2014-01-27 09:37:43

by George Cherian

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Subject: [PATCH v2 0/3] Enable ISOCH IN handling for AM335x


This series enables the ISOCH IN handling for AM335x HOST mode.
With this series webcam devices are now supported under AM335x
MUSB HOST with CPPI DMA enabled.

Patch 1 - Enable basic ISOCH IN handling
Patch 2 - Make CPPI aware of hb transfers
Patch 3 - Using hrtimer based polling for tx empty leads to hang , fixes it


v1 -> v2
Fix code-style comments.

George Cherian (3):
usb: musb: musb_host: Enable ISOCH IN handling for AM335x host
usb: musb: musb_cppi41: Make CPPI aware of high bandwidth transfers
usb: musb: musb_cppi41: Handle ISOCH differently and not use the
hrtimer.

drivers/usb/musb/musb_cppi41.c | 67 +++++++++++++++++++++++++++++++++++++++++-
drivers/usb/musb/musb_host.c | 30 ++++++++++++++++---
2 files changed, 92 insertions(+), 5 deletions(-)

--
1.8.1


2014-01-27 09:37:56

by George Cherian

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Subject: [PATCH v2 3/3] usb: musb: musb_cppi41: Handle ISOCH differently and not use the hrtimer.

In case of ISOCH transfers the hrtimer workaround for the hardware issue
is not very reliable. Instead of checking musb_is_tx_fifo_empty() in hrtimer
routine, schedule a completion work and check the same in completion work.

Signed-off-by: George Cherian <[email protected]>
---
drivers/usb/musb/musb_cppi41.c | 53 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 39ee516..5b0f2a5 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -39,6 +39,7 @@ struct cppi41_dma_channel {
u32 transferred;
u32 packet_sz;
struct list_head tx_check;
+ struct work_struct dma_completion;
};

#define MUSB_DMA_NUM_CHANNELS 15
@@ -112,6 +113,18 @@ static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
return true;
}

+static bool is_isoc(struct musb_hw_ep *hw_ep, bool in)
+{
+ if (in && hw_ep->in_qh) {
+ if (hw_ep->in_qh->type == USB_ENDPOINT_XFER_ISOC)
+ return true;
+ } else if (hw_ep->out_qh) {
+ if (hw_ep->out_qh->type == USB_ENDPOINT_XFER_ISOC)
+ return true;
+ }
+ return false;
+}
+
static void cppi41_dma_callback(void *private_data);

static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
@@ -165,6 +178,32 @@ static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
}
}

+static void cppi_trans_done_work(struct work_struct *work)
+{
+ unsigned long flags;
+ struct cppi41_dma_channel *cppi41_channel =
+ container_of(work, struct cppi41_dma_channel, dma_completion);
+ struct cppi41_dma_controller *controller = cppi41_channel->controller;
+ struct musb *musb = controller->musb;
+ struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+ bool empty;
+
+ if (!cppi41_channel->is_tx && is_isoc(hw_ep, 1)) {
+ spin_lock_irqsave(&musb->lock, flags);
+ cppi41_trans_done(cppi41_channel);
+ spin_unlock_irqrestore(&musb->lock, flags);
+ } else {
+ empty = musb_is_tx_fifo_empty(hw_ep);
+ if (empty) {
+ spin_lock_irqsave(&musb->lock, flags);
+ cppi41_trans_done(cppi41_channel);
+ spin_unlock_irqrestore(&musb->lock, flags);
+ } else {
+ schedule_work(&cppi41_channel->dma_completion);
+ }
+ }
+}
+
static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
{
struct cppi41_dma_controller *controller;
@@ -228,6 +267,14 @@ static void cppi41_dma_callback(void *private_data)
transferred < cppi41_channel->packet_sz)
cppi41_channel->prog_len = 0;

+ if (!cppi41_channel->is_tx) {
+ if (is_isoc(hw_ep, 1))
+ schedule_work(&cppi41_channel->dma_completion);
+ else
+ cppi41_trans_done(cppi41_channel);
+ goto out;
+ }
+
empty = musb_is_tx_fifo_empty(hw_ep);
if (empty) {
cppi41_trans_done(cppi41_channel);
@@ -264,6 +311,10 @@ static void cppi41_dma_callback(void *private_data)
goto out;
}
}
+ if (is_isoc(hw_ep, 0)) {
+ schedule_work(&cppi41_channel->dma_completion);
+ goto out;
+ }
list_add_tail(&cppi41_channel->tx_check,
&controller->early_tx_list);
if (!hrtimer_active(&controller->early_tx)) {
@@ -620,6 +671,8 @@ static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
cppi41_channel->port_num = port;
cppi41_channel->is_tx = is_tx;
INIT_LIST_HEAD(&cppi41_channel->tx_check);
+ INIT_WORK(&cppi41_channel->dma_completion,
+ cppi_trans_done_work);

musb_dma = &cppi41_channel->channel;
musb_dma->private_data = cppi41_channel;
--
1.8.1

2014-01-27 09:37:41

by George Cherian

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Subject: [PATCH v2 1/3] usb: musb: musb_host: Enable ISOCH IN handling for AM335x host

Enable the isochrounous IN handling for AM335x HOST.
Reprogram CPPI to receive consecutive ISOCH frames in the same URB.

Signed-off-by: George Cherian <[email protected]>
---
drivers/usb/musb/musb_host.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index ed45572..79b7510 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1691,7 +1691,8 @@ void musb_host_rx(struct musb *musb, u8 epnum)
| MUSB_RXCSR_RXPKTRDY);
musb_writew(hw_ep->regs, MUSB_RXCSR, val);

-#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
+#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
+ defined(CONFIG_USB_TI_CPPI41_DMA)
if (usb_pipeisoc(pipe)) {
struct usb_iso_packet_descriptor *d;

@@ -1704,10 +1705,30 @@ void musb_host_rx(struct musb *musb, u8 epnum)
if (d->status != -EILSEQ && d->status != -EOVERFLOW)
d->status = 0;

- if (++qh->iso_idx >= urb->number_of_packets)
+ if (++qh->iso_idx >= urb->number_of_packets) {
done = true;
- else
+ } else {
+#if defined(CONFIG_USB_TI_CPPI41_DMA)
+ struct dma_controller *c;
+ dma_addr_t *buf;
+ u32 length, ret;
+
+ c = musb->dma_controller;
+ buf = (void *)
+ urb->iso_frame_desc[qh->iso_idx].offset
+ + (u32)urb->transfer_dma;
+
+ length =
+ urb->iso_frame_desc[qh->iso_idx].length;
+
+ val |= MUSB_RXCSR_DMAENAB;
+ musb_writew(hw_ep->regs, MUSB_RXCSR, val);
+
+ ret = c->channel_program(dma, qh->maxpacket,
+ 0, (u32) buf, length);
+#endif
done = false;
+ }

} else {
/* done if urb buffer is full or short packet is recd */
@@ -1747,7 +1768,8 @@ void musb_host_rx(struct musb *musb, u8 epnum)
}

/* we are expecting IN packets */
-#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
+#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
+ defined(CONFIG_USB_TI_CPPI41_DMA)
if (dma) {
struct dma_controller *c;
u16 rx_count;
--
1.8.1

2014-01-27 09:38:46

by George Cherian

[permalink] [raw]
Subject: [PATCH v2 2/3] usb: musb: musb_cppi41: Make CPPI aware of high bandwidth transfers

Enable CPPI to handle high bandwidth transfers, especially to support
webcam captures. Use a single bd to get the whole of the data in case of
high bandwidth transfers.

Signed-off-by: George Cherian <[email protected]>
---
drivers/usb/musb/musb_cppi41.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index f889296..39ee516 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -448,12 +448,25 @@ static int cppi41_dma_channel_program(struct dma_channel *channel,
dma_addr_t dma_addr, u32 len)
{
int ret;
+ struct cppi41_dma_channel *cppi41_channel = channel->private_data;
+ int hb_mult = 0;

BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
channel->status == MUSB_DMA_STATUS_BUSY);

+ if (is_host_active(cppi41_channel->controller->musb)) {
+ if (cppi41_channel->is_tx)
+ hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
+ else
+ hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
+ }
+
channel->status = MUSB_DMA_STATUS_BUSY;
channel->actual_len = 0;
+
+ if (hb_mult)
+ packet_sz = hb_mult * (packet_sz & 0x7FF);
+
ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
if (!ret)
channel->status = MUSB_DMA_STATUS_FREE;
--
1.8.1