/*
* arch/ppc/kernel/ppc4xx_dma.c
*
* IBM PPC4xx DMA engine core library
*
* Copyright 2000-2004 MontaVista Software Inc.
*
* Cleaned up and converted to new DCR access
* Matt Porter <mporter@kernel.crashing.org>
*
* Original code by Armin Kuster <akuster@mvista.com>
* and Pete Popov <ppopov@mvista.com>
*
* 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.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/module.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/ppc4xx_dma.h>
ppc_dma_ch_t dma_channels[MAX_PPC4xx_DMA_CHANNELS];
int
ppc4xx_get_dma_status(void)
{
return (mfdcr(DCRN_DMASR));
}
void
ppc4xx_set_src_addr(int dmanr, phys_addr_t src_addr)
{
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("set_src_addr: bad channel: %d\n", dmanr);
return;
}
#ifdef PPC4xx_DMA_64BIT
mtdcr(DCRN_DMASAH0 + dmanr*2, (u32)(src_addr >> 32));
#else
mtdcr(DCRN_DMASA0 + dmanr*2, (u32)src_addr);
#endif
}
void
ppc4xx_set_dst_addr(int dmanr, phys_addr_t dst_addr)
{
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("set_dst_addr: bad channel: %d\n", dmanr);
return;
}
#ifdef PPC4xx_DMA_64BIT
mtdcr(DCRN_DMADAH0 + dmanr*2, (u32)(dst_addr >> 32));
#else
mtdcr(DCRN_DMADA0 + dmanr*2, (u32)dst_addr);
#endif
}
void
ppc4xx_enable_dma(unsigned int dmanr)
{
unsigned int control;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
unsigned int status_bits[] = { DMA_CS0 | DMA_TS0 | DMA_CH0_ERR,
DMA_CS1 | DMA_TS1 | DMA_CH1_ERR,
DMA_CS2 | DMA_TS2 | DMA_CH2_ERR,
DMA_CS3 | DMA_TS3 | DMA_CH3_ERR};
if (p_dma_ch->in_use) {
printk("enable_dma: channel %d in use\n", dmanr);
return;
}
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("enable_dma: bad channel: %d\n", dmanr);
return;
}
if (p_dma_ch->mode == DMA_MODE_READ) {
/* peripheral to memory */
ppc4xx_set_src_addr(dmanr, 0);
ppc4xx_set_dst_addr(dmanr, p_dma_ch->addr);
} else if (p_dma_ch->mode == DMA_MODE_WRITE) {
/* memory to peripheral */
ppc4xx_set_src_addr(dmanr, p_dma_ch->addr);
ppc4xx_set_dst_addr(dmanr, 0);
}
/* for other xfer modes, the addresses are already set */
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
control &= ~(DMA_TM_MASK | DMA_TD); /* clear all mode bits */
if (p_dma_ch->mode == DMA_MODE_MM) {
/* software initiated memory to memory */
control |= DMA_ETD_OUTPUT | DMA_TCE_ENABLE;
}
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
/*
* Clear the CS, TS, RI bits for the channel from DMASR. This
* has been observed to happen correctly only after the mode and
* ETD/DCE bits in DMACRx are set above. Must do this before
* enabling the channel.
*/
mtdcr(DCRN_DMASR, status_bits[dmanr]);
/*
* For device-paced transfers, Terminal Count Enable apparently
* must be on, and this must be turned on after the mode, etc.
* bits are cleared above (at least on Redwood-6).
*/
if ((p_dma_ch->mode == DMA_MODE_MM_DEVATDST) ||
(p_dma_ch->mode == DMA_MODE_MM_DEVATSRC))
control |= DMA_TCE_ENABLE;
/*
* Now enable the channel.
*/
control |= (p_dma_ch->mode | DMA_CE_ENABLE);
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
p_dma_ch->in_use = 1;
}
void
ppc4xx_disable_dma(unsigned int dmanr)
{
unsigned int control;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (!p_dma_ch->in_use) {
printk("disable_dma: channel %d not in use\n", dmanr);
return;
}
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("disable_dma: bad channel: %d\n", dmanr);
return;
}
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
control &= ~DMA_CE_ENABLE;
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
p_dma_ch->in_use = 0;
}
/*
* Sets the dma mode for single DMA transfers only.
* For scatter/gather transfers, the mode is passed to the
* alloc_dma_handle() function as one of the parameters.
*
* The mode is simply saved and used later. This allows
* the driver to call set_dma_mode() and set_dma_addr() in
* any order.
*
* Valid mode values are:
*
* DMA_MODE_READ peripheral to memory
* DMA_MODE_WRITE memory to peripheral
* DMA_MODE_MM memory to memory
* DMA_MODE_MM_DEVATSRC device-paced memory to memory, device at src
* DMA_MODE_MM_DEVATDST device-paced memory to memory, device at dst
*/
int
ppc4xx_set_dma_mode(unsigned int dmanr, unsigned int mode)
{
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("set_dma_mode: bad channel 0x%x\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
p_dma_ch->mode = mode;
return DMA_STATUS_GOOD;
}
/*
* Sets the DMA Count register. Note that 'count' is in bytes.
* However, the DMA Count register counts the number of "transfers",
* where each transfer is equal to the bus width. Thus, count
* MUST be a multiple of the bus width.
*/
void
ppc4xx_set_dma_count(unsigned int dmanr, unsigned int count)
{
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
#ifdef DEBUG_4xxDMA
{
int error = 0;
switch (p_dma_ch->pwidth) {
case PW_8:
break;
case PW_16:
if (count & 0x1)
error = 1;
break;
case PW_32:
if (count & 0x3)
error = 1;
break;
case PW_64:
if (count & 0x7)
error = 1;
break;
default:
printk("set_dma_count: invalid bus width: 0x%x\n",
p_dma_ch->pwidth);
return;
}
if (error)
printk
("Warning: set_dma_count count 0x%x bus width %d\n",
count, p_dma_ch->pwidth);
}
#endif
count = count >> p_dma_ch->shift;
mtdcr(DCRN_DMACT0 + (dmanr * 0x8), count);
}
/*
* Returns the number of bytes left to be transfered.
* After a DMA transfer, this should return zero.
* Reading this while a DMA transfer is still in progress will return
* unpredictable results.
*/
int
ppc4xx_get_dma_residue(unsigned int dmanr)
{
unsigned int count;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_get_dma_residue: bad channel 0x%x\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
count = mfdcr(DCRN_DMACT0 + (dmanr * 0x8));
return (count << p_dma_ch->shift);
}
/*
* Sets the DMA address for a memory to peripheral or peripheral
* to memory transfer. The address is just saved in the channel
* structure for now and used later in enable_dma().
*/
void
ppc4xx_set_dma_addr(unsigned int dmanr, phys_addr_t addr)
{
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_set_dma_addr: bad channel: %d\n", dmanr);
return;
}
#ifdef DEBUG_4xxDMA
{
int error = 0;
switch (p_dma_ch->pwidth) {
case PW_8:
break;
case PW_16:
if ((unsigned) addr & 0x1)
error = 1;
break;
case PW_32:
if ((unsigned) addr & 0x3)
error = 1;
break;
case PW_64:
if ((unsigned) addr & 0x7)
error = 1;
break;
default:
printk("ppc4xx_set_dma_addr: invalid bus width: 0x%x\n",
p_dma_ch->pwidth);
return;
}
if (error)
printk("Warning: ppc4xx_set_dma_addr addr 0x%x bus width %d\n",
addr, p_dma_ch->pwidth);
}
#endif
/* save dma address and program it later after we know the xfer mode */
p_dma_ch->addr = addr;
}
/*
* Sets both DMA addresses for a memory to memory transfer.
* For memory to peripheral or peripheral to memory transfers
* the function set_dma_addr() should be used instead.
*/
void
ppc4xx_set_dma_addr2(unsigned int dmanr, phys_addr_t src_dma_addr,
phys_addr_t dst_dma_addr)
{
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_set_dma_addr2: bad channel: %d\n", dmanr);
return;
}
#ifdef DEBUG_4xxDMA
{
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
int error = 0;
switch (p_dma_ch->pwidth) {
case PW_8:
break;
case PW_16:
if (((unsigned) src_dma_addr & 0x1) ||
((unsigned) dst_dma_addr & 0x1)
)
error = 1;
break;
case PW_32:
if (((unsigned) src_dma_addr & 0x3) ||
((unsigned) dst_dma_addr & 0x3)
)
error = 1;
break;
case PW_64:
if (((unsigned) src_dma_addr & 0x7) ||
((unsigned) dst_dma_addr & 0x7)
)
error = 1;
break;
default:
printk("ppc4xx_set_dma_addr2: invalid bus width: 0x%x\n",
p_dma_ch->pwidth);
return;
}
if (error)
printk
("Warning: ppc4xx_set_dma_addr2 src 0x%x dst 0x%x bus width %d\n",
src_dma_addr, dst_dma_addr, p_dma_ch->pwidth);
}
#endif
ppc4xx_set_src_addr(dmanr, src_dma_addr);
ppc4xx_set_dst_addr(dmanr, dst_dma_addr);
}
/*
* Enables the channel interrupt.
*
* If performing a scatter/gatter transfer, this function
* MUST be called before calling alloc_dma_handle() and building
* the sgl list. Otherwise, interrupts will not be enabled, if
* they were previously disabled.
*/
int
ppc4xx_enable_dma_interrupt(unsigned int dmanr)
{
unsigned int control;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_enable_dma_interrupt: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
p_dma_ch->int_enable = 1;
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
control |= DMA_CIE_ENABLE; /* Channel Interrupt Enable */
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
return DMA_STATUS_GOOD;
}
/*
* Disables the channel interrupt.
*
* If performing a scatter/gatter transfer, this function
* MUST be called before calling alloc_dma_handle() and building
* the sgl list. Otherwise, interrupts will not be disabled, if
* they were previously enabled.
*/
int
ppc4xx_disable_dma_interrupt(unsigned int dmanr)
{
unsigned int control;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_disable_dma_interrupt: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
p_dma_ch->int_enable = 0;
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
control &= ~DMA_CIE_ENABLE; /* Channel Interrupt Enable */
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
return DMA_STATUS_GOOD;
}
/*
* Configures a DMA channel, including the peripheral bus width, if a
* peripheral is attached to the channel, the polarity of the DMAReq and
* DMAAck signals, etc. This information should really be setup by the boot
* code, since most likely the configuration won't change dynamically.
* If the kernel has to call this function, it's recommended that it's
* called from platform specific init code. The driver should not need to
* call this function.
*/
int
ppc4xx_init_dma_channel(unsigned int dmanr, ppc_dma_ch_t * p_init)
{
unsigned int polarity;
uint32_t control = 0;
ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
DMA_MODE_READ = (unsigned long) DMA_TD; /* Peripheral to Memory */
DMA_MODE_WRITE = 0; /* Memory to Peripheral */
if (!p_init) {
printk("ppc4xx_init_dma_channel: NULL p_init\n");
return DMA_STATUS_NULL_POINTER;
}
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_init_dma_channel: bad channel %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
#if DCRN_POL > 0
polarity = mfdcr(DCRN_POL);
#else
polarity = 0;
#endif
/* Setup the control register based on the values passed to
* us in p_init. Then, over-write the control register with this
* new value.
*/
control |= SET_DMA_CONTROL;
/* clear all polarity signals and then "or" in new signal levels */
polarity &= ~GET_DMA_POLARITY(dmanr);
polarity |= p_init->polarity;
#if DCRN_POL > 0
mtdcr(DCRN_POL, polarity);
#endif
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
/* save these values in our dma channel structure */
memcpy(p_dma_ch, p_init, sizeof (ppc_dma_ch_t));
/*
* The peripheral width values written in the control register are:
* PW_8 0
* PW_16 1
* PW_32 2
* PW_64 3
*
* Since the DMA count register takes the number of "transfers",
* we need to divide the count sent to us in certain
* functions by the appropriate number. It so happens that our
* right shift value is equal to the peripheral width value.
*/
p_dma_ch->shift = p_init->pwidth;
/*
* Save the control word for easy access.
*/
p_dma_ch->control = control;
mtdcr(DCRN_DMASR, 0xffffffff); /* clear status register */
return DMA_STATUS_GOOD;
}
/*
* This function returns the channel configuration.
*/
int
ppc4xx_get_channel_config(unsigned int dmanr, ppc_dma_ch_t * p_dma_ch)
{
unsigned int polarity;
unsigned int control;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_get_channel_config: bad channel %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
memcpy(p_dma_ch, &dma_channels[dmanr], sizeof (ppc_dma_ch_t));
#if DCRN_POL > 0
polarity = mfdcr(DCRN_POL);
#else
polarity = 0;
#endif
p_dma_ch->polarity = polarity & GET_DMA_POLARITY(dmanr);
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
p_dma_ch->cp = GET_DMA_PRIORITY(control);
p_dma_ch->pwidth = GET_DMA_PW(control);
p_dma_ch->psc = GET_DMA_PSC(control);
p_dma_ch->pwc = GET_DMA_PWC(control);
p_dma_ch->phc = GET_DMA_PHC(control);
p_dma_ch->ce = GET_DMA_CE_ENABLE(control);
p_dma_ch->int_enable = GET_DMA_CIE_ENABLE(control);
p_dma_ch->shift = GET_DMA_PW(control);
#ifdef CONFIG_PPC4xx_EDMA
p_dma_ch->pf = GET_DMA_PREFETCH(control);
#else
p_dma_ch->ch_enable = GET_DMA_CH(control);
p_dma_ch->ece_enable = GET_DMA_ECE(control);
p_dma_ch->tcd_disable = GET_DMA_TCD(control);
#endif
return DMA_STATUS_GOOD;
}
/*
* Sets the priority for the DMA channel dmanr.
* Since this is setup by the hardware init function, this function
* can be used to dynamically change the priority of a channel.
*
* Acceptable priorities:
*
* PRIORITY_LOW
* PRIORITY_MID_LOW
* PRIORITY_MID_HIGH
* PRIORITY_HIGH
*
*/
int
ppc4xx_set_channel_priority(unsigned int dmanr, unsigned int priority)
{
unsigned int control;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_set_channel_priority: bad channel %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
if ((priority != PRIORITY_LOW) &&
(priority != PRIORITY_MID_LOW) &&
(priority != PRIORITY_MID_HIGH) && (priority != PRIORITY_HIGH)) {
printk("ppc4xx_set_channel_priority: bad priority: 0x%x\n", priority);
}
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
control |= SET_DMA_PRIORITY(priority);
mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
return DMA_STATUS_GOOD;
}
/*
* Returns the width of the peripheral attached to this channel. This assumes
* that someone who knows the hardware configuration, boot code or some other
* init code, already set the width.
*
* The return value is one of:
* PW_8
* PW_16
* PW_32
* PW_64
*
* The function returns 0 on error.
*/
unsigned int
ppc4xx_get_peripheral_width(unsigned int dmanr)
{
unsigned int control;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk("ppc4xx_get_peripheral_width: bad channel %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
return (GET_DMA_PW(control));
}
/*
* Clears the channel status bits
*/
int
ppc4xx_clr_dma_status(unsigned int dmanr)
{
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk(KERN_ERR "ppc4xx_clr_dma_status: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
mtdcr(DCRN_DMASR, ((u32)DMA_CH0_ERR | (u32)DMA_CS0 | (u32)DMA_TS0) >> dmanr);
return DMA_STATUS_GOOD;
}
/*
* Enables the burst on the channel (BTEN bit in the control/count register)
* Note:
* For scatter/gather dma, this function MUST be called before the
* ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
* sgl list and used as each sgl element is added.
*/
int
ppc4xx_enable_burst(unsigned int dmanr)
{
unsigned int ctc;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk(KERN_ERR "ppc4xx_enable_burst: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) | DMA_CTC_BTEN;
mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
return DMA_STATUS_GOOD;
}
/*
* Disables the burst on the channel (BTEN bit in the control/count register)
* Note:
* For scatter/gather dma, this function MUST be called before the
* ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
* sgl list and used as each sgl element is added.
*/
int
ppc4xx_disable_burst(unsigned int dmanr)
{
unsigned int ctc;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk(KERN_ERR "ppc4xx_disable_burst: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) &~ DMA_CTC_BTEN;
mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
return DMA_STATUS_GOOD;
}
/*
* Sets the burst size (number of peripheral widths) for the channel
* (BSIZ bits in the control/count register))
* must be one of:
* DMA_CTC_BSIZ_2
* DMA_CTC_BSIZ_4
* DMA_CTC_BSIZ_8
* DMA_CTC_BSIZ_16
* Note:
* For scatter/gather dma, this function MUST be called before the
* ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
* sgl list and used as each sgl element is added.
*/
int
ppc4xx_set_burst_size(unsigned int dmanr, unsigned int bsize)
{
unsigned int ctc;
if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
printk(KERN_ERR "ppc4xx_set_burst_size: bad channel: %d\n", dmanr);
return DMA_STATUS_BAD_CHANNEL;
}
ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) &~ DMA_CTC_BSIZ_MSK;
ctc |= (bsize & DMA_CTC_BSIZ_MSK);
mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
return DMA_STATUS_GOOD;
}
EXPORT_SYMBOL(ppc4xx_init_dma_channel);
EXPORT_SYMBOL(ppc4xx_get_channel_config);
EXPORT_SYMBOL(ppc4xx_set_channel_priority);
EXPORT_SYMBOL(ppc4xx_get_peripheral_width);
EXPORT_SYMBOL(dma_channels);
EXPORT_SYMBOL(ppc4xx_set_src_addr);
EXPORT_SYMBOL(ppc4xx_set_dst_addr);
EXPORT_SYMBOL(ppc4xx_set_dma_addr);
EXPORT_SYMBOL(ppc4xx_set_dma_addr2);
EXPORT_SYMBOL(ppc4xx_enable_dma);
EXPORT_SYMBOL(ppc4xx_disable_dma);
EXPORT_SYMBOL(ppc4xx_set_dma_mode);
EXPORT_SYMBOL(ppc4xx_set_dma_count);
EXPORT_SYMBOL(ppc4xx_get_dma_residue);
EXPORT_SYMBOL(ppc4xx_enable_dma_interrupt);
EXPORT_SYMBOL(ppc4xx_disable_dma_interrupt);
EXPORT_SYMBOL(ppc4xx_get_dma_status);
EXPORT_SYMBOL(ppc4xx_clr_dma_status);
EXPORT_SYMBOL(ppc4xx_enable_burst);
EXPORT_SYMBOL(ppc4xx_disable_burst);
EXPORT_SYMBOL(ppc4xx_set_burst_size);
