Thanks for the reply Richard.         The interrupt is not a GPIO  pin. I have read something about UIO (userspace I/O). Also, I want the operation to be asynchronous. Any pointer to such mechanism will be very helpful. Regards, Amit. On Sunday, 26 January 2014 8:53 PM, Richard Weinberger <richard.weinberger@gmail.com> wrote: On Sun, Jan 26, 2014 at 1:25 PM, Amit Mahadik <amitmahadik35@yahoo.com> wrote:

Hello,           I am using a custom ARM board. I have a SPI slave device and using the spidev_test utility I am able to do ioctls on the slave device. However, I have a problem. The SPI slave device has an interrupt pin and I want to process the interrupt and send some data into the userspace when I receive the interrupt. Can anybody please suggest me a way to do this using spidev driver?

Is the interrupt pin a gpio? If so, you can access it from userspace and identify interrupts using poll(). -- Thanks, //richard _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Thanks for your input. But I dont want to block the read call. Also I dont want to miss the interrupts. Regards, Amit. On Monday, 27 January 2014 12:22 PM, Richard Weinberger <richard@nod.at> wrote: Am 27.01.2014 06:37, schrieb Amit Mahadik:

Thanks for the reply Richard.         The interrupt is not a GPIO  pin. I have read something about UIO (userspace I/O). Also, I want the operation to be asynchronous. Any pointer to such mechanism will be very helpful.

Using UIO you can also catch an interrupt in userspace. You can have a read() which blocks till data is available. Thanks, //richard _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Thanks Richard. One more question. If I register an SPI irq  struct spi_board_info spi_board_info[] structure in machine board.c file; then the request irq api and irq handler should be written in board.c file or in the spidev driver. Regards, Amit. On Monday, 27 January 2014 2:54 PM, Richard Weinberger <richard@nod.at> wrote: Am 27.01.2014 10:21, schrieb Amit Mahadik:

Thanks for your input. But I dont want to block the read call. Also I dont want to miss the interrupts.

Look how other drivers/programs deal with that... Thanks, //richard

Regards, Amit.

On Monday, 27 January 2014 12:22 PM, Richard Weinberger <richard@nod.at> wrote: Am 27.01.2014 06:37, schrieb Amit Mahadik:

...

Thanks for the reply Richard.         The interrupt is not a GPIO  pin. I have read something about UIO (userspace I/O). Also, I want the operation to be asynchronous. Any pointer to such mechanism will be very helpful.

Using UIO you can also catch an interrupt in userspace. You can have a read() which blocks till data is available.

Thanks, //richard

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You can implement irq handler in spi driver itself. SPI specific platform data can pass it from board file. Regards Vishwa On Tue, Jan 28, 2014 at 9:24 PM, Richard Weinberger <richard@nod.at> wrote:

Am 28.01.2014 15:12, schrieb Amit Mahadik:

...

Thanks Richard. One more question. If I register an SPI irq struct spi_board_info spi_board_info[] structure in machine board.c file; then the request irq api and irq handler should be written in board.c file or in the spidev driver.

Never do any programming in the board file. The purpose if the board file it describing the hardware. Please note, board files go away, device tree is the way to go.

Thanks, //richard

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Hi All, You can use netlink socket to send data from kernel to user space. -Anand Moon On Friday, February 14, 2014 11:51 AM, Nilesh Bacchewar <b.nilesh2005@gmail.com> wrote: you can use Asynchronous notification  , FASYNC . http://www.makelinux.net/ldd3/chp-6-sect-4 Regards, Nilesh On Tue, Jan 28, 2014 at 9:47 PM, Vishwanath Govind <vishwanath.govind@gmail.com> wrote: You can implement irq handler in spi driver itself. SPI specific platform data can pass it from board file.

Regards Vishwa

On Tue, Jan 28, 2014 at 9:24 PM, Richard Weinberger <richard@nod.at> wrote:

Am 28.01.2014 15:12, schrieb Amit Mahadik:

...

...

Thanks Richard. One more question. If I register an SPI irq  struct spi_board_info spi_board_info[] structure in machine board.c file; then the request irq api and irq handler should be written in board.c file or in the spidev driver.

Never do any programming in the board file. The purpose if the board file it describing the hardware. Please note, board files go away, device tree is the way to go.

Thanks, //richard

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