Re: [RFC PATCH v2 5/5] mtd: hyperbus: Add driver for TI's Hyperbus memory controller

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Vignesh Raghavendra <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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	tudor.ambarus@microchip.com, nsekhar@ti.com,
	Mason Yang <masonccyang@mxic.com.tw>
Subject: Re: [RFC PATCH v2 5/5] mtd: hyperbus: Add driver for TI's Hyperbus memory controller
Date: Tue, 26 Mar 2019 13:40:45 +0300	[thread overview]
Message-ID: <c537220a-63bd-9279-bbf0-fbbb1b4eb10a@cogentembedded.com> (raw)
In-Reply-To: <20190321174548.9288-6-vigneshr@ti.com>

On 03/21/2019 08:45 PM, Vignesh Raghavendra 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.
> 
> Add basic support for the IP without DMA. Second ChipSelect is not
> supported for now.
> 
> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
[...]
> diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile
> index ca61dedd730d..24abd1d43ade 100644
> --- a/drivers/mtd/hyperbus/Makefile
> +++ b/drivers/mtd/hyperbus/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
>  obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus-core.o
> +obj-$(CONFIG_HBMC_AM654)	+= hbmc_am654.o
> diff --git a/drivers/mtd/hyperbus/hbmc_am654.c b/drivers/mtd/hyperbus/hbmc_am654.c
> new file mode 100644
> index 000000000000..abf2b0959a35
> --- /dev/null
> +++ b/drivers/mtd/hyperbus/hbmc_am654.c
> @@ -0,0 +1,108 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
> +// Author: Vignesh Raghavendra <vigneshr@ti.com>
> +
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mtd/hyperbus.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/types.h>
> +
> +struct am654_hbmc_priv {
> +	struct hyperbus_ctlr ctlr;
> +	struct hyperbus_device hbdev;
> +	void __iomem	*regbase;
> +};
> +
> +static const struct hyperbus_ops am654_hbmc_ops = {
> +	.calibrate = hyperbus_calibrate,
> +};
> +
> +static int am654_hbmc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct am654_hbmc_priv *priv;
> +	struct resource *res;
> +	int ret;
> +
> +	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 (!res) {

   This is redundant as devm_ioremap_resource() checks for !res anyway.

> +		dev_err(&pdev->dev, "failed to get memory resource\n");
> +		return -ENOENT;
> +	}
> +
> +	priv->regbase = devm_ioremap_resource(dev, res);

   BTW, there's devm_platform_ioremap_resource() now...

[...]

MBR, Sergei