diff options
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 82 | ||||
| -rw-r--r-- | include/linux/mhi_ep.h | 9 |
2 files changed, 91 insertions, 0 deletions
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index e2ed10b4a9d2..660d1e9791d3 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -434,6 +434,88 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem return 0; } +/* TODO: Handle partially formed TDs */ +int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb) +{ + struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl; + struct mhi_ep_chan *mhi_chan = mhi_dev->dl_chan; + struct device *dev = &mhi_chan->mhi_dev->dev; + struct mhi_ring_element *el; + u32 buf_left, read_offset; + struct mhi_ep_ring *ring; + enum mhi_ev_ccs code; + void *read_addr; + u64 write_addr; + size_t tr_len; + u32 tre_len; + int ret; + + buf_left = skb->len; + ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring; + + mutex_lock(&mhi_chan->lock); + + do { + /* Don't process the transfer ring if the channel is not in RUNNING state */ + if (mhi_chan->state != MHI_CH_STATE_RUNNING) { + dev_err(dev, "Channel not available\n"); + ret = -ENODEV; + goto err_exit; + } + + if (mhi_ep_queue_is_empty(mhi_dev, DMA_FROM_DEVICE)) { + dev_err(dev, "TRE not available!\n"); + ret = -ENOSPC; + goto err_exit; + } + + el = &ring->ring_cache[ring->rd_offset]; + tre_len = MHI_TRE_DATA_GET_LEN(el); + + tr_len = min(buf_left, tre_len); + read_offset = skb->len - buf_left; + read_addr = skb->data + read_offset; + write_addr = MHI_TRE_DATA_GET_PTR(el); + + dev_dbg(dev, "Writing %zd bytes to channel (%u)\n", tr_len, ring->ch_id); + ret = mhi_cntrl->write_to_host(mhi_cntrl, read_addr, write_addr, tr_len); + if (ret < 0) { + dev_err(dev, "Error writing to the channel\n"); + goto err_exit; + } + + buf_left -= tr_len; + /* + * For all TREs queued by the host for DL channel, only the EOT flag will be set. + * If the packet doesn't fit into a single TRE, send the OVERFLOW event to + * the host so that the host can adjust the packet boundary to next TREs. Else send + * the EOT event to the host indicating the packet boundary. + */ + if (buf_left) + code = MHI_EV_CC_OVERFLOW; + else + code = MHI_EV_CC_EOT; + + ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, tr_len, code); + if (ret) { + dev_err(dev, "Error sending transfer completion event\n"); + goto err_exit; + } + + mhi_ep_ring_inc_index(ring); + } while (buf_left); + + mutex_unlock(&mhi_chan->lock); + + return 0; + +err_exit: + mutex_unlock(&mhi_chan->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_ep_queue_skb); + static int mhi_ep_cache_host_cfg(struct mhi_ep_cntrl *mhi_cntrl) { size_t cmd_ctx_host_size, ch_ctx_host_size, ev_ctx_host_size; diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index eecc8f35d630..478aece17046 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -265,4 +265,13 @@ void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl); */ bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir); +/** + * mhi_ep_queue_skb - Send SKBs to host over MHI Endpoint + * @mhi_dev: Device associated with the DL channel + * @skb: SKBs to be queued + * + * Return: 0 if the SKBs has been sent successfully, a negative error code otherwise. + */ +int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb); + #endif |