Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: Re: [RFC PATCH 5/5] mtd: hyperbus: Add driver for TI's Hyperbus
 memory controller
To:     "Vignesh R (by way of Boris Brezillon <bbrezillon@kernel.org>)" 
        <vigneshr@ti.com>, David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Boris Brezillon <bbrezillon@kernel.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Rob Herring <robh+dt@kernel.org>
Cc:     devicetree@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
        tudor.ambarus@microchip.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        nsekhar@ti.com, linux-kernel@vger.kernel.org,
        linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org
References: <20190219063607.29949-1-vigneshr@ti.com>
 <20190219063607.29949-6-vigneshr@ti.com>
Organization: Cogent Embedded
Message-ID: <907041d1-8412-22ca-3716-109a56251850@cogentembedded.com>
Date:   Mon, 25 Feb 2019 19:29:17 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.2.1
MIME-Version: 1.0
In-Reply-To: <20190219063607.29949-6-vigneshr@ti.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-MW
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hello!

On 02/19/2019 09:36 AM, Vignesh R (by way of Boris Brezillon <bbrezillon@kernel.org>) wrote:

> Add driver for Hyperbus memory controller on TI's AM654 SoC. Programming
> IP is pretty simple and provides direct memory mapped access to
> connected Flash devices.

   Are you sure you posted the _complete_ driver?

> Add basic support for the IP without DMA. Second ChipSelect is not
> supported for now.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
>  drivers/mtd/hyperbus/hbmc_am654.c | 105 ++++++++++++++++++++++++++++++
>  1 file changed, 105 insertions(+)
>  create mode 100644 drivers/mtd/hyperbus/hbmc_am654.c
> 
> diff --git a/drivers/mtd/hyperbus/hbmc_am654.c b/drivers/mtd/hyperbus/hbmc_am654.c
> new file mode 100644
> index 000000000000..1f0d2dc52f9f
> --- /dev/null
> +++ b/drivers/mtd/hyperbus/hbmc_am654.c
> @@ -0,0 +1,105 @@
[...]
> +static int am654_hbmc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct am654_hbmc_priv *priv;
> +	struct resource *res;
> +	int err;
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (IS_ERR(res)) {
> +		dev_err(&pdev->dev, "failed to get memory resource\n");
> +		return -ENOENT;
> +	}
> +
> +	priv->regbase = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(priv->regbase)) {
> +		dev_err(dev, "Cannot remap controller address.\n");
> +		return PTR_ERR(priv->regbase);
> +	}
> +
> +	pm_runtime_enable(&pdev->dev);
> +	err = pm_runtime_get_sync(&pdev->dev);

   That's all nice but where's the code that accesses the actual registers?

> +	if (err < 0) {
> +		pm_runtime_put_noidle(&pdev->dev);

   Calling "put" with previously failed "get" sees strange...

> +		return err;
> +	}
> +
> +	priv->hbdev.needs_calib = true;
> +	priv->hbdev.dev = &pdev->dev;
> +	priv->hbdev.np = of_get_next_child(dev->of_node, NULL);
> +	err = hb_register_device(&priv->hbdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "failed to register controller\n");
> +		goto err_destroy;
> +	}
> +
> +	return 0;
> +
> +err_destroy:
> +	hb_unregister_device(&priv->hbdev);

   Calling "unregister" with "register" previously failed also looks strange...

> +	pm_runtime_put_sync(&pdev->dev);

   Why the sync() version?

> +	return err;
> +}
[...]

MBR, Sergei