android_kernel_xiaomi_sm8350/sound/aoa/soundbus/i2sbus/i2sbus.h
Paul Mackerras 547ac2ae38 [ALSA] aoa i2sbus: Stop Apple i2s DMA gracefully
This fixes the problem of getting extra bytes inserted at the
beginning of a recording when using the Apple i2s interface and DBDMA
controller.  It turns out that we can't just abort the DMA; we have to
let it stop at the end of a command, and then wait for the S7 bit to
be set before turning off the DBDMA controller.  Doing that for
playback doesn't seem to be necessary, but doesn't hurt either.
We use the technique used by the Darwin driver: make each transfer
command branch to a stop command if the S0 status bit is set.  Thus we
can ask the DMA controller to stop at the end of the current command
by setting S0.
The interrupt routine now looks at and clears the status word of the
DBDMA command ring.  This is necessary so it can know when the DBDMA
controller has seen that S0 is set, and so when it should look for the
DBDMA controller being stopped and S7 being set.  This also ended up
simplifying the calculation in i2sbus_pcm_pointer.
Tested on a 15 inch albook.
[Addition by Johannes]
I modified this patch and added the suspend/resume bits to it to get my
powermac into a decent state when playing sound across suspend to disk
that has a different bitrate from what the firmware programs the
hardware to.
I also added the SNDRV_PCM_INFO_JOINT_DUPLEX flag because it seemed the
right thing to do and I was looking at the info stuff.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
2007-02-09 09:04:02 +01:00

127 lines
3.2 KiB
C

/*
* i2sbus driver -- private definitions
*
* Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
*
* GPL v2, can be found in COPYING.
*/
#ifndef __I2SBUS_H
#define __I2SBUS_H
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <sound/pcm.h>
#include <asm/prom.h>
#include <asm/pmac_feature.h>
#include <asm/dbdma.h>
#include "i2sbus-interface.h"
#include "../soundbus.h"
struct i2sbus_control {
struct list_head list;
struct macio_chip *macio;
};
#define MAX_DBDMA_COMMANDS 32
struct dbdma_command_mem {
dma_addr_t bus_addr;
dma_addr_t bus_cmd_start;
struct dbdma_cmd *cmds;
void *space;
int size;
u32 running:1;
u32 stopping:1;
};
struct pcm_info {
u32 created:1, /* has this direction been created with alsa? */
active:1; /* is this stream active? */
/* runtime information */
struct snd_pcm_substream *substream;
int current_period;
u32 frame_count;
struct dbdma_command_mem dbdma_ring;
volatile struct dbdma_regs __iomem *dbdma;
struct completion *stop_completion;
};
enum {
aoa_resource_i2smmio = 0,
aoa_resource_txdbdma,
aoa_resource_rxdbdma,
};
struct i2sbus_dev {
struct soundbus_dev sound;
struct macio_dev *macio;
struct i2sbus_control *control;
volatile struct i2s_interface_regs __iomem *intfregs;
struct resource resources[3];
struct resource *allocated_resource[3];
int interrupts[3];
char rnames[3][32];
/* info about currently active substreams */
struct pcm_info out, in;
snd_pcm_format_t format;
unsigned int rate;
/* list for a single controller */
struct list_head item;
/* number of bus on controller */
int bus_number;
/* for use by control layer */
struct pmf_function *enable,
*cell_enable,
*cell_disable,
*clock_enable,
*clock_disable;
/* locks */
/* spinlock for low-level interrupt locking */
spinlock_t low_lock;
/* mutex for high-level consistency */
struct mutex lock;
};
#define soundbus_dev_to_i2sbus_dev(sdev) \
container_of(sdev, struct i2sbus_dev, sound)
/* pcm specific functions */
extern int
i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
struct codec_info *ci, void *data);
extern void
i2sbus_detach_codec(struct soundbus_dev *dev, void *data);
extern irqreturn_t
i2sbus_tx_intr(int irq, void *devid);
extern irqreturn_t
i2sbus_rx_intr(int irq, void *devid);
extern void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev);
extern void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev);
/* control specific functions */
extern int i2sbus_control_init(struct macio_dev* dev,
struct i2sbus_control **c);
extern void i2sbus_control_destroy(struct i2sbus_control *c);
extern int i2sbus_control_add_dev(struct i2sbus_control *c,
struct i2sbus_dev *i2sdev);
extern void i2sbus_control_remove_dev(struct i2sbus_control *c,
struct i2sbus_dev *i2sdev);
extern int i2sbus_control_enable(struct i2sbus_control *c,
struct i2sbus_dev *i2sdev);
extern int i2sbus_control_cell(struct i2sbus_control *c,
struct i2sbus_dev *i2sdev,
int enable);
extern int i2sbus_control_clock(struct i2sbus_control *c,
struct i2sbus_dev *i2sdev,
int enable);
#endif /* __I2SBUS_H */