464 lines
11 KiB
C
464 lines
11 KiB
C
/*
|
|
* DMA helper routines for Freescale STMP37XX/STMP378X
|
|
*
|
|
* Author: dmitry pervushin <dpervushin@embeddedalley.com>
|
|
*
|
|
* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
|
|
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
|
|
*/
|
|
|
|
/*
|
|
* The code contained herein is licensed under the GNU General Public
|
|
* License. You may obtain a copy of the GNU General Public License
|
|
* Version 2 or later at the following locations:
|
|
*
|
|
* http://www.opensource.org/licenses/gpl-license.html
|
|
* http://www.gnu.org/copyleft/gpl.html
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/device.h>
|
|
#include <linux/dmapool.h>
|
|
#include <linux/sysdev.h>
|
|
#include <linux/cpufreq.h>
|
|
|
|
#include <asm/page.h>
|
|
|
|
#include <mach/platform.h>
|
|
#include <mach/dma.h>
|
|
#include <mach/regs-apbx.h>
|
|
#include <mach/regs-apbh.h>
|
|
|
|
static const size_t pool_item_size = sizeof(struct stmp3xxx_dma_command);
|
|
static const size_t pool_alignment = 8;
|
|
static struct stmp3xxx_dma_user {
|
|
void *pool;
|
|
int inuse;
|
|
const char *name;
|
|
} channels[MAX_DMA_CHANNELS];
|
|
|
|
#define IS_VALID_CHANNEL(ch) ((ch) >= 0 && (ch) < MAX_DMA_CHANNELS)
|
|
#define IS_USED(ch) (channels[ch].inuse)
|
|
|
|
int stmp3xxx_dma_request(int ch, struct device *dev, const char *name)
|
|
{
|
|
struct stmp3xxx_dma_user *user;
|
|
int err = 0;
|
|
|
|
user = channels + ch;
|
|
if (!IS_VALID_CHANNEL(ch)) {
|
|
err = -ENODEV;
|
|
goto out;
|
|
}
|
|
if (IS_USED(ch)) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
/* Create a pool to allocate dma commands from */
|
|
user->pool = dma_pool_create(name, dev, pool_item_size,
|
|
pool_alignment, PAGE_SIZE);
|
|
if (user->pool == NULL) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
user->name = name;
|
|
user->inuse++;
|
|
out:
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_request);
|
|
|
|
int stmp3xxx_dma_release(int ch)
|
|
{
|
|
struct stmp3xxx_dma_user *user = channels + ch;
|
|
int err = 0;
|
|
|
|
if (!IS_VALID_CHANNEL(ch)) {
|
|
err = -ENODEV;
|
|
goto out;
|
|
}
|
|
if (!IS_USED(ch)) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
BUG_ON(user->pool == NULL);
|
|
dma_pool_destroy(user->pool);
|
|
user->inuse--;
|
|
out:
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_release);
|
|
|
|
int stmp3xxx_dma_read_semaphore(int channel)
|
|
{
|
|
int sem = -1;
|
|
|
|
switch (STMP3XXX_DMA_BUS(channel)) {
|
|
case STMP3XXX_BUS_APBH:
|
|
sem = __raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA +
|
|
STMP3XXX_DMA_CHANNEL(channel) * 0x70);
|
|
sem &= BM_APBH_CHn_SEMA_PHORE;
|
|
sem >>= BP_APBH_CHn_SEMA_PHORE;
|
|
break;
|
|
|
|
case STMP3XXX_BUS_APBX:
|
|
sem = __raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA +
|
|
STMP3XXX_DMA_CHANNEL(channel) * 0x70);
|
|
sem &= BM_APBX_CHn_SEMA_PHORE;
|
|
sem >>= BP_APBX_CHn_SEMA_PHORE;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
return sem;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_read_semaphore);
|
|
|
|
int stmp3xxx_dma_allocate_command(int channel,
|
|
struct stmp3xxx_dma_descriptor *descriptor)
|
|
{
|
|
struct stmp3xxx_dma_user *user = channels + channel;
|
|
int err = 0;
|
|
|
|
if (!IS_VALID_CHANNEL(channel)) {
|
|
err = -ENODEV;
|
|
goto out;
|
|
}
|
|
if (!IS_USED(channel)) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
if (descriptor == NULL) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* Allocate memory for a command from the buffer */
|
|
descriptor->command =
|
|
dma_pool_alloc(user->pool, GFP_KERNEL, &descriptor->handle);
|
|
|
|
/* Check it worked */
|
|
if (!descriptor->command) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
memset(descriptor->command, 0, pool_item_size);
|
|
out:
|
|
WARN_ON(err);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_allocate_command);
|
|
|
|
int stmp3xxx_dma_free_command(int channel,
|
|
struct stmp3xxx_dma_descriptor *descriptor)
|
|
{
|
|
int err = 0;
|
|
|
|
if (!IS_VALID_CHANNEL(channel)) {
|
|
err = -ENODEV;
|
|
goto out;
|
|
}
|
|
if (!IS_USED(channel)) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
/* Return the command memory to the pool */
|
|
dma_pool_free(channels[channel].pool, descriptor->command,
|
|
descriptor->handle);
|
|
|
|
/* Initialise descriptor so we're not tempted to use it */
|
|
descriptor->command = NULL;
|
|
descriptor->handle = 0;
|
|
descriptor->virtual_buf_ptr = NULL;
|
|
descriptor->next_descr = NULL;
|
|
|
|
WARN_ON(err);
|
|
out:
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_free_command);
|
|
|
|
void stmp3xxx_dma_go(int channel,
|
|
struct stmp3xxx_dma_descriptor *head, u32 semaphore)
|
|
{
|
|
int ch = STMP3XXX_DMA_CHANNEL(channel);
|
|
void __iomem *c, *s;
|
|
|
|
switch (STMP3XXX_DMA_BUS(channel)) {
|
|
case STMP3XXX_BUS_APBH:
|
|
c = REGS_APBH_BASE + HW_APBH_CHn_NXTCMDAR + 0x70 * ch;
|
|
s = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * ch;
|
|
break;
|
|
|
|
case STMP3XXX_BUS_APBX:
|
|
c = REGS_APBX_BASE + HW_APBX_CHn_NXTCMDAR + 0x70 * ch;
|
|
s = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * ch;
|
|
break;
|
|
|
|
default:
|
|
return;
|
|
}
|
|
|
|
/* Set next command */
|
|
__raw_writel(head->handle, c);
|
|
/* Set counting semaphore (kicks off transfer). Assumes
|
|
peripheral has been set up correctly */
|
|
__raw_writel(semaphore, s);
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_go);
|
|
|
|
int stmp3xxx_dma_running(int channel)
|
|
{
|
|
switch (STMP3XXX_DMA_BUS(channel)) {
|
|
case STMP3XXX_BUS_APBH:
|
|
return (__raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA +
|
|
0x70 * STMP3XXX_DMA_CHANNEL(channel))) &
|
|
BM_APBH_CHn_SEMA_PHORE;
|
|
|
|
case STMP3XXX_BUS_APBX:
|
|
return (__raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA +
|
|
0x70 * STMP3XXX_DMA_CHANNEL(channel))) &
|
|
BM_APBX_CHn_SEMA_PHORE;
|
|
default:
|
|
BUG();
|
|
return 0;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_running);
|
|
|
|
/*
|
|
* Circular dma chain management
|
|
*/
|
|
void stmp3xxx_dma_free_chain(struct stmp37xx_circ_dma_chain *chain)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < chain->total_count; i++)
|
|
stmp3xxx_dma_free_command(
|
|
STMP3XXX_DMA(chain->channel, chain->bus),
|
|
&chain->chain[i]);
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_free_chain);
|
|
|
|
int stmp3xxx_dma_make_chain(int ch, struct stmp37xx_circ_dma_chain *chain,
|
|
struct stmp3xxx_dma_descriptor descriptors[],
|
|
unsigned items)
|
|
{
|
|
int i;
|
|
int err = 0;
|
|
|
|
if (items == 0)
|
|
return err;
|
|
|
|
for (i = 0; i < items; i++) {
|
|
err = stmp3xxx_dma_allocate_command(ch, &descriptors[i]);
|
|
if (err) {
|
|
WARN_ON(err);
|
|
/*
|
|
* Couldn't allocate the whole chain.
|
|
* deallocate what has been allocated
|
|
*/
|
|
if (i) {
|
|
do {
|
|
stmp3xxx_dma_free_command(ch,
|
|
&descriptors
|
|
[i]);
|
|
} while (i-- >= 0);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/* link them! */
|
|
if (i > 0) {
|
|
descriptors[i - 1].next_descr = &descriptors[i];
|
|
descriptors[i - 1].command->next =
|
|
descriptors[i].handle;
|
|
}
|
|
}
|
|
|
|
/* make list circular */
|
|
descriptors[items - 1].next_descr = &descriptors[0];
|
|
descriptors[items - 1].command->next = descriptors[0].handle;
|
|
|
|
chain->total_count = items;
|
|
chain->chain = descriptors;
|
|
chain->free_index = 0;
|
|
chain->active_index = 0;
|
|
chain->cooked_index = 0;
|
|
chain->free_count = items;
|
|
chain->active_count = 0;
|
|
chain->cooked_count = 0;
|
|
chain->bus = STMP3XXX_DMA_BUS(ch);
|
|
chain->channel = STMP3XXX_DMA_CHANNEL(ch);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_make_chain);
|
|
|
|
void stmp37xx_circ_clear_chain(struct stmp37xx_circ_dma_chain *chain)
|
|
{
|
|
BUG_ON(stmp3xxx_dma_running(STMP3XXX_DMA(chain->channel, chain->bus)));
|
|
chain->free_index = 0;
|
|
chain->active_index = 0;
|
|
chain->cooked_index = 0;
|
|
chain->free_count = chain->total_count;
|
|
chain->active_count = 0;
|
|
chain->cooked_count = 0;
|
|
}
|
|
EXPORT_SYMBOL(stmp37xx_circ_clear_chain);
|
|
|
|
void stmp37xx_circ_advance_free(struct stmp37xx_circ_dma_chain *chain,
|
|
unsigned count)
|
|
{
|
|
BUG_ON(chain->cooked_count < count);
|
|
|
|
chain->cooked_count -= count;
|
|
chain->cooked_index += count;
|
|
chain->cooked_index %= chain->total_count;
|
|
chain->free_count += count;
|
|
}
|
|
EXPORT_SYMBOL(stmp37xx_circ_advance_free);
|
|
|
|
void stmp37xx_circ_advance_active(struct stmp37xx_circ_dma_chain *chain,
|
|
unsigned count)
|
|
{
|
|
void __iomem *c;
|
|
u32 mask_clr, mask;
|
|
BUG_ON(chain->free_count < count);
|
|
|
|
chain->free_count -= count;
|
|
chain->free_index += count;
|
|
chain->free_index %= chain->total_count;
|
|
chain->active_count += count;
|
|
|
|
switch (chain->bus) {
|
|
case STMP3XXX_BUS_APBH:
|
|
c = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * chain->channel;
|
|
mask_clr = BM_APBH_CHn_SEMA_INCREMENT_SEMA;
|
|
mask = BF(count, APBH_CHn_SEMA_INCREMENT_SEMA);
|
|
break;
|
|
case STMP3XXX_BUS_APBX:
|
|
c = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * chain->channel;
|
|
mask_clr = BM_APBX_CHn_SEMA_INCREMENT_SEMA;
|
|
mask = BF(count, APBX_CHn_SEMA_INCREMENT_SEMA);
|
|
break;
|
|
default:
|
|
BUG();
|
|
return;
|
|
}
|
|
|
|
/* Set counting semaphore (kicks off transfer). Assumes
|
|
peripheral has been set up correctly */
|
|
stmp3xxx_clearl(mask_clr, c);
|
|
stmp3xxx_setl(mask, c);
|
|
}
|
|
EXPORT_SYMBOL(stmp37xx_circ_advance_active);
|
|
|
|
unsigned stmp37xx_circ_advance_cooked(struct stmp37xx_circ_dma_chain *chain)
|
|
{
|
|
unsigned cooked;
|
|
|
|
cooked = chain->active_count -
|
|
stmp3xxx_dma_read_semaphore(STMP3XXX_DMA(chain->channel, chain->bus));
|
|
|
|
chain->active_count -= cooked;
|
|
chain->active_index += cooked;
|
|
chain->active_index %= chain->total_count;
|
|
|
|
chain->cooked_count += cooked;
|
|
|
|
return cooked;
|
|
}
|
|
EXPORT_SYMBOL(stmp37xx_circ_advance_cooked);
|
|
|
|
void stmp3xxx_dma_set_alt_target(int channel, int function)
|
|
{
|
|
#if defined(CONFIG_ARCH_STMP37XX)
|
|
unsigned bits = 4;
|
|
#elif defined(CONFIG_ARCH_STMP378X)
|
|
unsigned bits = 2;
|
|
#else
|
|
#error wrong arch
|
|
#endif
|
|
int shift = STMP3XXX_DMA_CHANNEL(channel) * bits;
|
|
unsigned mask = (1<<bits) - 1;
|
|
void __iomem *c;
|
|
|
|
BUG_ON(function < 0 || function >= (1<<bits));
|
|
pr_debug("%s: channel = %d, using mask %x, "
|
|
"shift = %d\n", __func__, channel, mask, shift);
|
|
|
|
switch (STMP3XXX_DMA_BUS(channel)) {
|
|
case STMP3XXX_BUS_APBH:
|
|
c = REGS_APBH_BASE + HW_APBH_DEVSEL;
|
|
break;
|
|
case STMP3XXX_BUS_APBX:
|
|
c = REGS_APBX_BASE + HW_APBX_DEVSEL;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
stmp3xxx_clearl(mask << shift, c);
|
|
stmp3xxx_setl(mask << shift, c);
|
|
}
|
|
EXPORT_SYMBOL(stmp3xxx_dma_set_alt_target);
|
|
|
|
void stmp3xxx_dma_suspend(void)
|
|
{
|
|
stmp3xxx_setl(BM_APBH_CTRL0_CLKGATE, REGS_APBH_BASE + HW_APBH_CTRL0);
|
|
stmp3xxx_setl(BM_APBX_CTRL0_CLKGATE, REGS_APBX_BASE + HW_APBX_CTRL0);
|
|
}
|
|
|
|
void stmp3xxx_dma_resume(void)
|
|
{
|
|
stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST,
|
|
REGS_APBH_BASE + HW_APBH_CTRL0);
|
|
stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST,
|
|
REGS_APBX_BASE + HW_APBX_CTRL0);
|
|
}
|
|
|
|
#ifdef CONFIG_CPU_FREQ
|
|
|
|
struct dma_notifier_block {
|
|
struct notifier_block nb;
|
|
void *data;
|
|
};
|
|
|
|
static int dma_cpufreq_notifier(struct notifier_block *self,
|
|
unsigned long phase, void *p)
|
|
{
|
|
switch (phase) {
|
|
case CPUFREQ_POSTCHANGE:
|
|
stmp3xxx_dma_resume();
|
|
break;
|
|
|
|
case CPUFREQ_PRECHANGE:
|
|
stmp3xxx_dma_suspend();
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct dma_notifier_block dma_cpufreq_nb = {
|
|
.nb = {
|
|
.notifier_call = dma_cpufreq_notifier,
|
|
},
|
|
};
|
|
#endif /* CONFIG_CPU_FREQ */
|
|
|
|
void __init stmp3xxx_dma_init(void)
|
|
{
|
|
stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST,
|
|
REGS_APBH_BASE + HW_APBH_CTRL0);
|
|
stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST,
|
|
REGS_APBX_BASE + HW_APBX_CTRL0);
|
|
#ifdef CONFIG_CPU_FREQ
|
|
cpufreq_register_notifier(&dma_cpufreq_nb.nb,
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
#endif /* CONFIG_CPU_FREQ */
|
|
}
|