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From:   Siddharth Vadapalli <s-vadapalli@ti.com>
To:     <peter.ujfalusi@gmail.com>, <vkoul@kernel.org>
CC:     <dmaengine@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <srk@ti.com>,
        <vigneshr@ti.com>, <s-vadapalli@ti.com>
Subject: [PATCH] dmaengine: ti: k3-udma-glue: do not create glue dma devices for udma channels
Date:   Tue, 4 Apr 2023 13:41:58 +0530
Message-ID: <20230404081158.1266530-1-s-vadapalli@ti.com>
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From: Grygorii Strashko <grygorii.strashko@ti.com>

In case K3 DMA glue layer is using UDMA channels (AM65/J721E/J7200) it
doesn't need to create own DMA devices per RX/TX channels as they are never
used and just waste resources. The UDMA based platforms are coherent and
UDMA device iteslf is used for DMA memory management.

Hence, update K3 DMA glue layer to create K3 DMA glue DMA devices per RX/TX
channels only in case of PKTDMA (AM64) where coherency configurable per DMA
channel.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
 drivers/dma/ti/k3-udma-glue.c | 70 +++++++++++++++++------------------
 1 file changed, 34 insertions(+), 36 deletions(-)

diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
index 789193ed0386..b0c9572b0d02 100644
--- a/drivers/dma/ti/k3-udma-glue.c
+++ b/drivers/dma/ti/k3-udma-glue.c
@@ -293,19 +293,18 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 	}
 	tx_chn->udma_tchan_id = xudma_tchan_get_id(tx_chn->udma_tchanx);
 
-	tx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
-	tx_chn->common.chan_dev.parent = xudma_get_device(tx_chn->common.udmax);
-	dev_set_name(&tx_chn->common.chan_dev, "tchan%d-0x%04x",
-		     tx_chn->udma_tchan_id, tx_chn->common.dst_thread);
-	ret = device_register(&tx_chn->common.chan_dev);
-	if (ret) {
-		dev_err(dev, "Channel Device registration failed %d\n", ret);
-		put_device(&tx_chn->common.chan_dev);
-		tx_chn->common.chan_dev.parent = NULL;
-		goto err;
-	}
-
 	if (xudma_is_pktdma(tx_chn->common.udmax)) {
+		tx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
+		tx_chn->common.chan_dev.parent = xudma_get_device(tx_chn->common.udmax);
+		dev_set_name(&tx_chn->common.chan_dev, "tchan%d-0x%04x",
+			     tx_chn->udma_tchan_id, tx_chn->common.dst_thread);
+		ret = device_register(&tx_chn->common.chan_dev);
+		if (ret) {
+			dev_err(dev, "Channel Device registration failed %d\n", ret);
+			tx_chn->common.chan_dev.parent = NULL;
+			goto err;
+		}
+
 		/* prepare the channel device as coherent */
 		tx_chn->common.chan_dev.dma_coherent = true;
 		dma_coerce_mask_and_coherent(&tx_chn->common.chan_dev,
@@ -912,19 +911,18 @@ k3_udma_glue_request_rx_chn_priv(struct device *dev, const char *name,
 	}
 	rx_chn->udma_rchan_id = xudma_rchan_get_id(rx_chn->udma_rchanx);
 
-	rx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
-	rx_chn->common.chan_dev.parent = xudma_get_device(rx_chn->common.udmax);
-	dev_set_name(&rx_chn->common.chan_dev, "rchan%d-0x%04x",
-		     rx_chn->udma_rchan_id, rx_chn->common.src_thread);
-	ret = device_register(&rx_chn->common.chan_dev);
-	if (ret) {
-		dev_err(dev, "Channel Device registration failed %d\n", ret);
-		put_device(&rx_chn->common.chan_dev);
-		rx_chn->common.chan_dev.parent = NULL;
-		goto err;
-	}
-
 	if (xudma_is_pktdma(rx_chn->common.udmax)) {
+		rx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
+		rx_chn->common.chan_dev.parent = xudma_get_device(rx_chn->common.udmax);
+		dev_set_name(&rx_chn->common.chan_dev, "rchan%d-0x%04x",
+			     rx_chn->udma_rchan_id, rx_chn->common.src_thread);
+		ret = device_register(&rx_chn->common.chan_dev);
+		if (ret) {
+			dev_err(dev, "Channel Device registration failed %d\n", ret);
+			rx_chn->common.chan_dev.parent = NULL;
+			goto err;
+		}
+
 		/* prepare the channel device as coherent */
 		rx_chn->common.chan_dev.dma_coherent = true;
 		dma_coerce_mask_and_coherent(&rx_chn->common.chan_dev,
@@ -1044,19 +1042,19 @@ k3_udma_glue_request_remote_rx_chn(struct device *dev, const char *name,
 		goto err;
 	}
 
-	rx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
-	rx_chn->common.chan_dev.parent = xudma_get_device(rx_chn->common.udmax);
-	dev_set_name(&rx_chn->common.chan_dev, "rchan_remote-0x%04x",
-		     rx_chn->common.src_thread);
-	ret = device_register(&rx_chn->common.chan_dev);
-	if (ret) {
-		dev_err(dev, "Channel Device registration failed %d\n", ret);
-		put_device(&rx_chn->common.chan_dev);
-		rx_chn->common.chan_dev.parent = NULL;
-		goto err;
-	}
-
 	if (xudma_is_pktdma(rx_chn->common.udmax)) {
+		rx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
+		rx_chn->common.chan_dev.parent = xudma_get_device(rx_chn->common.udmax);
+		dev_set_name(&rx_chn->common.chan_dev, "rchan_remote-0x%04x",
+			     rx_chn->common.src_thread);
+
+		ret = device_register(&rx_chn->common.chan_dev);
+		if (ret) {
+			dev_err(dev, "Channel Device registration failed %d\n", ret);
+			rx_chn->common.chan_dev.parent = NULL;
+			goto err;
+		}
+
 		/* prepare the channel device as coherent */
 		rx_chn->common.chan_dev.dma_coherent = true;
 		dma_coerce_mask_and_coherent(&rx_chn->common.chan_dev,
-- 
2.25.1