i2c-msm-v2: Create rx completion object for dma mode

Use dedicated rx completion object for DMA transfer mode.
Currently a single completion object is being used for tx, BAM
driver can signal for tx complete while there can be rx process
in active stage. Resulting in BAM_ERROR_IRQ for the pipe connect
as part of the next BAM transfer. Use rx completion callback to
wait for BAM to complete rx transfer.

Change-Id: I65677ed0791c231622a0c33b44f619675a3d8f93
Signed-off-by: Shrey Vijay <shreyv@codeaurora.org>

2 files changed, 24 insertions, 6 deletions

diff --git a/drivers/i2c/busses/i2c-msm-v2.c b/drivers/i2c/busses/i2c-msm-v2.c
index bf2a1dd7cf15..7f98d9f527b9 100644
--- a/drivers/i2c/busses/i2c-msm-v2.c
+++ b/drivers/i2c/busses/i2c-msm-v2.c
@@ -1151,12 +1151,20 @@ static void i2c_msm_dma_xfer_unprepare(struct i2c_msm_ctrl *ctrl)
 							buf_itr->dma_dir);
 }
 
-static void i2c_msm_dma_callback_xfer_complete(void *dma_async_param)
+static void i2c_msm_dma_callback_tx_complete(void *dma_async_param)
 {
 	struct i2c_msm_ctrl *ctrl = dma_async_param;
+
 	complete(&ctrl->xfer.complete);
 }
 
+static void i2c_msm_dma_callback_rx_complete(void *dma_async_param)
+{
+	struct i2c_msm_ctrl *ctrl = dma_async_param;
+
+	complete(&ctrl->xfer.rx_complete);
+}
+
 /*
  * i2c_msm_dma_xfer_process: Queue transfers to DMA
  * @pre 1)QUP is in run state. 2) i2c_msm_dma_xfer_prepare() was called.
@@ -1269,14 +1277,16 @@ static int i2c_msm_dma_xfer_process(struct i2c_msm_ctrl *ctrl)
 	}
 
 	/* callback defined for tx dma desc */
-	dma_desc_tx->callback       = i2c_msm_dma_callback_xfer_complete;
+	dma_desc_tx->callback       = i2c_msm_dma_callback_tx_complete;
 	dma_desc_tx->callback_param = ctrl;
 	dmaengine_submit(dma_desc_tx);
 	dma_async_issue_pending(tx->dma_chan);
 
 	/* queue the rx dma desc */
 	dma_desc_rx = dmaengine_prep_slave_sg(rx->dma_chan, sg_rx,
-					sg_rx_itr - sg_rx, rx->dir, 0);
+					sg_rx_itr - sg_rx, rx->dir,
+					(SPS_IOVEC_FLAG_EOT |
+							SPS_IOVEC_FLAG_NWD));
 	if (dma_desc_rx < 0) {
 		dev_err(ctrl->dev,
 			"error dmaengine_prep_slave_sg rx:%ld\n",
@@ -1285,6 +1295,8 @@ static int i2c_msm_dma_xfer_process(struct i2c_msm_ctrl *ctrl)
 		goto dma_xfer_end;
 	}
 
+	dma_desc_rx->callback       = i2c_msm_dma_callback_rx_complete;
+	dma_desc_rx->callback_param = ctrl;
 	dmaengine_submit(dma_desc_rx);
 	dma_async_issue_pending(rx->dma_chan);
 
@@ -1297,6 +1309,8 @@ static int i2c_msm_dma_xfer_process(struct i2c_msm_ctrl *ctrl)
 	}
 
 	ret = i2c_msm_xfer_wait_for_completion(ctrl, &ctrl->xfer.complete);
+	if (!ret && ctrl->xfer.rx_cnt)
+		i2c_msm_xfer_wait_for_completion(ctrl, &ctrl->xfer.rx_complete);
 
 dma_xfer_end:
 	/* free scatter-gather lists */
@@ -2054,13 +2068,14 @@ static int i2c_msm_xfer_wait_for_completion(struct i2c_msm_ctrl *ctrl,
 	long  time_left;
 	int   ret = 0;
 
-	time_left = wait_for_completion_timeout(complete, xfer->timeout);
+	time_left = wait_for_completion_timeout(complete,
+						xfer->timeout);
 	if (!time_left) {
 		xfer->err = I2C_MSM_ERR_TIMEOUT;
 		i2c_msm_dbg_dump_diag(ctrl, false, 0, 0);
 		ret = -EIO;
 		i2c_msm_prof_evnt_add(ctrl, MSM_ERR, I2C_MSM_COMPLT_FL,
-						xfer->timeout, time_left, 0);
+					xfer->timeout, time_left, 0);
 	} else {
 		/* return an error if one detected by ISR */
 		if (xfer->err)
@@ -2327,6 +2342,8 @@ i2c_msm_frmwrk_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	xfer->tx_ovrhd_cnt = 0;
 	atomic_set(&xfer->event_cnt, 0);
 	init_completion(&xfer->complete);
+	init_completion(&xfer->rx_complete);
+
 	xfer->cur_buf.is_init = false;
 	xfer->cur_buf.msg_idx = 0;
 
diff --git a/include/linux/i2c/i2c-msm-v2.h b/include/linux/i2c/i2c-msm-v2.h
index 54974c02725d..468a1d6fa58d 100644
--- a/include/linux/i2c/i2c-msm-v2.h
+++ b/include/linux/i2c/i2c-msm-v2.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2014-2015,2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -552,6 +552,7 @@ struct i2c_msm_xfer {
 	int                        msg_cnt;
 	enum i2c_msm_xfer_mode_id  mode_id;
 	struct completion          complete;
+	struct completion          rx_complete;
 	size_t                     rx_cnt;
 	size_t                     tx_cnt;
 	size_t                     rx_ovrhd_cnt;