From: Vignesh Raghavendra <vigneshr@ti.com>
To: Chuanhong Guo <gch981213@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Tudor Ambarus <tudor.ambarus@microchip.com>,
Richard Weinberger <richard@nod.at>,
open list <linux-kernel@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>,
linux-mtd@lists.infradead.org,
Miquel Raynal <miquel.raynal@bootlin.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-mediatek@lists.infradead.org,
Brian Norris <computersforpeace@gmail.com>,
David Woodhouse <dwmw2@infradead.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] mtd: mtk-quadspi: add support for memory-mapped flash reading
Date: Thu, 7 Nov 2019 17:55:40 +0530 [thread overview]
Message-ID: <efd471a6-daad-a191-5528-62313dd4e4a4@ti.com> (raw)
In-Reply-To: <CAJsYDVJgUNxLhcO9iLKwRZHPQ9FT8XuKQq8ru_djD2nryT5o9A@mail.gmail.com>
On 07/11/19 3:01 PM, Chuanhong Guo wrote:
> Hi!
>
> On Thu, Nov 7, 2019 at 2:05 PM Vignesh Raghavendra <vigneshr@ti.com> wrote:
>>> @@ -272,6 +273,11 @@ static ssize_t mtk_nor_read(struct spi_nor *nor, loff_t from, size_t length,
>>> mtk_nor_set_read_mode(mtk_nor);
>>> mtk_nor_set_addr(mtk_nor, addr);
>>>
>>> + if (mtk_nor->flash_base) {
>>> + memcpy_fromio(buffer, mtk_nor->flash_base + from, length);
>>> + return length;
>>> + }
>>> +
>>
>> Don't you need to check if access is still within valid memory mapped
>> window?
>
> The mapped area is 256MB and I don't quite believe there will be such
> a big NOR flash.
> I'll add a check here in the next version.
>
There are 256MB (2GiB) NORs out there in market already. So, pretty
soon, 256MB window won't be big enough :)
>>
>>> for (i = 0; i < length; i++) {
>>> ret = mtk_nor_execute_cmd(mtk_nor, MTK_NOR_PIO_READ_CMD);
>>> if (ret < 0)
>>> @@ -475,6 +481,11 @@ static int mtk_nor_drv_probe(struct platform_device *pdev)
>>> if (IS_ERR(mtk_nor->base))
>>> return PTR_ERR(mtk_nor->base);
>>>
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>> + mtk_nor->flash_base = devm_ioremap_resource(&pdev->dev, res);
>>
>> There is a single API now: devm_platform_ioremap_resource().
>
> Cool. I'll change it.
> Should I add another patch to change the same mapping operation right
> above this piece of code?
>
That would be nice to do too, please send a separate patch.
--
Regards
Vignesh
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next prev parent reply other threads:[~2019-11-07 12:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-06 14:07 [PATCH 0/2] mtd: mtk-quadspi: add support for memory-mapped flash reading Chuanhong Guo
2019-11-06 14:07 ` [PATCH 1/2] " Chuanhong Guo
2019-11-07 6:06 ` Vignesh Raghavendra
2019-11-07 9:31 ` Chuanhong Guo
2019-11-07 12:25 ` Vignesh Raghavendra [this message]
2019-11-07 13:23 ` Yingjoe Chen
2019-11-07 15:34 ` Chuanhong Guo
2019-11-08 3:52 ` Chuanhong Guo
2019-11-06 14:07 ` [PATCH 2/2] dt-bindings: mtd: mtk-quadspi: update bindings for mmap flash read Chuanhong Guo
2019-11-07 1:09 ` Rob Herring
2019-11-07 9:25 ` Chuanhong Guo
2019-11-08 3:51 ` Chuanhong Guo
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