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OpenCloudOS-Kernel/drivers/dma/tegra20-apb-dma.c

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/*
* DMA driver for Nvidia's Tegra20 APB DMA controller.
*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <mach/clk.h>
#include "dmaengine.h"
#define TEGRA_APBDMA_GENERAL 0x0
#define TEGRA_APBDMA_GENERAL_ENABLE BIT(31)
#define TEGRA_APBDMA_CONTROL 0x010
#define TEGRA_APBDMA_IRQ_MASK 0x01c
#define TEGRA_APBDMA_IRQ_MASK_SET 0x020
/* CSR register */
#define TEGRA_APBDMA_CHAN_CSR 0x00
#define TEGRA_APBDMA_CSR_ENB BIT(31)
#define TEGRA_APBDMA_CSR_IE_EOC BIT(30)
#define TEGRA_APBDMA_CSR_HOLD BIT(29)
#define TEGRA_APBDMA_CSR_DIR BIT(28)
#define TEGRA_APBDMA_CSR_ONCE BIT(27)
#define TEGRA_APBDMA_CSR_FLOW BIT(21)
#define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT 16
#define TEGRA_APBDMA_CSR_WCOUNT_MASK 0xFFFC
/* STATUS register */
#define TEGRA_APBDMA_CHAN_STATUS 0x004
#define TEGRA_APBDMA_STATUS_BUSY BIT(31)
#define TEGRA_APBDMA_STATUS_ISE_EOC BIT(30)
#define TEGRA_APBDMA_STATUS_HALT BIT(29)
#define TEGRA_APBDMA_STATUS_PING_PONG BIT(28)
#define TEGRA_APBDMA_STATUS_COUNT_SHIFT 2
#define TEGRA_APBDMA_STATUS_COUNT_MASK 0xFFFC
/* AHB memory address */
#define TEGRA_APBDMA_CHAN_AHBPTR 0x010
/* AHB sequence register */
#define TEGRA_APBDMA_CHAN_AHBSEQ 0x14
#define TEGRA_APBDMA_AHBSEQ_INTR_ENB BIT(31)
#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_8 (0 << 28)
#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_16 (1 << 28)
#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32 (2 << 28)
#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_64 (3 << 28)
#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_128 (4 << 28)
#define TEGRA_APBDMA_AHBSEQ_DATA_SWAP BIT(27)
#define TEGRA_APBDMA_AHBSEQ_BURST_1 (4 << 24)
#define TEGRA_APBDMA_AHBSEQ_BURST_4 (5 << 24)
#define TEGRA_APBDMA_AHBSEQ_BURST_8 (6 << 24)
#define TEGRA_APBDMA_AHBSEQ_DBL_BUF BIT(19)
#define TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT 16
#define TEGRA_APBDMA_AHBSEQ_WRAP_NONE 0
/* APB address */
#define TEGRA_APBDMA_CHAN_APBPTR 0x018
/* APB sequence register */
#define TEGRA_APBDMA_CHAN_APBSEQ 0x01c
#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8 (0 << 28)
#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16 (1 << 28)
#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32 (2 << 28)
#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64 (3 << 28)
#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_128 (4 << 28)
#define TEGRA_APBDMA_APBSEQ_DATA_SWAP BIT(27)
#define TEGRA_APBDMA_APBSEQ_WRAP_WORD_1 (1 << 16)
/*
* If any burst is in flight and DMA paused then this is the time to complete
* on-flight burst and update DMA status register.
*/
#define TEGRA_APBDMA_BURST_COMPLETE_TIME 20
/* Channel base address offset from APBDMA base address */
#define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET 0x1000
/* DMA channel register space size */
#define TEGRA_APBDMA_CHANNEL_REGISTER_SIZE 0x20
struct tegra_dma;
/*
* tegra_dma_chip_data Tegra chip specific DMA data
* @nr_channels: Number of channels available in the controller.
* @max_dma_count: Maximum DMA transfer count supported by DMA controller.
*/
struct tegra_dma_chip_data {
int nr_channels;
int max_dma_count;
};
/* DMA channel registers */
struct tegra_dma_channel_regs {
unsigned long csr;
unsigned long ahb_ptr;
unsigned long apb_ptr;
unsigned long ahb_seq;
unsigned long apb_seq;
};
/*
* tegra_dma_sg_req: Dma request details to configure hardware. This
* contains the details for one transfer to configure DMA hw.
* The client's request for data transfer can be broken into multiple
* sub-transfer as per requester details and hw support.
* This sub transfer get added in the list of transfer and point to Tegra
* DMA descriptor which manages the transfer details.
*/
struct tegra_dma_sg_req {
struct tegra_dma_channel_regs ch_regs;
int req_len;
bool configured;
bool last_sg;
bool half_done;
struct list_head node;
struct tegra_dma_desc *dma_desc;
};
/*
* tegra_dma_desc: Tegra DMA descriptors which manages the client requests.
* This descriptor keep track of transfer status, callbacks and request
* counts etc.
*/
struct tegra_dma_desc {
struct dma_async_tx_descriptor txd;
int bytes_requested;
int bytes_transferred;
enum dma_status dma_status;
struct list_head node;
struct list_head tx_list;
struct list_head cb_node;
int cb_count;
};
struct tegra_dma_channel;
typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
bool to_terminate);
/* tegra_dma_channel: Channel specific information */
struct tegra_dma_channel {
struct dma_chan dma_chan;
char name[30];
bool config_init;
int id;
int irq;
unsigned long chan_base_offset;
spinlock_t lock;
bool busy;
struct tegra_dma *tdma;
bool cyclic;
/* Different lists for managing the requests */
struct list_head free_sg_req;
struct list_head pending_sg_req;
struct list_head free_dma_desc;
struct list_head cb_desc;
/* ISR handler and tasklet for bottom half of isr handling */
dma_isr_handler isr_handler;
struct tasklet_struct tasklet;
dma_async_tx_callback callback;
void *callback_param;
/* Channel-slave specific configuration */
struct dma_slave_config dma_sconfig;
};
/* tegra_dma: Tegra DMA specific information */
struct tegra_dma {
struct dma_device dma_dev;
struct device *dev;
struct clk *dma_clk;
spinlock_t global_lock;
void __iomem *base_addr;
const struct tegra_dma_chip_data *chip_data;
/* Some register need to be cache before suspend */
u32 reg_gen;
/* Last member of the structure */
struct tegra_dma_channel channels[0];
};
static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
{
writel(val, tdma->base_addr + reg);
}
static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
{
return readl(tdma->base_addr + reg);
}
static inline void tdc_write(struct tegra_dma_channel *tdc,
u32 reg, u32 val)
{
writel(val, tdc->tdma->base_addr + tdc->chan_base_offset + reg);
}
static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
{
return readl(tdc->tdma->base_addr + tdc->chan_base_offset + reg);
}
static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
{
return container_of(dc, struct tegra_dma_channel, dma_chan);
}
static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
struct dma_async_tx_descriptor *td)
{
return container_of(td, struct tegra_dma_desc, txd);
}
static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
{
return &tdc->dma_chan.dev->device;
}
static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
static int tegra_dma_runtime_suspend(struct device *dev);
static int tegra_dma_runtime_resume(struct device *dev);
/* Get DMA desc from free list, if not there then allocate it. */
static struct tegra_dma_desc *tegra_dma_desc_get(
struct tegra_dma_channel *tdc)
{
struct tegra_dma_desc *dma_desc;
unsigned long flags;
spin_lock_irqsave(&tdc->lock, flags);
/* Do not allocate if desc are waiting for ack */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
if (async_tx_test_ack(&dma_desc->txd)) {
list_del(&dma_desc->node);
spin_unlock_irqrestore(&tdc->lock, flags);
return dma_desc;
}
}
spin_unlock_irqrestore(&tdc->lock, flags);
/* Allocate DMA desc */
dma_desc = kzalloc(sizeof(*dma_desc), GFP_ATOMIC);
if (!dma_desc) {
dev_err(tdc2dev(tdc), "dma_desc alloc failed\n");
return NULL;
}
dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
dma_desc->txd.tx_submit = tegra_dma_tx_submit;
dma_desc->txd.flags = 0;
return dma_desc;
}
static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
struct tegra_dma_desc *dma_desc)
{
unsigned long flags;
spin_lock_irqsave(&tdc->lock, flags);
if (!list_empty(&dma_desc->tx_list))
list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
spin_unlock_irqrestore(&tdc->lock, flags);
}
static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
struct tegra_dma_channel *tdc)
{
struct tegra_dma_sg_req *sg_req = NULL;
unsigned long flags;
spin_lock_irqsave(&tdc->lock, flags);
if (!list_empty(&tdc->free_sg_req)) {
sg_req = list_first_entry(&tdc->free_sg_req,
typeof(*sg_req), node);
list_del(&sg_req->node);
spin_unlock_irqrestore(&tdc->lock, flags);
return sg_req;
}
spin_unlock_irqrestore(&tdc->lock, flags);
sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_ATOMIC);
if (!sg_req)
dev_err(tdc2dev(tdc), "sg_req alloc failed\n");
return sg_req;
}
static int tegra_dma_slave_config(struct dma_chan *dc,
struct dma_slave_config *sconfig)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
if (!list_empty(&tdc->pending_sg_req)) {
dev_err(tdc2dev(tdc), "Configuration not allowed\n");
return -EBUSY;
}
memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
tdc->config_init = true;
return 0;
}
static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
bool wait_for_burst_complete)
{
struct tegra_dma *tdma = tdc->tdma;
spin_lock(&tdma->global_lock);
tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
if (wait_for_burst_complete)
udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
}
static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
{
struct tegra_dma *tdma = tdc->tdma;
tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
spin_unlock(&tdma->global_lock);
}
static void tegra_dma_stop(struct tegra_dma_channel *tdc)
{
u32 csr;
u32 status;
/* Disable interrupts */
csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
/* Disable DMA */
csr &= ~TEGRA_APBDMA_CSR_ENB;
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
/* Clear interrupt status if it is there */
status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
}
tdc->busy = false;
}
static void tegra_dma_start(struct tegra_dma_channel *tdc,
struct tegra_dma_sg_req *sg_req)
{
struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
/* Start DMA */
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
}
static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
struct tegra_dma_sg_req *nsg_req)
{
unsigned long status;
/*
* The DMA controller reloads the new configuration for next transfer
* after last burst of current transfer completes.
* If there is no IEC status then this makes sure that last burst
* has not be completed. There may be case that last burst is on
* flight and so it can complete but because DMA is paused, it
* will not generates interrupt as well as not reload the new
* configuration.
* If there is already IEC status then interrupt handler need to
* load new configuration.
*/
tegra_dma_global_pause(tdc, false);
status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
/*
* If interrupt is pending then do nothing as the ISR will handle
* the programing for new request.
*/
if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
dev_err(tdc2dev(tdc),
"Skipping new configuration as interrupt is pending\n");
tegra_dma_global_resume(tdc);
return;
}
/* Safe to program new configuration */
tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
nsg_req->configured = true;
tegra_dma_global_resume(tdc);
}
static void tdc_start_head_req(struct tegra_dma_channel *tdc)
{
struct tegra_dma_sg_req *sg_req;
if (list_empty(&tdc->pending_sg_req))
return;
sg_req = list_first_entry(&tdc->pending_sg_req,
typeof(*sg_req), node);
tegra_dma_start(tdc, sg_req);
sg_req->configured = true;
tdc->busy = true;
}
static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
{
struct tegra_dma_sg_req *hsgreq;
struct tegra_dma_sg_req *hnsgreq;
if (list_empty(&tdc->pending_sg_req))
return;
hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
hnsgreq = list_first_entry(&hsgreq->node,
typeof(*hnsgreq), node);
tegra_dma_configure_for_next(tdc, hnsgreq);
}
}
static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
struct tegra_dma_sg_req *sg_req, unsigned long status)
{
return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
}
static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
{
struct tegra_dma_sg_req *sgreq;
struct tegra_dma_desc *dma_desc;
while (!list_empty(&tdc->pending_sg_req)) {
sgreq = list_first_entry(&tdc->pending_sg_req,
typeof(*sgreq), node);
list_move_tail(&sgreq->node, &tdc->free_sg_req);
if (sgreq->last_sg) {
dma_desc = sgreq->dma_desc;
dma_desc->dma_status = DMA_ERROR;
list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
/* Add in cb list if it is not there. */
if (!dma_desc->cb_count)
list_add_tail(&dma_desc->cb_node,
&tdc->cb_desc);
dma_desc->cb_count++;
}
}
tdc->isr_handler = NULL;
}
static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
{
struct tegra_dma_sg_req *hsgreq = NULL;
if (list_empty(&tdc->pending_sg_req)) {
dev_err(tdc2dev(tdc), "Dma is running without req\n");
tegra_dma_stop(tdc);
return false;
}
/*
* Check that head req on list should be in flight.
* If it is not in flight then abort transfer as
* looping of transfer can not continue.
*/
hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
if (!hsgreq->configured) {
tegra_dma_stop(tdc);
dev_err(tdc2dev(tdc), "Error in dma transfer, aborting dma\n");
tegra_dma_abort_all(tdc);
return false;
}
/* Configure next request */
if (!to_terminate)
tdc_configure_next_head_desc(tdc);
return true;
}
static void handle_once_dma_done(struct tegra_dma_channel *tdc,
bool to_terminate)
{
struct tegra_dma_sg_req *sgreq;
struct tegra_dma_desc *dma_desc;
tdc->busy = false;
sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
dma_desc = sgreq->dma_desc;
dma_desc->bytes_transferred += sgreq->req_len;
list_del(&sgreq->node);
if (sgreq->last_sg) {
dma_desc->dma_status = DMA_SUCCESS;
dma_cookie_complete(&dma_desc->txd);
if (!dma_desc->cb_count)
list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
dma_desc->cb_count++;
list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
}
list_add_tail(&sgreq->node, &tdc->free_sg_req);
/* Do not start DMA if it is going to be terminate */
if (to_terminate || list_empty(&tdc->pending_sg_req))
return;
tdc_start_head_req(tdc);
return;
}
static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
bool to_terminate)
{
struct tegra_dma_sg_req *sgreq;
struct tegra_dma_desc *dma_desc;
bool st;
sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
dma_desc = sgreq->dma_desc;
dma_desc->bytes_transferred += sgreq->req_len;
/* Callback need to be call */
if (!dma_desc->cb_count)
list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
dma_desc->cb_count++;
/* If not last req then put at end of pending list */
if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
list_move_tail(&sgreq->node, &tdc->pending_sg_req);
sgreq->configured = false;
st = handle_continuous_head_request(tdc, sgreq, to_terminate);
if (!st)
dma_desc->dma_status = DMA_ERROR;
}
return;
}
static void tegra_dma_tasklet(unsigned long data)
{
struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
dma_async_tx_callback callback = NULL;
void *callback_param = NULL;
struct tegra_dma_desc *dma_desc;
unsigned long flags;
int cb_count;
spin_lock_irqsave(&tdc->lock, flags);
while (!list_empty(&tdc->cb_desc)) {
dma_desc = list_first_entry(&tdc->cb_desc,
typeof(*dma_desc), cb_node);
list_del(&dma_desc->cb_node);
callback = dma_desc->txd.callback;
callback_param = dma_desc->txd.callback_param;
cb_count = dma_desc->cb_count;
dma_desc->cb_count = 0;
spin_unlock_irqrestore(&tdc->lock, flags);
while (cb_count-- && callback)
callback(callback_param);
spin_lock_irqsave(&tdc->lock, flags);
}
spin_unlock_irqrestore(&tdc->lock, flags);
}
static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
{
struct tegra_dma_channel *tdc = dev_id;
unsigned long status;
unsigned long flags;
spin_lock_irqsave(&tdc->lock, flags);
status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
tdc->isr_handler(tdc, false);
tasklet_schedule(&tdc->tasklet);
spin_unlock_irqrestore(&tdc->lock, flags);
return IRQ_HANDLED;
}
spin_unlock_irqrestore(&tdc->lock, flags);
dev_info(tdc2dev(tdc),
"Interrupt already served status 0x%08lx\n", status);
return IRQ_NONE;
}
static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
{
struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
unsigned long flags;
dma_cookie_t cookie;
spin_lock_irqsave(&tdc->lock, flags);
dma_desc->dma_status = DMA_IN_PROGRESS;
cookie = dma_cookie_assign(&dma_desc->txd);
list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
spin_unlock_irqrestore(&tdc->lock, flags);
return cookie;
}
static void tegra_dma_issue_pending(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
unsigned long flags;
spin_lock_irqsave(&tdc->lock, flags);
if (list_empty(&tdc->pending_sg_req)) {
dev_err(tdc2dev(tdc), "No DMA request\n");
goto end;
}
if (!tdc->busy) {
tdc_start_head_req(tdc);
/* Continuous single mode: Configure next req */
if (tdc->cyclic) {
/*
* Wait for 1 burst time for configure DMA for
* next transfer.
*/
udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
tdc_configure_next_head_desc(tdc);
}
}
end:
spin_unlock_irqrestore(&tdc->lock, flags);
return;
}
static void tegra_dma_terminate_all(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_sg_req *sgreq;
struct tegra_dma_desc *dma_desc;
unsigned long flags;
unsigned long status;
bool was_busy;
spin_lock_irqsave(&tdc->lock, flags);
if (list_empty(&tdc->pending_sg_req)) {
spin_unlock_irqrestore(&tdc->lock, flags);
return;
}
if (!tdc->busy)
goto skip_dma_stop;
/* Pause DMA before checking the queue status */
tegra_dma_global_pause(tdc, true);
status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
tdc->isr_handler(tdc, true);
status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
}
was_busy = tdc->busy;
tegra_dma_stop(tdc);
if (!list_empty(&tdc->pending_sg_req) && was_busy) {
sgreq = list_first_entry(&tdc->pending_sg_req,
typeof(*sgreq), node);
sgreq->dma_desc->bytes_transferred +=
get_current_xferred_count(tdc, sgreq, status);
}
tegra_dma_global_resume(tdc);
skip_dma_stop:
tegra_dma_abort_all(tdc);
while (!list_empty(&tdc->cb_desc)) {
dma_desc = list_first_entry(&tdc->cb_desc,
typeof(*dma_desc), cb_node);
list_del(&dma_desc->cb_node);
dma_desc->cb_count = 0;
}
spin_unlock_irqrestore(&tdc->lock, flags);
}
static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_desc *dma_desc;
struct tegra_dma_sg_req *sg_req;
enum dma_status ret;
unsigned long flags;
unsigned int residual;
spin_lock_irqsave(&tdc->lock, flags);
ret = dma_cookie_status(dc, cookie, txstate);
if (ret == DMA_SUCCESS) {
dma_set_residue(txstate, 0);
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
}
/* Check on wait_ack desc status */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
if (dma_desc->txd.cookie == cookie) {
residual = dma_desc->bytes_requested -
(dma_desc->bytes_transferred %
dma_desc->bytes_requested);
dma_set_residue(txstate, residual);
ret = dma_desc->dma_status;
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
}
}
/* Check in pending list */
list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
dma_desc = sg_req->dma_desc;
if (dma_desc->txd.cookie == cookie) {
residual = dma_desc->bytes_requested -
(dma_desc->bytes_transferred %
dma_desc->bytes_requested);
dma_set_residue(txstate, residual);
ret = dma_desc->dma_status;
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
}
}
dev_dbg(tdc2dev(tdc), "cookie %d does not found\n", cookie);
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
}
static int tegra_dma_device_control(struct dma_chan *dc, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
switch (cmd) {
case DMA_SLAVE_CONFIG:
return tegra_dma_slave_config(dc,
(struct dma_slave_config *)arg);
case DMA_TERMINATE_ALL:
tegra_dma_terminate_all(dc);
return 0;
default:
break;
}
return -ENXIO;
}
static inline int get_bus_width(struct tegra_dma_channel *tdc,
enum dma_slave_buswidth slave_bw)
{
switch (slave_bw) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
case DMA_SLAVE_BUSWIDTH_8_BYTES:
return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
default:
dev_warn(tdc2dev(tdc),
"slave bw is not supported, using 32bits\n");
return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
}
}
static inline int get_burst_size(struct tegra_dma_channel *tdc,
u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
{
int burst_byte;
int burst_ahb_width;
/*
* burst_size from client is in terms of the bus_width.
* convert them into AHB memory width which is 4 byte.
*/
burst_byte = burst_size * slave_bw;
burst_ahb_width = burst_byte / 4;
/* If burst size is 0 then calculate the burst size based on length */
if (!burst_ahb_width) {
if (len & 0xF)
return TEGRA_APBDMA_AHBSEQ_BURST_1;
else if ((len >> 4) & 0x1)
return TEGRA_APBDMA_AHBSEQ_BURST_4;
else
return TEGRA_APBDMA_AHBSEQ_BURST_8;
}
if (burst_ahb_width < 4)
return TEGRA_APBDMA_AHBSEQ_BURST_1;
else if (burst_ahb_width < 8)
return TEGRA_APBDMA_AHBSEQ_BURST_4;
else
return TEGRA_APBDMA_AHBSEQ_BURST_8;
}
static int get_transfer_param(struct tegra_dma_channel *tdc,
enum dma_transfer_direction direction, unsigned long *apb_addr,
unsigned long *apb_seq, unsigned long *csr, unsigned int *burst_size,
enum dma_slave_buswidth *slave_bw)
{
switch (direction) {
case DMA_MEM_TO_DEV:
*apb_addr = tdc->dma_sconfig.dst_addr;
*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
*burst_size = tdc->dma_sconfig.dst_maxburst;
*slave_bw = tdc->dma_sconfig.dst_addr_width;
*csr = TEGRA_APBDMA_CSR_DIR;
return 0;
case DMA_DEV_TO_MEM:
*apb_addr = tdc->dma_sconfig.src_addr;
*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
*burst_size = tdc->dma_sconfig.src_maxburst;
*slave_bw = tdc->dma_sconfig.src_addr_width;
*csr = 0;
return 0;
default:
dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
return -EINVAL;
}
return -EINVAL;
}
static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
enum dma_transfer_direction direction, unsigned long flags,
void *context)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_desc *dma_desc;
unsigned int i;
struct scatterlist *sg;
unsigned long csr, ahb_seq, apb_ptr, apb_seq;
struct list_head req_list;
struct tegra_dma_sg_req *sg_req = NULL;
u32 burst_size;
enum dma_slave_buswidth slave_bw;
int ret;
if (!tdc->config_init) {
dev_err(tdc2dev(tdc), "dma channel is not configured\n");
return NULL;
}
if (sg_len < 1) {
dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
return NULL;
}
ret = get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
&burst_size, &slave_bw);
if (ret < 0)
return NULL;
INIT_LIST_HEAD(&req_list);
ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
csr |= tdc->dma_sconfig.slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
if (flags & DMA_PREP_INTERRUPT)
csr |= TEGRA_APBDMA_CSR_IE_EOC;
apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
dma_desc = tegra_dma_desc_get(tdc);
if (!dma_desc) {
dev_err(tdc2dev(tdc), "Dma descriptors not available\n");
return NULL;
}
INIT_LIST_HEAD(&dma_desc->tx_list);
INIT_LIST_HEAD(&dma_desc->cb_node);
dma_desc->cb_count = 0;
dma_desc->bytes_requested = 0;
dma_desc->bytes_transferred = 0;
dma_desc->dma_status = DMA_IN_PROGRESS;
/* Make transfer requests */
for_each_sg(sgl, sg, sg_len, i) {
u32 len, mem;
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
if ((len & 3) || (mem & 3) ||
(len > tdc->tdma->chip_data->max_dma_count)) {
dev_err(tdc2dev(tdc),
"Dma length/memory address is not supported\n");
tegra_dma_desc_put(tdc, dma_desc);
return NULL;
}
sg_req = tegra_dma_sg_req_get(tdc);
if (!sg_req) {
dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
tegra_dma_desc_put(tdc, dma_desc);
return NULL;
}
ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
dma_desc->bytes_requested += len;
sg_req->ch_regs.apb_ptr = apb_ptr;
sg_req->ch_regs.ahb_ptr = mem;
sg_req->ch_regs.csr = csr | ((len - 4) & 0xFFFC);
sg_req->ch_regs.apb_seq = apb_seq;
sg_req->ch_regs.ahb_seq = ahb_seq;
sg_req->configured = false;
sg_req->last_sg = false;
sg_req->dma_desc = dma_desc;
sg_req->req_len = len;
list_add_tail(&sg_req->node, &dma_desc->tx_list);
}
sg_req->last_sg = true;
if (flags & DMA_CTRL_ACK)
dma_desc->txd.flags = DMA_CTRL_ACK;
/*
* Make sure that mode should not be conflicting with currently
* configured mode.
*/
if (!tdc->isr_handler) {
tdc->isr_handler = handle_once_dma_done;
tdc->cyclic = false;
} else {
if (tdc->cyclic) {
dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
tegra_dma_desc_put(tdc, dma_desc);
return NULL;
}
}
return &dma_desc->txd;
}
struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_desc *dma_desc = NULL;
struct tegra_dma_sg_req *sg_req = NULL;
unsigned long csr, ahb_seq, apb_ptr, apb_seq;
int len;
size_t remain_len;
dma_addr_t mem = buf_addr;
u32 burst_size;
enum dma_slave_buswidth slave_bw;
int ret;
if (!buf_len || !period_len) {
dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
return NULL;
}
if (!tdc->config_init) {
dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
return NULL;
}
/*
* We allow to take more number of requests till DMA is
* not started. The driver will loop over all requests.
* Once DMA is started then new requests can be queued only after
* terminating the DMA.
*/
if (tdc->busy) {
dev_err(tdc2dev(tdc), "Request not allowed when dma running\n");
return NULL;
}
/*
* We only support cycle transfer when buf_len is multiple of
* period_len.
*/
if (buf_len % period_len) {
dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
return NULL;
}
len = period_len;
if ((len & 3) || (buf_addr & 3) ||
(len > tdc->tdma->chip_data->max_dma_count)) {
dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
return NULL;
}
ret = get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
&burst_size, &slave_bw);
if (ret < 0)
return NULL;
ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
csr |= TEGRA_APBDMA_CSR_FLOW | TEGRA_APBDMA_CSR_IE_EOC;
csr |= tdc->dma_sconfig.slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
dma_desc = tegra_dma_desc_get(tdc);
if (!dma_desc) {
dev_err(tdc2dev(tdc), "not enough descriptors available\n");
return NULL;
}
INIT_LIST_HEAD(&dma_desc->tx_list);
INIT_LIST_HEAD(&dma_desc->cb_node);
dma_desc->cb_count = 0;
dma_desc->bytes_transferred = 0;
dma_desc->bytes_requested = buf_len;
remain_len = buf_len;
/* Split transfer equal to period size */
while (remain_len) {
sg_req = tegra_dma_sg_req_get(tdc);
if (!sg_req) {
dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
tegra_dma_desc_put(tdc, dma_desc);
return NULL;
}
ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
sg_req->ch_regs.apb_ptr = apb_ptr;
sg_req->ch_regs.ahb_ptr = mem;
sg_req->ch_regs.csr = csr | ((len - 4) & 0xFFFC);
sg_req->ch_regs.apb_seq = apb_seq;
sg_req->ch_regs.ahb_seq = ahb_seq;
sg_req->configured = false;
sg_req->half_done = false;
sg_req->last_sg = false;
sg_req->dma_desc = dma_desc;
sg_req->req_len = len;
list_add_tail(&sg_req->node, &dma_desc->tx_list);
remain_len -= len;
mem += len;
}
sg_req->last_sg = true;
dma_desc->txd.flags = 0;
/*
* Make sure that mode should not be conflicting with currently
* configured mode.
*/
if (!tdc->isr_handler) {
tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
tdc->cyclic = true;
} else {
if (!tdc->cyclic) {
dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
tegra_dma_desc_put(tdc, dma_desc);
return NULL;
}
}
return &dma_desc->txd;
}
static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma *tdma = tdc->tdma;
int ret;
dma_cookie_init(&tdc->dma_chan);
tdc->config_init = false;
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0)
dev_err(tdc2dev(tdc), "clk_prepare_enable failed: %d\n", ret);
return ret;
}
static void tegra_dma_free_chan_resources(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma *tdma = tdc->tdma;
struct tegra_dma_desc *dma_desc;
struct tegra_dma_sg_req *sg_req;
struct list_head dma_desc_list;
struct list_head sg_req_list;
unsigned long flags;
INIT_LIST_HEAD(&dma_desc_list);
INIT_LIST_HEAD(&sg_req_list);
dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
if (tdc->busy)
tegra_dma_terminate_all(dc);
spin_lock_irqsave(&tdc->lock, flags);
list_splice_init(&tdc->pending_sg_req, &sg_req_list);
list_splice_init(&tdc->free_sg_req, &sg_req_list);
list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
INIT_LIST_HEAD(&tdc->cb_desc);
tdc->config_init = false;
spin_unlock_irqrestore(&tdc->lock, flags);
while (!list_empty(&dma_desc_list)) {
dma_desc = list_first_entry(&dma_desc_list,
typeof(*dma_desc), node);
list_del(&dma_desc->node);
kfree(dma_desc);
}
while (!list_empty(&sg_req_list)) {
sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
list_del(&sg_req->node);
kfree(sg_req);
}
clk_disable_unprepare(tdma->dma_clk);
}
/* Tegra20 specific DMA controller information */
static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
.nr_channels = 16,
.max_dma_count = 1024UL * 64,
};
#if defined(CONFIG_OF)
/* Tegra30 specific DMA controller information */
static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
.nr_channels = 32,
.max_dma_count = 1024UL * 64,
};
static const struct of_device_id tegra_dma_of_match[] __devinitconst = {
{
.compatible = "nvidia,tegra30-apbdma",
.data = &tegra30_dma_chip_data,
}, {
.compatible = "nvidia,tegra20-apbdma",
.data = &tegra20_dma_chip_data,
}, {
},
};
MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
#endif
static int tegra_dma_probe(struct platform_device *pdev)
{
struct resource *res;
struct tegra_dma *tdma;
int ret;
int i;
const struct tegra_dma_chip_data *cdata = NULL;
if (pdev->dev.of_node) {
const struct of_device_id *match;
match = of_match_device(of_match_ptr(tegra_dma_of_match),
&pdev->dev);
if (!match) {
dev_err(&pdev->dev, "Error: No device match found\n");
return -ENODEV;
}
cdata = match->data;
} else {
/* If no device tree then fallback to tegra20 */
cdata = &tegra20_dma_chip_data;
}
tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
sizeof(struct tegra_dma_channel), GFP_KERNEL);
if (!tdma) {
dev_err(&pdev->dev, "Error: memory allocation failed\n");
return -ENOMEM;
}
tdma->dev = &pdev->dev;
tdma->chip_data = cdata;
platform_set_drvdata(pdev, tdma);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "No mem resource for DMA\n");
return -EINVAL;
}
tdma->base_addr = devm_request_and_ioremap(&pdev->dev, res);
if (!tdma->base_addr) {
dev_err(&pdev->dev,
"Cannot request memregion/iomap dma address\n");
return -EADDRNOTAVAIL;
}
tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(tdma->dma_clk)) {
dev_err(&pdev->dev, "Error: Missing controller clock\n");
return PTR_ERR(tdma->dma_clk);
}
spin_lock_init(&tdma->global_lock);
pm_runtime_enable(&pdev->dev);
if (!pm_runtime_enabled(&pdev->dev)) {
ret = tegra_dma_runtime_resume(&pdev->dev);
if (ret) {
dev_err(&pdev->dev, "dma_runtime_resume failed %d\n",
ret);
goto err_pm_disable;
}
}
/* Enable clock before accessing registers */
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0) {
dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
goto err_pm_disable;
}
/* Reset DMA controller */
tegra_periph_reset_assert(tdma->dma_clk);
udelay(2);
tegra_periph_reset_deassert(tdma->dma_clk);
/* Enable global DMA registers */
tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
clk_disable_unprepare(tdma->dma_clk);
INIT_LIST_HEAD(&tdma->dma_dev.channels);
for (i = 0; i < cdata->nr_channels; i++) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
tdc->chan_base_offset = TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
i * TEGRA_APBDMA_CHANNEL_REGISTER_SIZE;
res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
if (!res) {
ret = -EINVAL;
dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
goto err_irq;
}
tdc->irq = res->start;
snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
ret = devm_request_irq(&pdev->dev, tdc->irq,
tegra_dma_isr, 0, tdc->name, tdc);
if (ret) {
dev_err(&pdev->dev,
"request_irq failed with err %d channel %d\n",
i, ret);
goto err_irq;
}
tdc->dma_chan.device = &tdma->dma_dev;
dma_cookie_init(&tdc->dma_chan);
list_add_tail(&tdc->dma_chan.device_node,
&tdma->dma_dev.channels);
tdc->tdma = tdma;
tdc->id = i;
tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
(unsigned long)tdc);
spin_lock_init(&tdc->lock);
INIT_LIST_HEAD(&tdc->pending_sg_req);
INIT_LIST_HEAD(&tdc->free_sg_req);
INIT_LIST_HEAD(&tdc->free_dma_desc);
INIT_LIST_HEAD(&tdc->cb_desc);
}
dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
tdma->dma_dev.dev = &pdev->dev;
tdma->dma_dev.device_alloc_chan_resources =
tegra_dma_alloc_chan_resources;
tdma->dma_dev.device_free_chan_resources =
tegra_dma_free_chan_resources;
tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
tdma->dma_dev.device_control = tegra_dma_device_control;
tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
ret = dma_async_device_register(&tdma->dma_dev);
if (ret < 0) {
dev_err(&pdev->dev,
"Tegra20 APB DMA driver registration failed %d\n", ret);
goto err_irq;
}
dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
cdata->nr_channels);
return 0;
err_irq:
while (--i >= 0) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
tasklet_kill(&tdc->tasklet);
}
err_pm_disable:
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_dma_runtime_suspend(&pdev->dev);
return ret;
}
static int __devexit tegra_dma_remove(struct platform_device *pdev)
{
struct tegra_dma *tdma = platform_get_drvdata(pdev);
int i;
struct tegra_dma_channel *tdc;
dma_async_device_unregister(&tdma->dma_dev);
for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
tdc = &tdma->channels[i];
tasklet_kill(&tdc->tasklet);
}
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_dma_runtime_suspend(&pdev->dev);
return 0;
}
static int tegra_dma_runtime_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct tegra_dma *tdma = platform_get_drvdata(pdev);
clk_disable_unprepare(tdma->dma_clk);
return 0;
}
static int tegra_dma_runtime_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct tegra_dma *tdma = platform_get_drvdata(pdev);
int ret;
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0) {
dev_err(dev, "clk_enable failed: %d\n", ret);
return ret;
}
return 0;
}
static const struct dev_pm_ops tegra_dma_dev_pm_ops __devinitconst = {
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = tegra_dma_runtime_suspend,
.runtime_resume = tegra_dma_runtime_resume,
#endif
};
static struct platform_driver tegra_dmac_driver = {
.driver = {
.name = "tegra-apbdma",
.owner = THIS_MODULE,
.pm = &tegra_dma_dev_pm_ops,
.of_match_table = of_match_ptr(tegra_dma_of_match),
},
.probe = tegra_dma_probe,
.remove = tegra_dma_remove,
};
module_platform_driver(tegra_dmac_driver);
MODULE_ALIAS("platform:tegra20-apbdma");
MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");
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