amd7930.c

一个2.4.21版本的嵌入式linux内核

		if (info->Bb.channel_status == CHANNEL_AVAILABLE &&
		    info->Bc.channel_status == CHANNEL_AVAILABLE) {
			/* Disable B channel interrupts */
			sbus_writeb(AMR_MUX_MCR4, info->regs + CR);
			sbus_writeb(0, info->regs + DR);
		}
	}

	restore_flags(flags);
}

static void amd7930_bxmit(int dev, unsigned int chan,
                          __u8 * buffer, unsigned long count,
			  void (*callback)(void *, int), void *callback_arg)
{
	struct amd7930_info *info;
	struct amd7930_channel *Bchan;
	unsigned long flags;

	if (dev > num_drivers)
		return;

	info = (struct amd7930_info *) drivers[dev].private;
	Bchan = info->Bisdn[chan];

	if (Bchan) {
		save_and_cli(flags);

		Bchan->output_ptr = buffer;
		Bchan->output_count = count;
		Bchan->output_format = AUDIO_ENCODING_ULAW;
	        Bchan->output_callback = (void *) callback;
        	Bchan->output_callback_arg = callback_arg;

		restore_flags(flags);
	}
}

static void amd7930_brecv(int dev, unsigned int chan, 
                          __u8 * buffer, unsigned long size,
                          void (*callback)(void *, int, unsigned int),
                          void *callback_arg)
{
	struct amd7930_info *info;
	struct amd7930_channel *Bchan;
	unsigned long flags;

	if (dev > num_drivers)
		return;

	info = (struct amd7930_info *) drivers[dev].private;
	Bchan = info->Bisdn[chan];

	if (Bchan) {
		save_and_cli(flags);

		Bchan->input_ptr = buffer;
		Bchan->input_count = size;
		Bchan->input_format = AUDIO_ENCODING_ULAW;
		Bchan->input_callback = (void *) callback;
		Bchan->input_callback_arg = callback_arg;

		restore_flags(flags);
	}
}

struct foreign_interface amd7930_foreign_interface = {
        amd7930_get_irqnum,
        amd7930_get_liu_state,
        amd7930_liu_init,
        amd7930_liu_activate,
        amd7930_liu_deactivate,
        amd7930_dxmit,
        amd7930_drecv,
        amd7930_bopen,
        amd7930_bclose,
        amd7930_bxmit,
        amd7930_brecv
};
EXPORT_SYMBOL(amd7930_foreign_interface);
#endif


/*
 *	Device detection and initialization.
 */

static struct sparcaudio_operations amd7930_ops = {
	amd7930_open,
	amd7930_release,
	amd7930_ioctl,
	amd7930_start_output,
	amd7930_stop_output,
	amd7930_start_input,
	amd7930_stop_input,
	amd7930_sunaudio_getdev,
	amd7930_set_output_volume,
	amd7930_get_output_volume,
	amd7930_set_input_volume,
	amd7930_get_input_volume,
	amd7930_set_monitor_volume,
	amd7930_get_monitor_volume,
	NULL,			/* amd7930_set_output_balance */
	amd7930_get_output_balance,
	NULL,			/* amd7930_set_input_balance */
	amd7930_get_input_balance,
	amd7930_set_output_channels,
	amd7930_get_output_channels,
	amd7930_set_input_channels,
	amd7930_get_input_channels,
	amd7930_set_output_precision,
	amd7930_get_output_precision,
	amd7930_set_input_precision,
	amd7930_get_input_precision,
	amd7930_set_output_port,
	amd7930_get_output_port,
	NULL,			/* amd7930_set_input_port */
	amd7930_get_input_port,
	amd7930_set_encoding,
	amd7930_get_encoding,
	amd7930_set_encoding,
	amd7930_get_encoding,
	amd7930_set_output_rate,
	amd7930_get_output_rate,
	amd7930_set_input_rate,
	amd7930_get_input_rate,
	amd7930_sunaudio_getdev_sunos,
	amd7930_get_output_ports,
	amd7930_get_input_ports,
	NULL,                    /* amd7930_set_output_muted */
	amd7930_get_output_muted,
        NULL,                   /* amd7930_set_output_pause */
        NULL,                   /* amd7930_get_output_pause */
        NULL,                   /* amd7930_set_input_pause */
        NULL,                   /* amd7930_get_input_pause */
        NULL,                   /* amd7930_set_output_samples */
        NULL,                   /* amd7930_get_output_samples */
        NULL,                   /* amd7930_set_input_samples */
        NULL,                   /* amd7930_get_input_samples */
        NULL,                   /* amd7930_set_output_error */
        NULL,                   /* amd7930_get_output_error */
        NULL,                   /* amd7930_set_input_error */
        NULL,                   /* amd7930_get_input_error */
        amd7930_get_formats,
};

/* Attach to an amd7930 chip given its PROM node. */
static int amd7930_attach(struct sparcaudio_driver *drv, int node,
			  struct sbus_bus *sbus, struct sbus_dev *sdev)
{
	struct linux_prom_registers regs;
	struct linux_prom_irqs irq;
	struct resource res, *resp;
	struct amd7930_info *info;
	int err;

	/* Allocate our private information structure. */
	drv->private = kmalloc(sizeof(struct amd7930_info), GFP_KERNEL);
	if (drv->private == NULL)
		return -ENOMEM;

	/* Point at the information structure and initialize it. */
	drv->ops = &amd7930_ops;
	info = (struct amd7930_info *)drv->private;
	memset(info, 0, sizeof(*info));
	info->ints_on = 1; /* force disable below */

	drv->dev = sdev;

	/* Map the registers into memory. */
	prom_getproperty(node, "reg", (char *)&regs, sizeof(regs));
	if (sbus && sdev) {
		resp = &sdev->resource[0];
	} else {
		resp = &res;
		res.start = regs.phys_addr;
		res.end = res.start + regs.reg_size - 1;
		res.flags = IORESOURCE_IO | (regs.which_io & 0xff);
	}
	info->regs_size = regs.reg_size;
	info->regs = sbus_ioremap(resp, 0, regs.reg_size, "amd7930");
	if (!info->regs) {
		printk(KERN_ERR "amd7930: could not remap registers\n");
		kfree(drv->private);
		return -EIO;
	}

	/* Put amd7930 in idle mode (interrupts disabled) */
	amd7930_idle(info);

	/* Enable extended FIFO operation on D-channel */
	sbus_writeb(AMR_DLC_EFCR, info->regs + CR);
	sbus_writeb(AMR_DLC_EFCR_EXTEND_FIFO, info->regs + DR);
	sbus_writeb(AMR_DLC_DMR4, info->regs + CR);
	sbus_writeb(/* AMR_DLC_DMR4_RCV_30 | */ AMR_DLC_DMR4_XMT_14,
		    info->regs + DR);

	/* Attach the interrupt handler to the audio interrupt. */
	prom_getproperty(node, "intr", (char *)&irq, sizeof(irq));
	info->irq = irq.pri;
	request_irq(info->irq, amd7930_interrupt,
		    SA_INTERRUPT, "amd7930", drv);
	amd7930_enable_ints(info);

	/* Initalize the local copy of the MAP registers. */
	memset(&info->map, 0, sizeof(info->map));
	info->map.mmr1 = AM_MAP_MMR1_GX | AM_MAP_MMR1_GER |
			 AM_MAP_MMR1_GR | AM_MAP_MMR1_STG;
        /* Start out with speaker, microphone */
        info->map.mmr2 |= (AM_MAP_MMR2_LS | AM_MAP_MMR2_AINB);

	/* Set the default audio parameters. */
	info->rgain = 128;
	info->pgain = 200;
	info->mgain = 0;
	info->format_type = AUDIO_ENCODING_ULAW;
	info->Bb.input_format = AUDIO_ENCODING_ULAW;
	info->Bb.output_format = AUDIO_ENCODING_ULAW;
	info->Bc.input_format = AUDIO_ENCODING_ULAW;
	info->Bc.output_format = AUDIO_ENCODING_ULAW;
	amd7930_update_map(drv);

	/* Register the amd7930 with the midlevel audio driver. */
	err = register_sparcaudio_driver(drv, 1);
	if (err < 0) {
		printk(KERN_ERR "amd7930: unable to register\n");
		free_irq(info->irq, drv);
		sbus_iounmap(info->regs, info->regs_size);
		kfree(drv->private);
		return -EIO;
	}

	/* Announce the hardware to the user. */
	printk(KERN_INFO "amd7930 at %lx irq %d\n",
	       info->regs, info->irq);

	/* Success! */
	return 0;
}

/* Detach from an amd7930 chip given the device structure. */
static void __exit amd7930_detach(struct sparcaudio_driver *drv)
{
	struct amd7930_info *info = (struct amd7930_info *)drv->private;

	unregister_sparcaudio_driver(drv, 1);
	amd7930_idle(info);
	free_irq(info->irq, drv);
	sbus_iounmap(info->regs, info->regs_size);
	kfree(drv->private);
}

/* Probe for the amd7930 chip and then attach the driver. */
static int __init amd7930_init(void)
{
	struct sbus_bus *sbus;
	struct sbus_dev *sdev;
	int node;

	/* Try to find the sun4c "audio" node first. */
	node = prom_getchild(prom_root_node);
	node = prom_searchsiblings(node, "audio");
	if (node && amd7930_attach(&drivers[0], node, NULL, NULL) == 0)
		num_drivers = 1;
	else
		num_drivers = 0;

	/* Probe each SBUS for amd7930 chips. */
	for_all_sbusdev(sdev, sbus) {
		if (!strcmp(sdev->prom_name, "audio")) {
			/* Don't go over the max number of drivers. */
			if (num_drivers >= MAX_DRIVERS)
				continue;

			if (amd7930_attach(&drivers[num_drivers],
					   sdev->prom_node, sdev->bus, sdev) == 0)
				num_drivers++;
		}
	}

	/* Only return success if we found some amd7930 chips. */
	return (num_drivers > 0) ? 0 : -EIO;
}

static void __exit amd7930_exit(void)
{
	register int i;

	for (i = 0; i < num_drivers; i++) {
		amd7930_detach(&drivers[i]);
		num_drivers--;
	}
}

module_init(amd7930_init);
module_exit(amd7930_exit);
MODULE_LICENSE("GPL");

/*************************************************************/
/*                 Audio format conversion                   */
/*************************************************************/

/* Translation tables */

static unsigned char ulaw[] = {
    3,   7,  11,  15,  19,  23,  27,  31, 
   35,  39,  43,  47,  51,  55,  59,  63, 
   66,  68,  70,  72,  74,  76,  78,  80, 
   82,  84,  86,  88,  90,  92,  94,  96, 
   98,  99, 100, 101, 102, 103, 104, 105, 
  106, 107, 108, 109, 110, 111, 112, 113, 
  113, 114, 114, 115, 115, 116, 116, 117, 
  117, 118, 118, 119, 119, 120, 120, 121, 
  121, 121, 122, 122, 122, 122, 123, 123, 
  123, 123, 124, 124, 124, 124, 125, 125, 
  125, 125, 125, 125, 126, 126, 126, 126, 
  126, 126, 126, 126, 127, 127, 127, 127, 
  127, 127, 127, 127, 127, 127, 127, 127, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  253, 249, 245, 241, 237, 233, 229, 225, 
  221, 217, 213, 209, 205, 201, 197, 193, 
  190, 188, 186, 184, 182, 180, 178, 176, 
  174, 172, 170, 168, 166, 164, 162, 160, 
  158, 157, 156, 155, 154, 153, 152, 151, 
  150, 149, 148, 147, 146, 145, 144, 143, 
  143, 142, 142, 141, 141, 140, 140, 139, 
  139, 138, 138, 137, 137, 136, 136, 135, 
  135, 135, 134, 134, 134, 134, 133, 133, 
  133, 133, 132, 132, 132, 132, 131, 131, 
  131, 131, 131, 131, 130, 130, 130, 130, 
  130, 130, 130, 130, 129, 129, 129, 129, 
  129, 129, 129, 129, 129, 129, 129, 129, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128
};

static __u8 mulaw2bilinear(__u8 data)
{
	return ulaw[data];
}

static unsigned char linear[] = {
     0,    0,    0,    0,    0,    0,    0,    1,
     0,    0,    0,    2,    0,    0,    0,    3,
     0,    0,    0,    4,    0,    0,    0,    5,
     0,    0,    0,    6,    0,    0,    0,    7,
     0,    0,    0,    8,    0,    0,    0,    9,
     0,    0,    0,   10,    0,    0,    0,   11,
     0,    0,    0,   12,    0,    0,    0,   13,
     0,    0,    0,   14,    0,    0,    0,   15,
     0,    0,   16,    0,   17,    0,   18,    0,
    19,    0,   20,    0,   21,    0,   22,    0,
    23,    0,   24,    0,   25,    0,   26,    0,
    27,    0,   28,    0,   29,    0,   30,    0,
    31,    0,   32,   33,   34,   35,   36,   37,
    38,   39,   40,   41,   42,   43,   44,   45,
    46,   48,   50,   52,   54,   56,   58,   60,
    62,   65,   69,   73,   77,   83,   91,  103,
   255,  231,  219,  211,  205,  201,  197,  193,
   190,  188,  186,  184,  182,  180,  178,  176,
   174,  173,  172,  171,  170,  169,  168,  167,
   166,  165,  164,  163,  162,  161,  160,    0,
   159,    0,  158,    0,  157,    0,  156,    0,
   155,    0,  154,    0,  153,    0,  152,    0,
   151,    0,  150,    0,  149,    0,  148,    0,
   147,    0,  146,    0,  145,    0,  144,    0,
     0,  143,    0,    0,    0,  142,    0,    0,
     0,  141,    0,    0,    0,  140,    0,    0,
     0,  139,    0,    0,    0,  138,    0,    0,
     0,  137,    0,    0,    0,  136,    0,    0,
     0,  135,    0,    0,    0,  134,    0,    0,
     0,  133,    0,    0,    0,  132,    0,    0,
     0,  131,    0,    0,    0,  130,    0,    0,
     0,  129,    0,    0,    0,  128,    0,    0
};

static __u8 bilinear2mulaw(__u8 data)
{
	return linear[data];
}

static int exp_lut[256] = {
	0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
	5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};

#define BIAS 0x84
#define CLIP 32635

#define SWAP_ENDIAN(x) ((x >> 8) | ((x & 0xff) << 8))

static __u8  linear2mulaw(__u16 data)
{
	static int sign, exponent, mantissa;

	/* not really sure, if swapping is ok - comment next line to disable it */
	data = SWAP_ENDIAN(data);
	
	sign = (data >> 8) & 0x80;
	if (sign != 0) data = -data;

	if (data > CLIP) data = CLIP;
	data += BIAS;
	exponent = exp_lut[(data >> 7) & 0xFF];
	mantissa = (data >> (exponent + 3)) & 0x0F;

	return (~(sign | (exponent << 4) | mantissa));
}

static __u16 mulaw2linear(__u8 data)
{
	/* this conversion is not working */
	return data;
}

#if 0
#define INOUT(x,y) (((x) << 16) | (y))
static int convert_audio(int in_format, int out_format, __u8* buffer, int count)
{
	static int i,sign,exponent;
	static __u16 data;

	if (in_format == out_format) return count;

	switch(INOUT(in_format, out_format)) {
	case INOUT(AUDIO_ENCODING_ULAW, AUDIO_ENCODING_LINEAR8):
		for (i = 0;i < count; i++) {
			buffer[i] = ulaw[buffer[i]];
		};
		break;
	case INOUT(AUDIO_ENCODING_ULAW, AUDIO_ENCODING_LINEAR):
		break;
	case INOUT(AUDIO_ENCODING_LINEAR, AUDIO_ENCODING_ULAW):
		/* buffer is two-byte => convert to first */
		for (i = 0; i < count/2; i++) {
			data = ((__u16*)buffer)[i];
			sign = (data >> 8) & 0x80;
			if (data > CLIP) data = CLIP;
			data += BIAS;
			exponent = exp_lut[(data >> 7) & 0xFF];
			buffer[i] = ~(sign | (exponent << 4) | 
						  ((data >> (exponent + 3)) & 0x0F));
		};
		break;
	case INOUT(AUDIO_ENCODING_LINEAR8, AUDIO_ENCODING_ULAW):
		for (i = 0; i < count; i++) {
			buffer[i] = linear[buffer[i]];
		};
		break;
	default:
		return 0;
	};

	return count;
}
#undef INOUT
#endif

#undef BIAS
#undef CLIP
#undef SWAP_ENDIAN