Call for testing: spi-mem driver for Aspeed SMC controllers

Tue Mar 1 20:57:32 AEDT 2022

Joel Stanley <joel at jms.id.au> 于2022年2月25日周五 13:30写道：
>
> Cedric has authored a new drive for the SPI NOR devices on the ASPEED
> SoCs. It supports 2400, 2500 and 2600. It is written using the spi-mem
> subsystem, which should mean it can go upstream.
>
> This is great news, as our current driver is half upstream, half in
> the openbmc tree, due to some issues getting it merged as part of the
> spi-nor subsystem.
>
> It would be great to have testing. I've created a commit that patches
> in support to whatever kernel tree you're using. Hopefully this makes
> it easier to test atop your internal branches:
>
> https://gerrit.openbmc-project.xyz/c/openbmc/openbmc/+/51551

tested on a fp5280g2 (ast2500), it looks okay.

root at fp5280g2:~# dmesg |grep spi
[    1.594677] spi-nor spi0.0: mx66l51235f (65536 Kbytes)
[    1.728194] spi-aspeed-smc 1e620000.spi: CE0 read buswidth:2 [0x203c0641]
[    1.992733] spi-nor spi1.0: mx66l51235f (65536 Kbytes)
[    2.211741] spi-aspeed-smc 1e630000.spi: CE0 read buswidth:2 [0x203c0741]
[    3.175017] SPI driver bmp280 has no spi_device_id for bosch,bmp085

>
> Cherry pick this commit into your tree, and see how it goes, and report back.
>
> I plan to switch the openbmc tree to this driver when we next rebase
> the kernel. We could also backport it to dev-5.15 as an option.
>
> You can direct testing results to this thread, or reply directly to
> the upstream thread:
>
> https://lore.kernel.org/all/20220214094231.3753686-1-clg@kaod.org/
>
> Cheers,
>
> Joel
>
> ---------- Forwarded message ---------
> From: Cédric Le Goater <clg at kaod.org>
> Date: Mon, 14 Feb 2022 at 09:42
> Subject: [PATCH 00/10] spi: spi-mem: Add driver for Aspeed SMC controllers
> To: <linux-spi at vger.kernel.org>, <linux-mtd at lists.infradead.org>
> Cc: Mark Brown <broonie at kernel.org>, Tudor Ambarus
> <tudor.ambarus at microchip.com>, Pratyush Yadav <p.yadav at ti.com>, Miquel
> Raynal <miquel.raynal at bootlin.com>, Richard Weinberger
> <richard at nod.at>, Vignesh Raghavendra <vigneshr at ti.com>,
> <linux-aspeed at lists.ozlabs.org>, Joel Stanley <joel at jms.id.au>, Andrew
> Jeffery <andrew at aj.id.au>, Chin-Ting Kuo
> <chin-ting_kuo at aspeedtech.com>, <devicetree at vger.kernel.org>, Rob
> Herring <robh+dt at kernel.org>, <linux-arm-kernel at lists.infradead.org>,
> <linux-kernel at vger.kernel.org>, Cédric Le Goater <clg at kaod.org>
>
>
> Hi,
>
> This series adds a new SPI driver using the spi-mem interface for the
> Aspeed static memory controllers of the AST2600, AST2500 and AST2400
> SoCs.
>
>  * AST2600 Firmware SPI Memory Controller (FMC)
>  * AST2600 SPI Flash Controller (SPI1 and SPI2)
>  * AST2500 Firmware SPI Memory Controller (FMC)
>  * AST2500 SPI Flash Controller (SPI1 and SPI2)
>  * AST2400 New Static Memory Controller (also referred as FMC)
>  * AST2400 SPI Flash Controller (SPI)
>
> It is based on the current OpenBMC kernel driver [1], using directly
> the MTD SPI-NOR interface and on a patchset [2] previously proposed
> adding support for the AST2600 only. This driver takes a slightly
> different approach to cover all 6 controllers.
>
> It does not make use of the controller register disabling Address and
> Data byte lanes because is not available on the AST2400 SoC. We could
> introduce a specific handler for new features available on recent SoCs
> if needed. As there is not much difference on performance, the driver
> chooses the common denominator: "User mode" which has been heavily
> tested in [1]. "User mode" is also used as a fall back method when
> flash device mapping window is too small.
>
> Problems to address with spi-mem were the configuration of the mapping
> windows and the calibration of the read timings. The driver handles
> them in the direct mapping handler when some knowledge on the size of
> the flash device is know. It is not perfect but not incorrect either.
> The algorithm is one from [1] because it doesn't require the DMA
> registers which are not available on all controllers.
>
> Direct mapping for writes is not supported (yet). I have seen some
> corruption with writes and I preferred to use the safer and proven
> method of the initial driver [1]. We can improve that later.
>
> The driver supports Quad SPI RX transfers on the AST2600 SoC but it
> didn't have the expected results. Therefore it is not activated yet.
> This needs more tests.
>
> The series does not remove the current Aspeed SMC driver but prepares
> ground for its removal by changing its CONFIG option. This last step
> can be addressed as a followup when the new driver using the spi-mem
> interface has been sufficiently exposed.
>
> Tested on:
>
>  * OpenPOWER Palmetto (AST2400)
>  * Evaluation board (AST2500)
>  * OpenPOWER Witherspoon (AST2500)
>  * Evaluation board (AST2600 A0)
>  * Rainier board (AST2600)
>
> [1] https://github.com/openbmc/linux/blob/dev-5.15/drivers/mtd/spi-nor/controllers/aspeed-smc.c
> [2] https://patchwork.ozlabs.org/project/linux-aspeed/list/?series=212394
>
> Thanks,
>
> C.
>
> Cédric Le Goater (10):
>   mtd: spi-nor: aspeed: Rename Kconfig option
>   dt-bindings: spi: Add Aspeed SMC controllers device tree binding
>   spi: spi-mem: Add driver for Aspeed SMC controllers
>   spi: aspeed: Add support for direct mapping
>   spi: aspeed: Adjust direct mapping to device size
>   spi: aspeed: Workaround AST2500 limitations
>   spi: aspeed: Add support for the AST2400 SPI controller
>   spi: aspeed: Calibrate read timings
>   ARM: dts: aspeed: Enable Dual SPI RX transfers
>   spi: aspeed: Activate new spi-mem driver
>
>  drivers/spi/spi-aspeed-smc.c                  | 1241 +++++++++++++++++
>  .../bindings/spi/aspeed,ast2600-fmc.yaml      |   92 ++
>  arch/arm/boot/dts/aspeed-g4.dtsi              |    6 +
>  arch/arm/boot/dts/aspeed-g5.dtsi              |    7 +
>  arch/arm/boot/dts/aspeed-g6.dtsi              |    8 +
>  drivers/mtd/spi-nor/controllers/Kconfig       |    4 +-
>  drivers/mtd/spi-nor/controllers/Makefile      |    2 +-
>  drivers/spi/Kconfig                           |   11 +
>  drivers/spi/Makefile                          |    1 +
>  9 files changed, 1369 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/spi/spi-aspeed-smc.c
>  create mode 100644
> Documentation/devicetree/bindings/spi/aspeed,ast2600-fmc.yaml
>
> --
> 2.34.1