What is a platform driver?

What is a platform driver?

Platform drivers are dedicated to devices not based on conventional buses. I2C devices or SPI devices are platform devices, but respectively rely on I2C or SPI buses not on the platform bus. Everything needs to be done manually with the platform driver.

What is difference between platform driver and device driver?

Platform driver is for those devices that are on chip. Normal device driver are for those that are interfaced to the processor chip.

What is Platform bus?

The term platform bus refers to a specific Fuchsia driver with source code located at //fuchsia/src/devices/bus/drivers/platform/. On arm64 platforms, the platform bus driver uses information from the bootloader or boot shim to bind the correct board driver for the platform it is running on.

What are platform devices in Linux?

Platform devices are given a name, used in driver binding, and a list of resources such as addresses and IRQs: struct platform_device { const char *name; u32 id; struct device dev; u32 num_resources; struct resource *resource; };

What is struct device?

Description. At the lowest level, every device in a Linux system is represented by an instance of struct device. The device structure contains the information that the device model core needs to model the system. Most subsystems, however, track additional information about the devices they host.

How do I register my device?

To register a new device: Tap the menu icon. Tap anywhere in the section containing your name and profile picture. Tap DEVICES. Tap on Register Device.

Which is an example of a Linux platform driver?

Typical examples are i2c devices, kernel/Documentation/i2c/instantiating-devices states: Unlike PCI or USB devices, I2C devices are not enumerated at the hardware level (at run time). Instead, the software must know (at compile time) which devices are connected on each I2C bus segment. So USB and PCI are not platform devices.

Why are some drivers not converted to platform devices?

System setup also associates those clocks with the device, so that calls to clk_get (&pdev->dev, clock_name) return them as needed. Some drivers are not fully converted to the driver model, because they take on a non-driver role: the driver registers its platform device, rather than leaving that for system infrastructure.

How does probing work in a platform driver?

The probing can use device resources, including clocks, and device platform_data. Platform drivers register themselves the normal way: Or, in common situations where the device is known not to be hot-pluggable, the probe () routine can live in an init section to reduce the driver’s runtime memory footprint:

How is a platform device connected to a bus?

Rarely, a platform_device will be connected through a segment of some other kind of bus; but its registers will still be directly addressable. Platform devices are given a name, used in driver binding, and a list of resources such as addresses and IRQs: