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Date:   Sun, 22 Jul 2018 11:29:30 +0200
From:   Boris Brezillon <boris.brezillon@bootlin.com>
To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     Wenyou Yang <wenyou.yang@microchip.com>,
        Josh Wu <rainyfeeling@outlook.com>,
        Tudor Ambarus <Tudor.Ambarus@microchip.com>,
        Richard Weinberger <richard@nod.at>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Kamal Dasu <kdasu.kdev@gmail.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Han Xu <han.xu@nxp.com>,
        Harvey Hunt <harveyhuntnexus@gmail.com>,
        Vladimir Zapolskiy <vz@mleia.com>,
        Sylvain Lemieux <slemieux.tyco@gmail.com>,
        Xiaolei Li <xiaolei.li@mediatek.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Marc Gonzalez <marc.w.gonzalez@free.fr>,
        Mans Rullgard <mans@mansr.com>, Stefan Agner <stefan@agner.ch>,
        linux-mtd@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        bcm-kernel-feedback-list@broadcom.com,
        linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v4 31/35] mtd: rawnand: jz4740: convert driver to
 nand_scan()
Message-ID: <20180722112930.5d62c3e9@bbrezillon>
In-Reply-To: <20180720151527.16038-32-miquel.raynal@bootlin.com>
References: <20180720151527.16038-1-miquel.raynal@bootlin.com>
        <20180720151527.16038-32-miquel.raynal@bootlin.com>
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On Fri, 20 Jul 2018 17:15:23 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> Two helpers have been added to the core to make ECC-related
> configuration between the detection phase and the final NAND scan. Use
> these hooks and convert the driver to just use nand_scan() instead of
> both nand_scan_ident() and nand_scan_tail().
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/mtd/nand/raw/jz4740_nand.c | 46 ++++++++++++++++++++++++--------------
>  1 file changed, 29 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/jz4740_nand.c b/drivers/mtd/nand/raw/jz4740_nand.c
> index 9bb8a89e09f9..8f821fdf8a1c 100644
> --- a/drivers/mtd/nand/raw/jz4740_nand.c
> +++ b/drivers/mtd/nand/raw/jz4740_nand.c
> @@ -59,6 +59,7 @@
>  
>  struct jz_nand {
>  	struct nand_chip chip;
> +	struct platform_device *pdev;

You don't need this field. You can just do
to_platform_device(mtd->dev.parent) to get the platform_device.

>  	void __iomem *base;
>  	struct resource *mem;
>  
> @@ -329,8 +330,8 @@ static int jz_nand_detect_bank(struct platform_device *pdev,
>  	writel(ctrl, nand->base + JZ_REG_NAND_CTRL);
>  
>  	if (chipnr == 0) {
> -		/* Detect first chip. */
> -		ret = nand_scan_ident(mtd, 1, NULL);
> +		/* Detect the first chip and register it */
> +		ret = nand_scan(mtd, 1);
>  		if (ret)
>  			goto notfound_id;
>  
> @@ -367,6 +368,25 @@ static int jz_nand_detect_bank(struct platform_device *pdev,
>  	return ret;
>  }
>  
> +static int jz_nand_attach_chip(struct nand_chip *chip)
> +{
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	struct jz_nand *nand = mtd_to_jz_nand(mtd);
> +	struct device *dev = mtd->dev.parent;
> +	struct jz_nand_platform_data *pdata = dev_get_platdata(dev);
> +
> +	if (pdata && pdata->ident_callback) {
> +		pdata->ident_callback(nand->pdev, mtd, &pdata->partitions,
> +				      &pdata->num_partitions);
> +	}

Curly braces are not needed.

> +
> +	return 0;
> +}
> +
> +static const struct nand_controller_ops jz_nand_controller_ops = {
> +	.attach_chip = jz_nand_attach_chip,
> +};
> +
>  static int jz_nand_probe(struct platform_device *pdev)
>  {
>  	int ret;
> @@ -397,6 +417,7 @@ static int jz_nand_probe(struct platform_device *pdev)
>  	mtd		= nand_to_mtd(chip);
>  	mtd->dev.parent = &pdev->dev;
>  	mtd->name	= "jz4740-nand";
> +	nand->pdev	= pdev;
>  
>  	chip->ecc.hwctl		= jz_nand_hwctl;
>  	chip->ecc.calculate	= jz_nand_calculate_ecc_rs;
> @@ -410,6 +431,7 @@ static int jz_nand_probe(struct platform_device *pdev)
>  	chip->chip_delay = 50;
>  	chip->cmd_ctrl = jz_nand_cmd_ctrl;
>  	chip->select_chip = jz_nand_select_chip;
> +	chip->dummy_controller.ops = &jz_nand_controller_ops;
>  
>  	if (nand->busy_gpio)
>  		chip->dev_ready = jz_nand_dev_ready;
> @@ -450,20 +472,10 @@ static int jz_nand_probe(struct platform_device *pdev)
>  		else
>  			nand->banks[chipnr] = 0;
>  	}
> +
>  	if (chipnr == 0) {
>  		dev_err(&pdev->dev, "No NAND chips found\n");
> -		goto err_iounmap_mmio;
> -	}
> -
> -	if (pdata && pdata->ident_callback) {
> -		pdata->ident_callback(pdev, mtd, &pdata->partitions,
> -					&pdata->num_partitions);
> -	}
> -
> -	ret = nand_scan_tail(mtd);
> -	if (ret) {
> -		dev_err(&pdev->dev,  "Failed to scan NAND\n");
> -		goto err_unclaim_banks;
> +		goto err_nand_release;
>  	}

As for the atmel driver, I'd prefer to have one patch to moves
nand_scan_ident() and nand_scan_tail() in the same function so that the
transition to nand_scan()+attach_chip is easier to review.

>  
>  	ret = mtd_device_register(mtd, pdata ? pdata->partitions : NULL,
> @@ -471,15 +483,13 @@ static int jz_nand_probe(struct platform_device *pdev)
>  
>  	if (ret) {
>  		dev_err(&pdev->dev, "Failed to add mtd device\n");
> -		goto err_nand_release;
> +		goto err_unclaim_banks;
>  	}
>  
>  	dev_info(&pdev->dev, "Successfully registered JZ4740 NAND driver\n");
>  
>  	return 0;
>  
> -err_nand_release:
> -	nand_release(mtd);
>  err_unclaim_banks:
>  	while (chipnr--) {
>  		unsigned char bank = nand->banks[chipnr];
> @@ -487,6 +497,8 @@ static int jz_nand_probe(struct platform_device *pdev)
>  					 nand->bank_base[bank - 1]);
>  	}
>  	writel(0, nand->base + JZ_REG_NAND_CTRL);
> +err_nand_release:
> +	nand_release(mtd);
>  err_iounmap_mmio:
>  	jz_nand_iounmap_resource(nand->mem, nand->base);
>  err_free: