// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/plat-omap/dma.c
*
* Copyright (C) 2003 - 2008 Nokia Corporation
* Author: Juha Yrjölä <juha.yrjola@nokia.com>
* DMA channel linking for 1610 by Samuel Ortiz <samuel.ortiz@nokia.com>
* Graphics DMA and LCD DMA graphics tranformations
* by Imre Deak <imre.deak@nokia.com>
* OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
* Merged to support both OMAP1 and OMAP2 by Tony Lindgren <tony@atomide.com>
* Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
*
* Copyright (C) 2009 Texas Instruments
* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* Support functions for the OMAP internal DMA channels.
*
* Copyright (C) 2010 Texas Instruments Incorporated - https://www.ti.com/
* Converted DMA library into DMA platform driver.
* - G, Manjunath Kondaiah <manjugk@ti.com>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/omap-dma.h>
#include <linux/soc/ti/omap1-io.h>
#include <linux/soc/ti/omap1-soc.h>
#include "tc.h"
/*
* MAX_LOGICAL_DMA_CH_COUNT: the maximum number of logical DMA
* channels that an instance of the SDMA IP block can support. Used
* to size arrays. (The actual maximum on a particular SoC may be less
* than this -- for example, OMAP1 SDMA instances only support 17 logical
* DMA channels.)
*/
#define MAX_LOGICAL_DMA_CH_COUNT 32
#undef DEBUG
#define OMAP_DMA_ACTIVE 0x01
#define OMAP_FUNC_MUX_ARM_BASE (0xfffe1000 + 0xec)
static struct omap_system_dma_plat_info *p;
static struct omap_dma_dev_attr *d;
static int enable_1510_mode;
static u32 errata;
struct dma_link_info {
int *linked_dmach_q;
int no_of_lchs_linked;
int q_count;
int q_tail;
int q_head;
int chain_state;
int chain_mode;
};
static int dma_lch_count;
static int dma_chan_count;
static int omap_dma_reserve_channels;
static DEFINE_SPINLOCK(dma_chan_lock);
static struct omap_dma_lch *dma_chan;
static inline void omap_disable_channel_irq(int lch)
{
/* disable channel interrupts */
p->dma_write(0, CICR, lch);
/* Clear CSR */
p->dma_read(CSR, lch);
}
static inline void set_gdma_dev(int req, int dev)
{
u32 reg = OMAP_FUNC_MUX_ARM_BASE + ((req - 1) / 5) * 4;
int shift = ((req - 1) % 5) * 6;
u32 l;
l = omap_readl(reg);
l &= ~(0x3f << shift);
l |= (dev - 1) << shift;
omap_writel(l, reg);
}
#if IS_ENABLED(CONFIG_FB_OMAP)
void omap_set_dma_priority(int lch, int dst_port, int priority)
{
unsigned long reg;
u32 l;
if (dma_omap1()) {
switch (dst_port) {
case OMAP_DMA_PORT_OCP_T1: /* FFFECC00 */
reg = OMAP_TC_OCPT1_PRIOR;
break;
case OMAP_DMA_PORT_OCP_T2: /* FFFECCD0 */
reg = OMAP_TC_OCPT2_PRIOR;
break;
case OMAP_DMA_PORT_EMIFF: /* FFFECC08 */
reg = OMAP_TC_EMIFF_PRIOR;
break;
case OMAP_DMA_PORT_EMIFS: /* FFFECC04 */
reg = OMAP_TC_EMIFS_PRIOR;
break;
default:
BUG();
return;
}
l = omap_readl(reg);
l &= ~(0xf << 8);
l |= (priority & 0xf) << 8;
omap_writel(l, reg);
}
}
EXPORT_SYMBOL(omap_set_dma_priority);
#endif
#if IS_ENABLED(CONFIG_USB_OMAP)
#ifdef CONFIG_ARCH_OMAP15XX
/* Returns 1 if the DMA module is in OMAP1510-compatible mode, 0 otherwise */
static int omap_dma_in_1510_mode(void)
{
return enable_1510_mode;
}
#else
#define omap_dma_in_1510_mode() 0
#endif
void omap_set_dma_transfer_params(int lch, int data_type, int elem_count,
int frame_count, int sync_mode,
int dma_trigger, int src_or_dst_synch)
{
u32 l;
u16 ccr;
l = p->dma_read(CSDP, lch);
l &= ~0x03;
l |= data_type;
p->dma_write(l, CSDP, lch);
ccr = p->dma_read(CCR, lch);
ccr &= ~(1 << 5);
if (sync_mode == OMAP_DMA_SYNC_FRAME)
ccr |= 1 << 5;
p->dma_write(ccr, CCR, lch);
ccr = p->dma_read(CCR2, lch);
ccr &= ~(1 << 2);
if (sync_mode == OMAP_DMA_SYNC_BLOCK)
ccr |= 1 << 2;
p->dma_write(ccr, CCR2, lch);
p->dma_write(elem_count, CEN, lch);
p->dma_write(frame_count, CFN, lch);
}
EXPORT_SYMBOL(omap_set_dma_transfer_params);
void omap_set_dma_channel_mode(int lch, enum omap_dma_channel_mode mode)
{
if (!dma_omap15xx()) {
u32 l;
l = p->dma_read(LCH_CTRL, lch);
l &= ~0x7;
l |= mode;
p->dma_write(l, LCH_CTRL, lch);
}
}
EXPORT_SYMBOL(omap_set_dma_channel_mode);
/* Note that src_port is only for omap1 */
void omap_set_dma_src_params(int lch, int src_port, int src_amode,
unsigned long src_start,
int src_ei, int src_fi)
{
u32 l;
u16 w;
w = p->dma_read(CSDP, lch);
w &= ~(0x1f << 2);
w |= src_port << 2;
p->dma_write(w, CSDP, lch);
l = p->dma_read(CCR, lch);
l &= ~(0x03 << 12);
l |= src_amode << 12;
p->dma_write(l, CCR, lch);
p->dma_write(src_start, CSSA, lch);
p->dma_write(src_ei, CSEI, lch);
p->dma_write(src_fi, CSFI, lch);
}
EXPORT_SYMBOL(omap_set_dma_src_params);
void omap_set_dma_src_data_pack(int lch, int enable)
{
u32 l;
l = p->dma_read(CSDP, lch);
l &= ~(1 << 6);
if (enable)
l |= (1 << 6);
p->dma_write(l, CSDP, lch);
}
EXPORT_SYMBOL(omap_set_dma_src_data_pack);
void omap_set_dma_src_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
{
unsigned int burst = 0;
u32 l;
l = p->dma_read(CSDP, lch);
l &= ~(0x03 << 7);
switch (burst_mode) {
case OMAP_DMA_DATA_BURST_DIS:
break;
case OMAP_DMA_DATA_BURST_4:
burst = 0x2;
break;
case OMAP_DMA_DATA_BURST_8:
/*
* not supported by current hardware on OMAP1
* w |= (0x03 << 7);
*/
fallthrough;
case OMAP_DMA_DATA_BURST_16:
/* OMAP1 don't support burst 16 */
fallthrough;
default:
BUG();
}
l |= (burst << 7);
p->dma_write(l, CSDP, lch);
}
EXPORT_SYMBOL(omap_set_dma_src_burst_mode);
/* Note that dest_port is only for OMAP1 */
void omap_set_dma_dest_params(int lch, int dest_port, int dest_amode,
unsigned long dest_start,
int dst_ei, int dst_fi)
{
u32 l;
l = p->dma_read(CSDP, lch);
l &= ~(0x1f << 9);
l |= dest_port << 9;
p->dma_write(l, CSDP, lch);
l = p->dma_read(CCR, lch);
l &= ~(0x03 << 14);
l |= dest_amode << 14;
p->dma_write(l, CCR, lch);
p->dma_write(dest_start, CDSA, lch);
p->dma_write(dst_ei, CDEI, lch);
p->dma_write(dst_fi, CDFI, lch);
}
EXPORT_SYMBOL(omap_set_dma_dest_params);
void omap_set_dma_dest_data_pack(int lch, int enable)
{
u32 l;
l = p->dma_read(CSDP, lch);
l &= ~(1 << 13);
if (enable)
l |= 1 << 13;
p->dma_write(l, CSDP, lch);
}
EXPORT_SYMBOL(omap_set_dma_dest_data_pack);
void omap_set_dma_dest_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
{
unsigned int burst = 0;
u32 l;
l = p->dma_read(CSDP, lch);
l &= ~(0x03 << 14);
switch (burst_mode) {
case OMAP_DMA_DATA_BURST_DIS:
break;
case OMAP_DMA_DATA_BURST_4:
burst = 0x2;
break;
case OMAP_DMA_DATA_BURST_8:
burst = 0x3;
break;
case OMAP_DMA_DATA_BURST_16:
/* OMAP1 don't support burst 16 */
fallthrough;
default:
printk(KERN_ERR "Invalid DMA burst mode\n");
BUG();
return;
}
l |= (burst << 14);
p->dma_write(l, CSDP, lch);
}
EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
static inline void omap_enable_channel_irq(int lch)
{
/* Clear CSR */
p->dma_read(CSR, lch);
/* Enable some nice interrupts. */
p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
}
void omap_disable_dma_irq(int lch, u16 bits)
{
dma_chan[lch].enabled_irqs &= ~bits;
}
EXPORT_SYMBOL(omap_disable_dma_irq);
static inline void enable_lnk(int lch)
{
u32 l;
l = p->dma_read(CLNK_CTRL, lch);
l &= ~(1 << 14);
/* Set the ENABLE_LNK bits */
if (dma_chan[lch].next_lch != -1)
l = dma_chan[lch].next_lch | (1 << 15);
p->dma_write(l, CLNK_CTRL, lch);
}
static inline void disable_lnk(int lch)
{
u32 l;
l = p->dma_read(CLNK_CTRL, lch);
/* Disable interrupts */
omap_disable_channel_irq(lch);
/* Set the STOP_LNK bit */
l |= 1 << 14;
p->dma_write(l, CLNK_CTRL, lch);
dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
}
#endif
int omap_request_dma(int dev_id, const char *dev_name,
void (*callback)(int lch, u16 ch_status, void *data),
void *data, int *dma_ch_out)
{
int ch, free_ch = -1;
unsigned long flags;
struct omap_dma_lch *chan;
WARN(strcmp(dev_name, "DMA engine"), "Using deprecated platform DMA API - please update to DMA engine");
spin_lock_irqsave(&dma_chan_lock, flags);
for (ch = 0; ch < dma_chan_count; ch++) {
if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
free_ch = ch;
/* Exit after first free channel found */
break;
}
}
if (free_ch == -1) {
spin_unlock_irqrestore(&dma_chan_lock, flags);
return -EBUSY;
}
chan = dma_chan + free_ch;
chan->dev_id = dev_id;
if (p->clear_lch_regs)
p->clear_lch_regs(free_ch);
spin_unlock_irqrestore(&dma_chan_lock, flags);
chan->dev_name = dev_name;
chan->callback = callback;
chan->data = data;
chan->flags = 0;
chan->enabled_irqs = OMAP_DMA_DROP_IRQ | OMAP_DMA_BLOCK_IRQ;
chan->enabled_irqs |= OMAP1_DMA_TOUT_IRQ;
if (dma_omap16xx()) {
/* If the sync device is set, configure it dynamically. */
if (dev_id != 0) {
set_gdma_dev(free_ch + 1, dev_id);
dev_id = free_ch + 1;
}
/*
* Disable the 1510 compatibility mode and set the sync device
* id.
*/
p->dma_write(dev_id | (1 << 10), CCR, free_ch);
} else {
p->dma_write(dev_id, CCR, free_ch);
}
*dma_ch_out = free_ch;
return 0;
}
EXPORT_SYMBOL(omap_request_dma);
void omap_free_dma(int lch)
{
unsigned long flags;
if (dma_chan[lch].dev_id == -1) {
pr_err("omap_dma: trying to free unallocated DMA channel %d\n",
lch);
return;
}
/* Disable all DMA interrupts for the channel. */
omap_disable_channel_irq(lch);
/* Make sure the DMA transfer is stopped. */
p->dma_write(0, CCR, lch);
spin_lock_irqsave(&dma_chan_lock, flags);
dma_chan[lch].dev_id = -1;
dma_chan[lch].next_lch = -1;
dma_chan[lch].callback = NULL;
spin_unlock_irqrestore(&dma_chan_lock, flags);
}
EXPORT_SYMBOL(omap_free_dma);
/*
* Clears any DMA state so the DMA engine is ready to restart with new buffers
* through omap_start_dma(). Any buffers in flight are discarded.
*/
static void omap_clear_dma(int lch)
{
unsigned long flags;
local_irq_save(flags);
p->clear_dma(lch);
local_irq_restore(flags);
}
#if IS_ENABLED(CONFIG_USB_OMAP)
void omap_start_dma(int lch)
{
u32 l;
/*
* The CPC/CDAC register needs to be initialized to zero
* before starting dma transfer.
*/
if (dma_omap15xx())
p->dma_write(0, CPC, lch);
else
p->dma_write(0, CDAC, lch);
if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
int next_lch, cur_lch;
char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
/* Set the link register of the first channel */
enable_lnk(lch);
memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
dma_chan_link_map[lch] = 1;
cur_lch = dma_chan[lch].next_lch;
do {
next_lch = dma_chan[cur_lch].next_lch;
/* The loop case: we've been here already */
if (dma_chan_link_map[cur_lch])
break;
/* Mark the current channel */
dma_chan_link_map[cur_lch] = 1;
enable_lnk(cur_lch);
omap_enable_channel_irq(cur_lch);
cur_lch = next_lch;
} while (next_lch != -1);
} else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS))
p->dma_write(lch, CLNK_CTRL, lch);
omap_enable_channel_irq(lch);
l = p->dma_read(CCR, lch);
if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING))
l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
l |= OMAP_DMA_CCR_EN;
/*
* As dma_write() uses IO accessors which are weakly ordered, there
* is no guarantee that data in coherent DMA memory will be visible
* to the DMA device. Add a memory barrier here to ensure that any
* such data is visible prior to enabling DMA.
*/
mb();
p->dma_write(l, CCR, lch);
dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
}
EXPORT_SYMBOL(omap_start_dma);
void omap_stop_dma(int lch)
{
u32 l;
/* Disable all interrupts on the channel */
omap_disable_channel_irq(lch);
l = p->dma_read(CCR, lch);
if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
(l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
int i = 0;
u32 sys_cf;
/* Configure No-Standby */
l = p->dma_read(OCP_SYSCONFIG, lch);
sys_cf = l;
l &= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
p->dma_write(l , OCP_SYSCONFIG, 0);
l = p->dma_read(CCR, lch);
l &= ~OMAP_DMA_CCR_EN;
p->dma_write(l, CCR, lch);
/* Wait for sDMA FIFO drain */
l = p->dma_read(CCR, lch);
while (i < 100 && (l & (OMAP_DMA_CCR_RD_ACTIVE |
OMAP_DMA_CCR_WR_ACTIVE))) {
udelay(5);
i++;
l = p->dma_read(CCR, lch);
}
if (i >= 100)
pr_err("DMA drain did not complete on lch %d\n", lch);
/* Restore OCP_SYSCONFIG */
p->dma_write(sys_cf, OCP_SYSCONFIG, lch);
} else {
l &= ~OMAP_DMA_CCR_EN;
p->dma_write(l, CCR, lch);
}
/*
* Ensure that data transferred by DMA is visible to any access
* after DMA has been disabled. This is important for coherent
* DMA regions.
*/
mb();
if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
int next_lch, cur_lch = lch;
char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
do {
/* The loop case: we've been here already */
if (dma_chan_link_map[cur_lch])
break;
/* Mark the current channel */
dma_chan_link_map[cur_lch] = 1;
disable_lnk(cur_lch);
next_lch = dma_chan[cur_lch].next_lch;
cur_lch = next_lch;
} while (next_lch != -1);
}
dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
}
EXPORT_SYMBOL(omap_stop_dma);
/*
* Allows changing the DMA callback function or data. This may be needed if
* the driver shares a single DMA channel for multiple dma triggers.
*/
/*
* Returns current physical source address for the given DMA channel.
* If the channel is running the caller must disable interrupts prior calling
* this function and process the returned value before re-enabling interrupt to
* prevent races with the interrupt handler. Note that in continuous mode there
* is a chance for CSSA_L register overflow between the two reads resulting
* in incorrect return value.
*/
dma_addr_t omap_get_dma_src_pos(int lch)
{
dma_addr_t offset = 0;
if (dma_omap15xx())
offset = p->dma_read(CPC, lch);
else
offset = p->dma_read(CSAC, lch);
if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0)
offset = p->dma_read(CSAC, lch);
if (!dma_omap15xx()) {
/*
* CDAC == 0 indicates that the DMA transfer on the channel has
* not been started (no data has been transferred so far).
* Return the programmed source start address in this case.
*/
if (likely(p->dma_read(CDAC, lch)))
offset = p->dma_read(CSAC, lch);
else
offset = p->dma_read(CSSA, lch);
}
offset |= (p->dma_read(CSSA, lch) & 0xFFFF0000);
return offset;
}
EXPORT_SYMBOL(omap_get_dma_src_pos);
/*
* Returns current physical destination address for the given DMA channel.
* If the channel is running the caller must disable interrupts prior calling
* this function and process the returned value before re-enabling interrupt to
* prevent races with the interrupt handler. Note that in continuous mode there
* is a chance for CDSA_L register overflow between the two reads resulting
* in incorrect return value.
*/
dma_addr_t omap_get_dma_dst_pos(int lch)
{
dma_addr_t offset = 0;
if (dma_omap15xx())
offset = p->dma_read(CPC, lch);
else
offset = p->dma_read(CDAC, lch);
/*
* omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
* read before the DMA controller finished disabling the channel.
*/
if (!dma_omap15xx() && offset == 0) {
offset = p->dma_read(CDAC, lch);
/*
* CDAC == 0 indicates that the DMA transfer on the channel has
* not been started (no data has been transferred so far).
* Return the programmed destination start address in this case.
*/
if (unlikely(!offset))
offset = p->dma_read(CDSA, lch);
}
offset |= (p->dma_read(CDSA, lch) & 0xFFFF0000);
return offset;
}
EXPORT_SYMBOL(omap_get_dma_dst_pos);
int omap_get_dma_active_status(int lch)
{
return (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN) != 0;
}
EXPORT_SYMBOL(omap_get_dma_active_status);
#endif
int omap_dma_running(void)
{
int lch;
if (omap_lcd_dma_running())
return 1;
for (lch = 0; lch < dma_chan_count; lch++)
if (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN)
return 1;
return 0;
}
/*----------------------------------------------------------------------------*/
static int omap1_dma_handle_ch(int ch)
{
u32 csr;
if (enable_1510_mode && ch >= 6) {
csr = dma_chan[ch].saved_csr;
dma_chan[ch].saved_csr = 0;
} else
csr = p->dma_read(CSR, ch);
if (enable_1510_mode && ch <= 2 && (csr >> 7) != 0) {
dma_chan[ch + 6].saved_csr = csr >> 7;
csr &= 0x7f;
}
if ((csr & 0x3f) == 0)
return 0;
if (unlikely(dma_chan[ch].dev_id == -1)) {
pr_warn("Spurious interrupt from DMA channel %d (CSR %04x)\n",
ch, csr);
return 0;
}
if (unlikely(csr & OMAP1_DMA_TOUT_IRQ))
pr_warn("DMA timeout with device %d\n", dma_chan[ch].dev_id);
if (unlikely(csr & OMAP_DMA_DROP_IRQ))
pr_warn("DMA synchronization event drop occurred with device %d\n",
dma_chan[ch].dev_id);
if (likely(csr & OMAP_DMA_BLOCK_IRQ))
dma_chan[ch].flags &= ~OMAP_DMA_ACTIVE;
if (likely(dma_chan[ch].callback != NULL))
dma_chan[ch].callback(ch, csr, dma_chan[ch].data);
return 1;
}
static irqreturn_t omap1_dma_irq_handler(int irq, void *dev_id)
{
int ch = ((int) dev_id) - 1;
int handled = 0;
for (;;) {
int handled_now = 0;
handled_now += omap1_dma_handle_ch(ch);
if (enable_1510_mode && dma_chan[ch + 6].saved_csr)
handled_now += omap1_dma_handle_ch(ch + 6);
if (!handled_now)
break;
handled += handled_now;
}
return handled ? IRQ_HANDLED : IRQ_NONE;
}
struct omap_system_dma_plat_info *omap_get_plat_info(void)
{
return p;
}
EXPORT_SYMBOL_GPL(omap_get_plat_info);
static int omap_system_dma_probe(struct platform_device *pdev)
{
int ch, ret = 0;
int dma_irq;
char irq_name[4];
p = pdev->dev.platform_data;
if (!p) {
dev_err(&pdev->dev,
"%s: System DMA initialized without platform data\n",
__func__);
return -EINVAL;
}
d = p->dma_attr;
errata = p->errata;
if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
&& (omap_dma_reserve_channels < d->lch_count))
d->lch_count = omap_dma_reserve_channels;
dma_lch_count = d->lch_count;
dma_chan_count = dma_lch_count;
enable_1510_mode = d->dev_caps & ENABLE_1510_MODE;
dma_chan = devm_kcalloc(&pdev->dev, dma_lch_count,
sizeof(*dma_chan), GFP_KERNEL);
if (!dma_chan)
return -ENOMEM;
for (ch = 0; ch < dma_chan_count; ch++) {
omap_clear_dma(ch);
dma_chan[ch].dev_id = -1;
dma_chan[ch].next_lch = -1;
if (ch >= 6 && enable_1510_mode)
continue;
/*
* request_irq() doesn't like dev_id (ie. ch) being
* zero, so we have to kludge around this.
*/
sprintf(&irq_name[0], "%d", ch);
dma_irq = platform_get_irq_byname(pdev, irq_name);
if (dma_irq < 0) {
ret = dma_irq;
goto exit_dma_irq_fail;
}
/* INT_DMA_LCD is handled in lcd_dma.c */
if (dma_irq == INT_DMA_LCD)
continue;
ret = request_irq(dma_irq,
omap1_dma_irq_handler, 0, "DMA",
(void *) (ch + 1));
if (ret != 0)
goto exit_dma_irq_fail;
}
/* reserve dma channels 0 and 1 in high security devices on 34xx */
if (d->dev_caps & HS_CHANNELS_RESERVED) {
pr_info("Reserving DMA channels 0 and 1 for HS ROM code\n");
dma_chan[0].dev_id = 0;
dma_chan[1].dev_id = 1;
}
p->show_dma_caps();
return 0;
exit_dma_irq_fail:
return ret;
}
static void omap_system_dma_remove(struct platform_device *pdev)
{
int dma_irq, irq_rel = 0;
for ( ; irq_rel < dma_chan_count; irq_rel++) {
dma_irq = platform_get_irq(pdev, irq_rel);
free_irq(dma_irq, (void *)(irq_rel + 1));
}
}
static struct platform_driver omap_system_dma_driver = {
.probe = omap_system_dma_probe,
.remove_new = omap_system_dma_remove,
.driver = {
.name = "omap_dma_system"
},
};
static int __init omap_system_dma_init(void)
{
return platform_driver_register(&omap_system_dma_driver);
}
arch_initcall(omap_system_dma_init);
static void __exit omap_system_dma_exit(void)
{
platform_driver_unregister(&omap_system_dma_driver);
}
MODULE_DESCRIPTION("OMAP SYSTEM DMA DRIVER");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Texas Instruments Inc");
/*
* Reserve the omap SDMA channels using cmdline bootarg
* "omap_dma_reserve_ch=". The valid range is 1 to 32
*/
static int __init omap_dma_cmdline_reserve_ch(char *str)
{
if (get_option(&str, &omap_dma_reserve_channels) != 1)
omap_dma_reserve_channels = 0;
return 1;
}
__setup("omap_dma_reserve_ch=", omap_dma_cmdline_reserve_ch);