Tutorial 26: Controlling a SPI device using the ZYNQ SPI controller

Currently the player is controller through the terminal connected to the UART. The Zedboard has LEDs and buttons which we can use as user interface. It is normally a better choice to scan a keyboard in a periodic interrupt. The next tutorial shows how to add an AXI timer which triggers a periodic interrupt every 20 ms:.

We can now exchange […]. In that example we triggered […]. In this tutorial we create a bidirectional SPI interface. A regular SPI interface receives a word for every word it transmits. So, […]. Beauty is in the eye of the beholder.

Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. How to connect a second interrupt signal to the ZYNQ fabric. How to add a second interrupt handler. Open the Main Project Start with the project from this post. Or download the complete project further down. Remove the prescaler which is connected to the heartbeat LED. We need all 8 LEDs to form a bar graph display. Also remove the heartbeat output.

The first port is now the output although we configured the first port to be an input. I did not manage to connect only 3 bits of the LED vector using the drag-and-drop method. I had to resort to the constraint file instead and assign the pin numbers and logic levels manually. Run Connection Automation. The concat block merges the two interrupt signals into a 2-bit vector.

Add the concat block. Connect the interrupt output of the DMA controller to the first input of the concat block.For many applications in this blog and my Hackster projectsI use a bare metal approach. However, sometimes we need the capabilities provided by a operating system, e. The first thing we need is a Vivado design. As such, my Vivado design includes the following IP:. You can find the completed Vivado design on my GitHub.

It is this file we will use to to customize the PetaLinux build. Now this is where our development is different to previous examples. The first thing we need to do in PetaLinux is to create a project.

We can do this using the command:. This creates a project which will can be targeted at a Zynq series device. Of course, we need to be able to customize it for our hardware design. To do this, we import the HDF and apply it to the project using the command:. Once this has been imported, you will see a PetaLinux configuration box appear. Here is where we would make any changes we desire. For this example, though, we will not change anything. If prompted to save the new configuration as you exit, select yes.

Once you exit the configuration menu, bitbake will run and generate all of the files we need. Please note that this might take several minutes. Once this is built, we have all of the constituent parts required to run Petalinux.

The final stage is to create the Boot. This will generate the boot. When the board boots, if asked for a login and password use root for both.The PetaLinux Tools offers everything necessary to customize, build and deploy Embedded Linux solutions on Xilinx processing systems.

PetaLinux tools eases the development of Linux-based products; all the way from system boot to execution with the following tools:. With these tools developers can customize the boot loader, Linux kernel, or Linux applications. They can add new kernels, device drivers, applications, libraries, and boot and test software stacks on the included full system simulator QEMU or on physical hardware via network or JTAG.

PetaLinux tools enable developers to synchronize the software platform with the hardware design as it gains new features and devices.

PetaLinux tools will automatically generate a custom, Linux Board Support Package including device drivers for Xilinx embedded processing IP cores, kernel and boot loader configurations. Such capability allows software engineers to focus on their value-added applications rather than low level development tasks.

PetaLinux includes tools to customize the boot loader, Linux kernel, file system, libraries and system parameters. These configuration tools are fully aware of Xilinx hardware development tools and custom-hardware-specific data files so that, for example, device drivers for Xilinx embedded IP cores will be automatically built and deployed according to the engineer-specified address of that device.

PetaLinux tools integrate development templates that allow software teams to create custom device drivers, applications, libraries and BSP configurations. PetaLinux provides a complete, reference Linux distribution that has been integrated and tested for Xilinx devices. The reference Linux distribution includes both binary and source Linux packages including:. Built-in tools allow a single command to deploy and boot these elements to either physical hardware, or to the included full QEMU system emulator.

With PetaLinux, developers can have their Xilinx-based hardware booted and running within about 5 minutes after installation; ready for application, library and driver development. The PetaLinux Tools License is no longer required. Users can install and use PetaLinux tools to deploy royalty free OS images. PetaLinux Tools.

Xilinx - Adaptable. PetaLinux Tools host. Embedded Software Ecosystem. Linux Configuration Tools. Software Development Tools. Reference Linux Distribution. Quick-start Linux Images. Features supported by Xilinx Technical Support:. This download includes software corresponding to software releases: Xilinx Releases Download Mali User Space Components.

Training Forums. Page Bookmarked.I'm using Vivado and Petalinux This should be simple, right? Not really I then exported the hardware and imported it to my Petalinux project.

I added some device-tree entries for the LEDs I want to use and rebuilt everything. Problems :. It turns out this problem is the pl. The gpio-leds driver now loads and appears to properly connect the LEDs I defined with the proper gpio pins, but the LEDs do not actually turn on, which leads to problem number: 3 I cannot change the value of the GPIO pins. The first bank is input only and is tied to the push-button switches on the Zybo-Z7.

These work as expected, I can export the gpio, and the value reported via sysfs changes as I push the various switches. It is at this point I am giving up and asking for help. What can make the GPIO value stay stuck at zero when it's configured as an output? I have attached the dtsi files from the Petalinux build in case you might be able to review them and spot anything I did wrong.

The problem is with the clocking. I can set output values, use gpio-leds, and otherwise use the gpio pins as expected. I'm not really sure if this is an actual bug with the tools or not, but it's definitely annoying and it seems like something that ought to at least be documented. If I missed the documentation for this, please point me to it, it likely contains a bunch of other details I should be aware of!

petalinux axi gpio example

View solution in original post. But if the references in gpio-leds include a third cell I just used 0 for the value everything works as expected. Linux sees the LEDs, and I can manually export unused LEDs and set the value as expected via sysfs entries, using exactly the same commands that fail on the Zynq adjusting the GPIO value as needed for the platform.

Sign In Help. Turn on suggestions.Asked by Saad Zia. I need help regarding interrupt handling using UIO. I am using Vivado The board used is Zedboard. I made the following vivado project attached as image. But the issue is that this code is not catching the interrupt.

Kindly help me in this. Looking at your code again, it doesn't look like you ever initialize your gpio controller to trigger interrupts. Note that it will also be up to you to properly reset the Interrupt status register once an interrupt has been detected.

I'm happy it works for you, glad to help you.

petalinux axi gpio example

I glanced over your code quickly and it seems like you are doing things correctly. Please provide the device tree node for your UIO device. There is also an example in my answer that you link in your first message! You need to be a member in order to leave a comment.

Sign up for a new account in our community. It's easy! Already have an account? Sign in here. Embedded Linux Search In. How to detect and handle UIO interrupt. Asked by Saad Zia petalinux uio interrupts gpio zedboard. Posted August 30, Share this post Link to post Share on other sites. Recommended Posts. Posted September 11, Posted September 12, Posted September 6, Posted September 7, Following is my device tree node.

In your device tree, it seems that you missed the interrupt-cells. You may try to add it! But it still won't catch any interrupt. Posted November 21, Posted November 22, Posted November 23, That link was for adding UIO.

For AXI follow the above code. Create an account or sign in to comment You need to be a member in order to leave a comment Create an account Sign up for a new account in our community. Register a new account. Sign in Already have an account?After reading a lot of posts it seems like I am on the right track for doing this correctly, but yet it still does not quite work.

I took the zedboard release file, extracted it, and then copied it over to an SD card and booted from that. Seems to work fine. After that, I create a hardware. I generate the. Based on the system. I try to map just one byte because the GPIO register with the values is in the first byte at least I believe it is Even more aggravating is when I do a bare metal application and de-reference 0x, it accurately reads the switches. Thanks in advance for any help provided!

This has been driving me crazy for the past two days now Wondering if I'll give it a shot with an earlier version and post back here how it goes hopefully today, but for sure early next week. This is currently being done under This may have broken in Thanks for the response! When you talk about the DTS entry, how would I go about making that change? I know what it is and understand what it does, but I do not know how to update it appropriately. Same issue as before. Also I tried using the devmem command as well and it also freezes.

Guessing this is either a DTS issue or I need to build my own version of the boot. So in case anybody else needs to do this, here is what I had to do from SDK onwards; in Vivado the steps are adding the appropriate IP block, then building the. Otherwise you can brick the system by having an invalid SD card and make it very hard to re-boot it.

Select New 2c. A browser window will pop up. Hit Apply, then OK. In the pop up window, name the project for example, LinuxDeviceTree. Select that one and click Finish assuming you exported only one Hardware Platform.

Open the Project folder for the device tree BSP. In there you should see several. The one you can build and make work for the zedboard is the system. Open pl.

petalinux axi gpio example

We will use this in a little bit. Find the devicetree. A "devicetree. Open up this file.For this tutorial I am using Vivado This will bring up the IP configuration window. Wire them up to the corresponding pin on the SPI controller. Note: there will be many unused pins, since the controller can be used as a master, slave, or both. To do this, instantiate a constant IP module and set the value to 1.

My block design is shown below:. Note that I have also marked the pins for debug. This can be really useful for debugging your software using the embedded logic analyzer feature of Vivado. Generate a bitstream and export your design to SDK. You need to create a PetaLinux project and extract the hardware description from your project SDK directory as discussed in tutorial Before you build PetaLinux, though, you need to modify the device tree to create the appropriate device file for your SPI device.

Then you need to enable SPI support for your kernel.

Expanding Zynq with AXI BRAM and SPI Programmable Logic

To configure the kernel run the following command. Now you can run petalinux-build and petalinux-package to build and package Linux.

AXI GPIO Interrupt

Then copy the program to your board using ssh. Run the command, and if you use the embedded logic analyzer, you should see activity on the SPI interface. Will the block design in vivado be the same as given in this tutorial? How can i get my fpga to control the LMXevm? The constraints and PS configuration will differ depending on how you are connecting the device to the board.

How can I get hold of a copy of system-top. I tried to see your. I have a. The dts file is really Linux specific. You can use the techniques described in tutorial 24 to bit-bang the SPI interface.

If you only need low-speed control of a SPI device this can often be the simplest solution. Of course, sometimes it is just easier to read the spec on the SPI IP block and just program the registers. I am using Linux, Xilinx Pulsar Linux in particular.

Now I just need some insight into the MIO mapping syntax in the. Thanks for these helpful tutorial.

petalinux axi gpio example

Every steps look fine except spi check. There is no spidev in dev directory. Do you have any idea? Sorry for the late response.


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