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Commit 9903405b authored by Russell King's avatar Russell King
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ARM: sa11x0: remove old SoC private DMA driver 

Now that all users are converted over to using the DMA engine API,
we can get rid of the old platform dependent DMA driver.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 277dc7ae
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arch/arm/mach-sa1100/Makefile
View file @ 9903405b
......@@ -3,7 +3,7 @@
#
# Common support
obj-y := clock.o generic.o irq.o dma.o time.o #nmi-oopser.o
obj-y := clock.o generic.o irq.o time.o #nmi-oopser.o
obj-m :=
obj-n :=
obj- :=
......
arch/arm/mach-sa1100/dma.c deleted 100644 → 0
View file @ 277dc7ae
/*
* arch/arm/mach-sa1100/dma.c
*
* Support functions for the SA11x0 internal DMA channels.
*
* Copyright (C) 2000, 2001 by Nicolas Pitre
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/dma.h>
#undef DEBUG
#ifdef DEBUG
#define DPRINTK( s, arg... ) printk( "dma<%p>: " s, regs , ##arg )
#else
#define DPRINTK( x... )
#endif
typedef struct {
const char *device_id; /* device name */
u_long device; /* this channel device, 0 if unused*/
dma_callback_t callback; /* to call when DMA completes */
void *data; /* ... with private data ptr */
} sa1100_dma_t;
static sa1100_dma_t dma_chan[SA1100_DMA_CHANNELS];
static DEFINE_SPINLOCK(dma_list_lock);
static irqreturn_t dma_irq_handler(int irq, void *dev_id)
{
dma_regs_t *dma_regs = dev_id;
sa1100_dma_t *dma = dma_chan + (((u_int)dma_regs >> 5) & 7);
int status = dma_regs->RdDCSR;
if (status & (DCSR_ERROR)) {
printk(KERN_CRIT "DMA on \"%s\" caused an error\n", dma->device_id);
dma_regs->ClrDCSR = DCSR_ERROR;
}
dma_regs->ClrDCSR = status & (DCSR_DONEA | DCSR_DONEB);
if (dma->callback) {
if (status & DCSR_DONEA)
dma->callback(dma->data);
if (status & DCSR_DONEB)
dma->callback(dma->data);
}
return IRQ_HANDLED;
}
/**
* sa1100_request_dma - allocate one of the SA11x0's DMA channels
* @device: The SA11x0 peripheral targeted by this request
* @device_id: An ascii name for the claiming device
* @callback: Function to be called when the DMA completes
* @data: A cookie passed back to the callback function
* @dma_regs: Pointer to the location of the allocated channel's identifier
*
* This function will search for a free DMA channel and returns the
* address of the hardware registers for that channel as the channel
* identifier. This identifier is written to the location pointed by
* @dma_regs. The list of possible values for @device are listed into
* arch/arm/mach-sa1100/include/mach/dma.h as a dma_device_t enum.
*
* Note that reading from a port and writing to the same port are
* actually considered as two different streams requiring separate
* DMA registrations.
*
* The @callback function is called from interrupt context when one
* of the two possible DMA buffers in flight has terminated. That
* function has to be small and efficient while posponing more complex
* processing to a lower priority execution context.
*
* If no channels are available, or if the desired @device is already in
* use by another DMA channel, then an error code is returned. This
* function must be called before any other DMA calls.
**/
int sa1100_request_dma (dma_device_t device, const char *device_id,
dma_callback_t callback, void *data,
dma_regs_t **dma_regs)
{
sa1100_dma_t *dma = NULL;
dma_regs_t *regs;
int i, err;
*dma_regs = NULL;
err = 0;
spin_lock(&dma_list_lock);
for (i = 0; i < SA1100_DMA_CHANNELS; i++) {
if (dma_chan[i].device == device) {
err = -EBUSY;
break;
} else if (!dma_chan[i].device && !dma) {
dma = &dma_chan[i];
}
}
if (!err) {
if (dma)
dma->device = device;
else
err = -ENOSR;
}
spin_unlock(&dma_list_lock);
if (err)
return err;
i = dma - dma_chan;
regs = (dma_regs_t *)&DDAR(i);
err = request_irq(IRQ_DMA0 + i, dma_irq_handler, IRQF_DISABLED,
device_id, regs);
if (err) {
printk(KERN_ERR
"%s: unable to request IRQ %d for %s\n",
__func__, IRQ_DMA0 + i, device_id);
dma->device = 0;
return err;
}
*dma_regs = regs;
dma->device_id = device_id;
dma->callback = callback;
dma->data = data;
regs->ClrDCSR =
(DCSR_DONEA | DCSR_DONEB | DCSR_STRTA | DCSR_STRTB |
DCSR_IE | DCSR_ERROR | DCSR_RUN);
regs->DDAR = device;
return 0;
}
/**
* sa1100_free_dma - free a SA11x0 DMA channel
* @regs: identifier for the channel to free
*
* This clears all activities on a given DMA channel and releases it
* for future requests. The @regs identifier is provided by a
* successful call to sa1100_request_dma().
**/
void sa1100_free_dma(dma_regs_t *regs)
{
int i;
for (i = 0; i < SA1100_DMA_CHANNELS; i++)
if (regs == (dma_regs_t *)&DDAR(i))
break;
if (i >= SA1100_DMA_CHANNELS) {
printk(KERN_ERR "%s: bad DMA identifier\n", __func__);
return;
}
if (!dma_chan[i].device) {
printk(KERN_ERR "%s: Trying to free free DMA\n", __func__);
return;
}
regs->ClrDCSR =
(DCSR_DONEA | DCSR_DONEB | DCSR_STRTA | DCSR_STRTB |
DCSR_IE | DCSR_ERROR | DCSR_RUN);
free_irq(IRQ_DMA0 + i, regs);
dma_chan[i].device = 0;
}
/**
* sa1100_start_dma - submit a data buffer for DMA
* @regs: identifier for the channel to use
* @dma_ptr: buffer physical (or bus) start address
* @size: buffer size
*
* This function hands the given data buffer to the hardware for DMA
* access. If another buffer is already in flight then this buffer
* will be queued so the DMA engine will switch to it automatically
* when the previous one is done. The DMA engine is actually toggling
* between two buffers so at most 2 successful calls can be made before
* one of them terminates and the callback function is called.
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
*
* The @size must not be larger than %MAX_DMA_SIZE. If a given buffer
* is larger than that then it's the caller's responsibility to split
* it into smaller chunks and submit them separately. If this is the
* case then a @size of %CUT_DMA_SIZE is recommended to avoid ending
* up with too small chunks. The callback function can be used to chain
* submissions of buffer chunks.
*
* Error return values:
* %-EOVERFLOW: Given buffer size is too big.
* %-EBUSY: Both DMA buffers are already in use.
* %-EAGAIN: Both buffers were busy but one of them just completed
* but the interrupt handler has to execute first.
*
* This function returs 0 on success.
**/
int sa1100_start_dma(dma_regs_t *regs, dma_addr_t dma_ptr, u_int size)
{
unsigned long flags;
u_long status;
int ret;
if (dma_ptr & 3)
printk(KERN_WARNING "DMA: unaligned start address (0x%08lx)\n",
(unsigned long)dma_ptr);
if (size > MAX_DMA_SIZE)
return -EOVERFLOW;
local_irq_save(flags);
status = regs->RdDCSR;
/* If both DMA buffers are started, there's nothing else we can do. */
if ((status & (DCSR_STRTA | DCSR_STRTB)) == (DCSR_STRTA | DCSR_STRTB)) {
DPRINTK("start: st %#x busy\n", status);
ret = -EBUSY;
goto out;
}
if (((status & DCSR_BIU) && (status & DCSR_STRTB)) ||
(!(status & DCSR_BIU) && !(status & DCSR_STRTA))) {
if (status & DCSR_DONEA) {
/* give a chance for the interrupt to be processed */
ret = -EAGAIN;
goto out;
}
regs->DBSA = dma_ptr;
regs->DBTA = size;
regs->SetDCSR = DCSR_STRTA | DCSR_IE | DCSR_RUN;
DPRINTK("start a=%#x s=%d on A\n", dma_ptr, size);
} else {
if (status & DCSR_DONEB) {
/* give a chance for the interrupt to be processed */
ret = -EAGAIN;
goto out;
}
regs->DBSB = dma_ptr;
regs->DBTB = size;
regs->SetDCSR = DCSR_STRTB | DCSR_IE | DCSR_RUN;
DPRINTK("start a=%#x s=%d on B\n", dma_ptr, size);
}
ret = 0;
out:
local_irq_restore(flags);
return ret;
}
/**
* sa1100_get_dma_pos - return current DMA position
* @regs: identifier for the channel to use
*
* This function returns the current physical (or bus) address for the
* given DMA channel. If the channel is running i.e. not in a stopped
* state then the caller must disable interrupts prior calling this
* function and process the returned value before re-enabling them to
* prevent races with the completion interrupt handler and the callback
* function. The validation of the returned value is the caller's
* responsibility as well -- the hardware seems to return out of range
* values when the DMA engine completes a buffer.
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
**/
dma_addr_t sa1100_get_dma_pos(dma_regs_t *regs)
{
int status;
/*
* We must determine whether buffer A or B is active.
* Two possibilities: either we are in the middle of
* a buffer, or the DMA controller just switched to the
* next toggle but the interrupt hasn't been serviced yet.
* The former case is straight forward. In the later case,
* we'll do like if DMA is just at the end of the previous
* toggle since all registers haven't been reset yet.
* This goes around the edge case and since we're always
* a little behind anyways it shouldn't make a big difference.
* If DMA has been stopped prior calling this then the
* position is exact.
*/
status = regs->RdDCSR;
if ((!(status & DCSR_BIU) && (status & DCSR_STRTA)) ||
( (status & DCSR_BIU) && !(status & DCSR_STRTB)))
return regs->DBSA;
else
return regs->DBSB;
}
/**
* sa1100_reset_dma - reset a DMA channel
* @regs: identifier for the channel to use
*
* This function resets and reconfigure the given DMA channel. This is
* particularly useful after a sleep/wakeup event.
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
**/
void sa1100_reset_dma(dma_regs_t *regs)
{
int i;
for (i = 0; i < SA1100_DMA_CHANNELS; i++)
if (regs == (dma_regs_t *)&DDAR(i))
break;
if (i >= SA1100_DMA_CHANNELS) {
printk(KERN_ERR "%s: bad DMA identifier\n", __func__);
return;
}
regs->ClrDCSR =
(DCSR_DONEA | DCSR_DONEB | DCSR_STRTA | DCSR_STRTB |
DCSR_IE | DCSR_ERROR | DCSR_RUN);
regs->DDAR = dma_chan[i].device;
}
EXPORT_SYMBOL(sa1100_request_dma);
EXPORT_SYMBOL(sa1100_free_dma);
EXPORT_SYMBOL(sa1100_start_dma);
EXPORT_SYMBOL(sa1100_get_dma_pos);
EXPORT_SYMBOL(sa1100_reset_dma);
arch/arm/mach-sa1100/include/mach/dma.h deleted 100644 → 0
View file @ 277dc7ae
/*
* arch/arm/mach-sa1100/include/mach/dma.h
*
* Generic SA1100 DMA support
*
* Copyright (C) 2000 Nicolas Pitre
*
*/
#ifndef __ASM_ARCH_DMA_H
#define __ASM_ARCH_DMA_H
#include "hardware.h"
/*
* The SA1100 has six internal DMA channels.
*/
#define SA1100_DMA_CHANNELS 6
/*
* Maximum physical DMA buffer size
*/
#define MAX_DMA_SIZE 0x1fff
#define CUT_DMA_SIZE 0x1000
/*
* All possible SA1100 devices a DMA channel can be attached to.
*/
typedef enum {
DMA_Ser0UDCWr = DDAR_Ser0UDCWr, /* Ser. port 0 UDC Write */
DMA_Ser0UDCRd = DDAR_Ser0UDCRd, /* Ser. port 0 UDC Read */
DMA_Ser1UARTWr = DDAR_Ser1UARTWr, /* Ser. port 1 UART Write */
DMA_Ser1UARTRd = DDAR_Ser1UARTRd, /* Ser. port 1 UART Read */
DMA_Ser1SDLCWr = DDAR_Ser1SDLCWr, /* Ser. port 1 SDLC Write */
DMA_Ser1SDLCRd = DDAR_Ser1SDLCRd, /* Ser. port 1 SDLC Read */
DMA_Ser2UARTWr = DDAR_Ser2UARTWr, /* Ser. port 2 UART Write */
DMA_Ser2UARTRd = DDAR_Ser2UARTRd, /* Ser. port 2 UART Read */
DMA_Ser2HSSPWr = DDAR_Ser2HSSPWr, /* Ser. port 2 HSSP Write */
DMA_Ser2HSSPRd = DDAR_Ser2HSSPRd, /* Ser. port 2 HSSP Read */
DMA_Ser3UARTWr = DDAR_Ser3UARTWr, /* Ser. port 3 UART Write */
DMA_Ser3UARTRd = DDAR_Ser3UARTRd, /* Ser. port 3 UART Read */
DMA_Ser4MCP0Wr = DDAR_Ser4MCP0Wr, /* Ser. port 4 MCP 0 Write (audio) */
DMA_Ser4MCP0Rd = DDAR_Ser4MCP0Rd, /* Ser. port 4 MCP 0 Read (audio) */
DMA_Ser4MCP1Wr = DDAR_Ser4MCP1Wr, /* Ser. port 4 MCP 1 Write */
DMA_Ser4MCP1Rd = DDAR_Ser4MCP1Rd, /* Ser. port 4 MCP 1 Read */
DMA_Ser4SSPWr = DDAR_Ser4SSPWr, /* Ser. port 4 SSP Write (16 bits) */
DMA_Ser4SSPRd = DDAR_Ser4SSPRd /* Ser. port 4 SSP Read (16 bits) */
} dma_device_t;
typedef struct {
volatile u_long DDAR;
volatile u_long SetDCSR;
volatile u_long ClrDCSR;
volatile u_long RdDCSR;
volatile dma_addr_t DBSA;
volatile u_long DBTA;
volatile dma_addr_t DBSB;
volatile u_long DBTB;
} dma_regs_t;
typedef void (*dma_callback_t)(void *data);
/*
* DMA function prototypes
*/
extern int sa1100_request_dma( dma_device_t device, const char *device_id,
dma_callback_t callback, void *data,
dma_regs_t **regs );
extern void sa1100_free_dma( dma_regs_t *regs );
extern int sa1100_start_dma( dma_regs_t *regs, dma_addr_t dma_ptr, u_int size );
extern dma_addr_t sa1100_get_dma_pos(dma_regs_t *regs);
extern void sa1100_reset_dma(dma_regs_t *regs);
/**
* sa1100_stop_dma - stop DMA in progress
* @regs: identifier for the channel to use
*
* This stops DMA without clearing buffer pointers. Unlike
* sa1100_clear_dma() this allows subsequent use of sa1100_resume_dma()
* or sa1100_get_dma_pos().
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
**/
#define sa1100_stop_dma(regs) ((regs)->ClrDCSR = DCSR_IE|DCSR_RUN)
/**
* sa1100_resume_dma - resume DMA on a stopped channel
* @regs: identifier for the channel to use
*
* This resumes DMA on a channel previously stopped with
* sa1100_stop_dma().
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
**/
#define sa1100_resume_dma(regs) ((regs)->SetDCSR = DCSR_IE|DCSR_RUN)
/**
* sa1100_clear_dma - clear DMA pointers
* @regs: identifier for the channel to use
*
* This clear any DMA state so the DMA engine is ready to restart
* with new buffers through sa1100_start_dma(). Any buffers in flight
* are discarded.
*
* The @regs identifier is provided by a successful call to
* sa1100_request_dma().
**/
#define sa1100_clear_dma(regs) ((regs)->ClrDCSR = DCSR_IE|DCSR_RUN|DCSR_STRTA|DCSR_STRTB)
#endif /* _ASM_ARCH_DMA_H */
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