rpi4-osdev/part7-bluetooth/kernel.c

#include "io.h"
#include "fb.h"
#include "bt.h"

enum {
    OGF_HOST_CONTROL = 0x03,
    OGF_LE_CONTROL = 0x08,
    OGF_VENDOR = 0x3f,
    COMMAND_RESET_CHIP = 0x03,
    VENDOR_LOAD_FIRMWARE = 0x2e,
    HCI_COMMAND_PKT = 0x01,
    HCI_EVENT_PKT = 0x04,
    LL_SCAN_ACTIVE = 0x01,
    EVENT_TYPE_COMMAND_STATUS = 0x0e
};

unsigned char lo(unsigned int val) { return (unsigned char)(val & 0xff); }
unsigned char hi(unsigned int val) { return (unsigned char)((val & 0xff00) >> 8); }

unsigned char empty[] = {};

int hciCommandBytes(unsigned char *opcodebytes, unsigned char *data, unsigned char length)
{
    unsigned char c=0;

    bt_writeByte(HCI_COMMAND_PKT);
    bt_writeByte(opcodebytes[0]);
    bt_writeByte(opcodebytes[1]);
    bt_writeByte(length);

    while (c++<length) bt_writeByte(*data++);

    if (bt_waitReadByte() != HCI_EVENT_PKT) return 0;
    if (bt_waitReadByte() != EVENT_TYPE_COMMAND_STATUS) return 0;
    if (bt_waitReadByte() != 4) return 0;
    if (bt_waitReadByte() == 0) return 0;
    if (bt_waitReadByte() != opcodebytes[0]) return 0;
    if (bt_waitReadByte() != opcodebytes[1]) return 0;
    if (bt_waitReadByte() != 0) return 0;

    return 1;
}

int hciCommand(unsigned short ogf, unsigned short ocf, unsigned char *data, unsigned char length)
{
    unsigned short opcode = ogf << 10 | ocf;
    unsigned char opcodebytes[2] = { lo(opcode), hi(opcode) };

    return hciCommandBytes(opcodebytes, data, length);
}

void loadFirmware()
{
    if (!hciCommand(OGF_VENDOR, VENDOR_LOAD_FIRMWARE, empty, 0)) uart_writeText("loadFirmware() failed\n");

    extern unsigned char _binary_BCM4345C0_hcd_start[];
    extern unsigned char _binary_BCM4345C0_hcd_size[];

    unsigned int c=0;
    unsigned int size = (long)&_binary_BCM4345C0_hcd_size;

    while (c < size) {
        unsigned char opcodebytes[] = { _binary_BCM4345C0_hcd_start[c], _binary_BCM4345C0_hcd_start[c+1] };
        unsigned char length = _binary_BCM4345C0_hcd_start[c+2];
        unsigned char *data = &(_binary_BCM4345C0_hcd_start[c+3]);

        if (!hciCommandBytes(opcodebytes, data, length)) {
	   uart_writeText("Firmware data load failed\n");
	   break;
	}
	c += 3 + length;
    }

    wait_msec(0x100000);
}

void setLEeventmask(unsigned char mask)
{
    unsigned char params[] = { mask, 0, 0, 0, 0, 0, 0, 0 };
    if (!hciCommand(OGF_LE_CONTROL, 0x01, params, 8)) uart_writeText("setLEeventmask failed\n");
}

void setLEscanenable(unsigned char state, unsigned char duplicates) {
    unsigned char params[] = { state, duplicates };
    if (!hciCommand(OGF_LE_CONTROL, 0x0c, params, 2)) uart_writeText("setLEscanenable failed\n");
}

void setLEscanparameters(unsigned char type, unsigned char linterval, unsigned char hinterval, unsigned char lwindow, unsigned char hwindow, unsigned char own_address_type, unsigned char filter_policy) {
    unsigned char params[] = { type, linterval, hinterval, lwindow, hwindow, own_address_type, filter_policy };
    if (!hciCommand(OGF_LE_CONTROL, 0x0b, params, 7)) uart_writeText("setLEscanparameters failed\n");
}

void startActiveScanning() {
    float BleScanUnitsPerSecond = 1600;
    float BleScanInterval = 0.8;
    float BleScanWindow = 0.4;

    unsigned int p = BleScanInterval * BleScanUnitsPerSecond;
    unsigned int q = BleScanWindow * BleScanUnitsPerSecond;

    setLEscanparameters(LL_SCAN_ACTIVE, lo(p), hi(p), lo(q), hi(q), 0, 0);
    setLEscanenable(1, 0);
}

void main()
{
    fb_init();
    uart_init();
    bt_init();

    uart_writeText("reset()\n");
    if (!hciCommand(OGF_HOST_CONTROL, COMMAND_RESET_CHIP, empty, 0)) uart_writeText("reset() failed\n");

    uart_writeText("loadfirmware()\n");
    loadFirmware();

    setLEeventmask(0xff);
    startActiveScanning();

    uart_writeText("Waiting for input...\n");
    while (1) uart_update();
}