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

quoted

quoted

quoted

we're about to get new MPC8377 based hardware with various 
peripherals.

quoted

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 ?

quoted

quoted

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
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner