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Message-ID: <e5a8524c-8961-9ff0-db30-3b648345319e@pengutronix.de>
Date:   Tue, 18 Jul 2023 11:08:37 +0200
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Subject: Re: [Linux-stm32] [PATCH V4] nvmem: add explicit config option to
 read old syntax fixed OF cells
Content-Language: en-US
To:     =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc:     Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Alessandro Zummo <a.zummo@towertech.it>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Kunihiko Hayashi <hayashi.kunihiko@socionext.com>,
        linux-mtd@lists.infradead.org,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
        Evgeniy Polyakov <zbr@ioremap.net>,
        Fabio Estevam <festevam@gmail.com>,
        linux-stm32@st-md-mailman.stormreply.com,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Heiko Stuebner <heiko@sntech.de>, linux-rtc@vger.kernel.org,
        Samuel Holland <samuel@sholland.org>,
        Richard Weinberger <richard@nod.at>,
        Michal Simek <michal.simek@xilinx.com>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        linux-rockchip@lists.infradead.org, Chen-Yu Tsai <wens@csie.org>,
        Andy Gross <agross@kernel.org>,
        NXP Linux Team <linux-imx@nxp.com>,
        Vincent Shih <vincent.sunplus@gmail.com>,
        Orson Zhai <orsonzhai@gmail.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        linux-sunxi@lists.linux.dev, asahi@lists.linux.dev,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Sven Peter <sven@svenpeter.dev>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        linux-arm-msm@vger.kernel.org,
        Sascha Hauer <s.hauer@pengutronix.de>,
        linux-mediatek@lists.infradead.org,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Chunyan Zhang <zhang.lyra@gmail.com>,
        Bjorn Andersson <andersson@kernel.org>,
        Hector Martin <marcan@marcan.st>, linux-kernel@vger.kernel.org,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Michael Walle <michael@walle.cc>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Kevin Hilman <khilman@baylibre.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Claudiu Beznea <claudiu.beznea@microchip.com>
References: <20230403225540.1931-1-zajec5@gmail.com>
From:   Ahmad Fatoum <a.fatoum@pengutronix.de>
In-Reply-To: <20230403225540.1931-1-zajec5@gmail.com>
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Hello Rafał,

On 04.04.23 00:55, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Binding for fixed NVMEM cells defined directly as NVMEM device subnodes
> has been deprecated. It has been replaced by the "fixed-layout" NVMEM
> layout binding.
> 
> New syntax is meant to be clearer and should help avoiding imprecise
> bindings.
> 
> NVMEM subsystem already supports the new binding. It should be a good
> idea to limit support for old syntax to existing drivers that actually
> support & use it (we can't break backward compatibility!). That way we
> additionally encourage new bindings & drivers to ignore deprecated
> binding.
> 
> It wasn't clear (to me) if rtc and w1 code actually uses old syntax
> fixed cells. I enabled them to don't risk any breakage.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> [for meson-{efuse,mx-efuse}.c]
> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> [for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> [MT8192, MT8195 Chromebooks]
> Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> [for microchip-otpc.c]
> Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> [SAMA7G5-EK]
> Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>,

but small question below:

> ---

> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 60670b2f70b9..334adbae3690 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -522,6 +522,7 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
>  	config.dev = &mtd->dev;
>  	config.name = dev_name(&mtd->dev);
>  	config.owner = THIS_MODULE;
> +	config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");

How does the new binding look like in this situation?

Before it was:

&{flash/partitions} {
	compatible = "fixed-partitions";
	#address-cells = <1>;
	#size-cells = <1>;

	partition@0 {
		compatible = "nvmem-cells";
		reg = <0 0x100>;
		#address-cells = <1>;
		#size-cells = <1>;
		
		calib@1 {
			reg = <1 1>;
		};
	}
};

It it now the same, but s/"nvmem-cells"/"fixed-layout"/ ?

>  	config.reg_read = mtd_nvmem_reg_read;
>  	config.size = mtd->size;
>  	config.word_size = 1;
> @@ -889,6 +890,7 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
>  	config.name = compatible;
>  	config.id = NVMEM_DEVID_AUTO;
>  	config.owner = THIS_MODULE;
> +	config.add_legacy_fixed_of_cells = true;
>  	config.type = NVMEM_TYPE_OTP;
>  	config.root_only = true;
>  	config.ignore_wp = true;
> diff --git a/drivers/nvmem/apple-efuses.c b/drivers/nvmem/apple-efuses.c
> index 9b7c87102104..d3d49d22338b 100644
> --- a/drivers/nvmem/apple-efuses.c
> +++ b/drivers/nvmem/apple-efuses.c
> @@ -36,6 +36,7 @@ static int apple_efuses_probe(struct platform_device *pdev)
>  	struct resource *res;
>  	struct nvmem_config config = {
>  		.dev = &pdev->dev,
> +		.add_legacy_fixed_of_cells = true,
>  		.read_only = true,
>  		.reg_read = apple_efuses_read,
>  		.stride = sizeof(u32),
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index b3d5a29477f9..80c1d0a30a26 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -994,9 +994,11 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
>  	if (rval)
>  		goto err_remove_cells;
>  
> -	rval = nvmem_add_cells_from_legacy_of(nvmem);
> -	if (rval)
> -		goto err_remove_cells;
> +	if (config->add_legacy_fixed_of_cells) {
> +		rval = nvmem_add_cells_from_legacy_of(nvmem);
> +		if (rval)
> +			goto err_remove_cells;
> +	}
>  
>  	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
>  
> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
> index 399e1eb8b4c1..899e9108a521 100644
> --- a/drivers/nvmem/imx-ocotp-scu.c
> +++ b/drivers/nvmem/imx-ocotp-scu.c
> @@ -220,6 +220,7 @@ static int imx_scu_ocotp_write(void *context, unsigned int offset,
>  
>  static struct nvmem_config imx_scu_ocotp_nvmem_config = {
>  	.name = "imx-scu-ocotp",
> +	.add_legacy_fixed_of_cells = true,
>  	.read_only = false,
>  	.word_size = 4,
>  	.stride = 1,
> diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
> index ac0edb6398f1..0f7531a7e15d 100644
> --- a/drivers/nvmem/imx-ocotp.c
> +++ b/drivers/nvmem/imx-ocotp.c
> @@ -621,6 +621,7 @@ static int imx_ocotp_probe(struct platform_device *pdev)
>  		return PTR_ERR(priv->clk);
>  
>  	priv->params = of_device_get_match_data(&pdev->dev);
> +	imx_ocotp_nvmem_config.add_legacy_fixed_of_cells = true;
>  	imx_ocotp_nvmem_config.size = 4 * priv->params->nregs;
>  	imx_ocotp_nvmem_config.dev = dev;
>  	imx_ocotp_nvmem_config.priv = priv;
> diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c
> index d6b533497ce1..b922df99f9bc 100644
> --- a/drivers/nvmem/meson-efuse.c
> +++ b/drivers/nvmem/meson-efuse.c
> @@ -93,6 +93,7 @@ static int meson_efuse_probe(struct platform_device *pdev)
>  
>  	econfig->dev = dev;
>  	econfig->name = dev_name(dev);
> +	econfig->add_legacy_fixed_of_cells = true;
>  	econfig->stride = 1;
>  	econfig->word_size = 1;
>  	econfig->reg_read = meson_efuse_read;
> diff --git a/drivers/nvmem/meson-mx-efuse.c b/drivers/nvmem/meson-mx-efuse.c
> index 13eb14316f46..34a911696155 100644
> --- a/drivers/nvmem/meson-mx-efuse.c
> +++ b/drivers/nvmem/meson-mx-efuse.c
> @@ -213,6 +213,7 @@ static int meson_mx_efuse_probe(struct platform_device *pdev)
>  	efuse->config.owner = THIS_MODULE;
>  	efuse->config.dev = &pdev->dev;
>  	efuse->config.priv = efuse;
> +	efuse->config.add_legacy_fixed_of_cells = true;
>  	efuse->config.stride = drvdata->word_size;
>  	efuse->config.word_size = drvdata->word_size;
>  	efuse->config.size = SZ_512;
> diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c
> index 436e0dc4f337..7cf81738a3e0 100644
> --- a/drivers/nvmem/microchip-otpc.c
> +++ b/drivers/nvmem/microchip-otpc.c
> @@ -261,6 +261,7 @@ static int mchp_otpc_probe(struct platform_device *pdev)
>  		return ret;
>  
>  	mchp_nvmem_config.dev = otpc->dev;
> +	mchp_nvmem_config.add_legacy_fixed_of_cells = true;
>  	mchp_nvmem_config.size = size;
>  	mchp_nvmem_config.priv = otpc;
>  	nvmem = devm_nvmem_register(&pdev->dev, &mchp_nvmem_config);
> diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
> index b36cd0dcc8c7..87c94686cfd2 100644
> --- a/drivers/nvmem/mtk-efuse.c
> +++ b/drivers/nvmem/mtk-efuse.c
> @@ -83,6 +83,7 @@ static int mtk_efuse_probe(struct platform_device *pdev)
>  		return PTR_ERR(priv->base);
>  
>  	pdata = device_get_match_data(dev);
> +	econfig.add_legacy_fixed_of_cells = true;
>  	econfig.stride = 1;
>  	econfig.word_size = 1;
>  	econfig.reg_read = mtk_reg_read;
> diff --git a/drivers/nvmem/qcom-spmi-sdam.c b/drivers/nvmem/qcom-spmi-sdam.c
> index f822790db49e..be618ba8b550 100644
> --- a/drivers/nvmem/qcom-spmi-sdam.c
> +++ b/drivers/nvmem/qcom-spmi-sdam.c
> @@ -142,6 +142,7 @@ static int sdam_probe(struct platform_device *pdev)
>  	sdam->sdam_config.name = "spmi_sdam";
>  	sdam->sdam_config.id = NVMEM_DEVID_AUTO;
>  	sdam->sdam_config.owner = THIS_MODULE;
> +	sdam->sdam_config.add_legacy_fixed_of_cells = true;
>  	sdam->sdam_config.stride = 1;
>  	sdam->sdam_config.word_size = 1;
>  	sdam->sdam_config.reg_read = sdam_read;
> diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c
> index c1e893c8a247..e4dacde70fdd 100644
> --- a/drivers/nvmem/qfprom.c
> +++ b/drivers/nvmem/qfprom.c
> @@ -357,6 +357,7 @@ static int qfprom_probe(struct platform_device *pdev)
>  {
>  	struct nvmem_config econfig = {
>  		.name = "qfprom",
> +		.add_legacy_fixed_of_cells = true,
>  		.stride = 1,
>  		.word_size = 1,
>  		.id = NVMEM_DEVID_AUTO,
> diff --git a/drivers/nvmem/rave-sp-eeprom.c b/drivers/nvmem/rave-sp-eeprom.c
> index c456011b75e8..75d98fd25cb6 100644
> --- a/drivers/nvmem/rave-sp-eeprom.c
> +++ b/drivers/nvmem/rave-sp-eeprom.c
> @@ -328,6 +328,7 @@ static int rave_sp_eeprom_probe(struct platform_device *pdev)
>  	of_property_read_string(np, "zii,eeprom-name", &config.name);
>  	config.priv		= eeprom;
>  	config.dev		= dev;
> +	config.add_legacy_fixed_of_cells	= true;
>  	config.size		= size;
>  	config.reg_read		= rave_sp_eeprom_reg_read;
>  	config.reg_write	= rave_sp_eeprom_reg_write;
> diff --git a/drivers/nvmem/rockchip-efuse.c b/drivers/nvmem/rockchip-efuse.c
> index e4579de5d014..adc8bc70cffa 100644
> --- a/drivers/nvmem/rockchip-efuse.c
> +++ b/drivers/nvmem/rockchip-efuse.c
> @@ -205,6 +205,7 @@ static int rockchip_rk3399_efuse_read(void *context, unsigned int offset,
>  
>  static struct nvmem_config econfig = {
>  	.name = "rockchip-efuse",
> +	.add_legacy_fixed_of_cells = true,
>  	.stride = 1,
>  	.word_size = 1,
>  	.read_only = true,
> diff --git a/drivers/nvmem/sc27xx-efuse.c b/drivers/nvmem/sc27xx-efuse.c
> index c825fc902d10..8d13b81d5250 100644
> --- a/drivers/nvmem/sc27xx-efuse.c
> +++ b/drivers/nvmem/sc27xx-efuse.c
> @@ -248,6 +248,7 @@ static int sc27xx_efuse_probe(struct platform_device *pdev)
>  	econfig.reg_read = sc27xx_efuse_read;
>  	econfig.priv = efuse;
>  	econfig.dev = &pdev->dev;
> +	econfig.add_legacy_fixed_of_cells = true;
>  	nvmem = devm_nvmem_register(&pdev->dev, &econfig);
>  	if (IS_ERR(nvmem)) {
>  		dev_err(&pdev->dev, "failed to register nvmem config\n");
> diff --git a/drivers/nvmem/sprd-efuse.c b/drivers/nvmem/sprd-efuse.c
> index 4f1fcbfec394..ffc0cbfe87b3 100644
> --- a/drivers/nvmem/sprd-efuse.c
> +++ b/drivers/nvmem/sprd-efuse.c
> @@ -408,6 +408,7 @@ static int sprd_efuse_probe(struct platform_device *pdev)
>  	econfig.read_only = false;
>  	econfig.name = "sprd-efuse";
>  	econfig.size = efuse->data->blk_nums * SPRD_EFUSE_BLOCK_WIDTH;
> +	econfig.add_legacy_fixed_of_cells = true;
>  	econfig.reg_read = sprd_efuse_read;
>  	econfig.reg_write = sprd_efuse_write;
>  	econfig.priv = efuse;
> diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
> index 38d0bf557129..a44c2d6c20f9 100644
> --- a/drivers/nvmem/stm32-romem.c
> +++ b/drivers/nvmem/stm32-romem.c
> @@ -208,6 +208,7 @@ static int stm32_romem_probe(struct platform_device *pdev)
>  	priv->cfg.priv = priv;
>  	priv->cfg.owner = THIS_MODULE;
>  	priv->cfg.type = NVMEM_TYPE_OTP;
> +	priv->cfg.add_legacy_fixed_of_cells = true;
>  
>  	priv->lower = 0;
>  
> diff --git a/drivers/nvmem/sunplus-ocotp.c b/drivers/nvmem/sunplus-ocotp.c
> index 52b928a7a6d5..1b6632fb81ea 100644
> --- a/drivers/nvmem/sunplus-ocotp.c
> +++ b/drivers/nvmem/sunplus-ocotp.c
> @@ -145,6 +145,7 @@ static int sp_ocotp_read(void *priv, unsigned int offset, void *value, size_t by
>  
>  static struct nvmem_config sp_ocotp_nvmem_config = {
>  	.name = "sp-ocotp",
> +	.add_legacy_fixed_of_cells = true,
>  	.read_only = true,
>  	.word_size = 1,
>  	.size = QAC628_OTP_SIZE,
> diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
> index a970f1741cc6..155f07afd9cc 100644
> --- a/drivers/nvmem/sunxi_sid.c
> +++ b/drivers/nvmem/sunxi_sid.c
> @@ -156,6 +156,7 @@ static int sunxi_sid_probe(struct platform_device *pdev)
>  	nvmem_cfg->dev = dev;
>  	nvmem_cfg->name = "sunxi-sid";
>  	nvmem_cfg->type = NVMEM_TYPE_OTP;
> +	nvmem_cfg->add_legacy_fixed_of_cells = true;
>  	nvmem_cfg->read_only = true;
>  	nvmem_cfg->size = cfg->size;
>  	nvmem_cfg->word_size = 1;
> diff --git a/drivers/nvmem/uniphier-efuse.c b/drivers/nvmem/uniphier-efuse.c
> index aca910b3b6f8..d16ed22d105c 100644
> --- a/drivers/nvmem/uniphier-efuse.c
> +++ b/drivers/nvmem/uniphier-efuse.c
> @@ -53,6 +53,7 @@ static int uniphier_efuse_probe(struct platform_device *pdev)
>  	econfig.size = resource_size(res);
>  	econfig.priv = priv;
>  	econfig.dev = dev;
> +	econfig.add_legacy_fixed_of_cells = true;
>  	nvmem = devm_nvmem_register(dev, &econfig);
>  
>  	return PTR_ERR_OR_ZERO(nvmem);
> diff --git a/drivers/nvmem/zynqmp_nvmem.c b/drivers/nvmem/zynqmp_nvmem.c
> index e28d7b133e11..23cceb823cd0 100644
> --- a/drivers/nvmem/zynqmp_nvmem.c
> +++ b/drivers/nvmem/zynqmp_nvmem.c
> @@ -58,6 +58,7 @@ static int zynqmp_nvmem_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  	econfig.dev = dev;
> +	econfig.add_legacy_fixed_of_cells = true;
>  	econfig.reg_read = zynqmp_nvmem_read;
>  	econfig.priv = priv;
>  
> diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c
> index 07ede21cee34..37df7e80525b 100644
> --- a/drivers/rtc/nvmem.c
> +++ b/drivers/rtc/nvmem.c
> @@ -21,6 +21,7 @@ int devm_rtc_nvmem_register(struct rtc_device *rtc,
>  
>  	nvmem_config->dev = dev;
>  	nvmem_config->owner = rtc->owner;
> +	nvmem_config->add_legacy_fixed_of_cells = true;
>  	nvmem = devm_nvmem_register(dev, nvmem_config);
>  	if (IS_ERR(nvmem))
>  		dev_err(dev, "failed to register nvmem device for RTC\n");
> diff --git a/drivers/w1/slaves/w1_ds250x.c b/drivers/w1/slaves/w1_ds250x.c
> index 7592c7050d1d..cb426f7dd23d 100644
> --- a/drivers/w1/slaves/w1_ds250x.c
> +++ b/drivers/w1/slaves/w1_ds250x.c
> @@ -168,6 +168,7 @@ static int w1_eprom_add_slave(struct w1_slave *sl)
>  	struct nvmem_device *nvmem;
>  	struct nvmem_config nvmem_cfg = {
>  		.dev = &sl->dev,
> +		.add_legacy_fixed_of_cells = true,
>  		.reg_read = w1_nvmem_read,
>  		.type = NVMEM_TYPE_OTP,
>  		.read_only = true,
> diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
> index dae26295e6be..1b81adebdb8b 100644
> --- a/include/linux/nvmem-provider.h
> +++ b/include/linux/nvmem-provider.h
> @@ -82,6 +82,7 @@ struct nvmem_cell_info {
>   * @owner:	Pointer to exporter module. Used for refcounting.
>   * @cells:	Optional array of pre-defined NVMEM cells.
>   * @ncells:	Number of elements in cells.
> + * @add_legacy_fixed_of_cells:	Read fixed NVMEM cells from old OF syntax.
>   * @keepout:	Optional array of keepout ranges (sorted ascending by start).
>   * @nkeepout:	Number of elements in the keepout array.
>   * @type:	Type of the nvmem storage
> @@ -112,6 +113,7 @@ struct nvmem_config {
>  	struct module		*owner;
>  	const struct nvmem_cell_info	*cells;
>  	int			ncells;
> +	bool			add_legacy_fixed_of_cells;
>  	const struct nvmem_keepout *keepout;
>  	unsigned int		nkeepout;
>  	enum nvmem_type		type;

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