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linux/sound/pcmcia/pdaudiocf/pdaudiocf.h
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

146 lines
5.3 KiB
C
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/*
* Driver for Sound Cors PDAudioCF soundcard
*
* Copyright (c) 2003 by Jaroslav Kysela <perex@suse.cz>
*
* 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
*/
#ifndef __PDAUDIOCF_H
#define __PDAUDIOCF_H
#include <sound/pcm.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <pcmcia/cs_types.h>
#include <pcmcia/cs.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#include <sound/ak4117.h>
/* PDAUDIOCF registers */
#define PDAUDIOCF_REG_MD 0x00 /* music data, R/O */
#define PDAUDIOCF_REG_WDP 0x02 /* write data pointer / 2, R/O */
#define PDAUDIOCF_REG_RDP 0x04 /* read data pointer / 2, R/O */
#define PDAUDIOCF_REG_TCR 0x06 /* test control register W/O */
#define PDAUDIOCF_REG_SCR 0x08 /* status and control, R/W (see bit description) */
#define PDAUDIOCF_REG_ISR 0x0a /* interrupt status, R/O */
#define PDAUDIOCF_REG_IER 0x0c /* interrupt enable, R/W */
#define PDAUDIOCF_REG_AK_IFR 0x0e /* AK interface register, R/W */
/* PDAUDIOCF_REG_TCR */
#define PDAUDIOCF_ELIMAKMBIT (1<<0) /* simulate AKM music data */
#define PDAUDIOCF_TESTDATASEL (1<<1) /* test data selection, 0 = 0x55, 1 = pseudo-random */
/* PDAUDIOCF_REG_SCR */
#define PDAUDIOCF_AK_SBP (1<<0) /* serial port busy flag */
#define PDAUDIOCF_RST (1<<2) /* FPGA, AKM + SRAM buffer reset */
#define PDAUDIOCF_PDN (1<<3) /* power down bit */
#define PDAUDIOCF_CLKDIV0 (1<<4) /* choose 24.576Mhz clock divided by 1,2,3 or 4 */
#define PDAUDIOCF_CLKDIV1 (1<<5)
#define PDAUDIOCF_RECORD (1<<6) /* start capturing to SRAM */
#define PDAUDIOCF_AK_SDD (1<<7) /* music data detected */
#define PDAUDIOCF_RED_LED_OFF (1<<8) /* red LED off override */
#define PDAUDIOCF_BLUE_LED_OFF (1<<9) /* blue LED off override */
#define PDAUDIOCF_DATAFMT0 (1<<10) /* data format bits: 00 = 16-bit, 01 = 18-bit */
#define PDAUDIOCF_DATAFMT1 (1<<11) /* 10 = 20-bit, 11 = 24-bit, all right justified */
#define PDAUDIOCF_FPGAREV(x) ((x>>12)&0x0f) /* FPGA revision */
/* PDAUDIOCF_REG_ISR */
#define PDAUDIOCF_IRQLVL (1<<0) /* Buffer level IRQ */
#define PDAUDIOCF_IRQOVR (1<<1) /* Overrun IRQ */
#define PDAUDIOCF_IRQAKM (1<<2) /* AKM IRQ */
/* PDAUDIOCF_REG_IER */
#define PDAUDIOCF_IRQLVLEN0 (1<<0) /* fill threshold levels; 00 = none, 01 = 1/8th of buffer */
#define PDAUDIOCF_IRQLVLEN1 (1<<1) /* 10 = 1/4th of buffer, 11 = 1/2th of buffer */
#define PDAUDIOCF_IRQOVREN (1<<2) /* enable overrun IRQ */
#define PDAUDIOCF_IRQAKMEN (1<<3) /* enable AKM IRQ */
#define PDAUDIOCF_BLUEDUTY0 (1<<8) /* blue LED duty cycle; 00 = 100%, 01 = 50% */
#define PDAUDIOCF_BLUEDUTY1 (1<<9) /* 02 = 25%, 11 = 12% */
#define PDAUDIOCF_REDDUTY0 (1<<10) /* red LED duty cycle; 00 = 100%, 01 = 50% */
#define PDAUDIOCF_REDDUTY1 (1<<11) /* 02 = 25%, 11 = 12% */
#define PDAUDIOCF_BLUESDD (1<<12) /* blue LED against SDD bit */
#define PDAUDIOCF_BLUEMODULATE (1<<13) /* save power when 100% duty cycle selected */
#define PDAUDIOCF_REDMODULATE (1<<14) /* save power when 100% duty cycle selected */
#define PDAUDIOCF_HALFRATE (1<<15) /* slow both LED blinks by half (also spdif detect rate) */
/* chip status */
#define PDAUDIOCF_STAT_IS_STALE (1<<0)
#define PDAUDIOCF_STAT_IS_CONFIGURED (1<<1)
#define PDAUDIOCF_STAT_IS_SUSPENDED (1<<2)
struct snd_pdacf {
struct snd_card *card;
int index;
unsigned long port;
int irq;
spinlock_t reg_lock;
unsigned short regmap[8];
unsigned short suspend_reg_scr;
struct tasklet_struct tq;
spinlock_t ak4117_lock;
struct ak4117 *ak4117;
unsigned int chip_status;
struct snd_pcm *pcm;
struct snd_pcm_substream *pcm_substream;
unsigned int pcm_running: 1;
unsigned int pcm_channels;
unsigned int pcm_swab;
unsigned int pcm_little;
unsigned int pcm_frame;
unsigned int pcm_sample;
unsigned int pcm_xor;
unsigned int pcm_size;
unsigned int pcm_period;
unsigned int pcm_tdone;
unsigned int pcm_hwptr;
void *pcm_area;
/* pcmcia stuff */
struct pcmcia_device *p_dev;
dev_node_t node;
};
static inline void pdacf_reg_write(struct snd_pdacf *chip, unsigned char reg, unsigned short val)
{
outw(chip->regmap[reg>>1] = val, chip->port + reg);
}
static inline unsigned short pdacf_reg_read(struct snd_pdacf *chip, unsigned char reg)
{
return inw(chip->port + reg);
}
struct snd_pdacf *snd_pdacf_create(struct snd_card *card);
int snd_pdacf_ak4117_create(struct snd_pdacf *pdacf);
void snd_pdacf_powerdown(struct snd_pdacf *chip);
#ifdef CONFIG_PM
int snd_pdacf_suspend(struct snd_pdacf *chip, pm_message_t state);
int snd_pdacf_resume(struct snd_pdacf *chip);
#endif
int snd_pdacf_pcm_new(struct snd_pdacf *chip);
irqreturn_t pdacf_interrupt(int irq, void *dev);
void pdacf_tasklet(unsigned long private_data);
void pdacf_reinit(struct snd_pdacf *chip, int resume);
#endif /* __PDAUDIOCF_H */
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