REG_NANDECCED3	(0x96C)
>> +#define MA35_NFI_REG_NANDECCED4	(0x970)
>> +#define MA35_NFI_REG_NANDECCED5	(0x974)
>> +
>> +/* NAND-type Flash Redundant Area Registers */
>> +#define MA35_NFI_REG_NANDRA0		(0xA00)
>> +#define MA35_NFI_REG_NANDRA1		(0xA04)
>> +
>> +#define SKIP_SPARE_BYTES	4
>> +
>> +/* BCH algorithm related constants and variables */
>> +enum {
>> +	eBCH_NONE = 0,
>> +	eBCH_T8,
>> +	eBCH_T12,
>> +	eBCH_T24,
>> +	eBCH_CNT
>> +} E_BCHALGORITHM;
>> +
>> +static const int g_i32BCHAlgoIdx[eBCH_CNT] = {BCH_T8, BCH_T8, BCH_T12, BCH_T24};
>> +static struct nand_ecclayout_user ma35_nand_oob;
> Why this is file-scope?

I will remove the `static`.



>> +static const int g_i32ParityNum[3][eBCH_CNT] = {
>
> This is not a Linux coding style. Do not send Windows or some other
> platform-independent patches to review.
>
This is my mistake. I should have modified it instead of copying it 
directly.

I will fix it.



>> +	{0,  60,  92,  90},  /* for 2K */
>> +	{0, 120, 184, 180},  /* for 4K */
>> +	{0, 240, 368, 360},  /* for 8K */
>> +};
>> +
>> +
>> +struct ma35_nand_info {
>> +	struct nand_controller controller;
>> +	struct device *dev;
>> +	void __iomem *regs;
>> +	int irq;
>> +	struct clk *clk;
>> +	struct completion complete;
>> +
>> +	struct mtd_info mtd;
>> +	struct nand_chip chip;
>> +	struct mtd_partition *parts;
>> +	int nr_parts;
>> +
>> +	int eBCHAlgo;
> No, use Linux coding style.

I will fix it.



>> +	u8 *dma_buf;
>> +	spinlock_t dma_lock;
>> +	dma_addr_t dma_addr;
>> +};
>> +
>> +static int ma35_ooblayout_ecc(struct mtd_info *mtd, int section,
>> +			      struct mtd_oob_region *oobregion)
>> +{
>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>> +	struct nand_ecc_ctrl *ecc = &chip->ecc;
>> +
>> +	if (section || !ecc->total)
>> +		return -ERANGE;
>> +
>> +	oobregion->length = ecc->total;
>> +	oobregion->offset = mtd->oobsize - oobregion->length;
>> +
>> +	return 0;
>> +}
> ... this code looks poor, really poor.

I will rewrite this function.



>> +}
>> +
>> +static int ma35_nfi_correct(struct nand_chip *chip, unsigned long addr)
>> +{
>> +	struct ma35_nand_info *nand = nand_get_controller_data(chip);
>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>> +	int uStatus, i, j, i32FieldNum = 0;
>> +	int uReportErrCnt = 0;
>> +	int uErrorCnt = 0;
>> +
> More of weird coding style. Use Linux coding style. Patch is for Linux.

I will fix it.



>> +	if ((readl(nand->regs + MA35_NFI_REG_NANDCTL) & BCH_MASK) == BCH_T24)
>> +		i32FieldNum = mtd->writesize / 1024;
>> +	else
>> +		i32FieldNum = mtd->writesize / 512;
>
> ...

I will fix it.



>> +static int ma35_nand_probe(struct platform_device *pdev)
>> +{
>> +	struct ma35_nand_info *nand;
>> +	struct nand_chip *chip;
>> +	struct mtd_info *mtd;
>> +	int retval = 0;
>> +
>> +	nand = devm_kzalloc(&pdev->dev, sizeof(struct ma35_nand_info), GFP_KERNEL);
> sizeof(*)

I will fix it.



>> +	if (!nand)
>> +		return -ENOMEM;
>> +
>> +	nand_controller_init(&nand->controller);
>> +
>> +	nand->regs = devm_platform_ioremap_resource(pdev, 0);
>> +	if (IS_ERR(nand->regs))
>> +		return PTR_ERR(nand->regs);
>> +
>> +	nand->dev = &pdev->dev;
>> +	chip = &nand->chip;
>> +	mtd = nand_to_mtd(chip);
>> +	nand_set_controller_data(chip, nand);
>> +	nand_set_flash_node(chip, pdev->dev.of_node);
>> +
>> +	mtd->priv = chip;
>> +	mtd->owner = THIS_MODULE;
>> +	mtd->dev.parent = &pdev->dev;
>> +
>> +	nand->clk = of_clk_get(pdev->dev.of_node, 0);
> No, no. That's not how you get a clock. Use devm_clk_get().

I will fix it.



>> +	if (IS_ERR(nand->clk))
>> +		return dev_err_probe(&pdev->dev, PTR_ERR(nand->clk),
>> +				     "failed to find nand clock\n");
>> +
>> +	retval = clk_prepare_enable(nand->clk);
>> +	if (retval < 0) {
>> +		dev_err(&pdev->dev, "Failed to enable clock\n");
>> +		return -ENXIO;
>> +	}
>> +
>> +	nand->chip.controller    = &nand->controller;
>> +
>> +	chip->legacy.cmdfunc     = ma35_nand_command;
>> +	chip->legacy.waitfunc    = ma35_waitfunc;
>> +	chip->legacy.read_byte   = ma35_nand_read_byte;
>> +	chip->legacy.select_chip = ma35_nand_select_chip;
>> +	chip->legacy.read_buf    = ma35_read_buf_dma;
>> +	chip->legacy.write_buf   = ma35_write_buf_dma;
>> +	chip->legacy.dev_ready   = ma35_nand_devready;
>> +	chip->legacy.chip_delay  = 25; /* us */
>> +
>> +	/* Read OOB data first, then HW read page */
>> +	chip->ecc.hwctl      = ma35_nand_enable_hwecc;
>> +	chip->ecc.calculate  = ma35_nand_calculate_ecc;
>> +	chip->ecc.correct    = ma35_nand_correct_data;
>> +	chip->ecc.write_page = ma35_nand_write_page_hwecc;
>> +	chip->ecc.read_page  = ma35_nand_read_page_hwecc_oob_first;
>> +	chip->ecc.read_oob   = ma35_nand_read_oob_hwecc;
>> +	chip->options |= (NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA);
>> +
>> +	ma35_nand_initialize(nand);
>> +	platform_set_drvdata(pdev, nand);
>> +
>> +	nand->controller.ops = &ma35_nand_controller_ops;
>> +
>> +	nand->irq = platform_get_irq(pdev, 0);
>> +	if (nand->irq < 0) {
>> +		dev_err(&pdev->dev, "failed to get platform irq\n");
> Syntax is return dev_err_probe

I will fix it.



>> +		return -EINVAL;
>> +	}
>> +
>> +	if (request_irq(nand->irq, (irq_handler_t)&ma35_nand_irq,
>> +			IRQF_TRIGGER_HIGH, "ma35d1-nand", nand)) {
>> +		dev_err(&pdev->dev, "Error requesting NAND IRQ\n");
>> +		return -ENXIO;
>> +	}
>> +
>> +	retval = nand_scan(chip, 1);
>> +	if (retval)
>> +		return retval;
>> +
>> +	if (mtd_device_register(mtd, nand->parts, nand->nr_parts)) {
>> +		nand_cleanup(chip);
>> +		devm_kfree(&pdev->dev, nand);
>> +		return retval;
>> +	}
>> +
>> +	pr_info("ma35-nfi: registered successfully! mtdid=%s\n", mtd->name);
> Drop, does not help.
>
> Drivers do not use pr_xxx anyway. Why your code is so inconsistent? It's
> like random junk glued together.

I will remove all the `pr_info`.



>> +
>> +	return retval;
>> +}
>> +
>> +static void ma35_nand_remove(struct platform_device *pdev)
>> +{
>> +	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
>> +	struct nand_chip *chip = &nand->chip;
>> +	int ret;
>> +
>> +	ret = mtd_device_unregister(nand_to_mtd(chip));
>> +	WARN_ON(ret);
>> +	nand_cleanup(chip);
>> +
>> +	clk_disable_unprepare(nand->clk);
>> +
>> +	kfree(nand);
>> +	platform_set_drvdata(pdev, NULL);
>> +}
>> +
>> +/* PM Support */
>> +#ifdef CONFIG_PM
>> +static int ma35_nand_suspend(struct platform_device *pdev, pm_message_t pm)
>> +{
>> +	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
>> +	unsigned long timeo = jiffies + HZ/2;
>> +
>> +	/* wait DMAC to ready */
>> +	while (1) {
>> +		if ((readl(nand->regs + MA35_NFI_REG_DMACTL) & DMA_BUSY) == 0)
>> +			break;
>> +		if (time_after(jiffies, timeo))
>> +			return -ETIMEDOUT;
>> +	}
>> +
>> +	clk_disable(nand->clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int ma35_nand_resume(struct platform_device *pdev)
>> +{
>> +	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
>> +
>> +	clk_enable(nand->clk);
>> +	ma35_nand_hwecc_init(nand);
>> +	ma35_nand_dmac_init(nand);
>> +
>> +	return 0;
>> +}
>> +
>> +#else
>> +#define ma35_nand_suspend NULL
>> +#define ma35_nand_resume NULL
>> +#endif
>> +
>> +static const struct of_device_id ma35_nfi_of_match[] = {
>> +	{ .compatible = "nuvoton,ma35d1-nand" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, ma35_nfi_of_match);
>> +
>> +static struct platform_driver ma35_nand_driver = {
>> +		.driver = {
>> +		.name   = "ma35d1-nand",
>> +		.owner  = THIS_MODULE,
>> +		.of_match_table = of_match_ptr(ma35_nfi_of_match),
> Drop of_match_ptr. You have warnings here.

Okay. I will remove it.



>> +		},
>> +		.probe = ma35_nand_probe,
>> +		.remove_new = ma35_nand_remove,
>> +		.suspend = ma35_nand_suspend,
>> +		.resume = ma35_nand_resume,
>> +};
>> +
>> +static int __init ma35_nand_init(void)
>> +{
>> +	int ret;
>> +
>> +	pr_info("ma35 mtd nand driver\n");
> NAK, drop, useless and really pointless.

I will remove all the `pr_info`.



>> +
>> +	ret = platform_driver_register(&ma35_nand_driver);
>> +	if (ret) {
>> +		pr_warn("nand: failed to add device driver %s\n",
>> +			ma35_nand_driver.driver.name);
>> +		return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static void __exit ma35_nand_exit(void)
>> +{
>> +	platform_driver_unregister(&ma35_nand_driver);
>> +	pr_info("nand: unregistered successfully!\n");
> NAK, drop, useless and really pointless.

I will remove all the `pr_info`.



>> +}
>> +
>> +module_init(ma35_nand_init);
>> +module_exit(ma35_nand_exit);
> Do not open-code these functions, there are wrappers for this.

Okay. I will remove it.



>> +
>> +MODULE_DESCRIPTION("Nuvoton ma35 NAND driver");
>> +MODULE_AUTHOR("Hui-Ping Chen <hpchen0nvt@gmail.com>");
>> +MODULE_LICENSE("GPL");
> Best regards,
> Krzysztof


Best regards,

Hui-Ping Chen