[PATCH 02/12] bcm2835-dma: Add proper 40-bit DMA support
From: Andrea della Porta
Date: Sun Feb 04 2024 - 02:00:58 EST
From: Phil Elwell <phil@xxxxxxxxxxxxxxx>
BCM2711 has 4 DMA channels with a 40-bit address range, allowing them
to access the full 4GB of memory on a Pi 4.
Cc: Phil Elwell <phil@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <maxime@xxxxxxxxxx>
Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx>
---
drivers/dma/bcm2835-dma.c | 601 ++++++++++++++++++++++++++++++++------
1 file changed, 505 insertions(+), 96 deletions(-)
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 2704e2578e23..11c6bf7d8a4b 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -36,6 +36,11 @@
#define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14
#define BCM2835_DMA_CHAN_NAME_SIZE 8
+#define BCM2711_DMA_MEMCPY_CHAN 14
+
+struct bcm2835_dma_cfg_data {
+ u32 chan_40bit_mask;
+};
/**
* struct bcm2835_dmadev - BCM2835 DMA controller
@@ -48,6 +53,7 @@ struct bcm2835_dmadev {
struct dma_device ddev;
void __iomem *base;
dma_addr_t zero_page;
+ const struct bcm2835_dma_cfg_data *cfg_data;
};
struct bcm2835_dma_cb {
@@ -60,6 +66,17 @@ struct bcm2835_dma_cb {
uint32_t pad[2];
};
+struct bcm2711_dma40_scb {
+ u32 ti;
+ u32 src;
+ u32 srci;
+ u32 dst;
+ u32 dsti;
+ u32 len;
+ u32 next_cb;
+ u32 rsvd;
+};
+
struct bcm2835_cb_entry {
struct bcm2835_dma_cb *cb;
dma_addr_t paddr;
@@ -80,6 +97,7 @@ struct bcm2835_chan {
unsigned int irq_flags;
bool is_lite_channel;
+ bool is_40bit_channel;
};
struct bcm2835_desc {
@@ -169,13 +187,118 @@ struct bcm2835_desc {
#define BCM2835_DMA_DATA_TYPE_S128 16
/* Valid only for channels 0 - 14, 15 has its own base address */
-#define BCM2835_DMA_CHAN(n) ((n) << 8) /* Base address */
+#define BCM2835_DMA_CHAN_SIZE 0x100
+#define BCM2835_DMA_CHAN(n) ((n) * BCM2835_DMA_CHAN_SIZE) /* Base address */
#define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n))
/* the max dma length for different channels */
#define MAX_DMA_LEN SZ_1G
#define MAX_LITE_DMA_LEN (SZ_64K - 4)
+/* 40-bit DMA support */
+#define BCM2711_DMA40_CS 0x00
+#define BCM2711_DMA40_CB 0x04
+#define BCM2711_DMA40_DEBUG 0x0c
+#define BCM2711_DMA40_TI 0x10
+#define BCM2711_DMA40_SRC 0x14
+#define BCM2711_DMA40_SRCI 0x18
+#define BCM2711_DMA40_DEST 0x1c
+#define BCM2711_DMA40_DESTI 0x20
+#define BCM2711_DMA40_LEN 0x24
+#define BCM2711_DMA40_NEXT_CB 0x28
+#define BCM2711_DMA40_DEBUG2 0x2c
+
+#define BCM2711_DMA40_ACTIVE BIT(0)
+#define BCM2711_DMA40_END BIT(1)
+#define BCM2711_DMA40_INT BIT(2)
+#define BCM2711_DMA40_DREQ BIT(3) /* DREQ state */
+#define BCM2711_DMA40_RD_PAUSED BIT(4) /* Reading is paused */
+#define BCM2711_DMA40_WR_PAUSED BIT(5) /* Writing is paused */
+#define BCM2711_DMA40_DREQ_PAUSED BIT(6) /* Is paused by DREQ flow control */
+#define BCM2711_DMA40_WAITING_FOR_WRITES BIT(7) /* Waiting for last write */
+#define BCM2711_DMA40_ERR BIT(10)
+#define BCM2711_DMA40_QOS(x) (((x) & 0x1f) << 16)
+#define BCM2711_DMA40_PANIC_QOS(x) (((x) & 0x1f) << 20)
+#define BCM2711_DMA40_WAIT_FOR_WRITES BIT(28)
+#define BCM2711_DMA40_DISDEBUG BIT(29)
+#define BCM2711_DMA40_ABORT BIT(30)
+#define BCM2711_DMA40_HALT BIT(31)
+#define BCM2711_DMA40_CS_FLAGS(x) ((x) & (BCM2711_DMA40_QOS(15) | \
+ BCM2711_DMA40_PANIC_QOS(15) | \
+ BCM2711_DMA40_WAIT_FOR_WRITES | \
+ BCM2711_DMA40_DISDEBUG))
+
+/* Transfer information bits */
+#define BCM2711_DMA40_INTEN BIT(0)
+#define BCM2711_DMA40_TDMODE BIT(1) /* 2D-Mode */
+#define BCM2711_DMA40_WAIT_RESP BIT(2) /* wait for AXI write to be acked */
+#define BCM2711_DMA40_WAIT_RD_RESP BIT(3) /* wait for AXI read to complete */
+#define BCM2711_DMA40_PER_MAP(x) (((x) & 31) << 9) /* REQ source */
+#define BCM2711_DMA40_S_DREQ BIT(14) /* enable SREQ for source */
+#define BCM2711_DMA40_D_DREQ BIT(15) /* enable DREQ for destination */
+#define BCM2711_DMA40_S_WAIT(x) (((x) & 0xff) << 16) /* add DMA read-wait cycles */
+#define BCM2711_DMA40_D_WAIT(x) (((x) & 0xff) << 24) /* add DMA write-wait cycles */
+
+/* debug register bits */
+#define BCM2711_DMA40_DEBUG_WRITE_ERR BIT(0)
+#define BCM2711_DMA40_DEBUG_FIFO_ERR BIT(1)
+#define BCM2711_DMA40_DEBUG_READ_ERR BIT(2)
+#define BCM2711_DMA40_DEBUG_READ_CB_ERR BIT(3)
+#define BCM2711_DMA40_DEBUG_IN_ON_ERR BIT(8)
+#define BCM2711_DMA40_DEBUG_ABORT_ON_ERR BIT(9)
+#define BCM2711_DMA40_DEBUG_HALT_ON_ERR BIT(10)
+#define BCM2711_DMA40_DEBUG_DISABLE_CLK_GATE BIT(11)
+#define BCM2711_DMA40_DEBUG_RSTATE_SHIFT 14
+#define BCM2711_DMA40_DEBUG_RSTATE_BITS 4
+#define BCM2711_DMA40_DEBUG_WSTATE_SHIFT 18
+#define BCM2711_DMA40_DEBUG_WSTATE_BITS 4
+#define BCM2711_DMA40_DEBUG_RESET BIT(23)
+#define BCM2711_DMA40_DEBUG_ID_SHIFT 24
+#define BCM2711_DMA40_DEBUG_ID_BITS 4
+#define BCM2711_DMA40_DEBUG_VERSION_SHIFT 28
+#define BCM2711_DMA40_DEBUG_VERSION_BITS 4
+
+/* Valid only for channels 0 - 3 (11 - 14) */
+#define BCM2711_DMA40_CHAN(n) (((n) + 11) << 8) /* Base address */
+#define BCM2711_DMA40_CHANIO(base, n) ((base) + BCM2711_DMA_CHAN(n))
+
+/* the max dma length for different channels */
+#define MAX_DMA40_LEN SZ_1G
+
+#define BCM2711_DMA40_BURST_LEN(x) ((min(x, 16) - 1) << 8)
+#define BCM2711_DMA40_INC BIT(12)
+#define BCM2711_DMA40_SIZE_32 (0 << 13)
+#define BCM2711_DMA40_SIZE_64 (1 << 13)
+#define BCM2711_DMA40_SIZE_128 (2 << 13)
+#define BCM2711_DMA40_SIZE_256 (3 << 13)
+#define BCM2711_DMA40_IGNORE BIT(15)
+#define BCM2711_DMA40_STRIDE(x) ((x) << 16) /* For 2D mode */
+
+#define BCM2711_DMA40_MEMCPY_FLAGS \
+ (BCM2711_DMA40_QOS(0) | \
+ BCM2711_DMA40_PANIC_QOS(0) | \
+ BCM2711_DMA40_WAIT_FOR_WRITES | \
+ BCM2711_DMA40_DISDEBUG)
+
+#define BCM2711_DMA40_MEMCPY_XFER_INFO \
+ (BCM2711_DMA40_SIZE_128 | \
+ BCM2711_DMA40_INC | \
+ BCM2711_DMA40_BURST_LEN(16))
+
+struct bcm2835_dmadev *memcpy_parent;
+static void __iomem *memcpy_chan;
+static struct bcm2711_dma40_scb *memcpy_scb;
+static dma_addr_t memcpy_scb_dma;
+DEFINE_SPINLOCK(memcpy_lock);
+
+static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = {
+ .chan_40bit_mask = 0,
+};
+
+static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = {
+ .chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14),
+};
+
static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c)
{
/* lite and normal channels have different max frame length */
@@ -205,6 +328,32 @@ static inline struct bcm2835_desc *to_bcm2835_dma_desc(
return container_of(t, struct bcm2835_desc, vd.tx);
}
+static inline uint32_t to_bcm2711_ti(uint32_t info)
+{
+ return ((info & BCM2835_DMA_INT_EN) ? BCM2711_DMA40_INTEN : 0) |
+ ((info & BCM2835_DMA_WAIT_RESP) ? BCM2711_DMA40_WAIT_RESP : 0) |
+ ((info & BCM2835_DMA_S_DREQ) ?
+ (BCM2711_DMA40_S_DREQ | BCM2711_DMA40_WAIT_RD_RESP) : 0) |
+ ((info & BCM2835_DMA_D_DREQ) ? BCM2711_DMA40_D_DREQ : 0) |
+ BCM2711_DMA40_PER_MAP((info >> 16) & 0x1f);
+}
+
+static inline uint32_t to_bcm2711_srci(uint32_t info)
+{
+ return ((info & BCM2835_DMA_S_INC) ? BCM2711_DMA40_INC : 0);
+}
+
+static inline uint32_t to_bcm2711_dsti(uint32_t info)
+{
+ return ((info & BCM2835_DMA_D_INC) ? BCM2711_DMA40_INC : 0);
+}
+
+static inline uint32_t to_bcm2711_cbaddr(dma_addr_t addr)
+{
+ WARN_ON_ONCE(addr & 0x1f);
+ return (addr >> 5);
+}
+
static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc)
{
size_t i;
@@ -223,45 +372,53 @@ static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
}
static void bcm2835_dma_create_cb_set_length(
- struct bcm2835_chan *chan,
+ struct bcm2835_chan *c,
struct bcm2835_dma_cb *control_block,
size_t len,
size_t period_len,
size_t *total_len,
u32 finalextrainfo)
{
- size_t max_len = bcm2835_dma_max_frame_length(chan);
+ size_t max_len = bcm2835_dma_max_frame_length(c);
+ u32 cb_len;
/* set the length taking lite-channel limitations into account */
- control_block->length = min_t(u32, len, max_len);
+ cb_len = min_t(u32, len, max_len);
- /* finished if we have no period_length */
- if (!period_len)
- return;
+ if (period_len) {
+ /*
+ * period_len means: that we need to generate
+ * transfers that are terminating at every
+ * multiple of period_len - this is typically
+ * used to set the interrupt flag in info
+ * which is required during cyclic transfers
+ */
- /*
- * period_len means: that we need to generate
- * transfers that are terminating at every
- * multiple of period_len - this is typically
- * used to set the interrupt flag in info
- * which is required during cyclic transfers
- */
+ /* have we filled in period_length yet? */
+ if (*total_len + cb_len < period_len) {
+ /* update number of bytes in this period so far */
+ *total_len += cb_len;
+ } else {
+ /* calculate the length that remains to reach period_len */
+ cb_len = period_len - *total_len;
- /* have we filled in period_length yet? */
- if (*total_len + control_block->length < period_len) {
- /* update number of bytes in this period so far */
- *total_len += control_block->length;
- return;
+ /* reset total_length for next period */
+ *total_len = 0;
+ }
}
- /* calculate the length that remains to reach period_length */
- control_block->length = period_len - *total_len;
-
- /* reset total_length for next period */
- *total_len = 0;
+ if (c->is_40bit_channel) {
+ struct bcm2711_dma40_scb *scb =
+ (struct bcm2711_dma40_scb *)control_block;
- /* add extrainfo bits in info */
- control_block->info |= finalextrainfo;
+ scb->len = cb_len;
+ /* add extrainfo bits to ti */
+ scb->ti |= to_bcm2711_ti(finalextrainfo);
+ } else {
+ control_block->length = cb_len;
+ /* add extrainfo bits to info */
+ control_block->info |= finalextrainfo;
+ }
}
static inline size_t bcm2835_dma_count_frames_for_sg(
@@ -284,7 +441,7 @@ static inline size_t bcm2835_dma_count_frames_for_sg(
/**
* bcm2835_dma_create_cb_chain - create a control block and fills data in
*
- * @chan: the @dma_chan for which we run this
+ * @c: the @bcm2835_chan for which we run this
* @direction: the direction in which we transfer
* @cyclic: it is a cyclic transfer
* @info: the default info bits to apply per controlblock
@@ -302,12 +459,11 @@ static inline size_t bcm2835_dma_count_frames_for_sg(
* @gfp: the GFP flag to use for allocation
*/
static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
- struct dma_chan *chan, enum dma_transfer_direction direction,
+ struct bcm2835_chan *c, enum dma_transfer_direction direction,
bool cyclic, u32 info, u32 finalextrainfo, size_t frames,
dma_addr_t src, dma_addr_t dst, size_t buf_len,
size_t period_len, gfp_t gfp)
{
- struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
size_t len = buf_len, total_len;
size_t frame;
struct bcm2835_desc *d;
@@ -339,11 +495,23 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
/* fill in the control block */
control_block = cb_entry->cb;
- control_block->info = info;
- control_block->src = src;
- control_block->dst = dst;
- control_block->stride = 0;
- control_block->next = 0;
+ if (c->is_40bit_channel) {
+ struct bcm2711_dma40_scb *scb =
+ (struct bcm2711_dma40_scb *)control_block;
+ scb->ti = to_bcm2711_ti(info);
+ scb->src = lower_32_bits(src);
+ scb->srci = upper_32_bits(src) | to_bcm2711_srci(info);
+ scb->dst = lower_32_bits(dst);
+ scb->dsti = upper_32_bits(dst) | to_bcm2711_dsti(info);
+ scb->next_cb = 0;
+ } else {
+ control_block->info = info;
+ control_block->src = src;
+ control_block->dst = dst;
+ control_block->stride = 0;
+ control_block->next = 0;
+ }
+
/* set up length in control_block if requested */
if (buf_len) {
/* calculate length honoring period_length */
@@ -353,25 +521,51 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
cyclic ? finalextrainfo : 0);
/* calculate new remaining length */
- len -= control_block->length;
+ if (c->is_40bit_channel)
+ len -= ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ len -= control_block->length;
}
/* link this the last controlblock */
- if (frame)
+ if (frame && c->is_40bit_channel)
+ ((struct bcm2711_dma40_scb *)
+ d->cb_list[frame - 1].cb)->next_cb =
+ to_bcm2711_cbaddr(cb_entry->paddr);
+ if (frame && !c->is_40bit_channel)
d->cb_list[frame - 1].cb->next = cb_entry->paddr;
/* update src and dst and length */
- if (src && (info & BCM2835_DMA_S_INC))
- src += control_block->length;
- if (dst && (info & BCM2835_DMA_D_INC))
- dst += control_block->length;
+ if (src && (info & BCM2835_DMA_S_INC)) {
+ if (c->is_40bit_channel)
+ src += ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ src += control_block->length;
+ }
+
+ if (dst && (info & BCM2835_DMA_D_INC)) {
+ if (c->is_40bit_channel)
+ dst += ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ dst += control_block->length;
+ }
/* Length of total transfer */
- d->size += control_block->length;
+ if (c->is_40bit_channel)
+ d->size += ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ d->size += control_block->length;
}
/* the last frame requires extra flags */
- d->cb_list[d->frames - 1].cb->info |= finalextrainfo;
+ if (c->is_40bit_channel) {
+ struct bcm2711_dma40_scb *scb =
+ (struct bcm2711_dma40_scb *)d->cb_list[d->frames - 1].cb;
+
+ scb->ti |= to_bcm2711_ti(finalextrainfo);
+ } else {
+ d->cb_list[d->frames - 1].cb->info |= finalextrainfo;
+ }
/* detect a size missmatch */
if (buf_len && (d->size != buf_len))
@@ -385,13 +579,12 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
}
static void bcm2835_dma_fill_cb_chain_with_sg(
- struct dma_chan *chan,
+ struct bcm2835_chan *c,
enum dma_transfer_direction direction,
struct bcm2835_cb_entry *cb,
struct scatterlist *sgl,
unsigned int sg_len)
{
- struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
size_t len, max_len;
unsigned int i;
dma_addr_t addr;
@@ -399,14 +592,35 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
max_len = bcm2835_dma_max_frame_length(c);
for_each_sg(sgl, sgent, sg_len, i) {
- for (addr = sg_dma_address(sgent), len = sg_dma_len(sgent);
- len > 0;
- addr += cb->cb->length, len -= cb->cb->length, cb++) {
- if (direction == DMA_DEV_TO_MEM)
- cb->cb->dst = addr;
- else
- cb->cb->src = addr;
- cb->cb->length = min(len, max_len);
+ if (c->is_40bit_channel) {
+ struct bcm2711_dma40_scb *scb;
+
+ for (addr = sg_dma_address(sgent),
+ len = sg_dma_len(sgent);
+ len > 0;
+ addr += scb->len, len -= scb->len, cb++) {
+ scb = (struct bcm2711_dma40_scb *)cb->cb;
+ if (direction == DMA_DEV_TO_MEM) {
+ scb->dst = lower_32_bits(addr);
+ scb->dsti = upper_32_bits(addr) | BCM2711_DMA40_INC;
+ } else {
+ scb->src = lower_32_bits(addr);
+ scb->srci = upper_32_bits(addr) | BCM2711_DMA40_INC;
+ }
+ scb->len = min(len, max_len);
+ }
+ } else {
+ for (addr = sg_dma_address(sgent),
+ len = sg_dma_len(sgent);
+ len > 0;
+ addr += cb->cb->length, len -= cb->cb->length,
+ cb++) {
+ if (direction == DMA_DEV_TO_MEM)
+ cb->cb->dst = addr;
+ else
+ cb->cb->src = addr;
+ cb->cb->length = min(len, max_len);
+ }
}
}
}
@@ -423,20 +637,60 @@ static void bcm2835_dma_abort(struct bcm2835_chan *c)
if (!readl(chan_base + BCM2835_DMA_ADDR))
return;
- /* Write 0 to the active bit - Pause the DMA */
- writel(0, chan_base + BCM2835_DMA_CS);
+ if (c->is_40bit_channel) {
+ /* Halt the current DMA */
+ writel(readl(chan_base + BCM2711_DMA40_CS) | BCM2711_DMA40_HALT,
+ chan_base + BCM2711_DMA40_CS);
- /* Wait for any current AXI transfer to complete */
- while ((readl(chan_base + BCM2835_DMA_CS) &
- BCM2835_DMA_WAITING_FOR_WRITES) && --timeout)
- cpu_relax();
+ while ((readl(chan_base + BCM2711_DMA40_CS) & BCM2711_DMA40_HALT) && --timeout)
+ cpu_relax();
- /* Peripheral might be stuck and fail to signal AXI write responses */
- if (!timeout)
- dev_err(c->vc.chan.device->dev,
- "failed to complete outstanding writes\n");
+ /* Peripheral might be stuck and fail to halt */
+ if (!timeout)
+ dev_err(c->vc.chan.device->dev,
+ "failed to halt dma\n");
- writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
+ writel(0, chan_base + BCM2711_DMA40_CS);
+ writel(0, chan_base + BCM2711_DMA40_CB);
+ } else {
+ /*
+ * 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(readl(chan_base + BCM2835_DMA_CS) & ~BCM2835_DMA_ACTIVE,
+ chan_base + BCM2835_DMA_CS);
+
+ /* wait for DMA to be paused */
+ while ((readl(chan_base + BCM2835_DMA_CS) & BCM2835_DMA_WAITING_FOR_WRITES) &&
+ --timeout)
+ cpu_relax();
+
+ /* Peripheral might be stuck and fail to signal AXI write responses */
+ if (!timeout)
+ dev_err(c->vc.chan.device->dev,
+ "failed to pause dma\n");
+
+ /* We need to clear the next DMA block pending */
+ writel(0, chan_base + BCM2835_DMA_NEXTCB);
+
+ /* Abort the DMA, which needs to be enabled to complete */
+ writel(readl(chan_base + BCM2835_DMA_CS) | BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE,
+ chan_base + BCM2835_DMA_CS);
+
+ /* wait for DMA to have been aborted */
+ timeout = 10000;
+ while ((readl(chan_base + BCM2835_DMA_CS) & BCM2835_DMA_ABORT) && --timeout)
+ cpu_relax();
+
+ /* Peripheral might be stuck and fail to signal AXI write responses */
+ if (!timeout)
+ dev_err(c->vc.chan.device->dev,
+ "failed to abort dma\n");
+ }
}
static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
@@ -453,9 +707,16 @@ static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
c->desc = d = to_bcm2835_dma_desc(&vd->tx);
- writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR);
- writel(BCM2835_DMA_ACTIVE | BCM2835_DMA_CS_FLAGS(c->dreq),
- c->chan_base + BCM2835_DMA_CS);
+ if (c->is_40bit_channel) {
+ writel(to_bcm2711_cbaddr(d->cb_list[0].paddr),
+ c->chan_base + BCM2711_DMA40_CB);
+ writel(BCM2711_DMA40_ACTIVE | BCM2711_DMA40_CS_FLAGS(c->dreq),
+ c->chan_base + BCM2711_DMA40_CS);
+ } else {
+ writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR);
+ writel(BCM2835_DMA_ACTIVE | BCM2835_DMA_CS_FLAGS(c->dreq),
+ c->chan_base + BCM2835_DMA_CS);
+ }
}
static irqreturn_t bcm2835_dma_callback(int irq, void *data)
@@ -482,8 +743,7 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
* 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 |
- BCM2835_DMA_CS_FLAGS(c->dreq),
+ writel(BCM2835_DMA_INT | BCM2835_DMA_ACTIVE | BCM2835_DMA_CS_FLAGS(c->dreq),
c->chan_base + BCM2835_DMA_CS);
d = c->desc;
@@ -546,20 +806,39 @@ static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr)
unsigned int i;
size_t size;
- for (size = i = 0; i < d->frames; i++) {
- struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
- size_t this_size = control_block->length;
- dma_addr_t dma;
+ if (d->c->is_40bit_channel) {
+ for (size = i = 0; i < d->frames; i++) {
+ struct bcm2711_dma40_scb *control_block =
+ (struct bcm2711_dma40_scb *)d->cb_list[i].cb;
+ size_t this_size = control_block->len;
+ dma_addr_t dma;
- if (d->dir == DMA_DEV_TO_MEM)
- dma = control_block->dst;
- else
- dma = control_block->src;
+ if (d->dir == DMA_DEV_TO_MEM)
+ dma = control_block->dst;
+ else
+ dma = control_block->src;
- if (size)
- size += this_size;
- else if (addr >= dma && addr < dma + this_size)
- size += dma + this_size - addr;
+ if (size)
+ size += this_size;
+ else if (addr >= dma && addr < dma + this_size)
+ size += dma + this_size - addr;
+ }
+ } else {
+ for (size = i = 0; i < d->frames; i++) {
+ struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
+ size_t this_size = control_block->length;
+ dma_addr_t dma;
+
+ if (d->dir == DMA_DEV_TO_MEM)
+ dma = control_block->dst;
+ else
+ dma = control_block->src;
+
+ if (size)
+ size += this_size;
+ else if (addr >= dma && addr < dma + this_size)
+ size += dma + this_size - addr;
+ }
}
return size;
@@ -586,12 +865,25 @@ static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan,
struct bcm2835_desc *d = c->desc;
dma_addr_t pos;
- if (d->dir == DMA_MEM_TO_DEV)
+ if (d->dir == DMA_MEM_TO_DEV && c->is_40bit_channel) {
+ u64 lo_bits, hi_bits;
+
+ lo_bits = readl(c->chan_base + BCM2711_DMA40_SRC);
+ hi_bits = readl(c->chan_base + BCM2711_DMA40_SRCI) & 0xff;
+ pos = (hi_bits << 32) | lo_bits;
+ } else if (d->dir == DMA_MEM_TO_DEV && !c->is_40bit_channel) {
pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD);
- else if (d->dir == DMA_DEV_TO_MEM)
+ } else if (d->dir == DMA_DEV_TO_MEM && c->is_40bit_channel) {
+ u64 lo_bits, hi_bits;
+
+ lo_bits = readl(c->chan_base + BCM2711_DMA40_DEST);
+ hi_bits = readl(c->chan_base + BCM2711_DMA40_DESTI) & 0xff;
+ pos = (hi_bits << 32) | lo_bits;
+ } else if (d->dir == DMA_DEV_TO_MEM && !c->is_40bit_channel) {
pos = readl(c->chan_base + BCM2835_DMA_DEST_AD);
- else
+ } else {
pos = 0;
+ }
txstate->residue = bcm2835_dma_desc_size_pos(d, pos);
} else {
@@ -634,7 +926,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
frames = bcm2835_dma_frames_for_length(len, max_len);
/* allocate the CB chain - this also fills in the pointers */
- d = bcm2835_dma_create_cb_chain(chan, DMA_MEM_TO_MEM, false,
+ d = bcm2835_dma_create_cb_chain(c, DMA_MEM_TO_MEM, false,
info, extra, frames,
src, dst, len, 0, GFP_KERNEL);
if (!d)
@@ -669,11 +961,21 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
src = c->cfg.src_addr;
+ /*
+ * One would think it ought to be possible to get the physical
+ * to dma address mapping information from the dma-ranges DT
+ * property, but I've not found a way yet that doesn't involve
+ * open-coding the whole thing.
+ */
+ if (c->is_40bit_channel)
+ src |= 0x400000000ull;
info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC;
} else {
if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
dst = c->cfg.dst_addr;
+ if (c->is_40bit_channel)
+ dst |= 0x400000000ull;
info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC;
}
@@ -681,7 +983,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
frames = bcm2835_dma_count_frames_for_sg(c, sgl, sg_len);
/* allocate the CB chain */
- d = bcm2835_dma_create_cb_chain(chan, direction, false,
+ d = bcm2835_dma_create_cb_chain(c, direction, false,
info, extra,
frames, src, dst, 0, 0,
GFP_NOWAIT);
@@ -689,7 +991,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
return NULL;
/* fill in frames with scatterlist pointers */
- bcm2835_dma_fill_cb_chain_with_sg(chan, direction, d->cb_list,
+ bcm2835_dma_fill_cb_chain_with_sg(c, direction, d->cb_list,
sgl, sg_len);
return vchan_tx_prep(&c->vc, &d->vd, flags);
@@ -743,12 +1045,16 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
src = c->cfg.src_addr;
+ if (c->is_40bit_channel)
+ src |= 0x400000000ull;
dst = buf_addr;
info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC;
} else {
if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
dst = c->cfg.dst_addr;
+ if (c->is_40bit_channel)
+ dst |= 0x400000000ull;
src = buf_addr;
info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC;
@@ -768,7 +1074,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
* note that we need to use GFP_NOWAIT, as the ALSA i2s dmaengine
* implementation calls prep_dma_cyclic with interrupts disabled.
*/
- d = bcm2835_dma_create_cb_chain(chan, direction, true,
+ d = bcm2835_dma_create_cb_chain(c, direction, true,
info, extra,
frames, src, dst, buf_len,
period_len, GFP_NOWAIT);
@@ -776,7 +1082,12 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
return NULL;
/* wrap around into a loop */
- d->cb_list[d->frames - 1].cb->next = d->cb_list[0].paddr;
+ if (c->is_40bit_channel)
+ ((struct bcm2711_dma40_scb *)
+ d->cb_list[frames - 1].cb)->next_cb =
+ to_bcm2711_cbaddr(d->cb_list[0].paddr);
+ else
+ d->cb_list[d->frames - 1].cb->next = d->cb_list[0].paddr;
return vchan_tx_prep(&c->vc, &d->vd, flags);
}
@@ -837,9 +1148,11 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
c->irq_number = irq;
c->irq_flags = irq_flags;
- /* check in DEBUG register if this is a LITE channel */
- if (readl(c->chan_base + BCM2835_DMA_DEBUG) &
- BCM2835_DMA_DEBUG_LITE)
+ /* check for 40bit and lite channels */
+ if (d->cfg_data->chan_40bit_mask & BIT(chan_id))
+ c->is_40bit_channel = true;
+ else if (readl(c->chan_base + BCM2835_DMA_DEBUG) &
+ BCM2835_DMA_DEBUG_LITE)
c->is_lite_channel = true;
return 0;
@@ -859,8 +1172,58 @@ static void bcm2835_dma_free(struct bcm2835_dmadev *od)
DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
}
+int bcm2711_dma40_memcpy_init(void)
+{
+ if (!memcpy_parent)
+ return -EPROBE_DEFER;
+
+ if (!memcpy_chan)
+ return -EINVAL;
+
+ if (!memcpy_scb)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL(bcm2711_dma40_memcpy_init);
+
+void bcm2711_dma40_memcpy(dma_addr_t dst, dma_addr_t src, size_t size)
+{
+ struct bcm2711_dma40_scb *scb = memcpy_scb;
+ unsigned long flags;
+
+ if (!scb) {
+ pr_err("%s not initialised!\n", __func__);
+ return;
+ }
+
+ spin_lock_irqsave(&memcpy_lock, flags);
+
+ scb->ti = 0;
+ scb->src = lower_32_bits(src);
+ scb->srci = upper_32_bits(src) | BCM2711_DMA40_MEMCPY_XFER_INFO;
+ scb->dst = lower_32_bits(dst);
+ scb->dsti = upper_32_bits(dst) | BCM2711_DMA40_MEMCPY_XFER_INFO;
+ scb->len = size;
+ scb->next_cb = 0;
+
+ writel((u32)(memcpy_scb_dma >> 5), memcpy_chan + BCM2711_DMA40_CB);
+ writel(BCM2711_DMA40_MEMCPY_FLAGS + BCM2711_DMA40_ACTIVE,
+ memcpy_chan + BCM2711_DMA40_CS);
+
+ /* Poll for completion */
+ while (!(readl(memcpy_chan + BCM2711_DMA40_CS) & BCM2711_DMA40_END))
+ cpu_relax();
+
+ writel(BCM2711_DMA40_END, memcpy_chan + BCM2711_DMA40_CS);
+
+ spin_unlock_irqrestore(&memcpy_lock, flags);
+}
+EXPORT_SYMBOL(bcm2711_dma40_memcpy);
+
static const struct of_device_id bcm2835_dma_of_match[] = {
- { .compatible = "brcm,bcm2835-dma", },
+ { .compatible = "brcm,bcm2835-dma", .data = &bcm2835_dma_cfg },
+ { .compatible = "brcm,bcm2711-dma", .data = &bcm2711_dma_cfg },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match);
@@ -884,6 +1247,7 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
static int bcm2835_dma_probe(struct platform_device *pdev)
{
struct bcm2835_dmadev *od;
+ struct resource *res;
void __iomem *base;
int rc;
int i, j;
@@ -891,6 +1255,8 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
int irq_flags;
uint32_t chans_available;
char chan_name[BCM2835_DMA_CHAN_NAME_SIZE];
+ const struct of_device_id *of_id;
+ int chan_count, chan_start, chan_end;
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
@@ -907,10 +1273,17 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF);
- base = devm_platform_ioremap_resource(pdev, 0);
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(base))
return PTR_ERR(base);
+ /* The set of channels can be split across multiple instances. */
+ chan_start = ((u32)(uintptr_t)base / BCM2835_DMA_CHAN_SIZE) & 0xf;
+ base -= BCM2835_DMA_CHAN(chan_start);
+ chan_count = resource_size(res) / BCM2835_DMA_CHAN_SIZE;
+ chan_end = min(chan_start + chan_count,
+ BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED + 1);
+
od->base = base;
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
@@ -946,6 +1319,14 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
return -ENOMEM;
}
+ of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node);
+ if (!of_id) {
+ dev_err(&pdev->dev, "Failed to match compatible string\n");
+ return -EINVAL;
+ }
+
+ od->cfg_data = of_id->data;
+
/* Request DMA channel mask from device tree */
if (of_property_read_u32(pdev->dev.of_node,
"brcm,dma-channel-mask",
@@ -955,8 +1336,23 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
goto err_no_dma;
}
+ /* One channel is reserved for the 40-bit DMA memcpy API */
+ if (chans_available & od->cfg_data->chan_40bit_mask &
+ BIT(BCM2711_DMA_MEMCPY_CHAN)) {
+ memcpy_parent = od;
+ memcpy_chan = BCM2835_DMA_CHANIO(base, BCM2711_DMA_MEMCPY_CHAN);
+ memcpy_scb = dma_alloc_coherent(memcpy_parent->ddev.dev,
+ sizeof(*memcpy_scb),
+ &memcpy_scb_dma, GFP_KERNEL);
+ if (!memcpy_scb)
+ dev_warn(&pdev->dev,
+ "Failed to allocated memcpy scb\n");
+
+ chans_available &= ~BIT(BCM2711_DMA_MEMCPY_CHAN);
+ }
+
/* get irqs for each channel that we support */
- for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
+ for (i = chan_start; i < chan_end; i++) {
/* skip masked out channels */
if (!(chans_available & (1 << i))) {
irq[i] = -1;
@@ -979,13 +1375,18 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
irq[i] = platform_get_irq(pdev, i < 11 ? i : 11);
}
+ chan_count = 0;
+
/* get irqs for each channel */
- for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
+ for (i = chan_start; i < chan_end; i++) {
/* skip channels without irq */
if (irq[i] < 0)
continue;
/* check if there are other channels that also use this irq */
+ /* FIXME: This will fail if interrupts are shared across
+ * instances
+ */
irq_flags = 0;
for (j = 0; j <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; j++)
if ((i != j) && (irq[j] == irq[i])) {
@@ -997,9 +1398,10 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
rc = bcm2835_dma_chan_init(od, i, irq[i], irq_flags);
if (rc)
goto err_no_dma;
+ chan_count++;
}
- dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i);
+ dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", chan_count);
/* Device-tree DMA controller registration */
rc = of_dma_controller_register(pdev->dev.of_node,
@@ -1030,6 +1432,13 @@ static void bcm2835_dma_remove(struct platform_device *pdev)
struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
dma_async_device_unregister(&od->ddev);
+ if (memcpy_parent == od) {
+ dma_free_coherent(&pdev->dev, sizeof(*memcpy_scb), memcpy_scb,
+ memcpy_scb_dma);
+ memcpy_parent = NULL;
+ memcpy_scb = NULL;
+ memcpy_chan = NULL;
+ }
bcm2835_dma_free(od);
}
--
2.41.0