[PATCH v1 2/2] soundwire: qcom: Add set_channel_map support to SWR master DAI

[Mohammad Rafi Shaik <mohammad.rafi.shaik@oss.qualcomm.com>]

Add .set_channel_map support to the SWR master DAI so the ASoC
layer can program per-port channel masks used by port_enable().

Fix several issues in channel map handling: clip programming to
available ports to avoid out-of-bounds access, use 1-based port
indexing, and store TX/RX masks separately. Also track per-direction
validity and select the effective mask based on port role to avoid
incorrect precedence and ensure full-width masks are preserved.
Fall back to the SDW stream-provided channel mask when no mapping is
configured, preserving existing behaviour.

Fixes: 7796c97df6b1 ("soundwire: qcom: Add set_channel_map api support")
Reported-by: Yongqin Liu <yongqin.liu@linaro.org>
Closes: https://lore.kernel.org/all/4ddd6855-3817-4dc4-81c4-d8ddaa039865@oss.qualcomm.com/
Reported-by: Jie Gan <jie.gan@oss.qualcomm.com>
Closes: https://lore.kernel.org/all/CAMSo37U1kJq_gK8jiW9iMbhHXtn=Chr7NawiK4fPUPj4kyqH2w@mail.gmail.com/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/33fe8fe7-719a-405a-9ed2-d9f816ce1d57@sabinyo.mountain/
Signed-off-by: Mohammad Rafi Shaik <mohammad.rafi.shaik@oss.qualcomm.com>
---
 drivers/soundwire/qcom.c | 54 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 3d8f5a81eff1..e63736e82478 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -160,6 +160,10 @@ struct qcom_swrm_port_config {
 	u8 word_length;
 	u8 blk_group_count;
 	u8 lane_control;
+	u8 tx_ch_mask;
+	u8 rx_ch_mask;
+	bool tx_ch_map_valid;
+	bool rx_ch_map_valid;
 };
 
 /*
@@ -1109,12 +1113,28 @@ static int qcom_swrm_port_enable(struct sdw_bus *bus,
 {
 	u32 reg;
 	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	struct qcom_swrm_port_config *pcfg;
 	u32 val;
 	u32 offset = ctrl->reg_layout[SWRM_OFFSET_DP_PORT_CTRL_BANK];
 
 	reg = SWRM_DPn_PORT_CTRL_BANK(offset, enable_ch->port_num, bank);
 
 	ctrl->reg_read(ctrl, reg, &val);
+	pcfg = &ctrl->pconfig[enable_ch->port_num];
+
+	mutex_lock(&ctrl->port_lock);
+	if (enable_ch->port_num <= ctrl->num_dout_ports) {
+		if (pcfg->rx_ch_map_valid)
+			enable_ch->ch_mask = pcfg->rx_ch_mask;
+		else if (pcfg->tx_ch_map_valid)
+			enable_ch->ch_mask = pcfg->tx_ch_mask;
+	} else {
+		if (pcfg->tx_ch_map_valid)
+			enable_ch->ch_mask = pcfg->tx_ch_mask;
+		else if (pcfg->rx_ch_map_valid)
+			enable_ch->ch_mask = pcfg->rx_ch_mask;
+	}
+	mutex_unlock(&ctrl->port_lock);
 
 	if (enable_ch->enable)
 		val |= (enable_ch->ch_mask << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
@@ -1334,6 +1354,39 @@ static void *qcom_swrm_get_sdw_stream(struct snd_soc_dai *dai, int direction)
 	return ctrl->sruntime[dai->id];
 }
 
+static int qcom_swrm_set_channel_map(struct snd_soc_dai *dai,
+				     unsigned int tx_num, const unsigned int *tx_slot,
+				     unsigned int rx_num, const unsigned int *rx_slot)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+	unsigned int max_ports = ctrl->nports;
+	unsigned int i;
+
+	if ((tx_num && !tx_slot) || (rx_num && !rx_slot))
+		return -EINVAL;
+
+	mutex_lock(&ctrl->port_lock);
+	for (i = 1; i <= max_ports; i++) {
+		ctrl->pconfig[i].tx_ch_map_valid = false;
+		ctrl->pconfig[i].rx_ch_map_valid = false;
+
+		/* TX setup */
+		if (tx_slot && i < tx_num) {
+			ctrl->pconfig[i].tx_ch_mask = tx_slot[i];
+			ctrl->pconfig[i].tx_ch_map_valid = true;
+		}
+
+		/* RX setup */
+		if (rx_slot && i < rx_num) {
+			ctrl->pconfig[i].rx_ch_mask = rx_slot[i];
+			ctrl->pconfig[i].rx_ch_map_valid = true;
+		}
+	}
+	mutex_unlock(&ctrl->port_lock);
+
+	return 0;
+}
+
 static int qcom_swrm_startup(struct snd_pcm_substream *substream,
 			     struct snd_soc_dai *dai)
 {
@@ -1370,6 +1423,7 @@ static const struct snd_soc_dai_ops qcom_swrm_pdm_dai_ops = {
 	.shutdown = qcom_swrm_shutdown,
 	.set_stream = qcom_swrm_set_sdw_stream,
 	.get_stream = qcom_swrm_get_sdw_stream,
+	.set_channel_map = qcom_swrm_set_channel_map,
 };
 
 static const struct snd_soc_component_driver qcom_swrm_dai_component = {
-- 
2.34.1