On Wed, Dec 7, 2016 at 6:58 PM, Joel Fernandes <agnel.joel@xxxxxxxxx> wrote: > On Tue, Dec 6, 2016 at 11:02 PM, Greg KH <greg@xxxxxxxxx> wrote: >> On Tue, Dec 06, 2016 at 09:12:24PM -0800, Joel Fernandes wrote: >>> On Tue, Dec 6, 2016 at 11:42 AM, Ran Shalit <ranshalit@xxxxxxxxx> wrote: >>> > Hello, >>> > >>> > I have spi device which is registered using spi_register_board_info(), >>> > and I would like to get a pointer to this device in some other kernel module. >>> > >>> > Is there a simple way to get a pointer to pointer to a device , so >>> > that we can use it from other module ? (something like i2c_get_adapter >>> > for i2c) >>> >>> Find out what's the SPI bus number (for the master) and the chip >>> select on that SPI master (for the SPI device) >>> >>> Then you can use bus_for_each_device on spi_bus_type and find the >>> spi_device you're looking for. See the following code for an example >>> of how to use bus_for_each_device: >>> >>> http://lxr.free-electrons.com/source/drivers/spi/spi.c#L524 >>> >>> In your check function, just make sure your spi->master->bus_num is >>> the bus you want and the spi->chip_select is the chip select >>> corresponding to the device you want. If both these conditions are >>> satisfied, there you have your spi_device. >> >> Eeek, no, please never do that, use the proper spi apis to get your >> needed device. They are there somewhere, using a "raw" >> bus_for_each_device is never the answer unless you are a bus and >> iterating over your own device list. > > Yes I completely agree, maybe I assumed too much and thought he was > trying to do this for some quick debugging from some kernel module, > and was just looking for a quick and dirty way to get to a spi_device. > Was not really suggesting this for production code. :) > You were actually Right... That's exactly what I wanted :) , so I probably will try to use your simple method. I think that for production , spidev shows a good example how to use spi as a char device: https://github.com/Xilinx/linux-xlnx/blob/master/drivers/spi/spidev.c Thanks! Ran > Regards, > Joel > >> >> thanks, >> >> greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
