WIP 1wire

bsp/rp2040/m_default/1wire.c

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+#include <stdio.h>
+
+#include "m_default/1wire.h"

src/m_default/1wire.h

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+#ifndef _1WIRE_H
+#define _1WIRE_H  // we're too cool for #pragma once over here?
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+enum onewire_cmd {
+    // select controller or peripheral, and enable or disable overdrive mode
+    OW_SET_MODE = 0x00,
+
+    // controller
+    OW_WRITE_READ = 0x01,
+    OW_READ_ROM   = 0x02,
+    OW_MATCH_ROM  = 0x03,
+    OW_SEARCH_ROM = 0x04,
+
+    // peripheral
+    OW_SET_EMULATION_TYPE = 0x81,
+    OW_SET_EMULATION_DATA = 0x82,
+    OW_REPORT_TIMING      = 0x83,  // 🕵️📈
+};
+
+enum onewire_mode {
+    OWM_CONTROLLER    = 0x00,
+    OWM_CONTROLLER_OD = 0x10,
+    OWM_PERIPHERAL    = 0x01,
+    OWM_PERIPHERAL_OD = 0x11
+};
+
+enum ow_emulation_type {
+    DS2401 = 0x2401
+    // TODO: more
+};
+
+// low level init (eg, load and configure PIO program on rp2040)
+bool ow_bsp_init();
+// low level deinit (eg, unload PIO program on rp2040)
+bool ow_bsp_deinit();
+
+// write some bytes then read some bytes
+bool ow_write_read(bool od, uint8_t* out, size_t out_len, uint8_t* in, size_t in_len);
+// read rom (eg for 1w serial numbers / eeproms)
+bool ow_read_rom(bool od, uint8_t* in, size_t in_len);
+// TODO: match rom
+// bool ow_match_rom(...);
+// identify all connected devices
+bool ow_search_rom(bool od, uint64_t* discovered_devices, size_t max_devices);
+
+// execute an emulation of a 1w peripheral
+void ow_run_peripheral_emulation(
+        bool od, enum ow_emulation_type typ, uint8_t* data, size_t data_len);
+
+#endif