[PATCH v2 3/4] dmaengine: ti: k3-udma-glue: Add function to request TX channel by ID

[Siddharth Vadapalli <s-vadapalli@ti.com>]

The existing function k3_udma_glue_request_tx_chn() supports requesting
a TX DMA channel by its name. Add support to request TX channel by ID in
the form of a new function k3_udma_glue_request_tx_chn_by_id() and export
it for use by drivers which are probed by alternate methods (non
device-tree) but still wish to make use of the existing DMA APIs. Such
drivers could be informed about the TX channel to use by RPMsg for example.

Since the implementation of k3_udma_glue_request_tx_chn_by_id() reuses
most of the code in k3_udma_glue_request_tx_chn(), create a new function
for the common code named as k3_udma_glue_request_tx_chn_common().

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
Changes since v1:
- Updated commit message indicating the use-case for which the patch is
  being added.

 drivers/dma/ti/k3-udma-glue.c    | 101 +++++++++++++++++++++++--------
 include/linux/dma/k3-udma-glue.h |   4 ++
 2 files changed, 79 insertions(+), 26 deletions(-)

diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
index eff1ae3d3efe..ea5119a5e8eb 100644
--- a/drivers/dma/ti/k3-udma-glue.c
+++ b/drivers/dma/ti/k3-udma-glue.c
@@ -274,29 +274,13 @@ static int k3_udma_glue_cfg_tx_chn(struct k3_udma_glue_tx_channel *tx_chn)
 	return tisci_rm->tisci_udmap_ops->tx_ch_cfg(tisci_rm->tisci, &req);
 }
 
-struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
-		const char *name, struct k3_udma_glue_tx_channel_cfg *cfg)
+static int
+k3_udma_glue_request_tx_chn_common(struct device *dev,
+				   struct k3_udma_glue_tx_channel *tx_chn,
+				   struct k3_udma_glue_tx_channel_cfg *cfg)
 {
-	struct k3_udma_glue_tx_channel *tx_chn;
 	int ret;
 
-	tx_chn = devm_kzalloc(dev, sizeof(*tx_chn), GFP_KERNEL);
-	if (!tx_chn)
-		return ERR_PTR(-ENOMEM);
-
-	tx_chn->common.dev = dev;
-	tx_chn->common.swdata_size = cfg->swdata_size;
-	tx_chn->tx_pause_on_err = cfg->tx_pause_on_err;
-	tx_chn->tx_filt_einfo = cfg->tx_filt_einfo;
-	tx_chn->tx_filt_pswords = cfg->tx_filt_pswords;
-	tx_chn->tx_supr_tdpkt = cfg->tx_supr_tdpkt;
-
-	/* parse of udmap channel */
-	ret = of_k3_udma_glue_parse_chn(dev->of_node, name,
-					&tx_chn->common, true);
-	if (ret)
-		goto err;
-
 	tx_chn->common.hdesc_size = cppi5_hdesc_calc_size(tx_chn->common.epib,
 						tx_chn->common.psdata_size,
 						tx_chn->common.swdata_size);
@@ -312,7 +296,7 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 	if (IS_ERR(tx_chn->udma_tchanx)) {
 		ret = PTR_ERR(tx_chn->udma_tchanx);
 		dev_err(dev, "UDMAX tchanx get err %d\n", ret);
-		goto err;
+		return ret;
 	}
 	tx_chn->udma_tchan_id = xudma_tchan_get_id(tx_chn->udma_tchanx);
 
@@ -325,7 +309,7 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 		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;
+		return ret;
 	}
 
 	if (xudma_is_pktdma(tx_chn->common.udmax)) {
@@ -349,7 +333,7 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 					     &tx_chn->ringtxcq);
 	if (ret) {
 		dev_err(dev, "Failed to get TX/TXCQ rings %d\n", ret);
-		goto err;
+		return ret;
 	}
 
 	/* Set the dma_dev for the rings to be configured */
@@ -365,13 +349,13 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 	ret = k3_ringacc_ring_cfg(tx_chn->ringtx, &cfg->tx_cfg);
 	if (ret) {
 		dev_err(dev, "Failed to cfg ringtx %d\n", ret);
-		goto err;
+		return ret;
 	}
 
 	ret = k3_ringacc_ring_cfg(tx_chn->ringtxcq, &cfg->txcq_cfg);
 	if (ret) {
 		dev_err(dev, "Failed to cfg ringtx %d\n", ret);
-		goto err;
+		return ret;
 	}
 
 	/* request and cfg psi-l */
@@ -382,11 +366,42 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 	ret = k3_udma_glue_cfg_tx_chn(tx_chn);
 	if (ret) {
 		dev_err(dev, "Failed to cfg tchan %d\n", ret);
-		goto err;
+		return ret;
 	}
 
 	k3_udma_glue_dump_tx_chn(tx_chn);
 
+	return 0;
+}
+
+struct k3_udma_glue_tx_channel *
+k3_udma_glue_request_tx_chn(struct device *dev, const char *name,
+			    struct k3_udma_glue_tx_channel_cfg *cfg)
+{
+	struct k3_udma_glue_tx_channel *tx_chn;
+	int ret;
+
+	tx_chn = devm_kzalloc(dev, sizeof(*tx_chn), GFP_KERNEL);
+	if (!tx_chn)
+		return ERR_PTR(-ENOMEM);
+
+	tx_chn->common.dev = dev;
+	tx_chn->common.swdata_size = cfg->swdata_size;
+	tx_chn->tx_pause_on_err = cfg->tx_pause_on_err;
+	tx_chn->tx_filt_einfo = cfg->tx_filt_einfo;
+	tx_chn->tx_filt_pswords = cfg->tx_filt_pswords;
+	tx_chn->tx_supr_tdpkt = cfg->tx_supr_tdpkt;
+
+	/* parse of udmap channel */
+	ret = of_k3_udma_glue_parse_chn(dev->of_node, name,
+					&tx_chn->common, true);
+	if (ret)
+		goto err;
+
+	ret = k3_udma_glue_request_tx_chn_common(dev, tx_chn, cfg);
+	if (ret)
+		goto err;
+
 	return tx_chn;
 
 err:
@@ -395,6 +410,40 @@ struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(k3_udma_glue_request_tx_chn);
 
+struct k3_udma_glue_tx_channel *
+k3_udma_glue_request_tx_chn_by_id(struct device *dev, struct k3_udma_glue_tx_channel_cfg *cfg,
+				  struct device_node *udmax_np, u32 thread_id)
+{
+	struct k3_udma_glue_tx_channel *tx_chn;
+	int ret;
+
+	tx_chn = devm_kzalloc(dev, sizeof(*tx_chn), GFP_KERNEL);
+	if (!tx_chn)
+		return ERR_PTR(-ENOMEM);
+
+	tx_chn->common.dev = dev;
+	tx_chn->common.swdata_size = cfg->swdata_size;
+	tx_chn->tx_pause_on_err = cfg->tx_pause_on_err;
+	tx_chn->tx_filt_einfo = cfg->tx_filt_einfo;
+	tx_chn->tx_filt_pswords = cfg->tx_filt_pswords;
+	tx_chn->tx_supr_tdpkt = cfg->tx_supr_tdpkt;
+
+	ret = of_k3_udma_glue_parse_chn_by_id(udmax_np, &tx_chn->common, true, thread_id);
+	if (ret)
+		goto err;
+
+	ret = k3_udma_glue_request_tx_chn_common(dev, tx_chn, cfg);
+	if (ret)
+		goto err;
+
+	return tx_chn;
+
+err:
+	k3_udma_glue_release_tx_chn(tx_chn);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(k3_udma_glue_request_tx_chn_by_id);
+
 void k3_udma_glue_release_tx_chn(struct k3_udma_glue_tx_channel *tx_chn)
 {
 	if (tx_chn->psil_paired) {
diff --git a/include/linux/dma/k3-udma-glue.h b/include/linux/dma/k3-udma-glue.h
index e443be4d3b4b..6205d84430ca 100644
--- a/include/linux/dma/k3-udma-glue.h
+++ b/include/linux/dma/k3-udma-glue.h
@@ -26,6 +26,10 @@ struct k3_udma_glue_tx_channel;
 struct k3_udma_glue_tx_channel *k3_udma_glue_request_tx_chn(struct device *dev,
 		const char *name, struct k3_udma_glue_tx_channel_cfg *cfg);
 
+struct k3_udma_glue_tx_channel *
+k3_udma_glue_request_tx_chn_by_id(struct device *dev, struct k3_udma_glue_tx_channel_cfg *cfg,
+				  struct device_node *udmax_np, u32 thread_id);
+
 void k3_udma_glue_release_tx_chn(struct k3_udma_glue_tx_channel *tx_chn);
 int k3_udma_glue_push_tx_chn(struct k3_udma_glue_tx_channel *tx_chn,
 			     struct cppi5_host_desc_t *desc_tx,
-- 
2.34.1