FreeBSD/Linux Kernel Cross Reference
sys/arm/freescale/imx/imx6_ssi.c

     /*-
      * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /*
     * i.MX6 Synchronous Serial Interface (SSI)
     *
     * Chapter 61, i.MX 6Dual/6Quad Applications Processor Reference Manual,
     * Rev. 1, 04/2013
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/malloc.h>
    #include <sys/rman.h>
    #include <sys/timeet.h>
    #include <sys/timetc.h>
    
    #include <dev/sound/pcm/sound.h>
    #include <dev/sound/chip.h>
    #include <mixer_if.h>
    
    #include <dev/ofw/openfirm.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <machine/bus.h>
    #include <machine/cpu.h>
    #include <machine/intr.h>
    
    #include <arm/freescale/imx/imx6_sdma.h>
    #include <arm/freescale/imx/imx6_anatopvar.h>
    #include <arm/freescale/imx/imx_ccmvar.h>
    
    #define READ4(_sc, _reg)        \
            bus_space_read_4(_sc->bst, _sc->bsh, _reg)
    #define WRITE4(_sc, _reg, _val) \
            bus_space_write_4(_sc->bst, _sc->bsh, _reg, _val)
    
    #define SSI_NCHANNELS   1
    #define DMAS_TOTAL      8
    
    /* i.MX6 SSI registers */
    
    #define SSI_STX0        0x00 /* Transmit Data Register n */
    #define SSI_STX1        0x04 /* Transmit Data Register n */
    #define SSI_SRX0        0x08 /* Receive Data Register n */
    #define SSI_SRX1        0x0C /* Receive Data Register n */
    #define SSI_SCR         0x10 /* Control Register */
    #define  SCR_I2S_MODE_S 5    /* I2S Mode Select. */
    #define  SCR_I2S_MODE_M 0x3
    #define  SCR_SYN        (1 << 4)
    #define  SCR_NET        (1 << 3)  /* Network mode */
    #define  SCR_RE         (1 << 2)  /* Receive Enable. */
    #define  SCR_TE         (1 << 1)  /* Transmit Enable. */
    #define  SCR_SSIEN      (1 << 0)  /* SSI Enable */
    #define SSI_SISR        0x14      /* Interrupt Status Register */
    #define SSI_SIER        0x18      /* Interrupt Enable Register */
    #define  SIER_RDMAE     (1 << 22) /* Receive DMA Enable. */
    #define  SIER_RIE       (1 << 21) /* Receive Interrupt Enable. */
    #define  SIER_TDMAE     (1 << 20) /* Transmit DMA Enable. */
    #define  SIER_TIE       (1 << 19) /* Transmit Interrupt Enable. */
    #define  SIER_TDE0IE    (1 << 12) /* Transmit Data Register Empty 0. */
    #define  SIER_TUE0IE    (1 << 8)  /* Transmitter Underrun Error 0. */
    #define  SIER_TFE0IE    (1 << 0)  /* Transmit FIFO Empty 0 IE. */
    #define SSI_STCR        0x1C      /* Transmit Configuration Register */
    #define  STCR_TXBIT0    (1 << 9)  /* Transmit Bit 0 shift MSB/LSB */
    #define  STCR_TFEN1     (1 << 8)  /* Transmit FIFO Enable 1. */
    #define  STCR_TFEN0     (1 << 7)  /* Transmit FIFO Enable 0. */
    #define  STCR_TFDIR     (1 << 6)  /* Transmit Frame Direction. */
    #define  STCR_TXDIR     (1 << 5)  /* Transmit Clock Direction. */
   #define  STCR_TSHFD     (1 << 4)  /* Transmit Shift Direction. */
   #define  STCR_TSCKP     (1 << 3)  /* Transmit Clock Polarity. */
   #define  STCR_TFSI      (1 << 2)  /* Transmit Frame Sync Invert. */
   #define  STCR_TFSL      (1 << 1)  /* Transmit Frame Sync Length. */
   #define  STCR_TEFS      (1 << 0)  /* Transmit Early Frame Sync. */
   #define SSI_SRCR        0x20      /* Receive Configuration Register */
   #define SSI_STCCR       0x24      /* Transmit Clock Control Register */
   #define  STCCR_DIV2     (1 << 18) /* Divide By 2. */
   #define  STCCR_PSR      (1 << 17) /* Divide clock by 8. */
   #define  WL3_WL0_S      13
   #define  WL3_WL0_M      0xf
   #define  DC4_DC0_S      8
   #define  DC4_DC0_M      0x1f
   #define  PM7_PM0_S      0
   #define  PM7_PM0_M      0xff
   #define SSI_SRCCR       0x28    /* Receive Clock Control Register */
   #define SSI_SFCSR       0x2C    /* FIFO Control/Status Register */
   #define  SFCSR_RFWM1_S  20      /* Receive FIFO Empty WaterMark 1 */
   #define  SFCSR_RFWM1_M  0xf
   #define  SFCSR_TFWM1_S  16      /* Transmit FIFO Empty WaterMark 1 */
   #define  SFCSR_TFWM1_M  0xf
   #define  SFCSR_RFWM0_S  4       /* Receive FIFO Empty WaterMark 0 */
   #define  SFCSR_RFWM0_M  0xf
   #define  SFCSR_TFWM0_S  0       /* Transmit FIFO Empty WaterMark 0 */
   #define  SFCSR_TFWM0_M  0xf
   #define SSI_SACNT       0x38    /* AC97 Control Register */
   #define SSI_SACADD      0x3C    /* AC97 Command Address Register */
   #define SSI_SACDAT      0x40    /* AC97 Command Data Register */
   #define SSI_SATAG       0x44    /* AC97 Tag Register */
   #define SSI_STMSK       0x48    /* Transmit Time Slot Mask Register */
   #define SSI_SRMSK       0x4C    /* Receive Time Slot Mask Register */
   #define SSI_SACCST      0x50    /* AC97 Channel Status Register */
   #define SSI_SACCEN      0x54    /* AC97 Channel Enable Register */
   #define SSI_SACCDIS     0x58    /* AC97 Channel Disable Register */
   
   static MALLOC_DEFINE(M_SSI, "ssi", "ssi audio");
   
   uint32_t ssi_dma_intr(void *arg, int chn);
   
   struct ssi_rate {
           uint32_t speed;
           uint32_t mfi; /* PLL4 Multiplication Factor Integer */
           uint32_t mfn; /* PLL4 Multiplication Factor Numerator */
           uint32_t mfd; /* PLL4 Multiplication Factor Denominator */
           /* More dividers to configure can be added here */
   };
   
   static struct ssi_rate rate_map[] = {
           { 192000, 49, 152, 1000 }, /* PLL4 49.152 Mhz */
           /* TODO: add more frequences */
           { 0, 0 },
   };
   
   /*
    *  i.MX6 example bit clock formula
    *
    *  BCLK = 2 channels * 192000 hz * 24 bit = 9216000 hz = 
    *     (24000000 * (49 + 152/1000.0) / 4 / 4 / 2 / 2 / 2 / 1 / 1)
    *             ^     ^     ^      ^    ^   ^   ^   ^   ^   ^   ^
    *             |     |     |      |    |   |   |   |   |   |   |
    *  Fref ------/     |     |      |    |   |   |   |   |   |   |
    *  PLL4 div select -/     |      |    |   |   |   |   |   |   |
    *  PLL4 num --------------/      |    |   |   |   |   |   |   |
    *  PLL4 denom -------------------/    |   |   |   |   |   |   |
    *  PLL4 post div ---------------------/   |   |   |   |   |   |
    *  CCM ssi pre div (CCM_CS1CDR) ----------/   |   |   |   |   |
    *  CCM ssi post div (CCM_CS1CDR) -------------/   |   |   |   |
    *  SSI PM7_PM0_S ---------------------------------/   |   |   |
    *  SSI Fixed divider ---------------------------------/   |   |
    *  SSI DIV2 ----------------------------------------------/   |
    *  SSI PSR (prescaler /1 or /8) ------------------------------/
    *
    *  MCLK (Master clock) depends on DAC, usually BCLK * 4
    */
   
   struct sc_info {
           struct resource         *res[2];
           bus_space_tag_t         bst;
           bus_space_handle_t      bsh;
           device_t                dev;
           struct mtx              *lock;
           void                    *ih;
           int                     pos;
           int                     dma_size;
           bus_dma_tag_t           dma_tag;
           bus_dmamap_t            dma_map;
           bus_addr_t              buf_base_phys;
           uint32_t                *buf_base;
           struct sdma_conf        *conf;
           struct ssi_rate         *sr;
           struct sdma_softc       *sdma_sc;
           uint32_t                sdma_ev_rx;
           uint32_t                sdma_ev_tx;
           int                     sdma_channel;
   };
   
   /* Channel registers */
   struct sc_chinfo {
           struct snd_dbuf         *buffer;
           struct pcm_channel      *channel;
           struct sc_pcminfo       *parent;
   
           /* Channel information */
           uint32_t        dir;
           uint32_t        format;
   
           /* Flags */
           uint32_t        run;
   };
   
   /* PCM device private data */
   struct sc_pcminfo {
           device_t                dev;
           uint32_t                (*ih)(struct sc_pcminfo *scp);
           uint32_t                chnum;
           struct sc_chinfo        chan[SSI_NCHANNELS];
           struct sc_info          *sc;
   };
   
   static struct resource_spec ssi_spec[] = {
           { SYS_RES_MEMORY,       0,      RF_ACTIVE },
           { SYS_RES_IRQ,          0,      RF_ACTIVE },
           { -1, 0 }
   };
   
   static int setup_dma(struct sc_pcminfo *scp);
   static void setup_ssi(struct sc_info *);
   static void ssi_configure_clock(struct sc_info *);
   
   /*
    * Mixer interface.
    */
   
   static int
   ssimixer_init(struct snd_mixer *m)
   {
           struct sc_pcminfo *scp;
           struct sc_info *sc;
           int mask;
   
           scp = mix_getdevinfo(m);
           sc = scp->sc;
   
           if (sc == NULL)
                   return -1;
   
           mask = SOUND_MASK_PCM;
           mask |= SOUND_MASK_VOLUME;
   
           snd_mtxlock(sc->lock);
           pcm_setflags(scp->dev, pcm_getflags(scp->dev) | SD_F_SOFTPCMVOL);
           mix_setdevs(m, mask);
           snd_mtxunlock(sc->lock);
   
           return (0);
   }
   
   static int
   ssimixer_set(struct snd_mixer *m, unsigned dev,
       unsigned left, unsigned right)
   {
           struct sc_pcminfo *scp;
   
           scp = mix_getdevinfo(m);
   
           /* Here we can configure hardware volume on our DAC */
   
   #if 1
           device_printf(scp->dev, "ssimixer_set() %d %d\n",
               left, right);
   #endif
   
           return (0);
   }
   
   static kobj_method_t ssimixer_methods[] = {
           KOBJMETHOD(mixer_init,      ssimixer_init),
           KOBJMETHOD(mixer_set,       ssimixer_set),
           KOBJMETHOD_END
   };
   MIXER_DECLARE(ssimixer);
   
   /*
    * Channel interface.
    */
   
   static void *
   ssichan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b,
       struct pcm_channel *c, int dir)
   {
           struct sc_pcminfo *scp;
           struct sc_chinfo *ch;
           struct sc_info *sc;
   
           scp = (struct sc_pcminfo *)devinfo;
           sc = scp->sc;
   
           snd_mtxlock(sc->lock);
           ch = &scp->chan[0];
           ch->dir = dir;
           ch->run = 0;
           ch->buffer = b;
           ch->channel = c;
           ch->parent = scp;
           snd_mtxunlock(sc->lock);
   
           if (sndbuf_setup(ch->buffer, sc->buf_base, sc->dma_size) != 0) {
                   device_printf(scp->dev, "Can't setup sndbuf.\n");
                   return NULL;
           }
   
           return ch;
   }
   
   static int
   ssichan_free(kobj_t obj, void *data)
   {
           struct sc_chinfo *ch = data;
           struct sc_pcminfo *scp = ch->parent;
           struct sc_info *sc = scp->sc;
   
   #if 0
           device_printf(scp->dev, "ssichan_free()\n");
   #endif
   
           snd_mtxlock(sc->lock);
           /* TODO: free channel buffer */
           snd_mtxunlock(sc->lock);
   
           return (0);
   }
   
   static int
   ssichan_setformat(kobj_t obj, void *data, uint32_t format)
   {
           struct sc_chinfo *ch = data;
   
           ch->format = format;
   
           return (0);
   }
   
   static uint32_t
   ssichan_setspeed(kobj_t obj, void *data, uint32_t speed)
   {
           struct sc_pcminfo *scp;
           struct sc_chinfo *ch;
           struct ssi_rate *sr;
           struct sc_info *sc;
           int threshold;
           int i;
   
           ch = data;
           scp = ch->parent;
           sc = scp->sc;
   
           sr = NULL;
   
           /* First look for equal frequency. */
           for (i = 0; rate_map[i].speed != 0; i++) {
                   if (rate_map[i].speed == speed)
                           sr = &rate_map[i];
           }
   
           /* If no match, just find nearest. */
           if (sr == NULL) {
                   for (i = 0; rate_map[i].speed != 0; i++) {
                           sr = &rate_map[i];
                           threshold = sr->speed + ((rate_map[i + 1].speed != 0) ?
                               ((rate_map[i + 1].speed - sr->speed) >> 1) : 0);
                           if (speed < threshold)
                                   break;
                   }
           }
   
           sc->sr = sr;
   
           ssi_configure_clock(sc);
   
           return (sr->speed);
   }
   
   static void
   ssi_configure_clock(struct sc_info *sc)
   {
           struct ssi_rate *sr;
   
           sr = sc->sr;
   
           pll4_configure_output(sr->mfi, sr->mfn, sr->mfd);
   
           /* Configure other dividers here, if any */
   }
   
   static uint32_t
   ssichan_setblocksize(kobj_t obj, void *data, uint32_t blocksize)
   {
           struct sc_chinfo *ch = data;
           struct sc_pcminfo *scp = ch->parent;
           struct sc_info *sc = scp->sc;
   
           sndbuf_resize(ch->buffer, sc->dma_size / blocksize, blocksize);
   
           setup_dma(scp);
   
           return (sndbuf_getblksz(ch->buffer));
   }
   
   uint32_t
   ssi_dma_intr(void *arg, int chn)
   {
           struct sc_pcminfo *scp;
           struct sdma_conf *conf;
           struct sc_chinfo *ch;
           struct sc_info *sc;
           int bufsize;
   
           scp = arg;
           ch = &scp->chan[0];
           sc = scp->sc;
           conf = sc->conf;
   
           bufsize = sndbuf_getsize(ch->buffer);
   
           sc->pos += conf->period;
           if (sc->pos >= bufsize)
                   sc->pos -= bufsize;
   
           if (ch->run)
                   chn_intr(ch->channel);
   
           return (0);
   }
   
   static int
   find_sdma_controller(struct sc_info *sc)
   {
           struct sdma_softc *sdma_sc;
           phandle_t node;
           device_t sdma_dev;
           pcell_t dts_value[DMAS_TOTAL];
           int len;
   
           if ((node = ofw_bus_get_node(sc->dev)) == -1)
                   return (ENXIO);
   
           if ((len = OF_getproplen(node, "dmas")) <= 0)
                   return (ENXIO);
   
           if (len != sizeof(dts_value)) {
                   device_printf(sc->dev,
                       "\"dmas\" property length is invalid: %d (expected %d)",
                       len, sizeof(dts_value));
                   return (ENXIO);
           }
   
           OF_getencprop(node, "dmas", dts_value, sizeof(dts_value));
   
           sc->sdma_ev_rx = dts_value[1];
           sc->sdma_ev_tx = dts_value[5];
   
           sdma_sc = NULL;
   
           sdma_dev = devclass_get_device(devclass_find("sdma"), 0);
           if (sdma_dev)
                   sdma_sc = device_get_softc(sdma_dev);
   
           if (sdma_sc == NULL) {
                   device_printf(sc->dev, "No sDMA found. Can't operate\n");
                   return (ENXIO);
           }
   
           sc->sdma_sc = sdma_sc;
   
           return (0);
   };
   
   static int
   setup_dma(struct sc_pcminfo *scp)
   {
           struct sdma_conf *conf;
           struct sc_chinfo *ch;
           struct sc_info *sc;
           int fmt;
   
           ch = &scp->chan[0];
           sc = scp->sc;
           conf = sc->conf;
   
           conf->ih = ssi_dma_intr;
           conf->ih_user = scp;
           conf->saddr = sc->buf_base_phys;
           conf->daddr = rman_get_start(sc->res[0]) + SSI_STX0;
           conf->event = sc->sdma_ev_tx; /* SDMA TX event */
           conf->period = sndbuf_getblksz(ch->buffer);
           conf->num_bd = sndbuf_getblkcnt(ch->buffer);
   
           /*
            * Word Length
            * Can be 32, 24, 16 or 8 for sDMA.
            *
            * SSI supports 24 at max.
            */
   
           fmt = sndbuf_getfmt(ch->buffer);
   
           if (fmt & AFMT_16BIT) {
                   conf->word_length = 16;
                   conf->command = CMD_2BYTES;
           } else if (fmt & AFMT_24BIT) {
                   conf->word_length = 24;
                   conf->command = CMD_3BYTES;
           } else {
                   device_printf(sc->dev, "Unknown format\n");
                   return (-1);
           }
   
           return (0);
   }
   
   static int
   ssi_start(struct sc_pcminfo *scp)
   {
           struct sc_info *sc;
           int reg;
   
           sc = scp->sc;
   
           if (sdma_configure(sc->sdma_channel, sc->conf) != 0) {
                   device_printf(sc->dev, "Can't configure sDMA\n");
                   return (-1);
           }
   
           /* Enable DMA interrupt */
           reg = (SIER_TDMAE);
           WRITE4(sc, SSI_SIER, reg);
   
           sdma_start(sc->sdma_channel);
   
           return (0);
   }
   
   static int
   ssi_stop(struct sc_pcminfo *scp)
   {
           struct sc_info *sc;
           int reg;
   
           sc = scp->sc;
   
           reg = READ4(sc, SSI_SIER);
           reg &= ~(SIER_TDMAE);
           WRITE4(sc, SSI_SIER, reg);
   
           sdma_stop(sc->sdma_channel);
   
           bzero(sc->buf_base, sc->dma_size);
   
           return (0);
   }
   
   static int
   ssichan_trigger(kobj_t obj, void *data, int go)
   {
           struct sc_pcminfo *scp;
           struct sc_chinfo *ch;
           struct sc_info *sc;
   
           ch = data;
           scp = ch->parent;
           sc = scp->sc;
   
           snd_mtxlock(sc->lock);
   
           switch (go) {
           case PCMTRIG_START:
   #if 0
                   device_printf(scp->dev, "trigger start\n");
   #endif
                   ch->run = 1;
   
                   ssi_start(scp);
   
                   break;
   
           case PCMTRIG_STOP:
           case PCMTRIG_ABORT:
   #if 0
                   device_printf(scp->dev, "trigger stop or abort\n");
   #endif
                   ch->run = 0;
   
                   ssi_stop(scp);
   
                   break;
           }
   
           snd_mtxunlock(sc->lock);
   
           return (0);
   }
   
   static uint32_t
   ssichan_getptr(kobj_t obj, void *data)
   {
           struct sc_pcminfo *scp;
           struct sc_chinfo *ch;
           struct sc_info *sc;
   
           ch = data;
           scp = ch->parent;
           sc = scp->sc;
   
           return (sc->pos);
   }
   
   static uint32_t ssi_pfmt[] = {
           SND_FORMAT(AFMT_S24_LE, 2, 0),
           0
   };
   
   static struct pcmchan_caps ssi_pcaps = {44100, 192000, ssi_pfmt, 0};
   
   static struct pcmchan_caps *
   ssichan_getcaps(kobj_t obj, void *data)
   {
   
           return (&ssi_pcaps);
   }
   
   static kobj_method_t ssichan_methods[] = {
           KOBJMETHOD(channel_init,         ssichan_init),
           KOBJMETHOD(channel_free,         ssichan_free),
           KOBJMETHOD(channel_setformat,    ssichan_setformat),
           KOBJMETHOD(channel_setspeed,     ssichan_setspeed),
           KOBJMETHOD(channel_setblocksize, ssichan_setblocksize),
           KOBJMETHOD(channel_trigger,      ssichan_trigger),
           KOBJMETHOD(channel_getptr,       ssichan_getptr),
           KOBJMETHOD(channel_getcaps,      ssichan_getcaps),
           KOBJMETHOD_END
   };
   CHANNEL_DECLARE(ssichan);
   
   static int
   ssi_probe(device_t dev)
   {
   
           if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           if (!ofw_bus_is_compatible(dev, "fsl,imx6q-ssi"))
                   return (ENXIO);
   
           device_set_desc(dev, "i.MX6 Synchronous Serial Interface (SSI)");
           return (BUS_PROBE_DEFAULT);
   }
   
   static void
   ssi_intr(void *arg)
   {
   #if 0
           struct sc_pcminfo *scp;
           struct sc_info *sc;
    
           scp = arg;
           sc = scp->sc;
   #endif
   
           /* We don't use SSI interrupt */
   #if 0
           device_printf(scp->sc->dev, "SSI Intr 0x%08x\n",
               READ4(sc, SSI_SISR));
   #endif
   }
   
   static void
   setup_ssi(struct sc_info *sc)
   {
           int reg;
   
           reg = READ4(sc, SSI_STCCR);
           reg &= ~(WL3_WL0_M << WL3_WL0_S);
           reg |= (0xb << WL3_WL0_S); /* 24 bit */
           reg &= ~(DC4_DC0_M << DC4_DC0_S);
           reg |= (1 << DC4_DC0_S); /* 2 words per frame */
           reg &= ~(STCCR_DIV2); /* Divide by 1 */
           reg &= ~(STCCR_PSR); /* Divide by 1 */
           reg &= ~(PM7_PM0_M << PM7_PM0_S);
           reg |= (1 << PM7_PM0_S); /* Divide by 2 */
           WRITE4(sc, SSI_STCCR, reg);
   
           reg = READ4(sc, SSI_SFCSR);
           reg &= ~(SFCSR_TFWM0_M << SFCSR_TFWM0_S);
           reg |= (8 << SFCSR_TFWM0_S); /* empty slots */
           WRITE4(sc, SSI_SFCSR, reg);
   
           reg = READ4(sc, SSI_STCR);
           reg |= (STCR_TFEN0);
           reg &= ~(STCR_TFEN1);
           reg &= ~(STCR_TSHFD); /* MSB */
           reg |= (STCR_TXBIT0);
           reg |= (STCR_TXDIR | STCR_TFDIR);
           reg |= (STCR_TSCKP); /* falling edge */
           reg |= (STCR_TFSI);
           reg &= ~(STCR_TFSI); /* active high frame sync */
           reg &= ~(STCR_TFSL);
           reg |= STCR_TEFS;
           WRITE4(sc, SSI_STCR, reg);
   
           reg = READ4(sc, SSI_SCR);
           reg &= ~(SCR_I2S_MODE_M << SCR_I2S_MODE_S); /* Not master */
           reg |= (SCR_SSIEN | SCR_TE);
           reg |= (SCR_NET);
           reg |= (SCR_SYN);
           WRITE4(sc, SSI_SCR, reg);
   }
   
   static void
   ssi_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int err)
   {
           bus_addr_t *addr;
   
           if (err)
                   return;
   
           addr = (bus_addr_t*)arg;
           *addr = segs[0].ds_addr;
   }
   
   static int
   ssi_attach(device_t dev)
   {
           char status[SND_STATUSLEN];
           struct sc_pcminfo *scp;
           struct sc_info *sc;
           int err;
   
           sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO);
           sc->dev = dev;
           sc->sr = &rate_map[0];
           sc->pos = 0;
           sc->conf = malloc(sizeof(struct sdma_conf), M_DEVBUF, M_WAITOK | M_ZERO);
   
           sc->lock = snd_mtxcreate(device_get_nameunit(dev), "ssi softc");
           if (sc->lock == NULL) {
                   device_printf(dev, "Can't create mtx\n");
                   return (ENXIO);
           }
   
           if (bus_alloc_resources(dev, ssi_spec, sc->res)) {
                   device_printf(dev, "could not allocate resources\n");
                   return (ENXIO);
           }
   
           /* Memory interface */
           sc->bst = rman_get_bustag(sc->res[0]);
           sc->bsh = rman_get_bushandle(sc->res[0]);
   
           /* SDMA */
           if (find_sdma_controller(sc)) {
                   device_printf(dev, "could not find active SDMA\n");
                   return (ENXIO);
           }
   
           /* Setup PCM */
           scp = malloc(sizeof(struct sc_pcminfo), M_DEVBUF, M_NOWAIT | M_ZERO);
           scp->sc = sc;
           scp->dev = dev;
   
           /*
            * Maximum possible DMA buffer.
            * Will be used partially to match 24 bit word.
            */
           sc->dma_size = 131072;
   
           /*
            * Must use dma_size boundary as modulo feature required.
            * Modulo feature allows setup circular buffer.
            */
   
           err = bus_dma_tag_create(
               bus_get_dma_tag(sc->dev),
               4, sc->dma_size,            /* alignment, boundary */
               BUS_SPACE_MAXADDR_32BIT,    /* lowaddr */
               BUS_SPACE_MAXADDR,          /* highaddr */
               NULL, NULL,                 /* filter, filterarg */
               sc->dma_size, 1,            /* maxsize, nsegments */
               sc->dma_size, 0,            /* maxsegsize, flags */
               NULL, NULL,                 /* lockfunc, lockarg */
               &sc->dma_tag);
   
           err = bus_dmamem_alloc(sc->dma_tag, (void **)&sc->buf_base,
               BUS_DMA_NOWAIT | BUS_DMA_COHERENT, &sc->dma_map);
           if (err) {
                   device_printf(dev, "cannot allocate framebuffer\n");
                   return (ENXIO);
           }
   
           err = bus_dmamap_load(sc->dma_tag, sc->dma_map, sc->buf_base,
               sc->dma_size, ssi_dmamap_cb, &sc->buf_base_phys, BUS_DMA_NOWAIT);
           if (err) {
                   device_printf(dev, "cannot load DMA map\n");
                   return (ENXIO);
           }
   
           bzero(sc->buf_base, sc->dma_size);
   
           /* Setup interrupt handler */
           err = bus_setup_intr(dev, sc->res[1], INTR_MPSAFE | INTR_TYPE_AV,
               NULL, ssi_intr, scp, &sc->ih);
           if (err) {
                   device_printf(dev, "Unable to alloc interrupt resource.\n");
                   return (ENXIO);
           }
   
           pcm_setflags(dev, pcm_getflags(dev) | SD_F_MPSAFE);
   
           err = pcm_register(dev, scp, 1, 0);
           if (err) {
                   device_printf(dev, "Can't register pcm.\n");
                   return (ENXIO);
           }
   
           scp->chnum = 0;
           pcm_addchan(dev, PCMDIR_PLAY, &ssichan_class, scp);
           scp->chnum++;
   
           snprintf(status, SND_STATUSLEN, "at simplebus");
           pcm_setstatus(dev, status);
   
           mixer_init(dev, &ssimixer_class, scp);
           setup_ssi(sc);
   
           imx_ccm_ssi_configure(dev);
   
           sc->sdma_channel = sdma_alloc();
           if (sc->sdma_channel < 0) {
                   device_printf(sc->dev, "Can't get sDMA channel\n");
                   return (1);
           }
   
           return (0);
   }
   
   static device_method_t ssi_pcm_methods[] = {
           DEVMETHOD(device_probe,         ssi_probe),
           DEVMETHOD(device_attach,        ssi_attach),
           { 0, 0 }
   };
   
   static driver_t ssi_pcm_driver = {
           "pcm",
           ssi_pcm_methods,
           PCM_SOFTC_SIZE,
   };
   
   DRIVER_MODULE(ssi, simplebus, ssi_pcm_driver, 0, 0);
   MODULE_DEPEND(ssi, sound, SOUND_MINVER, SOUND_PREFVER, SOUND_MAXVER);
   MODULE_DEPEND(ssi, sdma, 0, 0, 0);
   MODULE_VERSION(ssi, 1);

Cache object: 1980ecadd1195d9a2bc1f0c0591240da