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path: root/drivers/dma/pl330.c
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Diffstat (limited to 'drivers/dma/pl330.c')
-rw-r--r--drivers/dma/pl330.c129
1 files changed, 115 insertions, 14 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 4839bfa74a10..bdf40b530032 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -27,6 +27,7 @@
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/err.h>
+#include <linux/pm_runtime.h>
#include "dmaengine.h"
#define PL330_MAX_CHAN 8
@@ -265,13 +266,16 @@ static unsigned cmd_line;
#define NR_DEFAULT_DESC 16
+/* Delay for runtime PM autosuspend, ms */
+#define PL330_AUTOSUSPEND_DELAY 20
+
/* Populated by the PL330 core driver for DMA API driver's info */
struct pl330_config {
u32 periph_id;
#define DMAC_MODE_NS (1 << 0)
unsigned int mode;
unsigned int data_bus_width:10; /* In number of bits */
- unsigned int data_buf_dep:10;
+ unsigned int data_buf_dep:11;
unsigned int num_chan:4;
unsigned int num_peri:6;
u32 peri_ns;
@@ -1958,6 +1962,7 @@ static void pl330_tasklet(unsigned long data)
struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;
struct dma_pl330_desc *desc, *_dt;
unsigned long flags;
+ bool power_down = false;
spin_lock_irqsave(&pch->lock, flags);
@@ -1972,10 +1977,17 @@ static void pl330_tasklet(unsigned long data)
/* Try to submit a req imm. next to the last completed cookie */
fill_queue(pch);
- /* Make sure the PL330 Channel thread is active */
- spin_lock(&pch->thread->dmac->lock);
- _start(pch->thread);
- spin_unlock(&pch->thread->dmac->lock);
+ if (list_empty(&pch->work_list)) {
+ spin_lock(&pch->thread->dmac->lock);
+ _stop(pch->thread);
+ spin_unlock(&pch->thread->dmac->lock);
+ power_down = true;
+ } else {
+ /* Make sure the PL330 Channel thread is active */
+ spin_lock(&pch->thread->dmac->lock);
+ _start(pch->thread);
+ spin_unlock(&pch->thread->dmac->lock);
+ }
while (!list_empty(&pch->completed_list)) {
dma_async_tx_callback callback;
@@ -1990,6 +2002,12 @@ static void pl330_tasklet(unsigned long data)
if (pch->cyclic) {
desc->status = PREP;
list_move_tail(&desc->node, &pch->work_list);
+ if (power_down) {
+ spin_lock(&pch->thread->dmac->lock);
+ _start(pch->thread);
+ spin_unlock(&pch->thread->dmac->lock);
+ power_down = false;
+ }
} else {
desc->status = FREE;
list_move_tail(&desc->node, &pch->dmac->desc_pool);
@@ -2004,6 +2022,12 @@ static void pl330_tasklet(unsigned long data)
}
}
spin_unlock_irqrestore(&pch->lock, flags);
+
+ /* If work list empty, power down */
+ if (power_down) {
+ pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
+ pm_runtime_put_autosuspend(pch->dmac->ddma.dev);
+ }
}
bool pl330_filter(struct dma_chan *chan, void *param)
@@ -2073,6 +2097,7 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned
switch (cmd) {
case DMA_TERMINATE_ALL:
+ pm_runtime_get_sync(pl330->ddma.dev);
spin_lock_irqsave(&pch->lock, flags);
spin_lock(&pl330->lock);
@@ -2099,10 +2124,15 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned
dma_cookie_complete(&desc->txd);
}
+ if (!list_empty(&pch->work_list))
+ pm_runtime_put(pl330->ddma.dev);
+
list_splice_tail_init(&pch->submitted_list, &pl330->desc_pool);
list_splice_tail_init(&pch->work_list, &pl330->desc_pool);
list_splice_tail_init(&pch->completed_list, &pl330->desc_pool);
spin_unlock_irqrestore(&pch->lock, flags);
+ pm_runtime_mark_last_busy(pl330->ddma.dev);
+ pm_runtime_put_autosuspend(pl330->ddma.dev);
break;
case DMA_SLAVE_CONFIG:
slave_config = (struct dma_slave_config *)arg;
@@ -2138,6 +2168,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
tasklet_kill(&pch->task);
+ pm_runtime_get_sync(pch->dmac->ddma.dev);
spin_lock_irqsave(&pch->lock, flags);
pl330_release_channel(pch->thread);
@@ -2147,6 +2178,8 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool);
spin_unlock_irqrestore(&pch->lock, flags);
+ pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
+ pm_runtime_put_autosuspend(pch->dmac->ddma.dev);
}
static enum dma_status
@@ -2162,6 +2195,15 @@ static void pl330_issue_pending(struct dma_chan *chan)
unsigned long flags;
spin_lock_irqsave(&pch->lock, flags);
+ if (list_empty(&pch->work_list)) {
+ /*
+ * Warn on nothing pending. Empty submitted_list may
+ * break our pm_runtime usage counter as it is
+ * updated on work_list emptiness status.
+ */
+ WARN_ON(list_empty(&pch->submitted_list));
+ pm_runtime_get_sync(pch->dmac->ddma.dev);
+ }
list_splice_tail_init(&pch->submitted_list, &pch->work_list);
spin_unlock_irqrestore(&pch->lock, flags);
@@ -2336,7 +2378,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
int burst_len;
burst_len = pl330->pcfg.data_bus_width / 8;
- burst_len *= pl330->pcfg.data_buf_dep;
+ burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan;
burst_len >>= desc->rqcfg.brst_size;
/* src/dst_burst_len can't be more than 16 */
@@ -2459,16 +2501,25 @@ pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
/* Select max possible burst size */
burst = pl330->pcfg.data_bus_width / 8;
- while (burst > 1) {
- if (!(len % burst))
- break;
+ /*
+ * Make sure we use a burst size that aligns with all the memcpy
+ * parameters because our DMA programming algorithm doesn't cope with
+ * transfers which straddle an entry in the DMA device's MFIFO.
+ */
+ while ((src | dst | len) & (burst - 1))
burst /= 2;
- }
desc->rqcfg.brst_size = 0;
while (burst != (1 << desc->rqcfg.brst_size))
desc->rqcfg.brst_size++;
+ /*
+ * If burst size is smaller than bus width then make sure we only
+ * transfer one at a time to avoid a burst stradling an MFIFO entry.
+ */
+ if (desc->rqcfg.brst_size * 8 < pl330->pcfg.data_bus_width)
+ desc->rqcfg.brst_len = 1;
+
desc->rqcfg.brst_len = get_burst_len(desc, len);
desc->txd.flags = flags;
@@ -2585,6 +2636,46 @@ static int pl330_dma_device_slave_caps(struct dma_chan *dchan,
return 0;
}
+/*
+ * Runtime PM callbacks are provided by amba/bus.c driver.
+ *
+ * It is assumed here that IRQ safe runtime PM is chosen in probe and amba
+ * bus driver will only disable/enable the clock in runtime PM callbacks.
+ */
+static int __maybe_unused pl330_suspend(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+
+ pm_runtime_disable(dev);
+
+ if (!pm_runtime_status_suspended(dev)) {
+ /* amba did not disable the clock */
+ amba_pclk_disable(pcdev);
+ }
+ amba_pclk_unprepare(pcdev);
+
+ return 0;
+}
+
+static int __maybe_unused pl330_resume(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int ret;
+
+ ret = amba_pclk_prepare(pcdev);
+ if (ret)
+ return ret;
+
+ if (!pm_runtime_status_suspended(dev))
+ ret = amba_pclk_enable(pcdev);
+
+ pm_runtime_enable(dev);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(pl330_pm, pl330_suspend, pl330_resume);
+
static int
pl330_probe(struct amba_device *adev, const struct amba_id *id)
{
@@ -2610,6 +2701,9 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
return -ENOMEM;
}
+ pd = &pl330->ddma;
+ pd->dev = &adev->dev;
+
pl330->mcbufsz = pdat ? pdat->mcbuf_sz : 0;
res = &adev->res;
@@ -2646,7 +2740,6 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
if (!add_desc(pl330, GFP_KERNEL, NR_DEFAULT_DESC))
dev_warn(&adev->dev, "unable to allocate desc\n");
- pd = &pl330->ddma;
INIT_LIST_HEAD(&pd->channels);
/* Initialize channel parameters */
@@ -2683,7 +2776,6 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
list_add_tail(&pch->chan.device_node, &pd->channels);
}
- pd->dev = &adev->dev;
if (pdat) {
pd->cap_mask = pdat->cap_mask;
} else {
@@ -2732,12 +2824,18 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
dev_info(&adev->dev,
- "Loaded driver for PL330 DMAC-%d\n", adev->periphid);
+ "Loaded driver for PL330 DMAC-%x\n", adev->periphid);
dev_info(&adev->dev,
"\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n",
pcfg->data_buf_dep, pcfg->data_bus_width / 8, pcfg->num_chan,
pcfg->num_peri, pcfg->num_events);
+ pm_runtime_irq_safe(&adev->dev);
+ pm_runtime_use_autosuspend(&adev->dev);
+ pm_runtime_set_autosuspend_delay(&adev->dev, PL330_AUTOSUSPEND_DELAY);
+ pm_runtime_mark_last_busy(&adev->dev);
+ pm_runtime_put_autosuspend(&adev->dev);
+
return 0;
probe_err3:
/* Idle the DMAC */
@@ -2764,6 +2862,8 @@ static int pl330_remove(struct amba_device *adev)
struct pl330_dmac *pl330 = amba_get_drvdata(adev);
struct dma_pl330_chan *pch, *_p;
+ pm_runtime_get_noresume(pl330->ddma.dev);
+
if (adev->dev.of_node)
of_dma_controller_free(adev->dev.of_node);
@@ -2802,6 +2902,7 @@ static struct amba_driver pl330_driver = {
.drv = {
.owner = THIS_MODULE,
.name = "dma-pl330",
+ .pm = &pl330_pm,
},
.id_table = pl330_ids,
.probe = pl330_probe,
@@ -2810,6 +2911,6 @@ static struct amba_driver pl330_driver = {
module_amba_driver(pl330_driver);
-MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
+MODULE_AUTHOR("Jaswinder Singh <jassisinghbrar@gmail.com>");
MODULE_DESCRIPTION("API Driver for PL330 DMAC");
MODULE_LICENSE("GPL");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.