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path: root/drivers/usb/musb/musb_cppi41.c
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Diffstat (limited to 'drivers/usb/musb/musb_cppi41.c')
-rw-r--r--drivers/usb/musb/musb_cppi41.c164
1 files changed, 140 insertions, 24 deletions
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index ff9d6de..a12bd30 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -38,6 +38,7 @@ struct cppi41_dma_channel {
u32 prog_len;
u32 transferred;
u32 packet_sz;
+ struct list_head tx_check;
};
#define MUSB_DMA_NUM_CHANNELS 15
@@ -47,6 +48,8 @@ struct cppi41_dma_controller {
struct cppi41_dma_channel rx_channel[MUSB_DMA_NUM_CHANNELS];
struct cppi41_dma_channel tx_channel[MUSB_DMA_NUM_CHANNELS];
struct musb *musb;
+ struct hrtimer early_tx;
+ struct list_head early_tx_list;
u32 rx_mode;
u32 tx_mode;
u32 auto_req;
@@ -96,31 +99,27 @@ static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
cppi41_channel->usb_toggle = toggle;
}
-static void cppi41_dma_callback(void *private_data)
+static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
{
- struct dma_channel *channel = private_data;
- struct cppi41_dma_channel *cppi41_channel = channel->private_data;
- struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
- struct musb *musb = hw_ep->musb;
- unsigned long flags;
- struct dma_tx_state txstate;
- u32 transferred;
+ u8 epnum = hw_ep->epnum;
+ struct musb *musb = hw_ep->musb;
+ void __iomem *epio = musb->endpoints[epnum].regs;
+ u16 csr;
- spin_lock_irqsave(&musb->lock, flags);
+ csr = musb_readw(epio, MUSB_TXCSR);
+ if (csr & MUSB_TXCSR_TXPKTRDY)
+ return false;
+ return true;
+}
- dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
- &txstate);
- transferred = cppi41_channel->prog_len - txstate.residue;
- cppi41_channel->transferred += transferred;
+static void cppi41_dma_callback(void *private_data);
- dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
- hw_ep->epnum, cppi41_channel->transferred,
- cppi41_channel->total_len);
+static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
+{
+ struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+ struct musb *musb = hw_ep->musb;
- update_rx_toggle(cppi41_channel);
-
- if (cppi41_channel->transferred == cppi41_channel->total_len ||
- transferred < cppi41_channel->packet_sz) {
+ if (!cppi41_channel->prog_len) {
/* done, complete */
cppi41_channel->channel.actual_len =
@@ -150,13 +149,11 @@ static void cppi41_dma_callback(void *private_data)
remain_bytes,
direction,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
- if (WARN_ON(!dma_desc)) {
- spin_unlock_irqrestore(&musb->lock, flags);
+ if (WARN_ON(!dma_desc))
return;
- }
dma_desc->callback = cppi41_dma_callback;
- dma_desc->callback_param = channel;
+ dma_desc->callback_param = &cppi41_channel->channel;
cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
dma_async_issue_pending(dc);
@@ -166,6 +163,117 @@ static void cppi41_dma_callback(void *private_data)
musb_writew(epio, MUSB_RXCSR, csr);
}
}
+}
+
+static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
+{
+ struct cppi41_dma_controller *controller;
+ struct cppi41_dma_channel *cppi41_channel, *n;
+ struct musb *musb;
+ unsigned long flags;
+ enum hrtimer_restart ret = HRTIMER_NORESTART;
+
+ controller = container_of(timer, struct cppi41_dma_controller,
+ early_tx);
+ musb = controller->musb;
+
+ spin_lock_irqsave(&musb->lock, flags);
+ list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
+ tx_check) {
+ bool empty;
+ struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+
+ empty = musb_is_tx_fifo_empty(hw_ep);
+ if (empty) {
+ list_del_init(&cppi41_channel->tx_check);
+ cppi41_trans_done(cppi41_channel);
+ }
+ }
+
+ if (!list_empty(&controller->early_tx_list)) {
+ ret = HRTIMER_RESTART;
+ hrtimer_forward_now(&controller->early_tx,
+ ktime_set(0, 150 * NSEC_PER_USEC));
+ }
+
+ spin_unlock_irqrestore(&musb->lock, flags);
+ return ret;
+}
+
+static void cppi41_dma_callback(void *private_data)
+{
+ struct dma_channel *channel = private_data;
+ struct cppi41_dma_channel *cppi41_channel = channel->private_data;
+ struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+ struct musb *musb = hw_ep->musb;
+ unsigned long flags;
+ struct dma_tx_state txstate;
+ u32 transferred;
+ bool empty;
+
+ spin_lock_irqsave(&musb->lock, flags);
+
+ dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
+ &txstate);
+ transferred = cppi41_channel->prog_len - txstate.residue;
+ cppi41_channel->transferred += transferred;
+
+ dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
+ hw_ep->epnum, cppi41_channel->transferred,
+ cppi41_channel->total_len);
+
+ update_rx_toggle(cppi41_channel);
+
+ if (cppi41_channel->transferred == cppi41_channel->total_len ||
+ transferred < cppi41_channel->packet_sz)
+ cppi41_channel->prog_len = 0;
+
+ empty = musb_is_tx_fifo_empty(hw_ep);
+ if (empty) {
+ cppi41_trans_done(cppi41_channel);
+ } else {
+ struct cppi41_dma_controller *controller;
+ /*
+ * On AM335x it has been observed that the TX interrupt fires
+ * too early that means the TXFIFO is not yet empty but the DMA
+ * engine says that it is done with the transfer. We don't
+ * receive a FIFO empty interrupt so the only thing we can do is
+ * to poll for the bit. On HS it usually takes 2us, on FS around
+ * 110us - 150us depending on the transfer size.
+ * We spin on HS (no longer than than 25us and setup a timer on
+ * FS to check for the bit and complete the transfer.
+ */
+ controller = cppi41_channel->controller;
+
+ if (musb->g.speed == USB_SPEED_HIGH) {
+ unsigned wait = 25;
+
+ do {
+ empty = musb_is_tx_fifo_empty(hw_ep);
+ if (empty)
+ break;
+ wait--;
+ if (!wait)
+ break;
+ udelay(1);
+ } while (1);
+
+ empty = musb_is_tx_fifo_empty(hw_ep);
+ if (empty) {
+ cppi41_trans_done(cppi41_channel);
+ goto out;
+ }
+ }
+ list_add_tail(&cppi41_channel->tx_check,
+ &controller->early_tx_list);
+ if (!hrtimer_active(&controller->early_tx)) {
+ hrtimer_start_range_ns(&controller->early_tx,
+ ktime_set(0, 140 * NSEC_PER_USEC),
+ 40 * NSEC_PER_USEC,
+ HRTIMER_MODE_REL);
+ }
+ }
+out:
spin_unlock_irqrestore(&musb->lock, flags);
}
@@ -364,6 +472,8 @@ static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
WARN_ON(1);
return 1;
}
+ if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
+ return 0;
if (cppi41_channel->is_tx)
return 1;
/* AM335x Advisory 1.0.13. No workaround for device RX mode */
@@ -388,6 +498,7 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel)
if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
return 0;
+ list_del_init(&cppi41_channel->tx_check);
if (is_tx) {
csr = musb_readw(epio, MUSB_TXCSR);
csr &= ~MUSB_TXCSR_DMAENAB;
@@ -495,6 +606,7 @@ static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
cppi41_channel->controller = controller;
cppi41_channel->port_num = port;
cppi41_channel->is_tx = is_tx;
+ INIT_LIST_HEAD(&cppi41_channel->tx_check);
musb_dma = &cppi41_channel->channel;
musb_dma->private_data = cppi41_channel;
@@ -520,6 +632,7 @@ void dma_controller_destroy(struct dma_controller *c)
struct cppi41_dma_controller *controller = container_of(c,
struct cppi41_dma_controller, controller);
+ hrtimer_cancel(&controller->early_tx);
cppi41_dma_controller_stop(controller);
kfree(controller);
}
@@ -539,6 +652,9 @@ struct dma_controller *dma_controller_create(struct musb *musb,
if (!controller)
goto kzalloc_fail;
+ hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ controller->early_tx.function = cppi41_recheck_tx_req;
+ INIT_LIST_HEAD(&controller->early_tx_list);
controller->musb = musb;
controller->controller.channel_alloc = cppi41_dma_channel_allocate;
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