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Date:      Sun, 25 Aug 2013 15:12:41 +0100
From:      fabiodive <fabiodive@gmail.com>
To:        Luiz Otavio O Souza <loos.br@gmail.com>
Cc:        freebsd-arm@freebsd.org
Subject:   Re: SPI driver for RPi
Message-ID:  <DFC3F00E-BEEB-4BB2-92F4-9C9246933144@gmail.com>
In-Reply-To: <126AAEEA-1F99-42E4-9620-9CB4F3610671@gmail.com>
References:  <126AAEEA-1F99-42E4-9620-9CB4F3610671@gmail.com>

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Hello Luiz,
after applying the patches,
should I compile the kernel with the  "device api" written into the =
kernel config file? =20
thank you,
f.

On Aug 22, 2013, at 2:57 PM, Luiz Otavio O Souza <loos.br@gmail.com> =
wrote:

> Hello,
>=20
> Here is a SPI driver for RPi.
>=20
> It has been tested with a hardware loopback (MOSI wired to MISO) and =
with a s25fl032 spansion flash (removed from a wr941nd router).
>=20
> I've tested the reading from the flash up to 10Mhz of clock and =
surprisingly my (simple) wiring support it without any fail.
>=20
> At boot the SPI clock is set to 500Khz, not fast and not too slow (as =
the 3.814Khz default):
>=20
> # dd if=3D/dev/flash/spi0 of=3Dflash-wr941nd-2 bs=3D64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 75.632316 secs (55457 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2
> # sysctl dev.spi.0.clock=3D1000000
> dev.spi.0.clock: 500000 -> 1000000
> # dd if=3D/dev/flash/spi0 of=3Dflash-wr941nd-2 bs=3D64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 37.896805 secs (110677 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2            =20
> # sysctl dev.spi.0.clock=3D2000000                =20
> dev.spi.0.clock: 1000000 -> 2016129
> # dd if=3D/dev/flash/spi0 of=3Dflash-wr941nd-2 bs=3D64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 18.879980 secs (222156 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2            =20
> # sysctl dev.spi.0.clock=3D4000000                =20
> dev.spi.0.clock: 2016129 -> 4032258
> # dd if=3D/dev/flash/spi0 of=3Dflash-wr941nd-2 bs=3D64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 9.642490 secs (434981 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2            =20
> # sysctl dev.spi.0.clock=3D10000000               =20
> dev.spi.0.clock: 4032258 -> 10416666
> # dd if=3D/dev/flash/spi0 of=3Dflash-wr941nd-2 bs=3D64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 4.317743 secs (971411 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2            =20
>=20
>=20
> It export a few handy sysctl knobs:
>=20
> # sysctl dev.spi
> dev.spi.0.%desc: BCM2708/2835 SPI controller
> dev.spi.0.%driver: spi
> dev.spi.0.%parent: simplebus0
> dev.spi.0.clock: 500000
> dev.spi.0.cpol: 0
> dev.spi.0.cpha: 0
> dev.spi.0.cspol0: 0
> dev.spi.0.cspol1: 0
>=20
>=20
> About the patches:
>=20
> - bcm2835_spi.diff implements the SPI driver, the dts and kernel =
changes;
>=20
> - ofw_spibus.diff adds the OFW SPI bus glue to attach the SPI children =
as described in the FDT.
>=20
> - mx25l-fdt-intr.diff adds the support for FDT and configure a intr =
hook so the device identification runs only when the interrupts are =
active (the SPI driver is interrupt based);
>=20
> - rpi-mx25l-dts.diff the change i did to add my mx25l on the rpi dts =
(only as reference).
>=20
>=20
> Luiz
>=20
>=20
>=20
>=20
> =
<bcm2835_spi.diff><ofw_spibus.diff><mx25l-fdt-intr.diff><rpi-mx25l-dts.dif=
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