cs8427.c

Linux ARM9 2440 Sound i2C 驱动程序开发

/*
 *  Routines for control of the CS8427 via i2c bus
 *  IEC958 (S/PDIF) receiver & transmitter by Cirrus Logic
 *  Copyright (c) by Jaroslav Kysela <[e-mail]>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <sound/driver.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/cs8427.h>
#include <sound/asoundef.h>

static void snd_cs8427_reset(snd_i2c_device_t *cs8427);

MODULE_AUTHOR("Jaroslav Kysela <[e-mail]>");
MODULE_DESCRIPTION("IEC958 (S/PDIF) receiver & transmitter by Cirrus Logic");
MODULE_LICENSE("GPL");

#define CS8427_ADDR			(0x20>>1) /* fixed address */

typedef struct {
	snd_pcm_substream_t *substream;
	char hw_status[24];		/* hardware status */
	char def_status[24];		/* default status */
	char pcm_status[24];		/* PCM private status */
	char hw_udata[32];
	snd_kcontrol_t *pcm_ctl;
} cs8427_stream_t;

typedef struct {
	unsigned char regmap[0x14];	/* map of first 1 + 13 registers */
	unsigned int rate;
	unsigned int reset_timeout;
	cs8427_stream_t playback;
	cs8427_stream_t capture;
} cs8427_t;

static unsigned char swapbits(unsigned char val)
{
	int bit;
	unsigned char res = 0;
	for (bit = 0; bit < 8; bit++) {
		res <<= 1;
		res |= val & 1;
		val >>= 1;
	}
	return res;
}

int snd_cs8427_reg_write(snd_i2c_device_t *device, unsigned char reg, unsigned char val)
{
	int err;
	unsigned char buf[2];

	buf[0] = reg & 0x7f;
	buf[1] = val;
	if ((err = snd_i2c_sendbytes(device, buf, 2)) != 2) {
		snd_printk("unable to send bytes 0x%02x:0x%02x to CS8427 (%i)\n", buf[0], buf[1], err);
		return err < 0 ? err : -EIO;
	}
	return 0;
}

static int snd_cs8427_reg_read(snd_i2c_device_t *device, unsigned char reg)
{
	int err;
	unsigned char buf;

	if ((err = snd_i2c_sendbytes(device, &reg, 1)) != 1) {
		snd_printk("unable to send register 0x%x byte to CS8427\n", reg);
		return err < 0 ? err : -EIO;
	}
	if ((err = snd_i2c_readbytes(device, &buf, 1)) != 1) {
		snd_printk("unable to read register 0x%x byte from CS8427\n", reg);
		return err < 0 ? err : -EIO;
	}
	return buf;
}

static int snd_cs8427_select_corudata(snd_i2c_device_t *device, int udata)
{
	cs8427_t *chip = device->private_data;
	int err;

	udata = udata ? CS8427_BSEL : 0;
	if (udata != (chip->regmap[CS8427_REG_CSDATABUF] & udata)) {
		chip->regmap[CS8427_REG_CSDATABUF] &= ~CS8427_BSEL;
		chip->regmap[CS8427_REG_CSDATABUF] |= udata;
		err = snd_cs8427_reg_write(device, CS8427_REG_CSDATABUF, chip->regmap[CS8427_REG_CSDATABUF]);
		if (err < 0)
			return err;
	}
	return 0;
}

static int snd_cs8427_send_corudata(snd_i2c_device_t *device,
				    int udata,
				    unsigned char *ndata,
				    int count)
{
	cs8427_t *chip = device->private_data;
	char *hw_data = udata ? chip->playback.hw_udata : chip->playback.hw_status;
	char data[32];
	int err, idx;

	if (!memcmp(hw_data, ndata, count))
		return 0;
	if ((err = snd_cs8427_select_corudata(device, udata)) < 0)
		return err;
	memcpy(hw_data, ndata, count);
	if (udata) {
		memset(data, 0, sizeof(data));
		if (memcmp(hw_data, data, count) == 0) {
			chip->regmap[CS8427_REG_UDATABUF] &= ~CS8427_UBMMASK;
			chip->regmap[CS8427_REG_UDATABUF] |= CS8427_UBMZEROS | CS8427_EFTUI;
			if ((err = snd_cs8427_reg_write(device, CS8427_REG_UDATABUF, chip->regmap[CS8427_REG_UDATABUF])) < 0)
				return err;
			return 0;
		}
	}
	data[0] = CS8427_REG_AUTOINC | CS8427_REG_CORU_DATABUF;
	for (idx = 0; idx < count; idx++)
		data[idx + 1] = swapbits(ndata[idx]);
	if (snd_i2c_sendbytes(device, data, count + 1) != count + 1)
		return -EIO;
	return 1;
}

static void snd_cs8427_free(snd_i2c_device_t *device)
{
	kfree(device->private_data);
}

int snd_cs8427_create(snd_i2c_bus_t *bus,
		      unsigned char addr,
		      unsigned int reset_timeout,
		      snd_i2c_device_t **r_cs8427)
{
	static unsigned char initvals1[] = {
	  CS8427_REG_CONTROL1 | CS8427_REG_AUTOINC,
	  /* CS8427_REG_CONTROL1: RMCK to OMCK, valid PCM audio, disable mutes, TCBL=output */
	  CS8427_SWCLK | CS8427_TCBLDIR,
	  /* CS8427_REG_CONTROL2: hold last valid audio sample, RMCK=256*Fs, normal stereo operation */
	  0x00,
	  /* CS8427_REG_DATAFLOW: output drivers normal operation, Tx<=serial, Rx=>serial */
	  CS8427_TXDSERIAL | CS8427_SPDAES3RECEIVER,
	  /* CS8427_REG_CLOCKSOURCE: Run off, CMCK=256*Fs, output time base = OMCK, input time base =
	     recovered input clock, recovered input clock source is ILRCK changed to AES3INPUT (workaround, see snd_cs8427_reset) */
	  CS8427_RXDILRCK,
	  /* CS8427_REG_SERIALINPUT: Serial audio input port data format = I2S, 24-bit, 64*Fsi */
	  CS8427_SIDEL | CS8427_SILRPOL,
	  /* CS8427_REG_SERIALOUTPUT: Serial audio output port data format = I2S, 24-bit, 64*Fsi */
	  CS8427_SODEL | CS8427_SOLRPOL,
	};
	static unsigned char initvals2[] = {
	  CS8427_REG_RECVERRMASK | CS8427_REG_AUTOINC,
	  /* CS8427_REG_RECVERRMASK: unmask the input PLL clock, V, confidence, biphase, parity status bits */
	  /* CS8427_UNLOCK | CS8427_V | CS8427_CONF | CS8427_BIP | CS8427_PAR, */
	  0xff, /* set everything */
	  /* CS8427_REG_CSDATABUF:
	     Registers 32-55 window to CS buffer
	     Inhibit D->E transfers from overwriting first 5 bytes of CS data.
	     Inhibit D->E transfers (all) of CS data.
	     Allow E->F transfer of CS data.
	     One byte mode; both A/B channels get same written CB data.
	     A channel info is output to chip's EMPH* pin. */
	  CS8427_CBMR | CS8427_DETCI,
	  /* CS8427_REG_UDATABUF:
	     Use internal buffer to transmit User (U) data.
	     Chip's U pin is an output.
	     Transmit all O's for user data.
	     Inhibit D->E transfers.
	     Inhibit E->F transfers. */
	  CS8427_UD | CS8427_EFTUI | CS8427_DETUI,
	};
	int err;
	cs8427_t *chip;
	snd_i2c_device_t *device;
	unsigned char buf[24];

	if ((err = snd_i2c_device_create(bus, "CS8427", CS8427_ADDR | (addr & 7), &device)) < 0)
		return err;
	chip = device->private_data = kcalloc(1, sizeof(*chip), GFP_KERNEL);
	if (chip == NULL) {
	      	snd_i2c_device_free(device);
		return -ENOMEM;
	}
	device->private_free = snd_cs8427_free;
	
	snd_i2c_lock(bus);
	if ((err = snd_cs8427_reg_read(device, CS8427_REG_ID_AND_VER)) != CS8427_VER8427A) {
		snd_i2c_unlock(bus);
		snd_printk("unable to find CS8427 signature (expected 0x%x, read 0x%x), initialization is not completed\n", CS8427_VER8427A, err);
		return -EFAULT;
	}
	/* turn off run bit while making changes to configuration */
	if ((err = snd_cs8427_reg_write(device, CS8427_REG_CLOCKSOURCE, 0x00)) < 0)
		goto __fail;
	/* send initial values */
	memcpy(chip->regmap + (initvals1[0] & 0x7f), initvals1 + 1, 6);
	if ((err = snd_i2c_sendbytes(device, initvals1, 7)) != 7) {
		err = err < 0 ? err : -EIO;
		goto __fail;
	}
	/* Turn off CS8427 interrupt stuff that is not used in hardware */
	memset(buf, 0, 7);
	/* from address 9 to 15 */
	buf[0] = 9;	/* register */
	if ((err = snd_i2c_sendbytes(device, buf, 7)) != 7)
		goto __fail;
	/* send transfer initialization sequence */
	memcpy(chip->regmap + (initvals2[0] & 0x7f), initvals2 + 1, 3);
	if ((err = snd_i2c_sendbytes(device, initvals2, 4)) != 4) {
		err = err < 0 ? err : -EIO;
		goto __fail;
	}
	/* write default channel status bytes */
	buf[0] = ((unsigned char)(SNDRV_PCM_DEFAULT_CON_SPDIF >> 0));
	buf[1] = ((unsigned char)(SNDRV_PCM_DEFAULT_CON_SPDIF >> 8));
	buf[2] = ((unsigned char)(SNDRV_PCM_DEFAULT_CON_SPDIF >> 16));
	buf[3] = ((unsigned char)(SNDRV_PCM_DEFAULT_CON_SPDIF >> 24));
	memset(buf + 4, 0, 24 - 4);
	if (snd_cs8427_send_corudata(device, 0, buf, 24) < 0)
		goto __fail;
	memcpy(chip->playback.def_status, buf, 24);
	memcpy(chip->playback.pcm_status, buf, 24);
	snd_i2c_unlock(bus);

	/* turn on run bit and rock'n'roll */
	if (reset_timeout < 1)
		reset_timeout = 1;
	chip->reset_timeout = reset_timeout;
	snd_cs8427_reset(device);

#if 0	// it's nice for read tests
	{
	char buf[128];
	int xx;
	buf[0] = 0x81;
	snd_i2c_sendbytes(device, buf, 1);
	snd_i2c_readbytes(device, buf, 127);
	for (xx = 0; xx < 127; xx++)
		printk("reg[0x%x] = 0x%x\n", xx+1, buf[xx]);
	}
#endif
	
	if (r_cs8427)
		*r_cs8427 = device;
	return 0;

      __fail:
      	snd_i2c_unlock(bus);
      	snd_i2c_device_free(device);
      	return err < 0 ? err : -EIO;
}

/*
 * Reset the chip using run bit, also lock PLL using ILRCK and
 * put back AES3INPUT. This workaround is described in latest
 * CS8427 datasheet, otherwise TXDSERIAL will not work.
 */
static void snd_cs8427_reset(snd_i2c_device_t *cs8427)
{
	cs8427_t *chip;
	unsigned long end_time;
	int data;