88 lines
2.4 KiB
Rust
88 lines
2.4 KiB
Rust
//! Simple "passthrough" bus device
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// use device_tree::{device_tree_driver, dt::DevTreeIndexNodeExt};
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// use libk::device::manager::DEVICE_REGISTRY;
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use core::ops::Range;
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use abi::error::Error;
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use alloc::{sync::Arc, vec::Vec};
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use device_api::{
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bus::Bus,
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device::{Device, DeviceInitContext},
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};
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use device_tree::{
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driver::{device_tree_driver, Node, ProbeContext},
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DeviceTreePropertyRead,
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};
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struct SimpleBus {
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ranges: Vec<(Range<u64>, u64)>,
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}
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impl Device for SimpleBus {
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unsafe fn init(self: Arc<Self>, _cx: DeviceInitContext) -> Result<(), Error> {
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Ok(())
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}
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fn as_bus(self: Arc<Self>) -> Option<Arc<dyn Bus>> {
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Some(self)
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}
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fn display_name(&self) -> &str {
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"simple-bus"
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}
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}
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impl Bus for SimpleBus {
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fn map_range(&self, bus_range: Range<u64>) -> Option<Range<u64>> {
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if self.ranges.is_empty() {
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return Some(bus_range);
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}
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let start = bus_range.start;
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let end = bus_range.end;
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for (range, offset) in self.ranges.iter() {
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if range.contains(&start) && range.contains(&end) {
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let start = start - range.start + *offset;
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let end = end - range.start + *offset;
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return Some(start..end);
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}
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}
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None
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}
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}
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device_tree_driver! {
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compatible: ["simple-bus"],
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driver: {
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fn probe(&self, node: &Arc<Node>, _context: &ProbeContext) -> Option<Arc<dyn Device>> {
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// Format per DT spec: (child-bus-address, parent-bus-address, length)
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// Where:
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// child-bus-address: #address-cells of this node
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// parent-bus-address: #address-cells of parent bus
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// length: #size-cells of this node
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let ranges = node.property("ranges")?;
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let parent_address_cells = node.bus_address_cells();
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let child_address_cells = node.self_address_cells()?;
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let child_size_cells = node.self_size_cells()?;
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let cell_sizes = (child_address_cells, parent_address_cells, child_size_cells);
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let mut items = Vec::new();
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for (child_address, parent_address, length) in ranges.iter_cells(cell_sizes) {
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let child_range = child_address..child_address + length;
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items.push((child_range, parent_address));
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}
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Some(Arc::new(SimpleBus {
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ranges: items,
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}))
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}
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}
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}
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