[PATCH v2 0/3] soundwire: qcom: add multi-master support

[PATCH v2 0/3] soundwire: qcom: add multi-master support

[Srinivas Kandagatla]

This patch series adds support to the multi-master in existing soundwire
controller driver.

On Qualcomm Glymur SoC, both TX and RX soundwire controllers are wired
up in multi master mode connecting to an SDCA compliant Tambora codec.

One of the two controllers (tx,rx) act as primary controller in this
instance its tx which provides clock and control and some data lines and
other controller instance in this case rx act as dependent controller
providing extra data lanes to primary controller. This is called multi
master mode in Qualcomm Soundwire controller.

Multi Master mode allows synchronous transport across two independent
soundwire masters. This includes synchronized clock-stop, clock-resume,
clock scaling and bank switch between both masters, the Primary master
will ensure that.

From the slave's point of view there is still one SoundWire bus with
one clock and one control lane; the extra DATA lanes just come from
a different pad on the SoC.

Currently the bindings are added in a way that its possible to add more
than one dependent, however to keep things simple the driver only
supports single dependent for now.

Topology (2+2 lane example):

     Primary IP                          Dependent IP
     +-----------------+                 +-----------------+
     |  MM_SYNC  <=====+=================+=====>  MM_SYNC  |
     |                 |                 |                 |
     |  SWR_CLK  ---+  |                 |                 |
     |  CTRL     ---+  |                 |                 |
     |  DATA0    ---+  |                 |  DATA0  ---+    |
     |  DATA1    ---+  |                 |  DATA1  ---+    |
     +--------------|--+                 +------------|----+
                    |                                 |
                    v                                 v
        +-----------+-----------+           +---------+---------+
        |  SWR_CLK, CTRL,       |           |  bus DATA2,       |
        |  bus DATA0, DATA1     |           |      DATA3        |
        +-----------+-----------+           +---------+---------+
                    |                                 |
                    +----------------+----------------+
                                     |
                                     v
                              +--------------+
                              |    Slave     |
                              +--------------+

Patch 1 adds two new DT properties qcom,multi-master-mode and
qcom,multi-master-peer for describing the pair.

Patch 2 wires up the primary and dependent roles in the driver.

Patch 3 programs SWRM_V3_MM_SYNC_CONFIG on both sides so their frame
generators lock to a single SWR_CLK.

Tested on Glymur (SC8480XP) CRD with WCD9378 in compute mode. HPH
playback and mic capture both work.

Changes in v2:
  - Dependent-side safety: skip ctrl->intr_mask and CPU_EN writes on
    the dependent
  - Probe init order: run qcom_swrm_init() on the primary first, then
    on the peer. The dependent's frame-gen poll cannot complete until
    the primary (sole SWR_CLK provider in MM mode) has started the
    clock.
  - Peer teardown on probe failure and remove: disable peer SWRM
    COMP_CFG + mask peer CPU IRQs so the peer releases the shared
    SWR_CLK and devres can free the primary without a dangling
    back-pointer.
  - wake_irq request failure now routes to err_clk (was err_init,
    which skipped the peer cross-link teardown and leaked hclk).
  - qcom_swrm_remove deletes the sdw bus before clearing peer_ctrl;
    in-flight bus ops dereference it.
  - Re-program the dependent's MM_SYNC from the primary's
    runtime_resume (dependent has no PM-runtime of its own).

v1: https://lore.kernel.org/all/cover.1789114385.git.srinivas.kandagatla@oss.qualcomm.com

Srinivas Kandagatla (3):
  dt-bindings: soundwire: qcom: describe multi-master
  soundwire: qcom: add multi-master support
  soundwire: qcom: program MM_SYNC for multi-master

 .../bindings/soundwire/qcom,soundwire.yaml    | 108 +++++++-
 drivers/soundwire/qcom.c                      | 261 ++++++++++++++++--
 2 files changed, 341 insertions(+), 28 deletions(-)

-- 
2.53.0

[PATCH v2 1/3] dt-bindings: soundwire: qcom: describe multi-master

[Srinivas Kandagatla]

v3.1.0+ Qualcomm SoundWire IPs can be paired to expose one logical
bus with more than two DATA lanes. Add three properties that describe
such a pair:

  qcom,multi-master-mode  role in the pair ("primary" or "dependent")
  qcom,multi-master-peer  <phandle, bus-port-offset> to the other IP
  num-lanes               DATA lanes each IP exposes locally

Both nodes carry qcom,multi-master-mode / qcom,multi-master-peer /
num-lanes.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
---
 .../bindings/soundwire/qcom,soundwire.yaml    | 108 ++++++++++++++++--
 1 file changed, 99 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/soundwire/qcom,soundwire.yaml b/Documentation/devicetree/bindings/soundwire/qcom,soundwire.yaml
index 8e6973fa229c..e627b92a3db5 100644
--- a/Documentation/devicetree/bindings/soundwire/qcom,soundwire.yaml
+++ b/Documentation/devicetree/bindings/soundwire/qcom,soundwire.yaml
@@ -215,6 +215,36 @@ properties:
           maximum: 4
         - const: 0xff
 
+  qcom,multi-master-mode:
+    description:
+      Role in v3.1.0+ multi-master mode. Both nodes set this; the
+      primary owns SWR_CLK, the dependent contributes DATA lanes
+      only.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [ primary, dependent ]
+
+  qcom,multi-master-peer:
+    description:
+      Peers in multi-master mode. Each entry is a
+      <peer-phandle, bus-port-offset> pair. Peer N's DPn slots
+      1, 2, 3, ... occupy bus ports (offset+1), (offset+2), ...
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      items:
+        - description: peer phandle
+        - description: bus port offset (last primary-local port)
+    minItems: 1
+
+  num-lanes:
+    description:
+      Number of DATA lanes this IP exposes locally. Required in
+      multi-master mode; on the primary it defines the boundary
+      between local bus lanes (0..num-lanes-1) and lanes contributed
+      by the dependent.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 8
+
   label:
     maxItems: 1
 
@@ -224,21 +254,81 @@ required:
   - interrupts
   - clocks
   - clock-names
-  - '#sound-dai-cells'
   - '#address-cells'
   - '#size-cells'
-  - qcom,ports-offset1
-  - qcom,ports-offset2
-
-oneOf:
-  - required:
-      - qcom,ports-sinterval-low
-  - required:
-      - qcom,ports-sinterval
 
 allOf:
   - $ref: soundwire-controller.yaml#
 
+  # Single-master (no qcom,multi-master-mode): needs port config.
+  - if:
+      not:
+        required:
+          - qcom,multi-master-mode
+    then:
+      required:
+        - '#sound-dai-cells'
+        - qcom,ports-offset1
+        - qcom,ports-offset2
+      oneOf:
+        - required:
+            - qcom,ports-sinterval-low
+        - required:
+            - qcom,ports-sinterval
+
+  # Multi-master primary: drives the bus, needs port config + MM props.
+  - if:
+      properties:
+        qcom,multi-master-mode:
+          const: primary
+      required:
+        - qcom,multi-master-mode
+    then:
+      properties:
+        compatible:
+          contains:
+            const: qcom,soundwire-v3.1.0
+      required:
+        - '#sound-dai-cells'
+        - qcom,ports-offset1
+        - qcom,ports-offset2
+        - qcom,multi-master-peer
+        - num-lanes
+      oneOf:
+        - required:
+            - qcom,ports-sinterval-low
+        - required:
+            - qcom,ports-sinterval
+
+  # Multi-master dependent: contributes DATA lanes only, no ports.
+  - if:
+      properties:
+        qcom,multi-master-mode:
+          const: dependent
+      required:
+        - qcom,multi-master-mode
+    then:
+      properties:
+        compatible:
+          contains:
+            const: qcom,soundwire-v3.1.0
+        '#sound-dai-cells': false
+        qcom,din-ports: false
+        qcom,dout-ports: false
+        qcom,ports-word-length: false
+        qcom,ports-sinterval-low: false
+        qcom,ports-sinterval: false
+        qcom,ports-offset1: false
+        qcom,ports-offset2: false
+        qcom,ports-lane-control: false
+        qcom,ports-block-pack-mode: false
+        qcom,ports-hstart: false
+        qcom,ports-hstop: false
+        qcom,ports-block-group-count: false
+      required:
+        - qcom,multi-master-peer
+        - num-lanes
+
 unevaluatedProperties: false
 
 examples:
-- 
2.53.0

[PATCH v2 2/3] soundwire: qcom: add multi-master support

[Srinivas Kandagatla]

v3.1.0+ Qualcomm SoundWire IPs can be paired to expose one logical
bus with more than two DATA lanes. One IP owns SWR_CLK and drives
the bus; the other contributes DATA lanes only.

Only the primary IP handles the SoundWire command protocol on
Column 0 (PING / READ / WRITE and all slave register access); the
dependent IP is data-only and never issues commands. From the
peripherals' perspective a single logical bus is presented.

Support this pairing on the driver side. A device link between the
two IPs enforces correct unbind ordering and keeps the peer resumed
while the primary is active.

Single-master deployments (no qcom,multi-master-mode in DT) are
unaffected.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
---
 drivers/soundwire/qcom.c | 205 +++++++++++++++++++++++++++++++++++----
 1 file changed, 186 insertions(+), 19 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 35ffffd541bd..767147a6635d 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -10,6 +10,7 @@
 #include <linux/debugfs.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
+#include <linux/of_platform.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
@@ -111,6 +112,7 @@
 #define SWRM_DPn_PORT_HCTRL_BANK(offset,  n, m)	(offset + 0x100 * (n - 1) + 0x40 * m)
 #define SWRM_DPn_BLOCK_CTRL3_BANK(offset, n, m)	(offset + 0x100 * (n - 1) + 0x40 * m)
 #define SWRM_DPn_SAMPLECTRL2_BANK(offset, n, m)	(offset + 0x100 * (n - 1) + 0x40 * m)
+#define SWRM_DPn_SLOT_STRIDE			0x100
 
 #define SWR_V1_3_MSTR_MAX_REG_ADDR				0x1740
 #define SWR_V2_0_MSTR_MAX_REG_ADDR				0x50ac
@@ -192,6 +194,13 @@ struct qcom_swrm_ctrl {
 	const unsigned int *reg_layout;
 	void __iomem *mmio;
 	struct reset_control *audio_cgcr;
+	u8 num_lanes;
+	bool is_dependent;
+	struct qcom_swrm_ctrl *peer_ctrl;
+	u8 peer_first_lane;
+	u8 num_peer_lanes;
+	bool is_primary;
+	u32 peer_dpn_offset;
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs;
 #endif
@@ -898,7 +907,9 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	/* Enable Auto enumeration */
 	ctrl->reg_write(ctrl, SWRM_ENUMERATOR_CFG_ADDR, 1);
 
-	ctrl->intr_mask = SWRM_INTERRUPT_STATUS_RMSK;
+	/* dependent has no sdw_bus; keep IRQ dispatch masked */
+	if (!ctrl->is_dependent)
+		ctrl->intr_mask = SWRM_INTERRUPT_STATUS_RMSK;
 	/* Mask soundwire interrupts */
 	if (ctrl->version < SWRM_VERSION_2_0_0)
 		ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_MASK_ADDR],
@@ -941,8 +952,8 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CLEAR],
 			0xFFFFFFFF);
 
-	/* enable CPU IRQs */
-	if (ctrl->mmio) {
+	/* dependent has no sdw_bus; leave its CPU IRQs masked */
+	if (ctrl->mmio && !ctrl->is_dependent) {
 		ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CPU_EN],
 				SWRM_INTERRUPT_STATUS_RMSK);
 	}
@@ -1040,9 +1051,41 @@ static int qcom_swrm_pre_bank_switch(struct sdw_bus *bus)
 	u32p_replace_bits(&val, ctrl->cols_index, SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK);
 	u32p_replace_bits(&val, ctrl->rows_index, SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK);
 
+	if (ctrl->peer_ctrl)
+		ctrl->peer_ctrl->reg_write(ctrl->peer_ctrl, reg, val);
+
 	return ctrl->reg_write(ctrl, reg, val);
 }
 
+static struct qcom_swrm_ctrl *
+qcom_swrm_port_target(struct qcom_swrm_ctrl *ctrl, u8 port_num, u32 *reg)
+{
+	u8 lane = ctrl->pconfig[port_num].lane_control;
+
+	if (ctrl->peer_ctrl && lane >= ctrl->peer_first_lane &&
+	    lane < ctrl->peer_first_lane + ctrl->num_peer_lanes) {
+		*reg -= ctrl->peer_dpn_offset;
+		return ctrl->peer_ctrl;
+	}
+	return ctrl;
+}
+
+static int qcom_swrm_port_reg_write(struct qcom_swrm_ctrl *ctrl, u8 port_num,
+				    u32 reg, u32 val)
+{
+	struct qcom_swrm_ctrl *tgt = qcom_swrm_port_target(ctrl, port_num, &reg);
+
+	return tgt->reg_write(tgt, reg, val);
+}
+
+static int qcom_swrm_port_reg_read(struct qcom_swrm_ctrl *ctrl, u8 port_num,
+				   u32 reg, u32 *val)
+{
+	struct qcom_swrm_ctrl *tgt = qcom_swrm_port_target(ctrl, port_num, &reg);
+
+	return tgt->reg_read(tgt, reg, val);
+}
+
 static int qcom_swrm_port_params(struct sdw_bus *bus,
 				 struct sdw_port_params *p_params,
 				 unsigned int bank)
@@ -1050,8 +1093,9 @@ static int qcom_swrm_port_params(struct sdw_bus *bus,
 	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
 	u32 offset = ctrl->reg_layout[SWRM_OFFSET_DP_BLOCK_CTRL_1];
 
-	return ctrl->reg_write(ctrl, SWRM_DPn_BLOCK_CTRL_1(offset, p_params->num),
-				p_params->bps - 1);
+	return qcom_swrm_port_reg_write(ctrl, p_params->num,
+					SWRM_DPn_BLOCK_CTRL_1(offset, p_params->num),
+					p_params->bps - 1);
 }
 
 static int qcom_swrm_transport_params(struct sdw_bus *bus,
@@ -1072,7 +1116,7 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 	value |= pcfg->off2 << SWRM_DP_PORT_CTRL_OFFSET2_SHFT;
 	value |= pcfg->si & 0xff;
 
-	ret = ctrl->reg_write(ctrl, reg, value);
+	ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 	if (ret)
 		goto err;
 
@@ -1081,7 +1125,7 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 		value = (pcfg->si >> 8) & 0xff;
 		reg = SWRM_DPn_SAMPLECTRL2_BANK(offset, params->port_num, bank);
 
-		ret = ctrl->reg_write(ctrl, reg, value);
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 		if (ret)
 			goto err;
 	}
@@ -1091,7 +1135,10 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 		reg = SWRM_DPn_PORT_CTRL_2_BANK(offset, params->port_num, bank);
 
 		value = pcfg->lane_control;
-		ret = ctrl->reg_write(ctrl, reg, value);
+		if (ctrl->peer_ctrl && value >= ctrl->peer_first_lane &&
+		    value < ctrl->peer_first_lane + ctrl->num_peer_lanes)
+			value -= ctrl->peer_first_lane;
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 		if (ret)
 			goto err;
 	}
@@ -1102,7 +1149,7 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 		reg = SWRM_DPn_BLOCK_CTRL2_BANK(offset, params->port_num, bank);
 
 		value = pcfg->blk_group_count;
-		ret = ctrl->reg_write(ctrl, reg, value);
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 		if (ret)
 			goto err;
 	}
@@ -1112,10 +1159,10 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 
 	if (pcfg->hstart != SWR_INVALID_PARAM && pcfg->hstop != SWR_INVALID_PARAM) {
 		value = (pcfg->hstop << 4) | pcfg->hstart;
-		ret = ctrl->reg_write(ctrl, reg, value);
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 	} else {
 		value = (SWR_HSTOP_MAX_VAL << 4) | SWR_HSTART_MIN_VAL;
-		ret = ctrl->reg_write(ctrl, reg, value);
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg, value);
 	}
 
 	if (ret)
@@ -1124,7 +1171,8 @@ static int qcom_swrm_transport_params(struct sdw_bus *bus,
 	if (pcfg->bp_mode != SWR_INVALID_PARAM) {
 		offset = ctrl->reg_layout[SWRM_OFFSET_DP_BLOCK_CTRL3_BANK];
 		reg = SWRM_DPn_BLOCK_CTRL3_BANK(offset, params->port_num, bank);
-		ret = ctrl->reg_write(ctrl, reg, pcfg->bp_mode);
+		ret = qcom_swrm_port_reg_write(ctrl, params->port_num, reg,
+					       pcfg->bp_mode);
 	}
 
 err:
@@ -1142,14 +1190,14 @@ static int qcom_swrm_port_enable(struct sdw_bus *bus,
 
 	reg = SWRM_DPn_PORT_CTRL_BANK(offset, enable_ch->port_num, bank);
 
-	ctrl->reg_read(ctrl, reg, &val);
+	qcom_swrm_port_reg_read(ctrl, enable_ch->port_num, reg, &val);
 
 	if (enable_ch->enable)
 		val |= (enable_ch->ch_mask << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
 	else
 		val &= ~(0xff << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
 
-	return ctrl->reg_write(ctrl, reg, val);
+	return qcom_swrm_port_reg_write(ctrl, enable_ch->port_num, reg, val);
 }
 
 static const struct sdw_master_port_ops qcom_swrm_port_ops = {
@@ -1562,6 +1610,73 @@ static int swrm_reg_show(struct seq_file *s_file, void *data)
 DEFINE_SHOW_ATTRIBUTE(swrm_reg);
 #endif
 
+static int qcom_swrm_multi_master_setup(struct qcom_swrm_ctrl *ctrl)
+{
+	struct of_phandle_args args;
+	struct qcom_swrm_ctrl *peer;
+	struct platform_device *pdev;
+	u32 offset;
+	int ret;
+
+	ret = of_parse_phandle_with_fixed_args(ctrl->dev->of_node,
+					       "qcom,multi-master-peer",
+					       1, 0, &args);
+	if (ret)
+		return -EINVAL;
+
+	pdev = of_find_device_by_node(args.np);
+	of_node_put(args.np);
+	if (!pdev)
+		return -EPROBE_DEFER;
+
+	if (!pdev->dev.driver) {
+		ret = -EPROBE_DEFER;
+		goto out;
+	}
+
+	if (pdev->dev.driver != ctrl->dev->driver) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	peer = platform_get_drvdata(pdev);
+	if (!peer || !peer->is_dependent) {
+		ret = -EPROBE_DEFER;
+		goto out;
+	}
+
+	if (!ctrl->num_lanes || !peer->num_lanes ||
+	    ctrl->num_lanes + peer->num_lanes > SDW_MAX_LANES) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	offset = args.args[0];
+	if (offset < ctrl->num_lanes) {
+		dev_err(ctrl->dev, "qcom,multi-master-peer: offset %u < num-lanes %u\n",
+			offset, ctrl->num_lanes);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!device_link_add(ctrl->dev, &pdev->dev,
+			     DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_PM_RUNTIME)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ctrl->peer_ctrl = peer;
+	peer->peer_ctrl = ctrl;
+	ctrl->peer_first_lane = ctrl->num_lanes;
+	ctrl->num_peer_lanes = peer->num_lanes;
+	ctrl->peer_dpn_offset = offset * SWRM_DPn_SLOT_STRIDE;
+
+	ret = 0;
+out:
+	put_device(&pdev->dev);
+	return ret;
+}
+
 static int qcom_swrm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1576,6 +1691,9 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 	if (!ctrl)
 		return -ENOMEM;
 
+	if (!of_property_read_u32(dev->of_node, "num-lanes", &val))
+		ctrl->num_lanes = val;
+
 	memset(ctrl->page1_cache, 0xff, sizeof(ctrl->page1_cache));
 	memset(ctrl->page2_cache, 0xff, sizeof(ctrl->page2_cache));
 
@@ -1636,9 +1754,19 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 	ctrl->bus.compute_params = &qcom_swrm_compute_params;
 	ctrl->bus.clk_stop_timeout = 300;
 
-	ret = qcom_swrm_get_port_config(ctrl);
-	if (ret)
-		goto err_clk;
+	if (of_property_match_string(dev->of_node, "qcom,multi-master-mode",
+				     "dependent") < 0) {
+		ret = qcom_swrm_get_port_config(ctrl);
+		if (ret)
+			goto err_clk;
+	}
+
+	if (of_property_match_string(dev->of_node, "qcom,multi-master-mode", "primary") >= 0) {
+		ret = qcom_swrm_multi_master_setup(ctrl);
+		if (ret)
+			goto err_clk;
+		ctrl->is_primary = true;
+	}
 
 	params = &ctrl->bus.params;
 	params->max_dr_freq = DEFAULT_CLK_FREQ;
@@ -1678,7 +1806,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 						"swr_wake_irq", ctrl);
 		if (ret) {
 			dev_err(dev, "Failed to request soundwire wake irq\n");
-			goto err_init;
+			goto err_clk;
 		}
 	}
 
@@ -1689,6 +1817,16 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 		ctrl->bus.controller_id = val;
 	}
 
+	if (of_property_match_string(dev->of_node, "qcom,multi-master-mode", "dependent") >= 0) {
+		ctrl->is_dependent = true;
+		dev_dbg(dev,
+			"Qualcomm SoundWire multi-master dependent v%x.%x.%x registered (%u lanes)\n",
+			(ctrl->version >> 24) & 0xff,
+			(ctrl->version >> 16) & 0xff,
+			ctrl->version & 0xffff, ctrl->num_lanes);
+		return 0;
+	}
+
 	ret = sdw_bus_master_add(&ctrl->bus, dev, dev->fwnode);
 	if (ret) {
 		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
@@ -1697,6 +1835,10 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 	}
 
 	qcom_swrm_init(ctrl);
+
+	if (ctrl->is_primary && ctrl->peer_ctrl)
+		qcom_swrm_init(ctrl->peer_ctrl);
+
 	wait_for_completion_timeout(&ctrl->enumeration,
 				    msecs_to_jiffies(TIMEOUT_MS));
 	ret = qcom_swrm_register_dais(ctrl);
@@ -1724,6 +1866,17 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 err_master_add:
 	sdw_bus_master_delete(&ctrl->bus);
 err_clk:
+	/* tear down cross-link + mask peer IRQs before devres frees us */
+	if (ctrl->is_primary && ctrl->peer_ctrl) {
+		struct qcom_swrm_ctrl *peer = ctrl->peer_ctrl;
+
+		peer->reg_write(peer,
+				peer->reg_layout[SWRM_REG_INTERRUPT_CPU_EN], 0);
+		/* disable peer SWRM; releases shared SWR_CLK */
+		peer->reg_write(peer, SWRM_COMP_CFG_ADDR, 0);
+		peer->peer_ctrl = NULL;
+		ctrl->peer_ctrl = NULL;
+	}
 	clk_disable_unprepare(ctrl->hclk);
 err_init:
 	return ret;
@@ -1733,7 +1886,21 @@ static void qcom_swrm_remove(struct platform_device *pdev)
 {
 	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
 
-	sdw_bus_master_delete(&ctrl->bus);
+	/* delete bus before dropping peer_ctrl; in-flight ops deref it */
+	if (!ctrl->is_dependent)
+		sdw_bus_master_delete(&ctrl->bus);
+
+	if (ctrl->is_primary && ctrl->peer_ctrl) {
+		struct qcom_swrm_ctrl *peer = ctrl->peer_ctrl;
+
+		peer->reg_write(peer,
+				peer->reg_layout[SWRM_REG_INTERRUPT_CPU_EN], 0);
+		/* disable peer SWRM; releases shared SWR_CLK */
+		peer->reg_write(peer, SWRM_COMP_CFG_ADDR, 0);
+		peer->peer_ctrl = NULL;
+		ctrl->peer_ctrl = NULL;
+	}
+
 	clk_disable_unprepare(ctrl->hclk);
 }
 
-- 
2.53.0

[PATCH v2 3/3] soundwire: qcom: program MM_SYNC for multi-master

[Srinivas Kandagatla]

The primary and dependent frame generators must lock to a single
SWR_CLK for the shared bus to run. Program SWRM_V3_MM_SYNC_CONFIG
on both sides at init, and re-apply on resume as the register does
not survive a clock stop.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
---
 drivers/soundwire/qcom.c | 56 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 767147a6635d..92e1644623c5 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -46,6 +46,18 @@
 #define SWRM_V3_COMP_PARAMS_RD_FIFO_DEPTH			GENMASK(23, 18)
 
 #define SWRM_COMP_MASTER_ID					0x104
+
+#define SWRM_V3_MM_SYNC_CONFIG					0x108
+#define SWRM_V3_MM_SYNC_CONNECTED_MASTER_MASK			GENMASK(15, 0)
+#define SWRM_V3_MM_SYNC_IS_DEPENDENT_MASTER			BIT(16)
+#define SWRM_V3_MM_SYNC_MASK_CONTROL_BITS			BIT(17)
+
+#define SWRM_V3_COMP_FEATURE_CFG				0x10
+#define  SWRM_V3_COMP_FEATURE_CFG_BASE				0x00E
+#define  SWRM_V3_COMP_FEATURE_CFG_FORCE_MODE_EN			BIT(9)
+#define  SWRM_V3_COMP_FEATURE_CFG_CLK_PIN_AVAIL			BIT(10)
+#define  SWRM_V3_COMP_FEATURE_CFG_CLK_STOP_EXEC_ON_CMD_IGNORE	BIT(12)
+
 #define SWRM_V1_3_INTERRUPT_STATUS				0x200
 #define SWRM_V2_0_INTERRUPT_STATUS				0x5000
 #define SWRM_INTERRUPT_STATUS_RMSK				GENMASK(16, 0)
@@ -892,6 +904,43 @@ static bool swrm_wait_for_frame_gen_enabled(struct qcom_swrm_ctrl *ctrl)
 	return false;
 }
 
+static void qcom_swrm_program_mm_sync(struct qcom_swrm_ctrl *ctrl)
+{
+	struct qcom_swrm_ctrl *peer = ctrl->peer_ctrl;
+	u32 conn_mask;
+
+	/*
+	 * peer_ctrl is only ever set on qcom,soundwire-v3.1.0 IPs (the
+	 * multi-master binding requires that compatible), so the V3-only
+	 * MM_SYNC / COMP_FEATURE_CFG registers written below are safe to
+	 * touch here.
+	 */
+	if (!peer || peer->bus.controller_id < 1)
+		return;
+
+	conn_mask = BIT(peer->bus.controller_id - 1) &
+		    SWRM_V3_MM_SYNC_CONNECTED_MASTER_MASK;
+
+	if (ctrl->is_primary) {
+		ctrl->reg_write(ctrl, SWRM_V3_MM_SYNC_CONFIG, conn_mask);
+		ctrl->reg_write(ctrl, SWRM_V3_COMP_FEATURE_CFG,
+				SWRM_V3_COMP_FEATURE_CFG_BASE |
+				SWRM_V3_COMP_FEATURE_CFG_FORCE_MODE_EN |
+				SWRM_V3_COMP_FEATURE_CFG_CLK_PIN_AVAIL |
+				SWRM_V3_COMP_FEATURE_CFG_CLK_STOP_EXEC_ON_CMD_IGNORE);
+		return;
+	}
+
+	ctrl->reg_write(ctrl, SWRM_V3_MM_SYNC_CONFIG,
+			SWRM_V3_MM_SYNC_IS_DEPENDENT_MASTER |
+			SWRM_V3_MM_SYNC_MASK_CONTROL_BITS | conn_mask);
+
+	ctrl->reg_write(ctrl, SWRM_V3_COMP_FEATURE_CFG,
+			SWRM_V3_COMP_FEATURE_CFG_BASE |
+			SWRM_V3_COMP_FEATURE_CFG_FORCE_MODE_EN |
+			SWRM_V3_COMP_FEATURE_CFG_CLK_STOP_EXEC_ON_CMD_IGNORE);
+}
+
 static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 {
 	u32 val;
@@ -920,6 +969,8 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	u32p_replace_bits(&val, SWRM_DEF_CMD_NO_PINGS, SWRM_MCP_CFG_MAX_NUM_OF_CMD_NO_PINGS_BMSK);
 	ctrl->reg_write(ctrl, SWRM_MCP_CFG_ADDR, val);
 
+	qcom_swrm_program_mm_sync(ctrl);
+
 	if (ctrl->version == SWRM_VERSION_1_7_0) {
 		ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
 		ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL,
@@ -1935,6 +1986,11 @@ static int __maybe_unused swrm_runtime_resume(struct device *dev)
 	} else {
 		reset_control_reset(ctrl->audio_cgcr);
 
+		qcom_swrm_program_mm_sync(ctrl);
+		/* dependent has no PM-runtime of its own */
+		if (ctrl->is_primary && ctrl->peer_ctrl)
+			qcom_swrm_program_mm_sync(ctrl->peer_ctrl);
+
 		if (ctrl->version == SWRM_VERSION_1_7_0) {
 			ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
 			ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL,
-- 
2.53.0

Re: [PATCH v2 2/3] soundwire: qcom: add multi-master support

[Pierre-Louis Bossart]

> @@ -192,6 +194,13 @@ struct qcom_swrm_ctrl {
>  	const unsigned int *reg_layout;
>  	void __iomem *mmio;
>  	struct reset_control *audio_cgcr;
> +	u8 num_lanes;
> +	bool is_dependent;
> +	struct qcom_swrm_ctrl *peer_ctrl;
> +	u8 peer_first_lane;
> +	u8 num_peer_lanes;
> +	bool is_primary;
> +	u32 peer_dpn_offset;

nit-pick: do you need both is_dependent and is_primary? One would think
that a single variable would be enough, no?

also without context it's hard to understand if lanes are independent in
terms of transport or not, not sure what 'peer' means in a multi-master
setup with a primary controller and N dependent ones? Code like this
function below is a bit cryptic...

> +static struct qcom_swrm_ctrl *
> +qcom_swrm_port_target(struct qcom_swrm_ctrl *ctrl, u8 port_num, u32 *reg)
> +{
> +	u8 lane = ctrl->pconfig[port_num].lane_control;
> +
> +	if (ctrl->peer_ctrl && lane >= ctrl->peer_first_lane &&
> +	    lane < ctrl->peer_first_lane + ctrl->num_peer_lanes) {
> +		*reg -= ctrl->peer_dpn_offset;
> +		return ctrl->peer_ctrl;
> +	}
> +	return ctrl;
> +}

Re: [PATCH v2 2/3] soundwire: qcom: add multi-master support

[Srinivas Kandagatla]

On 10/1/26 11:53 AM, Pierre-Louis Bossart wrote:
> 
>> @@ -192,6 +194,13 @@ struct qcom_swrm_ctrl {
>>  	const unsigned int *reg_layout;
>>  	void __iomem *mmio;
>>  	struct reset_control *audio_cgcr;
>> +	u8 num_lanes;
>> +	bool is_dependent;
>> +	struct qcom_swrm_ctrl *peer_ctrl;
>> +	u8 peer_first_lane;
>> +	u8 num_peer_lanes;
>> +	bool is_primary;
>> +	u32 peer_dpn_offset;
> 
> nit-pick: do you need both is_dependent and is_primary? One would think
> that a single variable would be enough, no?
I did try to do that which made the code bit confusing to read.


> 
> also without context it's hard to understand if lanes are independent in
> terms of transport or not, not sure what 'peer' means in a multi-master
> setup with a primary controller and N dependent ones? Code like this
For now its one, but Yes, technically we could have more dependent ones,
I wanted to keep the patchset simple and right now the only have one
peer and i dont know if we have other setups with more dependent
controrllers.
--srini

> function below is a bit cryptic...
> 
>> +static struct qcom_swrm_ctrl *
>> +qcom_swrm_port_target(struct qcom_swrm_ctrl *ctrl, u8 port_num, u32 *reg)
>> +{
>> +	u8 lane = ctrl->pconfig[port_num].lane_control;
>> +
>> +	if (ctrl->peer_ctrl && lane >= ctrl->peer_first_lane &&
>> +	    lane < ctrl->peer_first_lane + ctrl->num_peer_lanes) {
>> +		*reg -= ctrl->peer_dpn_offset;
>> +		return ctrl->peer_ctrl;
>> +	}
>> +	return ctrl;
>> +}
> 
>