On 03/25/2011 10:28 AM, Andre Schwarz wrote:
Grant, Anton,
got it.
providing modalis = "spidev" within spi_board_info works like a charme ...
Cheers,
André
we're about to get new MPC8377 based hardware with various
peripherals.
There are two I2C-to-SPI bridge devices (NXP SC18IS602) and I'm
not sure
how to define a proper dts...
Of course it's an easy thing creating 2 child nodes on the CPU's I2C
device - but how can I represent the created SPI bus ?
Um.. the same as the other SPI buses? I.e.
i2c-controller { /* SOC I2C controller */
spi-controller { /* The I2C-to-SPI bridge */
spi-device@0 {
};
spi-device@1 {
};
};
};
ok , thanks - looks straight forward.
Is this any more than plain definition, i.e. will this trigger any I2C
or SPI device registration/linking ?
Is the (possibly) required driver (of_sc18is60x_spi ?) supposed to
be an
I2C slave or an SPI host driver ?
It should be an I2C driver that registers an SPI master (i.e.
calls spi_alloc_master() and spi_register_master()).
hmm - ok. Will have to do it manually then ...
Yes, but this is the case for non-of drivers too. The i2c to spi
device driver must always create (and trigger population of) the spi
bus instance.
I've kicked that I2C-to-SPI stuff completely because it's been too slow.
We've connected the SPI busses to the FPGA controlling almost
everything now.
Unfortunately there are some questions left :
Following Anton's suggestion I've had a look at /drivers/mfd (sm501.c)
and implemented a pci driver for the FPGA using
subdevices for additional functionality it exports - besides others we
now have 2 SPI masters.
For both SPI masters I have created and registered a platform_device.
pdev->dev is then fed into spi_alloc_master() and the resulting master
goes into spi_register_master().
master->bus_num is set to 0 and 1, i.e. no dynamic numbering.
master->chipselect = 8;
Since I can probe the SPI device using FPGA intrinsic information I
decided to register the client
devices on runtime using a "struct spi_board_info" which is fed into
spi_new_device().
The current design has 2 clients on SPI-0 and 5 clients on SPI-1.
static struct spi_board_info mergerbox_spi_boardinfo[] = {
{ .bus_num = 0,
.chip_select = 0,
.max_speed_hz = 4<<20, },
{ .bus_num = 0,
.chip_select = 1,
.max_speed_hz = 4<<20, },
{ .bus_num = 1,
.chip_select = 0,
.max_speed_hz = 4<<20, },
.....
After loading my module I get :
#> ls /sys/devices/platform/AlteraSPI.0/
/sys/devices/platform/AlteraSPI.0/modalias
/sys/devices/platform/AlteraSPI.0/spi0.0/
/sys/devices/platform/AlteraSPI.0/spi0.1/
/sys/devices/platform/AlteraSPI.0/spi_master/
/sys/devices/platform/AlteraSPI.0/subsystem/
/sys/devices/platform/AlteraSPI.0/uevent
#> ls /sys/devices/platform/AlteraSPI.1/
/sys/devices/platform/AlteraSPI.1/modalias
/sys/devices/platform/AlteraSPI.1/spi1.0/
/sys/devices/platform/AlteraSPI.1/spi1.1/
/sys/devices/platform/AlteraSPI.1/spi1.2/
/sys/devices/platform/AlteraSPI.1/spi1.3/
/sys/devices/platform/AlteraSPI.1/spi1.4/
/sys/devices/platform/AlteraSPI.1/spi_master/
/sys/devices/platform/AlteraSPI.1/subsystem/
/sys/devices/platform/AlteraSPI.1/uevent
What I'm missing are the /dev/spi* entries.
There's also a spi_mpc8xxx driver using the CPU's SPI controller.
It is configured by dts (2 devices) and uses dynamic bus numbering:
#> ls /sys/bus/spi/devices/
spi0.0 spi1.0 spi1.2 spi1.4 spi32766.1
spi0.1 spi1.1 spi1.3 spi32766.0
This devices are processed by spidev and proper entries are created
ready for use :
#> ls /dev/spi*
/dev/spidev32766.0 /dev/spidev32766.1
Am I missing somehting obvious ?
Since there's no driver registration we don't have a probe function -
is this a problem regarding device binding ?
Do I need to use the .modalias in "struct spi_board_info" ?
Any help is welcome.
Regards,
André
MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
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