hardwaredevice.h

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// SPDX-License-Identifier: AGPL-3.0-or-later
 
#ifndef __HARDWAREDEVICE_H
#define __HARDWAREDEVICE_H
 
#include <cstdio>
#include <cstdint>
#include <string>
 
#include "logger.h"
 
enum HardwareQuirks {
    QUIRK_CODEC_FLUSH_WORKAROUND       = 1 << 0,     
};
 
static inline size_t ReadLineFromFile(char *buf, size_t size, const char * file) {
    FILE *fd = NULL;
    size_t character;
 
    fd = fopen(file, "r");
    if (fd == NULL) {
        LOGERROR("%s: Can't open %s", __FUNCTION__, file);
        return 0;
    }
 
    character = getline(&buf, &size, fd);
 
    fclose(fd);
 
    return character;
}
 
class cHardwareDevice
{
public:
    cHardwareDevice(void) {
        char *txt_buf;
        char *read_ptr;
        size_t bufsize = 128;
        size_t read_size;
 
        txt_buf = (char *) calloc(bufsize, sizeof(char));
 
        read_size = ReadLineFromFile(txt_buf, bufsize, "/sys/firmware/devicetree/base/compatible");
        if (!read_size) {
            free((void *)txt_buf);
            LOGERROR("could not from read /sys/firmware/devicetree/base/compatible, no quirks set");
            return;
        }
 
        read_ptr = txt_buf;
        // be aware: device tree string can contain \x0 bytes, so every C-string function
        // thinks, we already reached the string's terminating null bytes
        // so copy the string into a temporary string without the "\0"
        char *_txt_buf = (char *) calloc(bufsize, sizeof(char));
        char *_read_ptr = _txt_buf;
        for (size_t i = 0; i < bufsize; i++) {
            if (memcmp(read_ptr, "\0", sizeof(char))) {
                memcpy(_read_ptr, read_ptr, sizeof(char));
                _read_ptr++;
            }
            read_ptr++;
        }
 
        read_ptr = txt_buf;
        while(read_size) {
            if (strstr(read_ptr, "bcm2836")) {
                m_deviceName = "bcm2836 (Raspberry Pi 2 Model B)";
                m_quirks |= QUIRK_CODEC_FLUSH_WORKAROUND;
                break;
            }
            if (strstr(read_ptr, "bcm2837")) {
                m_deviceName = "bcm2837 (Raspberry Pi 2 Model B v1.2/ 3 Model B, Raspberry Pi 3 Compute Module 3)";
                m_quirks |= QUIRK_CODEC_FLUSH_WORKAROUND;
                break;
            }
            if (strstr(read_ptr, "bcm2711")) {
                m_deviceName = "bcm2711 (Raspberry Pi 4 Model B, Compute Module 4, Pi 400)";
                m_quirks |= QUIRK_CODEC_FLUSH_WORKAROUND;
                break;
            }
            if (strstr(read_ptr, "bcm2712")) {
                m_deviceName = "bcm2712 (Raspberry Pi 5, Compute Module 5, Pi 500)";
                m_quirks |= QUIRK_CODEC_FLUSH_WORKAROUND;
                break;
            }
 
            read_size -= strlen(read_ptr) + 1;
            read_ptr = (char *)&read_ptr[(strlen(read_ptr) + 1)];
        }
 
        if (m_deviceName)
            LOGDEBUG("%s found%s", m_deviceName,
                m_quirks & QUIRK_CODEC_FLUSH_WORKAROUND ? ", flush workaround" : "");
        else
            LOGDEBUG("%s found, no quirks set", txt_buf);
 
        free((void *)_txt_buf);
        free((void *)txt_buf);
    }
 
    int GetQuirks(void) { return m_quirks; };
    const char *GetName(void) { return m_deviceName; };
 
private:
    const char *m_deviceName = nullptr;  
    int m_quirks = 0;                    
};
 
#endif