ref: 9a6bf7f0787d050429da8b22a82c89ab5d869943
parent: 91f79ce9fab7c9920b6f331ca074d58c17755fc9
author: Sigrid Solveig Haflínudóttir <sigrid@ftrv.se>
date: Wed Aug 17 19:24:42 EDT 2022
imx8: add a semi-working SAI2 audio driver
--- a/sys/src/9/imx8/io.h
+++ b/sys/src/9/imx8/io.h
@@ -30,6 +30,8 @@
IRQpci2 = SPI+74,
+ IRQsai2 = SPI+96,
+
IRQenet1 = SPI+118,
IRQpci1 = SPI+122,
--- a/sys/src/9/imx8/reform
+++ b/sys/src/9/imx8/reform
@@ -22,6 +22,7 @@
i2c
rtc devi2c
sd
+ audio
link
usbxhciimx
@@ -31,6 +32,7 @@
netdevmedium
i2cimx devi2c
pciimx pci
+ sai
ip
tcp
--- /dev/null
+++ b/sys/src/9/imx8/sai.c
@@ -1,0 +1,393 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include "../port/audioif.h"
+#include "../port/error.h"
+
+typedef struct Ctlr Ctlr;
+typedef struct Ring Ring;
+
+enum {+ Byteps = 4,
+
+ TCSR = 0x08/4,
+ TCSR_TE = 1<<31,
+ TCSR_FR = 1<<25,
+ TCSR_SR = 1<<24,
+ TCSR_FEF = 1<<18, /* w1c fifo error */
+ TCSR_FWF = 1<<17,
+ TCSR_FRF = 1<<16, /* watermark hit */
+ TCSR_FEIE = 1<<10,
+ TCSR_FWIE = 1<<9,
+ TCSR_FRIE = 1<<8,
+ TCR1 = 0x0c/4,
+ TCR2 = 0x10/4,
+ TCR2_MSEL_MCLK1 = 1<<26,
+ TCR2_BCP = 1<<25,
+ TCR2_BCD_MASTER = 1<<24,
+ TCR3 = 0x14/4,
+ TCR3_TCE_SHIFT = 16,
+ TCR4 = 0x18/4,
+ TCR4_FPACK_16BIT = 3<<24,
+ TCR4_FRSZ_SHIFT = 16,
+ TCR4_SYWD_SHIFT = 8,
+ TCR4_CHMOD = 1<<5,
+ TCR4_MSB_FIRST = 1<<4,
+ TCR4_FSE = 1<<3,
+ TCR4_FSP_LOW = 1<<1,
+ TCR4_FSD_MASTER = 1<<0,
+ TCR5 = 0x1c/4,
+ TCR5_WNW_SHIFT = 24,
+ TCR5_W0W_SHIFT = 16,
+ TCR5_FBT_SHIFT = 8,
+ TDR0 = 0x20/4,
+ TFR0 = 0x40/4,
+ TFRx_WFP_SHIFT = 16,
+ TFRx_RFP_SHIFT = 0,
+ TMR = 0x60/4,
+};
+
+struct Ring {+ Rendez r;
+
+ uchar *buf;
+ ulong nbuf;
+
+ ulong ri;
+ ulong wi;
+};
+
+struct Ctlr {+ u32int *reg;
+ Audio *adev;
+
+ Ring w;
+ int wactive;
+
+ Lock;
+};
+
+#define wr(a, v) ctlr->reg[a] = v
+#define rd(a) ctlr->reg[a]
+
+static long
+buffered(Ring *r)
+{+ ulong ri, wi;
+
+ ri = r->ri;
+ wi = r->wi;
+ if(wi >= ri)
+ return wi - ri;
+ else
+ return r->nbuf - (ri - wi);
+}
+
+static long
+available(Ring *r)
+{+ long m;
+
+ m = (r->nbuf - Byteps) - buffered(r);
+ if(m < 0)
+ m = 0;
+ return m;
+}
+
+static long
+writering(Ring *r, uchar *p, long n)
+{+ long n0, m;
+
+ n0 = n;
+ while(n > 0){+ if((m = available(r)) <= 0)
+ break;
+ if(m > n)
+ m = n;
+ if(p){+ if(r->wi + m > r->nbuf)
+ m = r->nbuf - r->wi;
+ memmove(r->buf + r->wi, p, m);
+ p += m;
+ }
+ r->wi = (r->wi + m) % r->nbuf;
+ n -= m;
+ }
+ return n0 - n;
+}
+
+static int
+outavail(void *arg)
+{+ Ring *r = arg;
+
+ return available(r) > 0;
+}
+
+static int
+outrate(void *arg)
+{+ Ctlr *ctlr = arg;
+ int delay = ctlr->adev->delay*Byteps;
+
+ return delay <= 0 || buffered(&ctlr->w) <= delay || ctlr->wactive == 0;
+}
+
+static void
+saikick(Ctlr *ctlr)
+{+ int delay;
+
+ delay = ctlr->adev->delay*Byteps;
+ if(buffered(&ctlr->w) >= delay){+ ctlr->wactive = 1;
+ /* activate channel 1 */
+ wr(TCR3, 1<<TCR3_TCE_SHIFT);
+ wr(TCSR, TCSR_TE | TCSR_FEF | TCSR_FRIE | TCSR_FWIE | TCSR_FEIE);
+ }
+}
+
+static void
+saistop(Ctlr *ctlr)
+{+ if(!ctlr->wactive)
+ return;
+ ctlr->wactive = 0;
+ wr(TCSR, TCSR_FR | TCSR_SR);
+}
+
+static long
+saiwrite(Audio *adev, void *a, long n, vlong)
+{+ Ctlr *ctlr = adev->ctlr;
+ uchar *p, *e;
+ Ring *r;
+
+ p = a;
+ e = p + n;
+ r = &ctlr->w;
+ while(p < e){+ if((n = writering(r, p, e - p)) <= 0){+ saikick(ctlr);
+ sleep(&r->r, outavail, r);
+ continue;
+ }
+ p += n;
+ }
+ saikick(ctlr);
+ while(outrate(ctlr) == 0)
+ sleep(&r->r, outrate, ctlr);
+ return p - (uchar*)a;
+}
+
+static void
+saiclose(Audio *adev, int mode)
+{+ Ctlr *ctlr = adev->ctlr;
+
+ if(mode == OWRITE || mode == ORDWR)
+ saistop(ctlr);
+}
+
+static void
+saireset(Ctlr *ctlr)
+{+ /* fifo+software reset */
+ wr(TCSR, TCSR_FR | TCSR_SR);
+ delay(1);
+ wr(TCSR, 0);
+ delay(1);
+
+ /* watermark - hit early enough */
+ wr(TCR1, 32);
+ /* derive from mclk1; generate bitclock (active low), f = mclk1/(8+1)*2 = mclk1/18 */
+ wr(TCR2, TCR2_MSEL_MCLK1 | TCR2_BCD_MASTER | TCR2_BCP | 8);
+ /* activate channel 1 */
+ wr(TCR3, 1<<TCR3_TCE_SHIFT);
+ /* set up for i²s */
+ wr(TCR4,
+ TCR4_CHMOD | /* output mode, no TDM */
+ TCR4_MSB_FIRST |
+ TCR4_FPACK_16BIT | /* 16-bit packed words */
+ 1<<TCR4_FRSZ_SHIFT | /* two words per frame */
+ 15<<TCR4_SYWD_SHIFT | /* frame sync per word */
+ /* frame sync */
+ TCR4_FSE | /* one bit earlier */
+ TCR4_FSP_LOW | /* active high */
+ TCR4_FSD_MASTER /* generate internally */
+ );
+ /* 16-bit words, MSB first */
+ wr(TCR5, 15<<TCR5_WNW_SHIFT | 15<<TCR5_W0W_SHIFT | 15<<TCR5_FBT_SHIFT);
+ /* mask all but first two words */
+ wr(TMR, ~3UL);
+}
+
+static long
+saictl(Audio *adev, void *a, long n, vlong)
+{+ char *p, *e, *x, *tok[4];
+ Ctlr *ctlr = adev->ctlr;
+ int ntok;
+ u32int v;
+
+ p = a;
+ e = p + n;
+ for(; p < e; p = x){+ if(x = strchr(p, '\n'))
+ *x++ = 0;
+ else
+ x = e;
+ ntok = tokenize(p, tok, 4);
+ if(ntok <= 0)
+ continue;
+
+ if(cistrcmp(tok[0], "div") == 0 && ntok >= 2){+ v = strtoul(tok[1], nil, 0);
+ wr(TCR2, (rd(TCR2) & ~0xff) | (v & 0xff));
+ }else if(cistrcmp(tok[0], "msel") == 0 && ntok >= 2){+ v = strtoul(tok[1], nil, 0);
+ wr(TCR2, (rd(TCR2) & ~(3<<26)) | (v & 3)<<26);
+ }else if(cistrcmp(tok[0], "reset") == 0){+ saireset(ctlr);
+ }else
+ error(Ebadctl);
+ }
+ return n;
+}
+
+static long
+fifo(Ctlr *ctlr, long n)
+{+ long n0, m;
+ u32int *p;
+ Ring *r;
+
+ n0 = n;
+ r = &ctlr->w;
+ while(n > 0){+ if((m = buffered(r)) <= 0 || m < 4)
+ break;
+ if(m > n)
+ m = n;
+
+ if(r->ri + m > r->nbuf)
+ m = r->nbuf - r->ri;
+ m &= ~(Byteps-1);
+ for(p = (u32int*)(r->buf + r->ri); p < (u32int*)(r->buf + r->ri + m); p++)
+ wr(TDR0, *p);
+
+ r->ri = (r->ri + m) % r->nbuf;
+ n -= m;
+ }
+ return n0 - n;
+}
+
+static void
+saiinterrupt(Ureg *, void *arg)
+{+ Ctlr *ctlr = arg;
+ u32int v;
+ Ring *r;
+
+ ilock(ctlr);
+ v = rd(TCSR);
+ if(v & (TCSR_FEF | TCSR_FRF | TCSR_FWF)){+ r = &ctlr->w;
+ if(ctlr->wactive){+ if(buffered(r) < 128*Byteps) /* having less than fifo buffered */
+ saistop(ctlr);
+ else if(fifo(ctlr, (128-32)*Byteps) > 0)
+ v |= TCSR_TE;
+ }
+ wakeup(&r->r);
+ }
+ wr(TCSR, v | TCSR_FEF);
+ iunlock(ctlr);
+}
+
+static long
+saistatus(Audio *adev, void *a, long n, vlong)
+{+ Ctlr *ctlr = adev->ctlr;
+ u32int v, p;
+ char *s, *e;
+
+ s = a;
+ e = s + n;
+ v = rd(TCSR);
+ p = rd(TFR0);
+ s = seprint(s, e, "transmit wfp %d rfp %d delay %d buf %ld avail %ld active %d %s%s%s%s\n",
+ (p>>TFRx_WFP_SHIFT) & 0xff,
+ (p>>TFRx_RFP_SHIFT) & 0xff,
+ adev->delay,
+ buffered(&ctlr->w),
+ available(&ctlr->w),
+ ctlr->wactive,
+ (v & TCSR_TE) ? " enabled" : "",
+ (v & TCSR_FEF) ? " fifo_error" : "",
+ (v & TCSR_FWF) ? " fifo_warn" : "",
+ (v & TCSR_FRF) ? " fifo_req" : ""
+ );
+
+ return s - (char*)a;
+}
+
+static long
+saibuffered(Audio *adev)
+{+ Ctlr *ctlr = adev->ctlr;
+
+ return buffered(&ctlr->w);
+}
+
+static int
+saiprobe(Audio *adev)
+{+ Ctlr *ctlr;
+
+ if(adev->ctlrno > 0)
+ return -1;
+
+ ctlr = mallocz(sizeof(Ctlr), 1);
+ if(ctlr == nil)
+ return -1;
+
+ ctlr->w.buf = malloc(ctlr->w.nbuf = 44100*Byteps*2);
+ ctlr->reg = (u32int*)(VIRTIO + 0x8b0000);
+ ctlr->adev = adev;
+
+ adev->delay = 1024;
+ adev->ctlr = ctlr;
+ adev->write = saiwrite;
+ adev->close = saiclose;
+ adev->buffered = saibuffered;
+ adev->status = saistatus;
+ adev->ctl = saictl;
+
+ saireset(ctlr);
+
+ intrenable(IRQsai2, saiinterrupt, ctlr, BUSUNKNOWN, "sai2");
+
+ return 0;
+}
+
+void
+sailink(void)
+{+
+ iomuxpad("pad_sai2_rxfs", "sai2_rx_sync", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_rxc", "sai2_rx_bclk", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_rxd0", "sai2_rx_data0", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_txfs", "sai2_tx_sync", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_txc", "sai2_tx_bclk", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_txd0", "sai2_tx_data0", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+ iomuxpad("pad_sai2_mclk", "sai2_mclk", "SION ~LVTTL HYS PUE ~ODE FAST 45_OHM VSEL_0");+
+ setclkgate("sai2.ipg_clk", 1);+
+ addaudiocard("sai", saiprobe);+}