linux/drivers/dma/tegra20-apb-dma.c

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/*
* DMA driver for Nvidia's Tegra20 APB DMA controller.
*
* Copyright (c) 2012-2013, 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/err.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/of_dma.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/slab.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_REQ_SEL_MASK 0x1F
#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
#define TEGRA_APBDMA_CHAN_CSRE 0x00C
#define TEGRA_APBDMA_CHAN_CSRE_PAUSE (1 << 31)
/* 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)
/* Tegra148 specific registers */
#define TEGRA_APBDMA_CHAN_WCOUNT 0x20
#define TEGRA_APBDMA_CHAN_WORD_TRANSFER 0x24
/*
* 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
#define TEGRA_APBDMA_SLAVE_ID_INVALID (TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1)
struct tegra_dma;
/*
* tegra_dma_chip_data Tegra chip specific DMA data
* @nr_channels: Number of channels available in the controller.
* @channel_reg_size: Channel register size/stride.
* @max_dma_count: Maximum DMA transfer count supported by DMA controller.
* @support_channel_pause: Support channel wise pause of dma.
* @support_separate_wcount_reg: Support separate word count register.
*/
struct tegra_dma_chip_data {
int nr_channels;
int channel_reg_size;
int max_dma_count;
bool support_channel_pause;
bool support_separate_wcount_reg;
};
/* 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;
unsigned long wcount;
};
/*
* 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;
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;
void __iomem *chan_addr;
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;
/* Channel-slave specific configuration */
unsigned int slave_id;
struct dma_slave_config dma_sconfig;
struct tegra_dma_channel_regs channel_reg;
};
/* tegra_dma: Tegra DMA specific information */
struct tegra_dma {
struct dma_device dma_dev;
struct device *dev;
struct clk *dma_clk;
struct reset_control *rst;
spinlock_t global_lock;
void __iomem *base_addr;
const struct tegra_dma_chip_data *chip_data;
dmaengine: tegra-apb: Simplify locking for device using global pause Sparse reports the following with regard to locking in the tegra_dma_global_pause() and tegra_dma_global_resume() functions: drivers/dma/tegra20-apb-dma.c:362:9: warning: context imbalance in 'tegra_dma_global_pause' - wrong count at exit drivers/dma/tegra20-apb-dma.c:366:13: warning: context imbalance in 'tegra_dma_global_resume' - unexpected unlock The warning is caused because tegra_dma_global_pause() acquires a lock but does not release it. However, the lock is released by tegra_dma_global_resume(). These pause/resume functions are called in pairs and so it does appear to work. This global pause is used on early tegra devices that do not have an individual pause for each channel. The lock appears to be used to ensure that multiple channels do not attempt to assert/de-assert the global pause at the same time which could cause the DMA controller to be in the wrong paused state. Rather than locking around the entire code between the pause and resume, employ a simple counter to keep track of the global pause requests. By using a counter, it is only necessary to hold the lock when pausing and unpausing the DMA controller and hence, fixes the sparse warning. Please note that for devices that support individual channel pausing, the DMA controller lock is not held between pausing and unpausing the channel. Hence, this change will make the devices that use the global pause behave in the same way, with regard to locking, as those that don't. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-06 13:32:33 +00:00
/*
* Counter for managing global pausing of the DMA controller.
* Only applicable for devices that don't support individual
* channel pausing.
*/
u32 global_pause_count;
/* 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->chan_addr + reg);
}
static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
{
return readl(tdc->chan_addr + 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);
dma_desc->txd.flags = 0;
return dma_desc;
}
}
spin_unlock_irqrestore(&tdc->lock, flags);
/* Allocate DMA desc */
dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
if (!dma_desc)
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_NOWAIT);
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));
if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID &&
sconfig->device_fc) {
if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
return -EINVAL;
tdc->slave_id = sconfig->slave_id;
}
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);
dmaengine: tegra-apb: Simplify locking for device using global pause Sparse reports the following with regard to locking in the tegra_dma_global_pause() and tegra_dma_global_resume() functions: drivers/dma/tegra20-apb-dma.c:362:9: warning: context imbalance in 'tegra_dma_global_pause' - wrong count at exit drivers/dma/tegra20-apb-dma.c:366:13: warning: context imbalance in 'tegra_dma_global_resume' - unexpected unlock The warning is caused because tegra_dma_global_pause() acquires a lock but does not release it. However, the lock is released by tegra_dma_global_resume(). These pause/resume functions are called in pairs and so it does appear to work. This global pause is used on early tegra devices that do not have an individual pause for each channel. The lock appears to be used to ensure that multiple channels do not attempt to assert/de-assert the global pause at the same time which could cause the DMA controller to be in the wrong paused state. Rather than locking around the entire code between the pause and resume, employ a simple counter to keep track of the global pause requests. By using a counter, it is only necessary to hold the lock when pausing and unpausing the DMA controller and hence, fixes the sparse warning. Please note that for devices that support individual channel pausing, the DMA controller lock is not held between pausing and unpausing the channel. Hence, this change will make the devices that use the global pause behave in the same way, with regard to locking, as those that don't. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-06 13:32:33 +00:00
if (tdc->tdma->global_pause_count == 0) {
tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
if (wait_for_burst_complete)
udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
}
tdc->tdma->global_pause_count++;
spin_unlock(&tdma->global_lock);
}
static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
{
struct tegra_dma *tdma = tdc->tdma;
dmaengine: tegra-apb: Simplify locking for device using global pause Sparse reports the following with regard to locking in the tegra_dma_global_pause() and tegra_dma_global_resume() functions: drivers/dma/tegra20-apb-dma.c:362:9: warning: context imbalance in 'tegra_dma_global_pause' - wrong count at exit drivers/dma/tegra20-apb-dma.c:366:13: warning: context imbalance in 'tegra_dma_global_resume' - unexpected unlock The warning is caused because tegra_dma_global_pause() acquires a lock but does not release it. However, the lock is released by tegra_dma_global_resume(). These pause/resume functions are called in pairs and so it does appear to work. This global pause is used on early tegra devices that do not have an individual pause for each channel. The lock appears to be used to ensure that multiple channels do not attempt to assert/de-assert the global pause at the same time which could cause the DMA controller to be in the wrong paused state. Rather than locking around the entire code between the pause and resume, employ a simple counter to keep track of the global pause requests. By using a counter, it is only necessary to hold the lock when pausing and unpausing the DMA controller and hence, fixes the sparse warning. Please note that for devices that support individual channel pausing, the DMA controller lock is not held between pausing and unpausing the channel. Hence, this change will make the devices that use the global pause behave in the same way, with regard to locking, as those that don't. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-06 13:32:33 +00:00
spin_lock(&tdma->global_lock);
if (WARN_ON(tdc->tdma->global_pause_count == 0))
goto out;
if (--tdc->tdma->global_pause_count == 0)
tdma_write(tdma, TEGRA_APBDMA_GENERAL,
TEGRA_APBDMA_GENERAL_ENABLE);
out:
spin_unlock(&tdma->global_lock);
}
static void tegra_dma_pause(struct tegra_dma_channel *tdc,
bool wait_for_burst_complete)
{
struct tegra_dma *tdma = tdc->tdma;
if (tdma->chip_data->support_channel_pause) {
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
TEGRA_APBDMA_CHAN_CSRE_PAUSE);
if (wait_for_burst_complete)
udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
} else {
tegra_dma_global_pause(tdc, wait_for_burst_complete);
}
}
static void tegra_dma_resume(struct tegra_dma_channel *tdc)
{
struct tegra_dma *tdma = tdc->tdma;
if (tdma->chip_data->support_channel_pause) {
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
} else {
tegra_dma_global_resume(tdc);
}
}
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);
if (tdc->tdma->chip_data->support_separate_wcount_reg)
tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
/* 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_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_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);
if (tdc->tdma->chip_data->support_separate_wcount_reg)
tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
nsg_req->ch_regs.wcount);
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
nsg_req->configured = true;
tegra_dma_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_COMPLETE;
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);
}
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;
}
}
static void tegra_dma_tasklet(unsigned long data)
{
struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
struct dmaengine_desc_callback cb;
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);
dmaengine_desc_get_callback(&dma_desc->txd, &cb);
cb_count = dma_desc->cb_count;
dma_desc->cb_count = 0;
spin_unlock_irqrestore(&tdc->lock, flags);
while (cb_count--)
dmaengine_desc_callback_invoke(&cb, NULL);
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);
}
static int 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;
unsigned long wcount;
bool was_busy;
spin_lock_irqsave(&tdc->lock, flags);
if (list_empty(&tdc->pending_sg_req)) {
spin_unlock_irqrestore(&tdc->lock, flags);
return 0;
}
if (!tdc->busy)
goto skip_dma_stop;
/* Pause DMA before checking the queue status */
tegra_dma_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);
}
if (tdc->tdma->chip_data->support_separate_wcount_reg)
wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
else
wcount = 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, wcount);
}
tegra_dma_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);
return 0;
}
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;
ret = dma_cookie_status(dc, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
spin_lock_irqsave(&tdc->lock, flags);
/* Check on wait_ack desc status */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
if (dma_desc->txd.cookie == cookie) {
ret = dma_desc->dma_status;
goto found;
}
}
/* 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) {
ret = dma_desc->dma_status;
goto found;
}
}
dev_dbg(tdc2dev(tdc), "cookie %d not found\n", cookie);
dma_desc = NULL;
found:
if (dma_desc && txstate) {
residual = dma_desc->bytes_requested -
(dma_desc->bytes_transferred %
dma_desc->bytes_requested);
dma_set_residue(txstate, residual);
}
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
}
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 void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
struct tegra_dma_channel_regs *ch_regs, u32 len)
{
u32 len_field = (len - 4) & 0xFFFC;
if (tdc->tdma->chip_data->support_separate_wcount_reg)
ch_regs->wcount = len_field;
else
ch_regs->csr |= len_field;
}
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;
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;
}
if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
&burst_size, &slave_bw) < 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;
if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
csr |= TEGRA_APBDMA_CSR_FLOW;
csr |= tdc->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;
tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
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;
}
static 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)
{
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;
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;
}
if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
&burst_size, &slave_bw) < 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;
if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
csr |= TEGRA_APBDMA_CSR_FLOW;
csr |= tdc->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), "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;
tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
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);
remain_len -= len;
mem += len;
}
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_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 = pm_runtime_get_sync(tdma->dev);
if (ret < 0)
return ret;
return 0;
}
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;
tdc->isr_handler = NULL;
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);
}
pm_runtime_put(tdma->dev);
tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
}
static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct tegra_dma *tdma = ofdma->of_dma_data;
struct dma_chan *chan;
struct tegra_dma_channel *tdc;
if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
return NULL;
}
chan = dma_get_any_slave_channel(&tdma->dma_dev);
if (!chan)
return NULL;
tdc = to_tegra_dma_chan(chan);
tdc->slave_id = dma_spec->args[0];
return chan;
}
/* Tegra20 specific DMA controller information */
static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
.nr_channels = 16,
.channel_reg_size = 0x20,
.max_dma_count = 1024UL * 64,
.support_channel_pause = false,
.support_separate_wcount_reg = false,
};
/* Tegra30 specific DMA controller information */
static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
.nr_channels = 32,
.channel_reg_size = 0x20,
.max_dma_count = 1024UL * 64,
.support_channel_pause = false,
.support_separate_wcount_reg = false,
};
/* Tegra114 specific DMA controller information */
static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
.nr_channels = 32,
.channel_reg_size = 0x20,
.max_dma_count = 1024UL * 64,
.support_channel_pause = true,
.support_separate_wcount_reg = false,
};
/* Tegra148 specific DMA controller information */
static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
.nr_channels = 32,
.channel_reg_size = 0x40,
.max_dma_count = 1024UL * 64,
.support_channel_pause = true,
.support_separate_wcount_reg = true,
};
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;
cdata = of_device_get_match_data(&pdev->dev);
if (!cdata) {
dev_err(&pdev->dev, "Error: No device match data found\n");
return -ENODEV;
}
tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
sizeof(struct tegra_dma_channel), GFP_KERNEL);
if (!tdma)
return -ENOMEM;
tdma->dev = &pdev->dev;
tdma->chip_data = cdata;
platform_set_drvdata(pdev, tdma);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(tdma->base_addr))
return PTR_ERR(tdma->base_addr);
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);
}
tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
if (IS_ERR(tdma->rst)) {
dev_err(&pdev->dev, "Error: Missing reset\n");
return PTR_ERR(tdma->rst);
}
spin_lock_init(&tdma->global_lock);
pm_runtime_enable(&pdev->dev);
if (!pm_runtime_enabled(&pdev->dev))
ret = tegra_dma_runtime_resume(&pdev->dev);
else
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0) {
pm_runtime_disable(&pdev->dev);
return ret;
}
/* Reset DMA controller */
reset_control_assert(tdma->rst);
udelay(2);
reset_control_deassert(tdma->rst);
/* 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);
pm_runtime_put(&pdev->dev);
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_addr = tdma->base_addr +
TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
(i * cdata->channel_reg_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 = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
if (ret) {
dev_err(&pdev->dev,
"request_irq failed with err %d channel %d\n",
ret, i);
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;
tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
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);
dmaengine: tegra-apb: Simplify locking for device using global pause Sparse reports the following with regard to locking in the tegra_dma_global_pause() and tegra_dma_global_resume() functions: drivers/dma/tegra20-apb-dma.c:362:9: warning: context imbalance in 'tegra_dma_global_pause' - wrong count at exit drivers/dma/tegra20-apb-dma.c:366:13: warning: context imbalance in 'tegra_dma_global_resume' - unexpected unlock The warning is caused because tegra_dma_global_pause() acquires a lock but does not release it. However, the lock is released by tegra_dma_global_resume(). These pause/resume functions are called in pairs and so it does appear to work. This global pause is used on early tegra devices that do not have an individual pause for each channel. The lock appears to be used to ensure that multiple channels do not attempt to assert/de-assert the global pause at the same time which could cause the DMA controller to be in the wrong paused state. Rather than locking around the entire code between the pause and resume, employ a simple counter to keep track of the global pause requests. By using a counter, it is only necessary to hold the lock when pausing and unpausing the DMA controller and hence, fixes the sparse warning. Please note that for devices that support individual channel pausing, the DMA controller lock is not held between pausing and unpausing the channel. Hence, this change will make the devices that use the global pause behave in the same way, with regard to locking, as those that don't. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-06 13:32:33 +00:00
tdma->global_pause_count = 0;
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.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
/*
* XXX The hardware appears to support
* DMA_RESIDUE_GRANULARITY_BURST-level reporting, but it's
* only used by this driver during tegra_dma_terminate_all()
*/
tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
tdma->dma_dev.device_config = tegra_dma_slave_config;
tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
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;
}
ret = of_dma_controller_register(pdev->dev.of_node,
tegra_dma_of_xlate, tdma);
if (ret < 0) {
dev_err(&pdev->dev,
"Tegra20 APB DMA OF registration failed %d\n", ret);
goto err_unregister_dma_dev;
}
dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
cdata->nr_channels);
return 0;
err_unregister_dma_dev:
dma_async_device_unregister(&tdma->dma_dev);
err_irq:
while (--i >= 0) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
free_irq(tdc->irq, tdc);
tasklet_kill(&tdc->tasklet);
}
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_dma_runtime_suspend(&pdev->dev);
return ret;
}
static int 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];
free_irq(tdc->irq, tdc);
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 tegra_dma *tdma = dev_get_drvdata(dev);
int i;
tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
for (i = 0; i < tdma->chip_data->nr_channels; i++) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
/* Only save the state of DMA channels that are in use */
if (!tdc->config_init)
continue;
ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
if (tdma->chip_data->support_separate_wcount_reg)
ch_reg->wcount = tdc_read(tdc,
TEGRA_APBDMA_CHAN_WCOUNT);
}
clk_disable_unprepare(tdma->dma_clk);
return 0;
}
static int tegra_dma_runtime_resume(struct device *dev)
{
struct tegra_dma *tdma = dev_get_drvdata(dev);
int i, ret;
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0) {
dev_err(dev, "clk_enable failed: %d\n", ret);
return ret;
}
tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
for (i = 0; i < tdma->chip_data->nr_channels; i++) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
/* Only restore the state of DMA channels that are in use */
if (!tdc->config_init)
continue;
if (tdma->chip_data->support_separate_wcount_reg)
tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
ch_reg->wcount);
tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
(ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
}
return 0;
}
static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
NULL)
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
};
static const struct of_device_id tegra_dma_of_match[] = {
{
.compatible = "nvidia,tegra148-apbdma",
.data = &tegra148_dma_chip_data,
}, {
.compatible = "nvidia,tegra114-apbdma",
.data = &tegra114_dma_chip_data,
}, {
.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);
static struct platform_driver tegra_dmac_driver = {
.driver = {
.name = "tegra-apbdma",
.pm = &tegra_dma_dev_pm_ops,
.of_match_table = 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");