diff options
Diffstat (limited to 'drivers/usb/musb/musb_cppi41.c')
| -rw-r--r-- | drivers/usb/musb/musb_cppi41.c | 113 |
1 files changed, 108 insertions, 5 deletions
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index 83a8a1d125ac..a12bd30401e0 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; @@ -96,11 +99,23 @@ static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel) cppi41_channel->usb_toggle = toggle; } +static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep) +{ + u8 epnum = hw_ep->epnum; + struct musb *musb = hw_ep->musb; + void __iomem *epio = musb->endpoints[epnum].regs; + u16 csr; + + csr = musb_readw(epio, MUSB_TXCSR); + if (csr & MUSB_TXCSR_TXPKTRDY) + return false; + return true; +} + static void cppi41_dma_callback(void *private_data); -static void cppi41_trans_done(struct dma_channel *channel) +static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel) { - 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; @@ -138,7 +153,7 @@ static void cppi41_trans_done(struct dma_channel *channel) 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); @@ -150,6 +165,41 @@ static void cppi41_trans_done(struct dma_channel *channel) } } +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; @@ -159,6 +209,7 @@ static void cppi41_dma_callback(void *private_data) unsigned long flags; struct dma_tx_state txstate; u32 transferred; + bool empty; spin_lock_irqsave(&musb->lock, flags); @@ -177,8 +228,52 @@ static void cppi41_dma_callback(void *private_data) transferred < cppi41_channel->packet_sz) cppi41_channel->prog_len = 0; - cppi41_trans_done(channel); - + 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); } @@ -377,6 +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 */ @@ -401,6 +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; @@ -508,6 +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; @@ -533,6 +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); } @@ -552,6 +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; |