[PATCH 6/7 v5] k3dma: Add cyclic mode for audio

From: John Stultz
Date: Mon Aug 29 2016 - 13:31:43 EST

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From: Andy Green <andy.green@xxxxxxxxxx>

Currently the k3dma driver doesn't offer the cyclic mode
necessary for handling audio.

This patch adds it.

Cc: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
Cc: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Cc: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Andy Green <andy@xxxxxxxxxxx>
Acked-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
Signed-off-by: Andy Green <andy.green@xxxxxxxxxx>
[jstultz: Forward ported to mainline, removed a few
bits of logic that didn't seem to have much effect]
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
v2:
* Changed pr_debug() -> dev_debug() suggested by Zhangfei
---
drivers/dma/k3dma.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 103 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
index 8108fa1..814e6e0 100644
--- a/drivers/dma/k3dma.c
+++ b/drivers/dma/k3dma.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013 Linaro Ltd.
+ * Copyright (c) 2013 - 2015 Linaro Ltd.
* Copyright (c) 2013 Hisilicon Limited.
*
* This program is free software; you can redistribute it and/or modify
@@ -27,23 +27,28 @@

#define DRIVER_NAME "k3-dma"
#define DMA_MAX_SIZE 0x1ffc
+#define DMA_CYCLIC_MAX_PERIOD 0x1000
#define LLI_BLOCK_SIZE (4 * PAGE_SIZE)

#define INT_STAT 0x00
#define INT_TC1 0x04
+#define INT_TC2 0x08
#define INT_ERR1 0x0c
#define INT_ERR2 0x10
#define INT_TC1_MASK 0x18
+#define INT_TC2_MASK 0x1c
#define INT_ERR1_MASK 0x20
#define INT_ERR2_MASK 0x24
#define INT_TC1_RAW 0x600
+#define INT_TC2_RAW 0x608
#define INT_ERR1_RAW 0x610
#define INT_ERR2_RAW 0x618
#define CH_PRI 0x688
#define CH_STAT 0x690
#define CX_CUR_CNT 0x704
#define CX_LLI 0x800
-#define CX_CNT 0x810
+#define CX_CNT1 0x80c
+#define CX_CNT0 0x810
#define CX_SRC 0x814
#define CX_DST 0x818
#define CX_CFG 0x81c
@@ -52,6 +57,7 @@

#define CX_LLI_CHAIN_EN 0x2
#define CX_CFG_EN 0x1
+#define CX_CFG_NODEIRQ BIT(1)
#define CX_CFG_MEM2PER (0x1 << 2)
#define CX_CFG_PER2MEM (0x2 << 2)
#define CX_CFG_SRCINCR (0x1 << 31)
@@ -84,6 +90,7 @@ struct k3_dma_chan {
enum dma_transfer_direction dir;
dma_addr_t dev_addr;
enum dma_status status;
+ bool cyclic;
};

struct k3_dma_phy {
@@ -139,6 +146,7 @@ static void k3_dma_terminate_chan(struct k3_dma_phy *phy, struct k3_dma_dev *d)

val = 0x1 << phy->idx;
writel_relaxed(val, d->base + INT_TC1_RAW);
+ writel_relaxed(val, d->base + INT_TC2_RAW);
writel_relaxed(val, d->base + INT_ERR1_RAW);
writel_relaxed(val, d->base + INT_ERR2_RAW);
}
@@ -146,7 +154,7 @@ static void k3_dma_terminate_chan(struct k3_dma_phy *phy, struct k3_dma_dev *d)
static void k3_dma_set_desc(struct k3_dma_phy *phy, struct k3_desc_hw *hw)
{
writel_relaxed(hw->lli, phy->base + CX_LLI);
- writel_relaxed(hw->count, phy->base + CX_CNT);
+ writel_relaxed(hw->count, phy->base + CX_CNT0);
writel_relaxed(hw->saddr, phy->base + CX_SRC);
writel_relaxed(hw->daddr, phy->base + CX_DST);
writel_relaxed(AXI_CFG_DEFAULT, phy->base + AXI_CFG);
@@ -180,11 +188,13 @@ static void k3_dma_enable_dma(struct k3_dma_dev *d, bool on)

/* unmask irq */
writel_relaxed(0xffff, d->base + INT_TC1_MASK);
+ writel_relaxed(0xffff, d->base + INT_TC2_MASK);
writel_relaxed(0xffff, d->base + INT_ERR1_MASK);
writel_relaxed(0xffff, d->base + INT_ERR2_MASK);
} else {
/* mask irq */
writel_relaxed(0x0, d->base + INT_TC1_MASK);
+ writel_relaxed(0x0, d->base + INT_TC2_MASK);
writel_relaxed(0x0, d->base + INT_ERR1_MASK);
writel_relaxed(0x0, d->base + INT_ERR2_MASK);
}
@@ -197,19 +207,20 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
struct k3_dma_chan *c;
u32 stat = readl_relaxed(d->base + INT_STAT);
u32 tc1 = readl_relaxed(d->base + INT_TC1);
+ u32 tc2 = readl_relaxed(d->base + INT_TC2);
u32 err1 = readl_relaxed(d->base + INT_ERR1);
u32 err2 = readl_relaxed(d->base + INT_ERR2);
u32 i, irq_chan = 0;

while (stat) {
i = __ffs(stat);
- stat &= (stat - 1);
- if (likely(tc1 & BIT(i))) {
+ stat &= ~BIT(i);
+ if (likely(tc1 & BIT(i)) || (tc2 & BIT(i))) {
+ unsigned long flags;
+
p = &d->phy[i];
c = p->vchan;
- if (c) {
- unsigned long flags;
-
+ if (c && (tc1 & BIT(i))) {
spin_lock_irqsave(&c->vc.lock, flags);
vchan_cookie_complete(&p->ds_run->vd);
WARN_ON_ONCE(p->ds_done);
@@ -217,6 +228,12 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
p->ds_run = NULL;
spin_unlock_irqrestore(&c->vc.lock, flags);
}
+ if (c && (tc2 & BIT(i))) {
+ spin_lock_irqsave(&c->vc.lock, flags);
+ if (p->ds_run != NULL)
+ vchan_cyclic_callback(&p->ds_run->vd);
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+ }
irq_chan |= BIT(i);
}
if (unlikely((err1 & BIT(i)) || (err2 & BIT(i))))
@@ -224,6 +241,7 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
}

writel_relaxed(irq_chan, d->base + INT_TC1_RAW);
+ writel_relaxed(irq_chan, d->base + INT_TC2_RAW);
writel_relaxed(err1, d->base + INT_ERR1_RAW);
writel_relaxed(err2, d->base + INT_ERR2_RAW);

@@ -359,7 +377,7 @@ static enum dma_status k3_dma_tx_status(struct dma_chan *chan,
* its total size.
*/
vd = vchan_find_desc(&c->vc, cookie);
- if (vd) {
+ if (vd && !c->cyclic) {
bytes = container_of(vd, struct k3_dma_desc_sw, vd)->size;
} else if ((!p) || (!p->ds_run)) {
bytes = 0;
@@ -369,7 +387,8 @@ static enum dma_status k3_dma_tx_status(struct dma_chan *chan,

bytes = k3_dma_get_curr_cnt(d, p);
clli = k3_dma_get_curr_lli(p);
- index = (clli - ds->desc_hw_lli) / sizeof(struct k3_desc_hw);
+ index = ((clli - ds->desc_hw_lli) /
+ sizeof(struct k3_desc_hw)) + 1;
for (; index < ds->desc_num; index++) {
bytes += ds->desc_hw[index].count;
/* end of lli */
@@ -410,9 +429,10 @@ static void k3_dma_issue_pending(struct dma_chan *chan)
static void k3_dma_fill_desc(struct k3_dma_desc_sw *ds, dma_addr_t dst,
dma_addr_t src, size_t len, u32 num, u32 ccfg)
{
- if ((num + 1) < ds->desc_num)
+ if (num != ds->desc_num - 1)
ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
sizeof(struct k3_desc_hw);
+
ds->desc_hw[num].lli |= CX_LLI_CHAIN_EN;
ds->desc_hw[num].count = len;
ds->desc_hw[num].saddr = src;
@@ -467,6 +487,7 @@ static struct dma_async_tx_descriptor *k3_dma_prep_memcpy(
if (!ds)
return NULL;

+ c->cyclic = 0;
ds->size = len;
num = 0;

@@ -510,6 +531,8 @@ static struct dma_async_tx_descriptor *k3_dma_prep_slave_sg(
if (sgl == NULL)
return NULL;

+ c->cyclic = 0;
+
for_each_sg(sgl, sg, sglen, i) {
avail = sg_dma_len(sg);
if (avail > DMA_MAX_SIZE)
@@ -549,6 +572,73 @@ static struct dma_async_tx_descriptor *k3_dma_prep_slave_sg(
return vchan_tx_prep(&c->vc, &ds->vd, flags);
}

+static struct dma_async_tx_descriptor *
+k3_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
+ size_t buf_len, size_t period_len,
+ enum dma_transfer_direction dir,
+ unsigned long flags)
+{
+ struct k3_dma_chan *c = to_k3_chan(chan);
+ struct k3_dma_desc_sw *ds;
+ size_t len, avail, total = 0;
+ dma_addr_t addr, src = 0, dst = 0;
+ int num = 1, since = 0;
+ size_t modulo = DMA_CYCLIC_MAX_PERIOD;
+ u32 en_tc2 = 0;
+
+ dev_dbg(chan->device->dev, "%s: buf %p, dst %p, buf len %d, period_len = %d, dir %d\n",
+ __func__, (void *)buf_addr, (void *)to_k3_chan(chan)->dev_addr,
+ (int)buf_len, (int)period_len, (int)dir);
+
+ avail = buf_len;
+ if (avail > modulo)
+ num += DIV_ROUND_UP(avail, modulo) - 1;
+
+ ds = k3_dma_alloc_desc_resource(num, chan);
+ if (!ds)
+ return NULL;
+
+ c->cyclic = 1;
+ addr = buf_addr;
+ avail = buf_len;
+ total = avail;
+ num = 0;
+
+ if (period_len < modulo)
+ modulo = period_len;
+
+ do {
+ len = min_t(size_t, avail, modulo);
+
+ if (dir == DMA_MEM_TO_DEV) {
+ src = addr;
+ dst = c->dev_addr;
+ } else if (dir == DMA_DEV_TO_MEM) {
+ src = c->dev_addr;
+ dst = addr;
+ }
+ since += len;
+ if (since >= period_len) {
+ /* descriptor asks for TC2 interrupt on completion */
+ en_tc2 = CX_CFG_NODEIRQ;
+ since -= period_len;
+ } else
+ en_tc2 = 0;
+
+ k3_dma_fill_desc(ds, dst, src, len, num++, c->ccfg | en_tc2);
+
+ addr += len;
+ avail -= len;
+ } while (avail);
+
+ /* "Cyclic" == end of link points back to start of link */
+ ds->desc_hw[num - 1].lli |= ds->desc_hw_lli;
+
+ ds->size = total;
+
+ return vchan_tx_prep(&c->vc, &ds->vd, flags);
+}
+
static int k3_dma_config(struct dma_chan *chan,
struct dma_slave_config *cfg)
{
@@ -771,11 +861,13 @@ static int k3_dma_probe(struct platform_device *op)
INIT_LIST_HEAD(&d->slave.channels);
dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
+ dma_cap_set(DMA_CYCLIC, d->slave.cap_mask);
d->slave.dev = &op->dev;
d->slave.device_free_chan_resources = k3_dma_free_chan_resources;
d->slave.device_tx_status = k3_dma_tx_status;
d->slave.device_prep_dma_memcpy = k3_dma_prep_memcpy;
d->slave.device_prep_slave_sg = k3_dma_prep_slave_sg;
+ d->slave.device_prep_dma_cyclic = k3_dma_prep_dma_cyclic;
d->slave.device_issue_pending = k3_dma_issue_pending;
d->slave.device_config = k3_dma_config;
d->slave.device_pause = k3_dma_transfer_pause;
--
1.9.1

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