- 根目录:
- drivers
- dma
- qcom_bam_dma.c
/*
* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that 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.
*
*/
/*
* QCOM BAM DMA engine driver
*
* QCOM BAM DMA blocks are distributed amongst a number of the on-chip
* peripherals on the MSM 8x74. The configuration of the channels are dependent
* on the way they are hard wired to that specific peripheral. The peripheral
* device tree entries specify the configuration of each channel.
*
* The DMA controller requires the use of external memory for storage of the
* hardware descriptors for each channel. The descriptor FIFO is accessed as a
* circular buffer and operations are managed according to the offset within the
* FIFO. After pipe/channel reset, all of the pipe registers and internal state
* are back to defaults.
*
* During DMA operations, we write descriptors to the FIFO, being careful to
* handle wrapping and then write the last FIFO offset to that channel's
* P_EVNT_REG register to kick off the transaction. The P_SW_OFSTS register
* indicates the current FIFO offset that is being processed, so there is some
* indication of where the hardware is currently working.
*/
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_dma.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include "dmaengine.h"
#include "virt-dma.h"
struct bam_desc_hw {
u32 addr; /* Buffer physical address */
u16 size; /* Buffer size in bytes */
u16 flags;
};
#define DESC_FLAG_INT BIT(15)
#define DESC_FLAG_EOT BIT(14)
#define DESC_FLAG_EOB BIT(13)
#define DESC_FLAG_NWD BIT(12)
struct bam_async_desc {
struct virt_dma_desc vd;
u32 num_desc;
u32 xfer_len;
/* transaction flags, EOT|EOB|NWD */
u16 flags;
struct bam_desc_hw *curr_desc;
enum dma_transfer_direction dir;
size_t length;
struct bam_desc_hw desc[0];
};
#define BAM_CTRL 0x0000
#define BAM_REVISION 0x0004
#define BAM_SW_REVISION 0x0080
#define BAM_NUM_PIPES 0x003C
#define BAM_TIMER 0x0040
#define BAM_TIMER_CTRL 0x0044
#define BAM_DESC_CNT_TRSHLD 0x0008
#define BAM_IRQ_SRCS 0x000C
#define BAM_IRQ_SRCS_MSK 0x0010
#define BAM_IRQ_SRCS_UNMASKED 0x0030
#define BAM_IRQ_STTS 0x0014
#define BAM_IRQ_CLR 0x0018
#define BAM_IRQ_EN 0x001C
#define BAM_CNFG_BITS 0x007C
#define BAM_IRQ_SRCS_EE(ee) (0x0800 + ((ee) * 0x80))
#define BAM_IRQ_SRCS_MSK_EE(ee) (0x0804 + ((ee) * 0x80))
#define BAM_P_CTRL(pipe) (0x1000 + ((pipe) * 0x1000))
#define BAM_P_RST(pipe) (0x1004 + ((pipe) * 0x1000))
#define BAM_P_HALT(pipe) (0x1008 + ((pipe) * 0x1000))
#define BAM_P_IRQ_STTS(pipe) (0x1010 + ((pipe) * 0x1000))
#define BAM_P_IRQ_CLR(pipe) (0x1014 + ((pipe) * 0x1000))
#define BAM_P_IRQ_EN(pipe) (0x1018 + ((pipe) * 0x1000))
#define BAM_P_EVNT_DEST_ADDR(pipe) (0x182C + ((pipe) * 0x1000))
#define BAM_P_EVNT_REG(pipe) (0x1818 + ((pipe) * 0x1000))
#define BAM_P_SW_OFSTS(pipe) (0x1800 + ((pipe) * 0x1000))
#define BAM_P_DATA_FIFO_ADDR(pipe) (0x1824 + ((pipe) * 0x1000))
#define BAM_P_DESC_FIFO_ADDR(pipe) (0x181C + ((pipe) * 0x1000))
#define BAM_P_EVNT_TRSHLD(pipe) (0x1828 + ((pipe) * 0x1000))
#define BAM_P_FIFO_SIZES(pipe) (0x1820 + ((pipe) * 0x1000))
/* BAM CTRL */
#define BAM_SW_RST BIT(0)
#define BAM_EN BIT(1)
#define BAM_EN_ACCUM BIT(4)
#define BAM_TESTBUS_SEL_SHIFT 5
#define BAM_TESTBUS_SEL_MASK 0x3F
#define BAM_DESC_CACHE_SEL_SHIFT 13
#define BAM_DESC_CACHE_SEL_MASK 0x3
#define BAM_CACHED_DESC_STORE BIT(15)
#define IBC_DISABLE BIT(16)
/* BAM REVISION */
#define REVISION_SHIFT 0
#define REVISION_MASK 0xFF
#define NUM_EES_SHIFT 8
#define NUM_EES_MASK 0xF
#define CE_BUFFER_SIZE BIT(13)
#define AXI_ACTIVE BIT(14)
#define USE_VMIDMT BIT(15)
#define SECURED BIT(16)
#define BAM_HAS_NO_BYPASS BIT(17)
#define HIGH_FREQUENCY_BAM BIT(18)
#define INACTIV_TMRS_EXST BIT(19)
#define NUM_INACTIV_TMRS BIT(20)
#define DESC_CACHE_DEPTH_SHIFT 21
#define DESC_CACHE_DEPTH_1 (0 << DESC_CACHE_DEPTH_SHIFT)
#define DESC_CACHE_DEPTH_2 (1 << DESC_CACHE_DEPTH_SHIFT)
#define DESC_CACHE_DEPTH_3 (2 << DESC_CACHE_DEPTH_SHIFT)
#define DESC_CACHE_DEPTH_4 (3 << DESC_CACHE_DEPTH_SHIFT)
#define CMD_DESC_EN BIT(23)
#define INACTIV_TMR_BASE_SHIFT 24
#define INACTIV_TMR_BASE_MASK 0xFF
/* BAM NUM PIPES */
#define BAM_NUM_PIPES_SHIFT 0
#define BAM_NUM_PIPES_MASK 0xFF
#define PERIPH_NON_PIPE_GRP_SHIFT 16
#define PERIPH_NON_PIP_GRP_MASK 0xFF
#define BAM_NON_PIPE_GRP_SHIFT 24
#define BAM_NON_PIPE_GRP_MASK 0xFF
/* BAM CNFG BITS */
#define BAM_PIPE_CNFG BIT(2)
#define BAM_FULL_PIPE BIT(11)
#define BAM_NO_EXT_P_RST BIT(12)
#define BAM_IBC_DISABLE BIT(13)
#define BAM_SB_CLK_REQ BIT(14)
#define BAM_PSM_CSW_REQ BIT(15)
#define BAM_PSM_P_RES BIT(16)
#define BAM_AU_P_RES BIT(17)
#define BAM_SI_P_RES BIT(18)
#define BAM_WB_P_RES BIT(19)
#define BAM_WB_BLK_CSW BIT(20)
#define BAM_WB_CSW_ACK_IDL BIT(21)
#define BAM_WB_RETR_SVPNT BIT(22)
#define BAM_WB_DSC_AVL_P_RST BIT(23)
#define BAM_REG_P_EN BIT(24)
#define BAM_PSM_P_HD_DATA BIT(25)
#define BAM_AU_ACCUMED BIT(26)
#define BAM_CMD_ENABLE BIT(27)
#define BAM_CNFG_BITS_DEFAULT (BAM_PIPE_CNFG | \
BAM_NO_EXT_P_RST | \
BAM_IBC_DISABLE | \
BAM_SB_CLK_REQ | \
BAM_PSM_CSW_REQ | \
BAM_PSM_P_RES | \
BAM_AU_P_RES | \
BAM_SI_P_RES | \
BAM_WB_P_RES | \
BAM_WB_BLK_CSW | \
BAM_WB_CSW_ACK_IDL | \
BAM_WB_RETR_SVPNT | \
BAM_WB_DSC_AVL_P_RST | \
BAM_REG_P_EN | \
BAM_PSM_P_HD_DATA | \
BAM_AU_ACCUMED | \
BAM_CMD_ENABLE)
/* PIPE CTRL */
#define P_EN BIT(1)
#define P_DIRECTION BIT(3)
#define P_SYS_STRM BIT(4)
#define P_SYS_MODE BIT(5)
#define P_AUTO_EOB BIT(6)
#define P_AUTO_EOB_SEL_SHIFT 7
#define P_AUTO_EOB_SEL_512 (0 << P_AUTO_EOB_SEL_SHIFT)
#define P_AUTO_EOB_SEL_256 (1 << P_AUTO_EOB_SEL_SHIFT)
#define P_AUTO_EOB_SEL_128 (2 << P_AUTO_EOB_SEL_SHIFT)
#define P_AUTO_EOB_SEL_64 (3 << P_AUTO_EOB_SEL_SHIFT)
#define P_PREFETCH_LIMIT_SHIFT 9
#define P_PREFETCH_LIMIT_32 (0 << P_PREFETCH_LIMIT_SHIFT)
#define P_PREFETCH_LIMIT_16 (1 << P_PREFETCH_LIMIT_SHIFT)
#define P_PREFETCH_LIMIT_4 (2 << P_PREFETCH_LIMIT_SHIFT)
#define P_WRITE_NWD BIT(11)
#define P_LOCK_GROUP_SHIFT 16
#define P_LOCK_GROUP_MASK 0x1F
/* BAM_DESC_CNT_TRSHLD */
#define CNT_TRSHLD 0xffff
#define DEFAULT_CNT_THRSHLD 0x4
/* BAM_IRQ_SRCS */
#define BAM_IRQ BIT(31)
#define P_IRQ 0x7fffffff
/* BAM_IRQ_SRCS_MSK */
#define BAM_IRQ_MSK BAM_IRQ
#define P_IRQ_MSK P_IRQ
/* BAM_IRQ_STTS */
#define BAM_TIMER_IRQ BIT(4)
#define BAM_EMPTY_IRQ BIT(3)
#define BAM_ERROR_IRQ BIT(2)
#define BAM_HRESP_ERR_IRQ BIT(1)
/* BAM_IRQ_CLR */
#define BAM_TIMER_CLR BIT(4)
#define BAM_EMPTY_CLR BIT(3)
#define BAM_ERROR_CLR BIT(2)
#define BAM_HRESP_ERR_CLR BIT(1)
/* BAM_IRQ_EN */
#define BAM_TIMER_EN BIT(4)
#define BAM_EMPTY_EN BIT(3)
#define BAM_ERROR_EN BIT(2)
#define BAM_HRESP_ERR_EN BIT(1)
/* BAM_P_IRQ_EN */
#define P_PRCSD_DESC_EN BIT(0)
#define P_TIMER_EN BIT(1)
#define P_WAKE_EN BIT(2)
#define P_OUT_OF_DESC_EN BIT(3)
#define P_ERR_EN BIT(4)
#define P_TRNSFR_END_EN BIT(5)
#define P_DEFAULT_IRQS_EN (P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
/* BAM_P_SW_OFSTS */
#define P_SW_OFSTS_MASK 0xffff
#define BAM_DESC_FIFO_SIZE SZ_32K
#define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
#define BAM_MAX_DATA_SIZE (SZ_32K - 8)
struct bam_chan {
struct virt_dma_chan vc;
struct bam_device *bdev;
/* configuration from device tree */
u32 id;
struct bam_async_desc *curr_txd; /* current running dma */
/* runtime configuration */
struct dma_slave_config slave;
/* fifo storage */
struct bam_desc_hw *fifo_virt;
dma_addr_t fifo_phys;
/* fifo markers */
unsigned short head; /* start of active descriptor entries */
unsigned short tail; /* end of active descriptor entries */
unsigned int initialized; /* is the channel hw initialized? */
unsigned int paused; /* is the channel paused? */
unsigned int reconfigure; /* new slave config? */
struct list_head node;
};
static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
{
return container_of(common, struct bam_chan, vc.chan);
}
struct bam_device {
void __iomem *regs;
struct device *dev;
struct dma_device common;
struct device_dma_parameters dma_parms;
struct bam_chan *channels;
u32 num_channels;
/* execution environment ID, from DT */
u32 ee;
struct clk *bamclk;
int irq;
/* dma start transaction tasklet */
struct tasklet_struct task;
};
/**
* bam_reset_channel - Reset individual BAM DMA channel
* @bchan: bam channel
*
* This function resets a specific BAM channel
*/
static void bam_reset_channel(struct bam_chan *bchan)
{
struct bam_device *bdev = bchan->bdev;
lockdep_assert_held(&bchan->vc.lock);
/* reset channel */
writel_relaxed(1, bdev->regs + BAM_P_RST(bchan->id));
writel_relaxed(0, bdev->regs + BAM_P_RST(bchan->id));
/* don't allow cpu to reorder BAM register accesses done after this */
wmb();
/* make sure hw is initialized when channel is used the first time */
bchan->initialized = 0;
}
/**
* bam_chan_init_hw - Initialize channel hardware
* @bchan: bam channel
*
* This function resets and initializes the BAM channel
*/
static void bam_chan_init_hw(struct bam_chan *bchan,
enum dma_transfer_direction dir)
{
struct bam_device *bdev = bchan->bdev;
u32 val;
/* Reset the channel to clear internal state of the FIFO */
bam_reset_channel(bchan);
/*
* write out 8 byte aligned address. We have enough space for this
* because we allocated 1 more descriptor (8 bytes) than we can use
*/
writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
bdev->regs + BAM_P_DESC_FIFO_ADDR(bchan->id));
writel_relaxed(BAM_DESC_FIFO_SIZE, bdev->regs +
BAM_P_FIFO_SIZES(bchan->id));
/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
writel_relaxed(P_DEFAULT_IRQS_EN, bdev->regs + BAM_P_IRQ_EN(bchan->id));
/* unmask the specific pipe and EE combo */
val = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
val |= BIT(bchan->id);
writel_relaxed(val, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
/* don't allow cpu to reorder the channel enable done below */
wmb();
/* set fixed direction and mode, then enable channel */
val = P_EN | P_SYS_MODE;
if (dir == DMA_DEV_TO_MEM)
val |= P_DIRECTION;
writel_relaxed(val, bdev->regs + BAM_P_CTRL(bchan->id));
bchan->initialized = 1;
/* init FIFO pointers */
bchan->head = 0;
bchan->tail = 0;
}
/**
* bam_alloc_chan - Allocate channel resources for DMA channel.
* @chan: specified channel
*
* This function allocates the FIFO descriptor memory
*/
static int bam_alloc_chan(struct dma_chan *chan)
{
struct bam_chan *bchan = to_bam_chan(chan);
struct bam_device *bdev = bchan->bdev;
if (bchan->fifo_virt)
return 0;
/* allocate FIFO descriptor space, but only if necessary */
bchan->fifo_virt = dma_alloc_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE,
&bchan->fifo_phys, GFP_KERNEL);
if (!bchan->fifo_virt) {
dev_err(bdev->dev, "Failed to allocate desc fifo\n");
return -ENOMEM;
}
return 0;
}
/**
* bam_free_chan - Frees dma resources associated with specific channel
* @chan: specified channel
*
* Free the allocated fifo descriptor memory and channel resources
*
*/
static void bam_free_chan(struct dma_chan *chan)
{
struct bam_chan *bchan = to_bam_chan(chan);
struct bam_device *bdev = bchan->bdev;
u32 val;
unsigned long flags;
vchan_free_chan_resources(to_virt_chan(chan));
if (bchan->curr_txd) {
dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
return;
}
spin_lock_irqsave(&bchan->vc.lock, flags);
bam_reset_channel(bchan);
spin_unlock_irqrestore(&bchan->vc.lock, flags);
dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
bchan->fifo_phys);
bchan->fifo_virt = NULL;
/* mask irq for pipe/channel */
val = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
val &= ~BIT(bchan->id);
writel_relaxed(val, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
/* disable irq */
writel_relaxed(0, bdev->regs + BAM_P_IRQ_EN(bchan->id));
}
/**
* bam_slave_config - set slave configuration for channel
* @chan: dma channel
* @cfg: slave configuration
*
* Sets slave configuration for channel
*
*/
static void bam_slave_config(struct bam_chan *bchan,
struct dma_slave_config *cfg)
{
memcpy(&bchan->slave, cfg, sizeof(*cfg));
bchan->reconfigure = 1;
}
/**
* bam_prep_slave_sg - Prep slave sg transaction
*
* @chan: dma channel
* @sgl: scatter gather list
* @sg_len: length of sg
* @direction: DMA transfer direction
* @flags: DMA flags
* @context: transfer context (unused)
*/
static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
struct scatterlist *sgl, unsigned int sg_len,
enum dma_transfer_direction direction, unsigned long flags,
void *context)
{
struct bam_chan *bchan = to_bam_chan(chan);
struct bam_device *bdev = bchan->bdev;
struct bam_async_desc *async_desc;
struct scatterlist *sg;
u32 i;
struct bam_desc_hw *desc;
unsigned int num_alloc = 0;
if (!is_slave_direction(direction)) {
dev_err(bdev->dev, "invalid dma direction\n");
return NULL;
}
/* calculate number of required entries */
for_each_sg(sgl, sg, sg_len, i)
num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_MAX_DATA_SIZE);
/* allocate enough room to accomodate the number of entries */
async_desc = kzalloc(sizeof(*async_desc) +
(num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
if (!async_desc)
goto err_out;
if (flags & DMA_PREP_FENCE)
async_desc->flags |= DESC_FLAG_NWD;
if (flags & DMA_PREP_INTERRUPT)
async_desc->flags |= DESC_FLAG_EOT;
else
async_desc->flags |= DESC_FLAG_INT;
async_desc->num_desc = num_alloc;
async_desc->curr_desc = async_desc->desc;
async_desc->dir = direction;
/* fill in temporary descriptors */
desc = async_desc->desc;
for_each_sg(sgl, sg, sg_len, i) {
unsigned int remainder = sg_dma_len(sg);
unsigned int curr_offset = 0;
do {
desc->addr = sg_dma_address(sg) + curr_offset;
if (remainder > BAM_MAX_DATA_SIZE) {
desc->size = BAM_MAX_DATA_SIZE;
remainder -= BAM_MAX_DATA_SIZE;
curr_offset += BAM_MAX_DATA_SIZE;
} else {
desc->size = remainder;
remainder = 0;
}
async_desc->length += desc->size;
desc++;
} while (remainder > 0);
}
return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
err_out:
kfree(async_desc);
return NULL;
}
/**
* bam_dma_terminate_all - terminate all transactions on a channel
* @bchan: bam dma channel
*
* Dequeues and frees all transactions
* No callbacks are done
*
*/
static void bam_dma_terminate_all(struct bam_chan *bchan)
{
unsigned long flag;
LIST_HEAD(head);
/* remove all transactions, including active transaction */
spin_lock_irqsave(&bchan->vc.lock, flag);
if (bchan->curr_txd) {
list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
bchan->curr_txd = NULL;
}
vchan_get_all_descriptors(&bchan->vc, &head);
spin_unlock_irqrestore(&bchan->vc.lock, flag);
vchan_dma_desc_free_list(&bchan->vc, &head);
}
/**
* bam_control - DMA device control
* @chan: dma channel
* @cmd: control cmd
* @arg: cmd argument
*
* Perform DMA control command
*
*/
static int bam_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct bam_chan *bchan = to_bam_chan(chan);
struct bam_device *bdev = bchan->bdev;
int ret = 0;
unsigned long flag;
switch (cmd) {
case DMA_PAUSE:
spin_lock_irqsave(&bchan->vc.lock, flag);
writel_relaxed(1, bdev->regs + BAM_P_HALT(bchan->id));
bchan->paused = 1;
spin_unlock_irqrestore(&bchan->vc.lock, flag);
break;
case DMA_RESUME:
spin_lock_irqsave(&bchan->vc.lock, flag);
writel_relaxed(0, bdev->regs + BAM_P_HALT(bchan->id));
bchan->paused = 0;
spin_unlock_irqrestore(&bchan->vc.lock, flag);
break;
case DMA_TERMINATE_ALL:
bam_dma_terminate_all(bchan);
break;
case DMA_SLAVE_CONFIG:
spin_lock_irqsave(&bchan->vc.lock, flag);
bam_slave_config(bchan, (struct dma_slave_config *)arg);
spin_unlock_irqrestore(&bchan->vc.lock, flag);
break;
default:
ret = -ENXIO;
break;
}
return ret;
}
/**
* process_channel_irqs - processes the channel interrupts
* @bdev: bam controller
*
* This function processes the channel interrupts
*
*/
static u32 process_channel_irqs(struct bam_device *bdev)
{
u32 i, srcs, pipe_stts;
unsigned long flags;
struct bam_async_desc *async_desc;
srcs = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_EE(bdev->ee));
/* return early if no pipe/channel interrupts are present */
if (!(srcs & P_IRQ))
return srcs;
for (i = 0; i < bdev->num_channels; i++) {
struct bam_chan *bchan = &bdev->channels[i];
if (!(srcs & BIT(i)))
continue;
/* clear pipe irq */
pipe_stts = readl_relaxed(bdev->regs +
BAM_P_IRQ_STTS(i));
writel_relaxed(pipe_stts, bdev->regs +
BAM_P_IRQ_CLR(i));
spin_lock_irqsave(&bchan->vc.lock, flags);
async_desc = bchan->curr_txd;
if (async_desc) {
async_desc->num_desc -= async_desc->xfer_len;
async_desc->curr_desc += async_desc->xfer_len;
bchan->curr_txd = NULL;
/* manage FIFO */
bchan->head += async_desc->xfer_len;
bchan->head %= MAX_DESCRIPTORS;
/*
* if complete, process cookie. Otherwise
* push back to front of desc_issued so that
* it gets restarted by the tasklet
*/
if (!async_desc->num_desc)
vchan_cookie_complete(&async_desc->vd);
else
list_add(&async_desc->vd.node,
&bchan->vc.desc_issued);
}
spin_unlock_irqrestore(&bchan->vc.lock, flags);
}
return srcs;
}
/**
* bam_dma_irq - irq handler for bam controller
* @irq: IRQ of interrupt
* @data: callback data
*
* IRQ handler for the bam controller
*/
static irqreturn_t bam_dma_irq(int irq, void *data)
{
struct bam_device *bdev = data;
u32 clr_mask = 0, srcs = 0;
srcs |= process_channel_irqs(bdev);
/* kick off tasklet to start next dma transfer */
if (srcs & P_IRQ)
tasklet_schedule(&bdev->task);
if (srcs & BAM_IRQ)
clr_mask = readl_relaxed(bdev->regs + BAM_IRQ_STTS);
/* don't allow reorder of the various accesses to the BAM registers */
mb();
writel_relaxed(clr_mask, bdev->regs + BAM_IRQ_CLR);
return IRQ_HANDLED;
}
/**
* bam_tx_status - returns status of transaction
* @chan: dma channel
* @cookie: transaction cookie
* @txstate: DMA transaction state
*
* Return status of dma transaction
*/
static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct bam_chan *bchan = to_bam_chan(chan);
struct virt_dma_desc *vd;
int ret;
size_t residue = 0;
unsigned int i;
unsigned long flags;
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
if (!txstate)
return bchan->paused ? DMA_PAUSED : ret;
spin_lock_irqsave(&bchan->vc.lock, flags);
vd = vchan_find_desc(&bchan->vc, cookie);
if (vd)
residue = container_of(vd, struct bam_async_desc, vd)->length;
else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
for (i = 0; i < bchan->curr_txd->num_desc; i++)
residue += bchan->curr_txd->curr_desc[i].size;
spin_unlock_irqrestore(&bchan->vc.lock, flags);
dma_set_residue(txstate, residue);
if (ret == DMA_IN_PROGRESS && bchan->paused)
ret = DMA_PAUSED;
return ret;
}
/**
* bam_apply_new_config
* @bchan: bam dma channel
* @dir: DMA direction
*/
static void bam_apply_new_config(struct bam_chan *bchan,
enum dma_transfer_direction dir)
{
struct bam_device *bdev = bchan->bdev;
u32 maxburst;
if (dir == DMA_DEV_TO_MEM)
maxburst = bchan->slave.src_maxburst;
else
maxburst = bchan->slave.dst_maxburst;
writel_relaxed(maxburst, bdev->regs + BAM_DESC_CNT_TRSHLD);
bchan->reconfigure = 0;
}
/**
* bam_start_dma - start next transaction
* @bchan - bam dma channel
*/
static void bam_start_dma(struct bam_chan *bchan)
{
struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
struct bam_device *bdev = bchan->bdev;
struct bam_async_desc *async_desc;
struct bam_desc_hw *desc;
struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
sizeof(struct bam_desc_hw));
lockdep_assert_held(&bchan->vc.lock);
if (!vd)
return;
list_del(&vd->node);
async_desc = container_of(vd, struct bam_async_desc, vd);
bchan->curr_txd = async_desc;
/* on first use, initialize the channel hardware */
if (!bchan->initialized)
bam_chan_init_hw(bchan, async_desc->dir);
/* apply new slave config changes, if necessary */
if (bchan->reconfigure)
bam_apply_new_config(bchan, async_desc->dir);
desc = bchan->curr_txd->curr_desc;
if (async_desc->num_desc > MAX_DESCRIPTORS)
async_desc->xfer_len = MAX_DESCRIPTORS;
else
async_desc->xfer_len = async_desc->num_desc;
/* set any special flags on the last descriptor */
if (async_desc->num_desc == async_desc->xfer_len)
desc[async_desc->xfer_len - 1].flags = async_desc->flags;
else
desc[async_desc->xfer_len - 1].flags |= DESC_FLAG_INT;
if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
u32 partial = MAX_DESCRIPTORS - bchan->tail;
memcpy(&fifo[bchan->tail], desc,
partial * sizeof(struct bam_desc_hw));
memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
sizeof(struct bam_desc_hw));
} else {
memcpy(&fifo[bchan->tail], desc,
async_desc->xfer_len * sizeof(struct bam_desc_hw));
}
bchan->tail += async_desc->xfer_len;
bchan->tail %= MAX_DESCRIPTORS;
/* ensure descriptor writes and dma start not reordered */
wmb();
writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
bdev->regs + BAM_P_EVNT_REG(bchan->id));
}
/**
* dma_tasklet - DMA IRQ tasklet
* @data: tasklet argument (bam controller structure)
*
* Sets up next DMA operation and then processes all completed transactions
*/
static void dma_tasklet(unsigned long data)
{
struct bam_device *bdev = (struct bam_device *)data;
struct bam_chan *bchan;
unsigned long flags;
unsigned int i;
/* go through the channels and kick off transactions */
for (i = 0; i < bdev->num_channels; i++) {
bchan = &bdev->channels[i];
spin_lock_irqsave(&bchan->vc.lock, flags);
if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
bam_start_dma(bchan);
spin_unlock_irqrestore(&bchan->vc.lock, flags);
}
}
/**
* bam_issue_pending - starts pending transactions
* @chan: dma channel
*
* Calls tasklet directly which in turn starts any pending transactions
*/
static void bam_issue_pending(struct dma_chan *chan)
{
struct bam_chan *bchan = to_bam_chan(chan);
unsigned long flags;
spin_lock_irqsave(&bchan->vc.lock, flags);
/* if work pending and idle, start a transaction */
if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
bam_start_dma(bchan);
spin_unlock_irqrestore(&bchan->vc.lock, flags);
}
/**
* bam_dma_free_desc - free descriptor memory
* @vd: virtual descriptor
*
*/
static void bam_dma_free_desc(struct virt_dma_desc *vd)
{
struct bam_async_desc *async_desc = container_of(vd,
struct bam_async_desc, vd);
kfree(async_desc);
}
static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *of)
{
struct bam_device *bdev = container_of(of->of_dma_data,
struct bam_device, common);
unsigned int request;
if (dma_spec->args_count != 1)
return NULL;
request = dma_spec->args[0];
if (request >= bdev->num_channels)
return NULL;
return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
}
/**
* bam_init
* @bdev: bam device
*
* Initialization helper for global bam registers
*/
static int bam_init(struct bam_device *bdev)
{
u32 val;
/* read revision and configuration information */
val = readl_relaxed(bdev->regs + BAM_REVISION) >> NUM_EES_SHIFT;
val &= NUM_EES_MASK;
/* check that configured EE is within range */
if (bdev->ee >= val)
return -EINVAL;
val = readl_relaxed(bdev->regs + BAM_NUM_PIPES);
bdev->num_channels = val & BAM_NUM_PIPES_MASK;
/* s/w reset bam */
/* after reset all pipes are disabled and idle */
val = readl_relaxed(bdev->regs + BAM_CTRL);
val |= BAM_SW_RST;
writel_relaxed(val, bdev->regs + BAM_CTRL);
val &= ~BAM_SW_RST;
writel_relaxed(val, bdev->regs + BAM_CTRL);
/* make sure previous stores are visible before enabling BAM */
wmb();
/* enable bam */
val |= BAM_EN;
writel_relaxed(val, bdev->regs + BAM_CTRL);
/* set descriptor threshhold, start with 4 bytes */
writel_relaxed(DEFAULT_CNT_THRSHLD, bdev->regs + BAM_DESC_CNT_TRSHLD);
/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
writel_relaxed(BAM_CNFG_BITS_DEFAULT, bdev->regs + BAM_CNFG_BITS);
/* enable irqs for errors */
writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
bdev->regs + BAM_IRQ_EN);
/* unmask global bam interrupt */
writel_relaxed(BAM_IRQ_MSK, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
return 0;
}
static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
u32 index)
{
bchan->id = index;
bchan->bdev = bdev;
vchan_init(&bchan->vc, &bdev->common);
bchan->vc.desc_free = bam_dma_free_desc;
}
static int bam_dma_probe(struct platform_device *pdev)
{
struct bam_device *bdev;
struct resource *iores;
int ret, i;
bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
if (!bdev)
return -ENOMEM;
bdev->dev = &pdev->dev;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
if (IS_ERR(bdev->regs))
return PTR_ERR(bdev->regs);
bdev->irq = platform_get_irq(pdev, 0);
if (bdev->irq < 0)
return bdev->irq;
ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
if (ret) {
dev_err(bdev->dev, "Execution environment unspecified\n");
return ret;
}
bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
if (IS_ERR(bdev->bamclk))
return PTR_ERR(bdev->bamclk);
ret = clk_prepare_enable(bdev->bamclk);
if (ret) {
dev_err(bdev->dev, "failed to prepare/enable clock\n");
return ret;
}
ret = bam_init(bdev);
if (ret)
goto err_disable_clk;
tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
sizeof(*bdev->channels), GFP_KERNEL);
if (!bdev->channels) {
ret = -ENOMEM;
goto err_disable_clk;
}
/* allocate and initialize channels */
INIT_LIST_HEAD(&bdev->common.channels);
for (i = 0; i < bdev->num_channels; i++)
bam_channel_init(bdev, &bdev->channels[i], i);
ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
IRQF_TRIGGER_HIGH, "bam_dma", bdev);
if (ret)
goto err_disable_clk;
/* set max dma segment size */
bdev->common.dev = bdev->dev;
bdev->common.dev->dma_parms = &bdev->dma_parms;
ret = dma_set_max_seg_size(bdev->common.dev, BAM_MAX_DATA_SIZE);
if (ret) {
dev_err(bdev->dev, "cannot set maximum segment size\n");
goto err_disable_clk;
}
platform_set_drvdata(pdev, bdev);
/* set capabilities */
dma_cap_zero(bdev->common.cap_mask);
dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
/* initialize dmaengine apis */
bdev->common.device_alloc_chan_resources = bam_alloc_chan;
bdev->common.device_free_chan_resources = bam_free_chan;
bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
bdev->common.device_control = bam_control;
bdev->common.device_issue_pending = bam_issue_pending;
bdev->common.device_tx_status = bam_tx_status;
bdev->common.dev = bdev->dev;
ret = dma_async_device_register(&bdev->common);
if (ret) {
dev_err(bdev->dev, "failed to register dma async device\n");
goto err_disable_clk;
}
ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
&bdev->common);
if (ret)
goto err_unregister_dma;
return 0;
err_unregister_dma:
dma_async_device_unregister(&bdev->common);
err_disable_clk:
clk_disable_unprepare(bdev->bamclk);
return ret;
}
static int bam_dma_remove(struct platform_device *pdev)
{
struct bam_device *bdev = platform_get_drvdata(pdev);
u32 i;
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&bdev->common);
/* mask all interrupts for this execution environment */
writel_relaxed(0, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
devm_free_irq(bdev->dev, bdev->irq, bdev);
for (i = 0; i < bdev->num_channels; i++) {
bam_dma_terminate_all(&bdev->channels[i]);
tasklet_kill(&bdev->channels[i].vc.task);
dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE,
bdev->channels[i].fifo_virt,
bdev->channels[i].fifo_phys);
}
tasklet_kill(&bdev->task);
clk_disable_unprepare(bdev->bamclk);
return 0;
}
static const struct of_device_id bam_of_match[] = {
{ .compatible = "qcom,bam-v1.4.0", },
{}
};
MODULE_DEVICE_TABLE(of, bam_of_match);
static struct platform_driver bam_dma_driver = {
.probe = bam_dma_probe,
.remove = bam_dma_remove,
.driver = {
.name = "bam-dma-engine",
.owner = THIS_MODULE,
.of_match_table = bam_of_match,
},
};
module_platform_driver(bam_dma_driver);
MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
MODULE_LICENSE("GPL v2");