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Merge branch 'topic/brcm' into for-linus

This commit is contained in:
Vinod Koul 2019-03-12 12:03:42 +05:30
parent a3711d49be 37c22cabf2
commit 5c196f5efa
1 changed files with 31 additions and 61 deletions
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92
drivers/dma/bcm2835-dma.c
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@ -2,9 +2,6 @@
/*
* BCM2835 DMA engine support
*
* This driver only supports cyclic DMA transfers
* as needed for the I2S module.
*
* Author: Florian Meier <florian.meier@koalo.de>
* Copyright 2013
*
@ -42,7 +39,6 @@
struct bcm2835_dmadev {
struct dma_device ddev;
spinlock_t lock;
void __iomem *base;
struct device_dma_parameters dma_parms;
};
@ -64,7 +60,6 @@ struct bcm2835_cb_entry {
struct bcm2835_chan {
struct virt_dma_chan vc;
struct list_head node;
struct dma_slave_config cfg;
unsigned int dreq;
@ -405,39 +400,32 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
}
}
static int bcm2835_dma_abort(void __iomem *chan_base)
static void bcm2835_dma_abort(struct bcm2835_chan *c)
{
unsigned long cs;
void __iomem *chan_base = c->chan_base;
long int timeout = 10000;
cs = readl(chan_base + BCM2835_DMA_CS);
if (!(cs & BCM2835_DMA_ACTIVE))
return 0;
/*
* A zero control block address means the channel is idle.
* (The ACTIVE flag in the CS register is not a reliable indicator.)
*/
if (!readl(chan_base + BCM2835_DMA_ADDR))
return;
/* Write 0 to the active bit - Pause the DMA */
writel(0, chan_base + BCM2835_DMA_CS);
/* Wait for any current AXI transfer to complete */
while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) {
while ((readl(chan_base + BCM2835_DMA_CS) &
BCM2835_DMA_WAITING_FOR_WRITES) && --timeout)
cpu_relax();
cs = readl(chan_base + BCM2835_DMA_CS);
}
/* We'll un-pause when we set of our next DMA */
/* Peripheral might be stuck and fail to signal AXI write responses */
if (!timeout)
return -ETIMEDOUT;
dev_err(c->vc.chan.device->dev,
"failed to complete outstanding writes\n");
if (!(cs & BCM2835_DMA_ACTIVE))
return 0;
/* Terminate the control block chain */
writel(0, chan_base + BCM2835_DMA_NEXTCB);
/* Abort the whole DMA */
writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE,
chan_base + BCM2835_DMA_CS);
return 0;
writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
}
static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
@ -475,8 +463,15 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
spin_lock_irqsave(&c->vc.lock, flags);
/* Acknowledge interrupt */
writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS);
/*
* Clear the INT flag to receive further interrupts. Keep the channel
* active in case the descriptor is cyclic or in case the client has
* already terminated the descriptor and issued a new one. (May happen
* if this IRQ handler is threaded.) If the channel is finished, it
* will remain idle despite the ACTIVE flag being set.
*/
writel(BCM2835_DMA_INT | BCM2835_DMA_ACTIVE,
c->chan_base + BCM2835_DMA_CS);
d = c->desc;
@ -484,11 +479,7 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
if (d->cyclic) {
/* call the cyclic callback */
vchan_cyclic_callback(&d->vd);
/* Keep the DMA engine running */
writel(BCM2835_DMA_ACTIVE,
c->chan_base + BCM2835_DMA_CS);
} else {
} else if (!readl(c->chan_base + BCM2835_DMA_ADDR)) {
vchan_cookie_complete(&c->desc->vd);
bcm2835_dma_start_desc(c);
}
@ -506,8 +497,12 @@ static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan)
dev_dbg(dev, "Allocating DMA channel %d\n", c->ch);
/*
* Control blocks are 256 bit in length and must start at a 256 bit
* (32 byte) aligned address (BCM2835 ARM Peripherals, sec. 4.2.1.1).
*/
c->cb_pool = dma_pool_create(dev_name(dev), dev,
sizeof(struct bcm2835_dma_cb), 0, 0);
sizeof(struct bcm2835_dma_cb), 32, 0);
if (!c->cb_pool) {
dev_err(dev, "unable to allocate descriptor pool\n");
return -ENOMEM;
@ -776,39 +771,16 @@ static int bcm2835_dma_slave_config(struct dma_chan *chan,
static int bcm2835_dma_terminate_all(struct dma_chan *chan)
{
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
unsigned long flags;
int timeout = 10000;
LIST_HEAD(head);
spin_lock_irqsave(&c->vc.lock, flags);
/* Prevent this channel being scheduled */
spin_lock(&d->lock);
list_del_init(&c->node);
spin_unlock(&d->lock);
/*
* Stop DMA activity: we assume the callback will not be called
* after bcm_dma_abort() returns (even if it does, it will see
* c->desc is NULL and exit.)
*/
/* stop DMA activity */
if (c->desc) {
vchan_terminate_vdesc(&c->desc->vd);
c->desc = NULL;
bcm2835_dma_abort(c->chan_base);
/* Wait for stopping */
while (--timeout) {
if (!(readl(c->chan_base + BCM2835_DMA_CS) &
BCM2835_DMA_ACTIVE))
break;
cpu_relax();
}
if (!timeout)
dev_err(d->ddev.dev, "DMA transfer could not be terminated\n");
bcm2835_dma_abort(c);
}
vchan_get_all_descriptors(&c->vc, &head);
@ -836,7 +808,6 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
c->vc.desc_free = bcm2835_dma_desc_free;
vchan_init(&c->vc, &d->ddev);
INIT_LIST_HEAD(&c->node);
c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
c->ch = chan_id;
@ -939,7 +910,6 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);
spin_lock_init(&od->lock);
platform_set_drvdata(pdev, od);