nrf: Add NFCT driver.

Co-Authored-By: turbocool3r <turbocool3r@gmail.com>
Co-Authored-By: ferris <ferris@devdroplets.com>

examples/nrf52840/src/bin/nfct.rs

@@ -0,0 +1,79 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_nrf::config::HfclkSource;
+use embassy_nrf::nfct::{Config as NfcConfig, NfcId, NfcT};
+use embassy_nrf::{bind_interrupts, nfct};
+use {defmt_rtt as _, embassy_nrf as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    NFCT => nfct::InterruptHandler;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = embassy_nrf::config::Config::default();
+    config.hfclk_source = HfclkSource::ExternalXtal;
+    let p = embassy_nrf::init(config);
+
+    dbg!("Setting up...");
+    let config = NfcConfig {
+        nfcid1: NfcId::DoubleSize([0x04, 0x68, 0x95, 0x71, 0xFA, 0x5C, 0x64]),
+        sdd_pat: nfct::SddPat::SDD00100,
+        plat_conf: 0b0000,
+        protocol: nfct::SelResProtocol::Type4A,
+    };
+
+    let mut nfc = NfcT::new(p.NFCT, Irqs, &config);
+
+    let mut buf = [0u8; 256];
+
+    loop {
+        info!("activating");
+        nfc.activate().await;
+
+        loop {
+            info!("rxing");
+            let n = match nfc.receive(&mut buf).await {
+                Ok(n) => n,
+                Err(e) => {
+                    error!("rx error {}", e);
+                    break;
+                }
+            };
+            let req = &buf[..n];
+            info!("received frame {:02x}", req);
+
+            let mut deselect = false;
+            let resp = match req {
+                [0xe0, ..] => {
+                    info!("Got RATS, tx'ing ATS");
+                    &[0x06, 0x77, 0x77, 0x81, 0x02, 0x80][..]
+                }
+                [0xc2] => {
+                    info!("Got deselect!");
+                    deselect = true;
+                    &[0xc2]
+                }
+                _ => {
+                    info!("Got unknown command!");
+                    &[0xFF]
+                }
+            };
+
+            match nfc.transmit(resp).await {
+                Ok(()) => {}
+                Err(e) => {
+                    error!("tx error {}", e);
+                    break;
+                }
+            }
+
+            if deselect {
+                break;
+            }
+        }
+    }
+}