2010-05-12 15:17:01     Little Question abou register a SPI Kernel driver

2010-05-12 15:17:01     Little Question abou register a SPI Kernel driver

Raphael Lang (GERMANY)

Message: 89338   

Hey People,

I just wana write a simple driver to acces a microkontroller over SPI Framework...

I just follow the tutorial:

  linux-2.6.x/arch/blackfin/mach-bf537/boards/stamp.c.

I edit the file like that:

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

static struct bfin5xx_spi_chip pic_spi_chip_info = {

  .enable_dma = 0,

  .bits_per_word = 8,

};

#endif

and

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

    {

    .modalias = "pic_spi",

    .max_speed_hz = 3125000, /* max spi clock (SCK) speed in HZ */

    .bus_num = 0,

    .chip_select = 2,

    .controller_data = &pic_spi_chip_info,

    },

#endif

Now I should register the Kernel driver.

static struct spi_driver pic_spi_driver = {

    .driver = {

        .name   = "pic_spi",

        .bus    = &spi_bus_type,

        .owner  = THIS_MODULE,

    },

    .probe  = pic_spi_probe,

    .remove = __devexit_p(pic4_spi_remove),

};

.....

But where I need to put the code ? which file I need to edit or create ?

thanks

Raph

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2010-05-12 18:38:03     Re: Little Question abou register a SPI Kernel driver

Mike Frysinger (UNITED STATES)

Message: 89342   

can you just use the normal spidev interface instead ?  why must your driver be in kernel space ?

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2010-05-13 13:19:36     Re: Little Question abou register a SPI Kernel driver

Raphael Lang (GERMANY)

Message: 89381   

well, I tought I can use the interrupts of the Kernel Driver, but lets make thinks easy...

so I need to config the boardfile like that :

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

static struct bfin5xx_spi_chip pic_spi_chip_info = {

  .enable_dma = 0,

  .bits_per_word = 8,

};

#endif

and

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

    {

    .modalias = "spidev",

    .max_speed_hz = 3125000, /* max spi clock (SCK) speed in HZ */

    .bus_num = 0,

    .chip_select = 2,

    .controller_data = &pic_spi_chip_info,

    },

#endif

and after booting it will displayed spidev0.2

Did i need modprobe spidev0.2 ore something like that ?

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2010-05-14 04:23:41     Re: Little Question abou register a SPI Kerneldriver

Michael Hennerich (GERMANY)

Message: 89402    Take a look here:

  docs.blackfin.uclinux.org/doku.php?id=spi&s[]=spidev

Spidev (CONFIG_SPI_SPIDEV) is a user space driver - you need to build the driver into your kernel or load the module afterwards.

The module will be called spidev.ko

You can find some usage example here:

uclinux-dist-trunk/user/blkfin-apps/fpga/fpga_loader

-Michael

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2010-05-14 15:36:07     Re: Little Question abou register a SPI Kerneldriver

Raphael Lang (GERMANY)

Message: 89419   

jep I saw the documentation about the SPI , my Questions is:

Did I need to register my usermoder SPI Driver like that for my additional device:

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

...

};

#endif

and

#if defined(CONFIG_PIC_SPI) || defined(CONFIG_PIC_SPI_SPIDEV_MODULE)

    {

    .modalias = "spidev",

   .....

    },

#endif

because the documentations told me I should find the new device in /spidev0.2.

but there is nothing in /dev that sounds like my spi device ?

I could also not load anything with modprobe spidev.ko ?

Gruß von Stuttgart nach München

raph

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2010-05-15 11:37:41     Re: Little Question abou register a SPI Kerneldriver

Raphael Lang (GERMANY)

Message: 89434   

OK, now I understand, its easy like that:

// For SPI Device 1

#if defined(CONFIG_SPI_SPIDEV) || defined(CONFIG_SPI_SPIDEV_MODULE)

{

.modalias = "spidev",

.max_speed_hz = 3125000, /* max spi clock (SCK) speed in HZ */

.bus_num = 0,

.chip_select =2,

.controller_data = &spidev_chip_info,

},

//For SPI Device 2

#if defined(CONFIG_SPI_SPIDEV) || defined(CONFIG_SPI_SPIDEV_MODULE)

{

.modalias = "spidev",

.max_speed_hz = 3125000, /* max spi clock (SCK) speed in HZ */

.bus_num = 0,

.chip_select = 3,

.controller_data = &spidev_chip_info,

},

Now I can see all the devices spidev0.2 and spidev0.3 in /dev.

but now I have trouble with my AD 1836 (SPI_SSEL_4 ) after Booting  :

mmc_spi spi0.1: ASSUMING 3.2-3.4 V slot power                                  

mmc_spi spi0.1: SD/MMC host mmc0, no DMA, no WP, no poweroff                   

mmc_spi spi0.1: requested mode not fully supported                             

mmc_spi spi0.1: can't change chip-select polarity                              

Advanced Linux Sound Architecture Driver Version 1.0.18rc3.                    

dma_alloc_init: dma_page @ 0x0329a000 - 256 pages at 0x03f00000                

Hardware Trace:                                                                

   0 Target : <0x00004b44> { _dump_stack + 0x0 }                               

.... 

peripheral_request: Peripheral 59 function 0 is already reserved by spidev !   

bf53x_sport: Requesting Peripherals failed                                     

AD1836: Failed to find device on sport                                         

ALSA device list:                                                              

  No soundcards found.

cheers

Raphael

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2010-05-16 14:46:30     Re: Little Question abou register a SPI Kerneldriver

Mike Frysinger (UNITED STATES)

Message: 89449   

so select a different pin that isnt being used, or disable devices you arent using

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2010-05-16 14:47:19     Re: Little Question abou register a SPI Kernel driver

Mike Frysinger (UNITED STATES)

Message: 89450   

interrupts can be leveraged via the UIO interface, but typically SPI devices dont have dedicated interrupt lines.  what interrupt exactly are you talking about ?

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2010-05-19 12:55:54     Re: Little Question abou register a SPI Kernel driver

Raphael Lang (GERMANY)

Message: 89552   

jep, I have reed in a Linux Boock, that maybee it is better to use a kernel driver...

well, do have an Idea  why thy soundcard makes a problem when I am booting ?

thanks

Raph

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2010-05-19 12:58:12     Re: Little Question abou register a SPI Kernel driver

Raphael Lang (GERMANY)

Message: 89553   

jep, I have reed in a Linux Boock, that maybee it is better to use a kernel driver...

well, do have an Idea  why thy soundcard makes a problem when I am booting ?

thanks

Raph

---

SPI CHIP SELECT 4 is only used by the soundcart

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2010-05-19 15:21:49     Re: Little Question abou register a SPI Kernel driver

Mike Frysinger (UNITED STATES)

Message: 89556   

if that were true, you wouldnt have gotten the error.  double check your board resources.

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2010-05-27 06:01:07     Re: Little Question abou register a SPI Kernel driver

Raphael Lang (GERMANY)

Message: 89911   

well, I pluged my addtional devices from the spi bus, so only the AD 1836 and the mmc card are connected to the spi

bus... so it should boot normally ....but the message still apear...it seems when I only add the devices in the stamp.c file

there will be a problem ?

the Soundcart ad 1836 is on SPI_CS 4, MMC on SPI_CS_1, and 5 x(MAX7301 on SPI_CS_2, MAX7301 on SPI_CS_3 MAX 7301 on SPI_CS_5, MAX 7301 SPI_CS 6 and a MAX7301 on SPI_CS_7)

I added my stamp.c file

thanks

Raph

stamp.c

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2010-05-27 17:21:32     Re: Little Question abou register a SPI Kernel driver

Mike Frysinger (UNITED STATES)

Message: 89927   

which devices are physically connected is irrelevant to the resource management in the kernel

you've never said what hardware platform you're actually using nor what version of software.  in general, you need to fully describe these things when asking questions.

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