zynq-rs/libboard_zynq/src/sdio/adma.rs

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/// ADMA library
use core::mem::MaybeUninit;
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use super::SDIO;
use libcortex_a9::cache;
use libregister::{RegisterR, VolatileCell};
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#[repr(C, align(4))]
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pub struct Adma2Desc32 {
attribute: VolatileCell<u16>,
length: VolatileCell<u16>,
address: VolatileCell<u32>,
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}
// Default::default() cannot be used as it is not a constant function...
static mut ADMA2_DESCR32_TABLE: MaybeUninit<[Adma2Desc32; 32]> = MaybeUninit::uninit();
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#[allow(unused)]
const DESC_MAX_LENGTH: u32 = 65536;
#[allow(unused)]
const DESC_TRANS: u16 = 0x2 << 4;
#[allow(unused)]
const DESC_INT: u16 = 0x1 << 2;
#[allow(unused)]
const DESC_END: u16 = 0x1 << 1;
#[allow(unused)]
const DESC_VALID: u16 = 0x1 << 0;
#[allow(unused)]
impl Adma2Desc32 {
pub fn set_attribute(&mut self, attribute: u16) {
self.attribute.set(attribute)
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}
pub fn set_length(&mut self, length: u16) {
self.length.set(length)
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}
pub fn set_address(&mut self, address: u32) {
self.address.set(address)
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}
}
/// Initialize `ADMA2_DESCR32_TABLE` and setup `adma_system_address`
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pub fn setup_adma2_descr32(sdio: &mut SDIO, blk_cnt: u32, buffer: &[u8]) {
let descr_table = unsafe { &mut *ADMA2_DESCR32_TABLE.as_mut_ptr() };
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let blk_size = sdio
.regs
.block_size_block_count
.read()
.transfer_block_size() as u32;
let total_desc_lines = if blk_size * blk_cnt < DESC_MAX_LENGTH {
1
} else {
blk_size * blk_cnt / DESC_MAX_LENGTH
+ if (blk_size * blk_cnt) % DESC_MAX_LENGTH == 0 {
0
} else {
1
}
} as usize;
let ptr = buffer.as_ptr() as u32;
for desc_num in 0..total_desc_lines {
descr_table[desc_num].set_address(ptr + (desc_num as u32) * DESC_MAX_LENGTH);
descr_table[desc_num].set_attribute(DESC_TRANS | DESC_VALID);
// 0 is the max length (65536)
descr_table[desc_num].set_length(0);
}
descr_table[total_desc_lines - 1].set_attribute(DESC_TRANS | DESC_VALID | DESC_END);
descr_table[total_desc_lines - 1].set_length(
(blk_cnt * blk_size - ((total_desc_lines as u32) - 1) * DESC_MAX_LENGTH) as u16,
);
unsafe {
sdio.regs
.adma_system_address
.write(descr_table.as_ptr() as u32);
}
cache::dcci_slice(descr_table);
}