path: root/sound/aoa/codecs/tas.c

/*
 * Apple Onboard Audio driver for tas codec
 *
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * GPL v2, can be found in COPYING.
 *
 * Open questions:
 *  - How to distinguish between 3004 and versions?
 *
 * FIXMEs:
 *  - This codec driver doesn't honour the 'connected'
 *    property of the aoa_codec struct, hence if
 *    it is used in machines where not everything is
 *    connected it will display wrong mixer elements.
 *  - Driver assumes that the microphone is always
 *    monaureal and connected to the right channel of
 *    the input. This should also be a codec-dependent
 *    flag, maybe the codec should have 3 different
 *    bits for the three different possibilities how
 *    it can be hooked up...
 *    But as long as I don't see any hardware hooked
 *    up that way...
 *  - As Apple notes in their code, the tas3004 seems
 *    to delay the right channel by one sample. You can
 *    see this when for example recording stereo in
 *    audacity, or recording the tas output via cable
 *    on another machine (use a sinus generator or so).
 *    I tried programming the BiQuads but couldn't
 *    make the delay work, maybe someone can read the
 *    datasheet and fix it. The relevant Apple comment
 *    is in AppleTAS3004Audio.cpp lines 1637 ff. Note
 *    that their comment describing how they program
 *    the filters sucks...
 *
 * Other things:
 *  - this should actually register *two* aoa_codec
 *    structs since it has two inputs. Then it must
 *    use the prepare callback to forbid running the
 *    secondary output on a different clock.
 *    Also, whatever bus knows how to do this must
 *    provide two soundbus_dev devices and the fabric
 *    must be able to link them correctly.
 *
 *    I don't even know if Apple ever uses the second
 *    port on the tas3004 though, I don't think their
 *    i2s controllers can even do it. OTOH, they all
 *    derive the clocks from common clocks, so it
 *    might just be possible. The framework allows the
 *    codec to refine the transfer_info items in the
 *    usable callback, so we can simply remove the
 *    rates the second instance is not using when it
 *    actually is in use.
 *    Maybe we'll need to make the sound busses have
 *    a 'clock group id' value so the codec can
 *    determine if the two outputs can be driven at
 *    the same time. But that is likely overkill, up
 *    to the fabric to not link them up incorrectly,
 *    and up to the hardware designer to not wire
 *    them up in some weird unusable way.
 */
#include <stddef.h>
#include <linux/i2c.h>
#include <asm/pmac_low_i2c.h>
#include <asm/prom.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/mutex.h>

MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("tas codec driver for snd-aoa");

#include "tas.h"
#include "tas-gain-table.h"
#include "tas-basstreble.h"
#include "../aoa.h"
#include "../soundbus/soundbus.h"

#define PFX "snd-aoa-codec-tas: "


struct tas {
	struct aoa_codec	codec;
	struct i2c_client	i2c;
	u32			mute_l:1, mute_r:1 ,
				controls_created:1 ,
				drc_enabled:1,
				hw_enabled:1;
	u8			cached_volume_l, cached_volume_r;
	u8			mixer_l[3], mixer_r[3];
	u8			bass, treble;
	u8			acr;
	int			drc_range;
	/* protects hardware access against concurrency from
	 * userspace when hitting controls and during
	 * codec init/suspend/resume */
	struct mutex		mtx;
};

static int tas_reset_init(struct tas *tas);

static struct tas *codec_to_tas(struct aoa_codec *codec)
{
	return container_of(codec, struct tas, codec);
}

static inline int tas_write_reg(struct tas *tas, u8 reg, u8 len, u8 *data)
{
	if (len == 1)
		return i2c_smbus_write_byte_data(&tas->i2c, reg, *data);
	else
		return i2c_smbus_write_i2c_block_data(&tas->i2c, reg, len, data);
}

static void tas3004_set_drc(struct tas *tas)
{
	unsigned char val[6];

	if (tas->drc_enabled)
		val[0] = 0x50; /* 3:1 above threshold */
	else
		val[0] = 0x51; /* disabled */
	val[1] = 0x02; /* 1:1 below threshold */
	if (tas->drc_range > 0xef)
		val[2] = 0xef;
	else if (tas->drc_range < 0)
		val[2] = 0x00;
	else
		val[2] = tas->drc_range;
	val[3] = 0xb0;
	val[4] = 0x60;
	val[5] = 0xa0;

	tas_write_reg(tas, TAS_REG_DRC, 6, val);
}

static void tas_set_treble(struct tas *tas)
{
	u8 tmp;

	tmp = tas3004_treble(tas->treble);
	tas_write_reg(tas, TAS_REG_TREBLE, 1, &tmp);
}

static void tas_set_bass(struct tas *tas)
{
	u8 tmp;

	tmp = tas3004_bass(tas->bass);
	tas_write_reg(tas, TAS_REG_BASS, 1, &tmp);
}

static void tas_set_volume(struct tas *tas)
{
	u8 block[6];
	int tmp;
	u8 left, right;

	left = tas->cached_volume_l;
	right = tas->cached_volume_r;

	if (left > 177) left = 177;
	if (right > 177) right = 177;

	if (tas->mute_l) left = 0;
	if (tas->mute_r) right = 0;

	/* analysing the volume and mixer tables shows
	 * that they are similar enough when we shift
	 * the mixer table down by 4 bits. The error
	 * is miniscule, in just one item the error
	 * is 1, at a value of 0x07f17b (mixer table
	 * value is 0x07f17a) */
	tmp = tas_gaintable[left];
	block[0] = tmp>>20;