#define _GNU_SOURCE
/* probe_alsa.c — 探测 R3 Pro II CS43198 PCM 设备的 hw_params 约束（找可用的 access/format/rate）。
 * mipsel 交叉编译后推到设备运行，输出 kernel 支持哪些组合，诊断「hw_params ioctl 失败」。 */
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sound/asound.h>

static void pmask(struct snd_mask *m, unsigned bit) { m->bits[bit / 32] |= 1u << (bit % 32); }
static void pivset(struct snd_interval *iv, unsigned val)
{
    iv->min = iv->max = val; iv->integer = 1; iv->openmin = iv->openmax = 0; iv->empty = 0;
}
static const char *fmt_name(unsigned f)
{
#define N(x) case x: return #x
    switch (f) {
        N(SNDRV_PCM_FORMAT_S8); N(SNDRV_PCM_FORMAT_U8); N(SNDRV_PCM_FORMAT_S16_LE);
        N(SNDRV_PCM_FORMAT_S16_BE); N(SNDRV_PCM_FORMAT_U16_LE); N(SNDRV_PCM_FORMAT_U16_BE);
        N(SNDRV_PCM_FORMAT_S24_LE); N(SNDRV_PCM_FORMAT_S24_BE); N(SNDRV_PCM_FORMAT_S32_LE);
        N(SNDRV_PCM_FORMAT_S32_BE); N(SNDRV_PCM_FORMAT_FLOAT_LE); N(SNDRV_PCM_FORMAT_FLOAT_BE);
        N(SNDRV_PCM_FORMAT_S24_3LE); N(SNDRV_PCM_FORMAT_S24_3BE); N(SNDRV_PCM_FORMAT_U24_LE);
        N(SNDRV_PCM_FORMAT_S20_3LE); N(SNDRV_PCM_FORMAT_S20_3BE);
        default: return "?";
    }
#undef N
}

int main(void)
{
    setvbuf(stdout, NULL, _IONBF, 0);   /* 每行立即刷出，防 kill 丢输出 */
    const char *dev = "/dev/snd/pcmC0D0p";
    unsigned access[] = { SNDRV_PCM_ACCESS_MMAP_INTERLEAVED, SNDRV_PCM_ACCESS_RW_INTERLEAVED,
                          SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED, SNDRV_PCM_ACCESS_RW_NONINTERLEAVED, ~0u };
    unsigned fmts[] = { SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_FORMAT_S24_LE, SNDRV_PCM_FORMAT_S32_LE,
                        SNDRV_PCM_FORMAT_S24_3LE, ~0u };
    unsigned rates[] = { 44100, 48000, 96000, 88200, ~0u };
    for (unsigned ai = 0; access[ai] != ~0u; ai++) {
        for (unsigned fi = 0; fmts[fi] != ~0u; fi++) {
            printf("== access=%u fmt=%s ==\n", access[ai], fmt_name(fmts[fi]));
            struct snd_pcm_hw_params p;
            for (unsigned ri = 0; rates[ri] != ~0u; ri++) {
                int fd = open(dev, O_RDWR | O_NONBLOCK);
                if (fd < 0) { printf("  open: %s\n", strerror(errno)); break; }
                /* 「全放行」初始化：memset 0 的 interval =「只能取 0」→ refine 必空 EINVAL
                 *（2026-08-31 真机全灭的根因；libasound snd_pcm_hw_params_any 语义） */
                memset(&p, 0, sizeof p);
                unsigned nm = SNDRV_PCM_HW_PARAM_LAST_MASK - SNDRV_PCM_HW_PARAM_FIRST_MASK + 1;
                for (unsigned i = 0; i < nm; i++)
                    for (unsigned b = 0; b < sizeof p.masks[i].bits / sizeof p.masks[i].bits[0]; b++)
                        p.masks[i].bits[b] = ~0u;
                unsigned ni = SNDRV_PCM_HW_PARAM_LAST_INTERVAL - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL + 1;
                for (unsigned i = 0; i < ni; i++) { p.intervals[i].min = 0; p.intervals[i].max = ~0u; }
                /* mask 先清零再单点：全 1 会被 choose 取最低 bit（access→MMAP_INTERLEAVED） */
                struct snd_mask *am = &p.masks[SNDRV_PCM_HW_PARAM_ACCESS - SNDRV_PCM_HW_PARAM_FIRST_MASK];
                memset(am, 0, sizeof *am); pmask(am, access[ai]);
                struct snd_mask *fm = &p.masks[SNDRV_PCM_HW_PARAM_FORMAT - SNDRV_PCM_HW_PARAM_FIRST_MASK];
                memset(fm, 0, sizeof *fm); pmask(fm, fmts[fi]);
                struct snd_mask *sm = &p.masks[SNDRV_PCM_HW_PARAM_SUBFORMAT - SNDRV_PCM_HW_PARAM_FIRST_MASK];
                memset(sm, 0, sizeof *sm); pmask(sm, SNDRV_PCM_SUBFORMAT_STD);
                pivset(&p.intervals[SNDRV_PCM_HW_PARAM_CHANNELS - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL], 2);
                pivset(&p.intervals[SNDRV_PCM_HW_PARAM_RATE - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL], rates[ri]);
                p.rmask = ~0u; p.info = 0; p.msbits = 0; p.rate_num = 0; p.rate_den = 0; p.flags = 0;
                int rc = ioctl(fd, SNDRV_PCM_IOCTL_HW_PARAMS, &p);
                printf("  @%u: %s\n", rates[ri], rc ? strerror(errno) : "OK");
                close(fd);
            }
        }
    }
    return 0;
}