[PATCH v2 00/10] soundwire: intel: add multi-link support

[PATCH v2 00/10] soundwire: intel: add multi-link support

[Bard Liao]

This series enables multi-link support for Intel platforms.

Changes in v2:
- Remove the "soundwire: intel: Only call sdw stream APIs for the first
  cpu_dai" patch form this series. We will move the sounwdire stream
  operations to machine driver in another series.
- Update the commit message and title of "soundwire: intel: add error log
  for clock-stop invalid configs"

Pierre-Louis Bossart (10):
  soundwire: intel: disable shim wake on suspend
  soundwire: intel: ignore software command retries
  soundwire: intel: add multi-link support
  soundwire: intel: add missing support for all clock stop modes
  soundwire: bus: update multi-link definition with hw sync details
  soundwire: intel: add multi-link hw_synchronization information
  soundwire: stream: enable hw_sync as needed by hardware
  soundwire: intel: add error log for clock-stop invalid configs
  soundwire: intel: pass link_mask information to each master
  soundwire: intel: don't manage link power individually

 drivers/soundwire/intel.c      | 264 ++++++++++++++++++++++++++++-----
 drivers/soundwire/intel.h      |   2 +
 drivers/soundwire/intel_init.c |   1 +
 drivers/soundwire/stream.c     |  15 +-
 include/linux/soundwire/sdw.h  |   6 +
 5 files changed, 243 insertions(+), 45 deletions(-)

-- 
2.17.1

[PATCH v2 01/10] soundwire: intel: disable shim wake on suspend

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

If we enabled the clock stop mode and suspend, we need to disable the
shim wake. We do so only if the parent is pm_runtime active due to
power rail dependencies.

GitHub issue: https://github.com/thesofproject/linux/issues/1678
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index ebca8ced59ec..aa8484366c95 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1532,6 +1532,7 @@ static int __maybe_unused intel_suspend(struct device *dev)
 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;
+	u32 clock_stop_quirks;
 	int ret;
 
 	if (bus->prop.hw_disabled) {
@@ -1543,6 +1544,23 @@ static int __maybe_unused intel_suspend(struct device *dev)
 	if (pm_runtime_suspended(dev)) {
 		dev_dbg(dev, "%s: pm_runtime status: suspended\n", __func__);
 
+		clock_stop_quirks = sdw->link_res->clock_stop_quirks;
+
+		if ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET ||
+		     !clock_stop_quirks) &&
+		    !pm_runtime_suspended(dev->parent)) {
+
+			/*
+			 * if we've enabled clock stop, and the parent
+			 * is still active, disable shim wake. The
+			 * SHIM registers are not accessible if the
+			 * parent is already pm_runtime suspended so
+			 * it's too late to change that configuration
+			 */
+
+			intel_shim_wake(sdw, false);
+		}
+
 		return 0;
 	}
 
-- 
2.17.1

[PATCH v2 02/10] soundwire: intel: ignore software command retries

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

with multiple links synchronized in hardware, retrying commands in
software is not recommended.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index aa8484366c95..94a659e65f86 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1355,6 +1355,11 @@ static int intel_master_probe(struct platform_device *pdev)
 		dev_info(dev,
 			 "SoundWire master %d is disabled, will be ignored\n",
 			 bus->link_id);
+	/*
+	 * Ignore BIOS err_threshold, it's a really bad idea when dealing
+	 * with multiple hardware synchronized links
+	 */
+	bus->prop.err_threshold = 0;
 
 	return 0;
 }
-- 
2.17.1

[PATCH v2 03/10] soundwire: intel: add multi-link support

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

The multi-link support is enabled with a hardware gsync signal
connecting all links. All commands and operations which typically are
handled on an SSP boundary will be deferred further and enabled across
all links with the 'syncGo' sequence.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 120 ++++++++++++++++++++++++++++++++++----
 1 file changed, 110 insertions(+), 10 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 94a659e65f86..259e3da98e42 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -34,6 +34,7 @@
 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME		BIT(0)
 #define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP		BIT(1)
 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE	BIT(2)
+#define SDW_INTEL_MASTER_DISABLE_MULTI_LINK		BIT(3)
 
 static int md_flags;
 module_param_named(sdw_md_flags, md_flags, int, 0444);
@@ -555,6 +556,19 @@ static int intel_shim_sync_go_unlocked(struct sdw_intel *sdw)
 	return ret;
 }
 
+static int intel_shim_sync_go(struct sdw_intel *sdw)
+{
+	int ret;
+
+	mutex_lock(sdw->link_res->shim_lock);
+
+	ret = intel_shim_sync_go_unlocked(sdw);
+
+	mutex_unlock(sdw->link_res->shim_lock);
+
+	return ret;
+}
+
 /*
  * PDI routines
  */
@@ -1303,10 +1317,7 @@ static int intel_init(struct sdw_intel *sdw)
 
 	intel_shim_init(sdw, clock_stop);
 
-	if (clock_stop)
-		return 0;
-
-	return sdw_cdns_init(&sdw->cdns);
+	return 0;
 }
 
 /*
@@ -1372,6 +1383,7 @@ int intel_master_startup(struct platform_device *pdev)
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;
 	int link_flags;
+	bool multi_link;
 	u32 clock_stop_quirks;
 	int ret;
 
@@ -1382,7 +1394,16 @@ int intel_master_startup(struct platform_device *pdev)
 		return 0;
 	}
 
-	/* Initialize shim, controller and Cadence IP */
+	link_flags = md_flags >> (bus->link_id * 8);
+	multi_link = !(link_flags & SDW_INTEL_MASTER_DISABLE_MULTI_LINK);
+	if (!multi_link) {
+		dev_dbg(dev, "Multi-link is disabled\n");
+		bus->multi_link = false;
+	} else {
+		bus->multi_link = true;
+	}
+
+	/* Initialize shim, controller */
 	ret = intel_init(sdw);
 	if (ret)
 		goto err_init;
@@ -1401,12 +1422,33 @@ int intel_master_startup(struct platform_device *pdev)
 		goto err_init;
 	}
 
+	/*
+	 * follow recommended programming flows to avoid timeouts when
+	 * gsync is enabled
+	 */
+	if (multi_link)
+		intel_shim_sync_arm(sdw);
+
+	ret = sdw_cdns_init(cdns);
+	if (ret < 0) {
+		dev_err(dev, "unable to initialize Cadence IP\n");
+		goto err_interrupt;
+	}
+
 	ret = sdw_cdns_exit_reset(cdns);
 	if (ret < 0) {
 		dev_err(dev, "unable to exit bus reset sequence\n");
 		goto err_interrupt;
 	}
 
+	if (multi_link) {
+		ret = intel_shim_sync_go(sdw);
+		if (ret < 0) {
+			dev_err(dev, "sync go failed: %d\n", ret);
+			goto err_interrupt;
+		}
+	}
+
 	/* Register DAIs */
 	ret = intel_register_dai(sdw);
 	if (ret) {
@@ -1418,7 +1460,6 @@ int intel_master_startup(struct platform_device *pdev)
 	intel_debugfs_init(sdw);
 
 	/* Enable runtime PM */
-	link_flags = md_flags >> (bus->link_id * 8);
 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) {
 		pm_runtime_set_autosuspend_delay(dev,
 						 INTEL_MASTER_SUSPEND_DELAY_MS);
@@ -1654,6 +1695,7 @@ static int __maybe_unused intel_resume(struct device *dev)
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;
 	int link_flags;
+	bool multi_link;
 	int ret;
 
 	if (bus->prop.hw_disabled) {
@@ -1662,6 +1704,9 @@ static int __maybe_unused intel_resume(struct device *dev)
 		return 0;
 	}
 
+	link_flags = md_flags >> (bus->link_id * 8);
+	multi_link = !(link_flags & SDW_INTEL_MASTER_DISABLE_MULTI_LINK);
+
 	if (pm_runtime_suspended(dev)) {
 		dev_dbg(dev, "%s: pm_runtime status was suspended, forcing active\n", __func__);
 
@@ -1672,6 +1717,7 @@ static int __maybe_unused intel_resume(struct device *dev)
 		pm_runtime_enable(dev);
 
 		link_flags = md_flags >> (bus->link_id * 8);
+
 		if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
 			pm_runtime_idle(dev);
 	}
@@ -1694,12 +1740,33 @@ static int __maybe_unused intel_resume(struct device *dev)
 		return ret;
 	}
 
+	/*
+	 * follow recommended programming flows to avoid timeouts when
+	 * gsync is enabled
+	 */
+	if (multi_link)
+		intel_shim_sync_arm(sdw);
+
+	ret = sdw_cdns_init(&sdw->cdns);
+	if (ret < 0) {
+		dev_err(dev, "unable to initialize Cadence IP during resume\n");
+		return ret;
+	}
+
 	ret = sdw_cdns_exit_reset(cdns);
 	if (ret < 0) {
 		dev_err(dev, "unable to exit bus reset sequence during resume\n");
 		return ret;
 	}
 
+	if (multi_link) {
+		ret = intel_shim_sync_go(sdw);
+		if (ret < 0) {
+			dev_err(dev, "sync go failed during resume\n");
+			return ret;
+		}
+	}
+
 	/*
 	 * after system resume, the pm_runtime suspend() may kick in
 	 * during the enumeration, before any children device force the
@@ -1722,6 +1789,8 @@ static int intel_resume_runtime(struct device *dev)
 	struct sdw_bus *bus = &cdns->bus;
 	u32 clock_stop_quirks;
 	bool clock_stop0;
+	int link_flags;
+	bool multi_link;
 	int status;
 	int ret;
 
@@ -1731,6 +1800,9 @@ static int intel_resume_runtime(struct device *dev)
 		return 0;
 	}
 
+	link_flags = md_flags >> (bus->link_id * 8);
+	multi_link = !(link_flags & SDW_INTEL_MASTER_DISABLE_MULTI_LINK);
+
 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 
 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
@@ -1752,11 +1824,32 @@ static int intel_resume_runtime(struct device *dev)
 			return ret;
 		}
 
+		/*
+		 * follow recommended programming flows to avoid
+		 * timeouts when gsync is enabled
+		 */
+		if (multi_link)
+			intel_shim_sync_arm(sdw);
+
+		ret = sdw_cdns_init(&sdw->cdns);
+		if (ret < 0) {
+			dev_err(dev, "unable to initialize Cadence IP during resume\n");
+			return ret;
+		}
+
 		ret = sdw_cdns_exit_reset(cdns);
 		if (ret < 0) {
 			dev_err(dev, "unable to exit bus reset sequence during resume\n");
 			return ret;
 		}
+
+		if (multi_link) {
+			ret = intel_shim_sync_go(sdw);
+			if (ret < 0) {
+				dev_err(dev, "sync go failed during resume\n");
+				return ret;
+			}
+		}
 	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
 		ret = intel_init(sdw);
 		if (ret) {
@@ -1773,11 +1866,18 @@ static int intel_resume_runtime(struct device *dev)
 		 */
 		clock_stop0 = sdw_cdns_is_clock_stop(&sdw->cdns);
 
-		/*
-		 * make sure all Slaves are tagged as UNATTACHED and
-		 * provide reason for reinitialization
-		 */
 		if (!clock_stop0) {
+
+			/*
+			 * Re-initialize the IP since it was powered-off
+			 */
+			sdw_cdns_init(&sdw->cdns);
+
+			/*
+			 * make sure all Slaves are tagged as UNATTACHED and
+			 * provide reason for reinitialization
+			 */
+
 			status = SDW_UNATTACH_REQUEST_MASTER_RESET;
 			sdw_clear_slave_status(bus, status);
 		}
-- 
2.17.1

[PATCH v2 04/10] soundwire: intel: add missing support for all clock stop modes

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Deal with the BUS_RESET case, which is the default. The only change is
to add support for the exit sequence using the syncArm/syncGo mode for
the exit reset sequence.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 49 +++++++++++++++++++++++++++++++--------
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 259e3da98e42..8634d33c388c 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1868,11 +1868,6 @@ static int intel_resume_runtime(struct device *dev)
 
 		if (!clock_stop0) {
 
-			/*
-			 * Re-initialize the IP since it was powered-off
-			 */
-			sdw_cdns_init(&sdw->cdns);
-
 			/*
 			 * make sure all Slaves are tagged as UNATTACHED and
 			 * provide reason for reinitialization
@@ -1880,13 +1875,31 @@ static int intel_resume_runtime(struct device *dev)
 
 			status = SDW_UNATTACH_REQUEST_MASTER_RESET;
 			sdw_clear_slave_status(bus, status);
-		}
 
+			ret = sdw_cdns_enable_interrupt(cdns, true);
+			if (ret < 0) {
+				dev_err(dev, "cannot enable interrupts during resume\n");
+				return ret;
+			}
 
-		ret = sdw_cdns_enable_interrupt(cdns, true);
-		if (ret < 0) {
-			dev_err(dev, "cannot enable interrupts during resume\n");
-			return ret;
+			/*
+			 * follow recommended programming flows to avoid
+			 * timeouts when gsync is enabled
+			 */
+			if (multi_link)
+				intel_shim_sync_arm(sdw);
+
+			/*
+			 * Re-initialize the IP since it was powered-off
+			 */
+			sdw_cdns_init(&sdw->cdns);
+
+		} else {
+			ret = sdw_cdns_enable_interrupt(cdns, true);
+			if (ret < 0) {
+				dev_err(dev, "cannot enable interrupts during resume\n");
+				return ret;
+			}
 		}
 
 		ret = sdw_cdns_clock_restart(cdns, !clock_stop0);
@@ -1894,6 +1907,22 @@ static int intel_resume_runtime(struct device *dev)
 			dev_err(dev, "unable to restart clock during resume\n");
 			return ret;
 		}
+
+		if (!clock_stop0) {
+			ret = sdw_cdns_exit_reset(cdns);
+			if (ret < 0) {
+				dev_err(dev, "unable to exit bus reset sequence during resume\n");
+				return ret;
+			}
+
+			if (multi_link) {
+				ret = intel_shim_sync_go(sdw);
+				if (ret < 0) {
+					dev_err(sdw->cdns.dev, "sync go failed during resume\n");
+					return ret;
+				}
+			}
+		}
 	} else if (!clock_stop_quirks) {
 		ret = intel_init(sdw);
 		if (ret) {
-- 
2.17.1

[PATCH v2 05/10] soundwire: bus: update multi-link definition with hw sync details

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Hardware-based synchronization is typically required when the
bus->multi_link flag is set.

On Intel platforms, when the Cadence IP is configured in 'Multi Master
Mode', the hardware synchronization is required even when a stream
only uses a single segment. The existing code only deal with hardware
synchronization when a stream uses more than one segment so to remain
backwards compatible we add a configuration threshold. For Intel cases
this threshold will be set to one, other platforms may be able to use
the SSP-based sync in those cases.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 include/linux/soundwire/sdw.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index 76052f12c9f7..9adbe4fd7980 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -827,6 +827,11 @@ struct sdw_master_ops {
  * @multi_link: Store bus property that indicates if multi links
  * are supported. This flag is populated by drivers after reading
  * appropriate firmware (ACPI/DT).
+ * @hw_sync_min_links: Number of links used by a stream above which
+ * hardware-based synchronization is required. This value is only
+ * meaningful if multi_link is set. If set to 1, hardware-based
+ * synchronization will be used even if a stream only uses a single
+ * SoundWire segment.
  */
 struct sdw_bus {
 	struct device *dev;
@@ -850,6 +855,7 @@ struct sdw_bus {
 	unsigned int clk_stop_timeout;
 	u32 bank_switch_timeout;
 	bool multi_link;
+	int hw_sync_min_links;
 };
 
 int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
-- 
2.17.1

[PATCH v2 06/10] soundwire: intel: add multi-link hw_synchronization information

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

set the flags as required by hardware implementation

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 8634d33c388c..272826973426 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1400,7 +1400,14 @@ int intel_master_startup(struct platform_device *pdev)
 		dev_dbg(dev, "Multi-link is disabled\n");
 		bus->multi_link = false;
 	} else {
+		/*
+		 * hardware-based synchronization is required regardless
+		 * of the number of segments used by a stream: SSP-based
+		 * synchronization is gated by gsync when the multi-master
+		 * mode is set.
+		 */
 		bus->multi_link = true;
+		bus->hw_sync_min_links = 1;
 	}
 
 	/* Initialize shim, controller */
-- 
2.17.1

[PATCH v2 07/10] soundwire: stream: enable hw_sync as needed by hardware

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Use platform-specific information to decide when to use hw_sync, not
only a number of links > 1.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/stream.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 37290a799023..e4cf484f5905 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -689,9 +689,9 @@ static int sdw_bank_switch(struct sdw_bus *bus, int m_rt_count)
 
 	/*
 	 * Set the multi_link flag only when both the hardware supports
-	 * and there is a stream handled by multiple masters
+	 * and hardware-based sync is required
 	 */
-	multi_link = bus->multi_link && (m_rt_count > 1);
+	multi_link = bus->multi_link && (m_rt_count >= bus->hw_sync_min_links);
 
 	if (multi_link)
 		ret = sdw_transfer_defer(bus, wr_msg, &bus->defer_msg);
@@ -760,13 +760,16 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 	const struct sdw_master_ops *ops;
 	struct sdw_bus *bus;
 	bool multi_link = false;
+	int m_rt_count;
 	int ret = 0;
 
+	m_rt_count = stream->m_rt_count;
+
 	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
 		bus = m_rt->bus;
 		ops = bus->ops;
 
-		if (bus->multi_link) {
+		if (bus->multi_link && m_rt_count >= bus->hw_sync_min_links) {
 			multi_link = true;
 			mutex_lock(&bus->msg_lock);
 		}
@@ -787,7 +790,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 		 * synchronized across all Masters and happens later as a
 		 * part of post_bank_switch ops.
 		 */
-		ret = sdw_bank_switch(bus, stream->m_rt_count);
+		ret = sdw_bank_switch(bus, m_rt_count);
 		if (ret < 0) {
 			dev_err(bus->dev, "Bank switch failed: %d\n", ret);
 			goto error;
@@ -813,7 +816,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 					ret);
 				goto error;
 			}
-		} else if (bus->multi_link && stream->m_rt_count > 1) {
+		} else if (multi_link) {
 			dev_err(bus->dev,
 				"Post bank switch ops not implemented\n");
 			goto error;
@@ -831,7 +834,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 			goto error;
 		}
 
-		if (bus->multi_link)
+		if (multi_link)
 			mutex_unlock(&bus->msg_lock);
 	}
 
-- 
2.17.1

[PATCH v2 08/10] soundwire: intel: add error log for clock-stop invalid configs

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Detect cases where the clock is assumed to be stopped but the IP is
not in the relevant state. There is no real way to recover here, but
adding an error log can help detect bad programming sequences or race
conditions.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 272826973426..97c8cfc54ddd 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1931,6 +1931,11 @@ static int intel_resume_runtime(struct device *dev)
 			}
 		}
 	} else if (!clock_stop_quirks) {
+
+		clock_stop0 = sdw_cdns_is_clock_stop(&sdw->cdns);
+		if (!clock_stop0)
+			dev_err(dev, "%s invalid configuration, clock was not stopped", __func__);
+
 		ret = intel_init(sdw);
 		if (ret) {
 			dev_err(dev, "%s failed: %d", __func__, ret);
-- 
2.17.1

[PATCH v2 09/10] soundwire: intel: pass link_mask information to each master

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

While the hardware exposes independent bits to power-up each master,
the recommended sequence is to power all links or none. Idle links can
still use the clock stop mode while the master is powered.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.h      | 2 ++
 drivers/soundwire/intel_init.c | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/soundwire/intel.h b/drivers/soundwire/intel.h
index 23daab9da329..76820d0b9deb 100644
--- a/drivers/soundwire/intel.h
+++ b/drivers/soundwire/intel.h
@@ -18,6 +18,7 @@
  * @shim_lock: mutex to handle access to shared SHIM registers
  * @shim_mask: global pointer to check SHIM register initialization
  * @clock_stop_quirks: mask defining requested behavior on pm_suspend
+ * @link_mask: global mask needed for power-up/down sequences
  * @cdns: Cadence master descriptor
  * @list: used to walk-through all masters exposed by the same controller
  */
@@ -33,6 +34,7 @@ struct sdw_intel_link_res {
 	struct mutex *shim_lock; /* protect shared registers */
 	u32 *shim_mask;
 	u32 clock_stop_quirks;
+	u32 link_mask;
 	struct sdw_cdns *cdns;
 	struct list_head list;
 };
diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index add46d8fc85c..65d9b9bd2106 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -255,6 +255,7 @@ static struct sdw_intel_ctx
 		link->clock_stop_quirks = res->clock_stop_quirks;
 		link->shim_lock = &ctx->shim_lock;
 		link->shim_mask = &ctx->shim_mask;
+		link->link_mask = link_mask;
 
 		memset(&pdevinfo, 0, sizeof(pdevinfo));
 
-- 
2.17.1

[PATCH v2 10/10] soundwire: intel: don't manage link power individually

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Each link has separate power controls, but experimental results show
we need to use an all-or-none approach to the link power management.

This change has marginal power impacts, the DSP needs to be powered
anyways before SoundWire links can be powered, and even when powered a
link can be in clock-stopped mode.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel.c | 70 +++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 24 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 97c8cfc54ddd..710f5eba936b 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -63,7 +63,9 @@ MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off
 #define SDW_SHIM_WAKESTS		0x192
 
 #define SDW_SHIM_LCTL_SPA		BIT(0)
+#define SDW_SHIM_LCTL_SPA_MASK		GENMASK(3, 0)
 #define SDW_SHIM_LCTL_CPA		BIT(8)
+#define SDW_SHIM_LCTL_CPA_MASK		GENMASK(11, 8)
 
 #define SDW_SHIM_SYNC_SYNCPRD_VAL_24	(24000 / SDW_CADENCE_GSYNC_KHZ - 1)
 #define SDW_SHIM_SYNC_SYNCPRD_VAL_38_4	(38400 / SDW_CADENCE_GSYNC_KHZ - 1)
@@ -295,8 +297,8 @@ static int intel_link_power_up(struct sdw_intel *sdw)
 	u32 *shim_mask = sdw->link_res->shim_mask;
 	struct sdw_bus *bus = &sdw->cdns.bus;
 	struct sdw_master_prop *prop = &bus->prop;
-	int spa_mask, cpa_mask;
-	int link_control;
+	u32 spa_mask, cpa_mask;
+	u32 link_control;
 	int ret = 0;
 	u32 syncprd;
 	u32 sync_reg;
@@ -319,6 +321,8 @@ static int intel_link_power_up(struct sdw_intel *sdw)
 		syncprd = SDW_SHIM_SYNC_SYNCPRD_VAL_24;
 
 	if (!*shim_mask) {
+		dev_dbg(sdw->cdns.dev, "%s: powering up all links\n", __func__);
+
 		/* we first need to program the SyncPRD/CPU registers */
 		dev_dbg(sdw->cdns.dev,
 			"%s: first link up, programming SYNCPRD\n", __func__);
@@ -331,21 +335,24 @@ static int intel_link_power_up(struct sdw_intel *sdw)
 		/* Set SyncCPU bit */
 		sync_reg |= SDW_SHIM_SYNC_SYNCCPU;
 		intel_writel(shim, SDW_SHIM_SYNC, sync_reg);
-	}
 
-	/* Link power up sequence */
-	link_control = intel_readl(shim, SDW_SHIM_LCTL);
-	spa_mask = (SDW_SHIM_LCTL_SPA << link_id);
-	cpa_mask = (SDW_SHIM_LCTL_CPA << link_id);
-	link_control |=  spa_mask;
+		/* Link power up sequence */
+		link_control = intel_readl(shim, SDW_SHIM_LCTL);
 
-	ret = intel_set_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask);
-	if (ret < 0) {
-		dev_err(sdw->cdns.dev, "Failed to power up link: %d\n", ret);
-		goto out;
-	}
+		/* only power-up enabled links */
+		spa_mask = sdw->link_res->link_mask <<
+			SDW_REG_SHIFT(SDW_SHIM_LCTL_SPA_MASK);
+		cpa_mask = sdw->link_res->link_mask <<
+			SDW_REG_SHIFT(SDW_SHIM_LCTL_CPA_MASK);
+
+		link_control |=  spa_mask;
+
+		ret = intel_set_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask);
+		if (ret < 0) {
+			dev_err(sdw->cdns.dev, "Failed to power up link: %d\n", ret);
+			goto out;
+		}
 
-	if (!*shim_mask) {
 		/* SyncCPU will change once link is active */
 		ret = intel_wait_bit(shim, SDW_SHIM_SYNC,
 				     SDW_SHIM_SYNC_SYNCCPU, 0);
@@ -483,7 +490,7 @@ static void intel_shim_wake(struct sdw_intel *sdw, bool wake_enable)
 
 static int intel_link_power_down(struct sdw_intel *sdw)
 {
-	int link_control, spa_mask, cpa_mask;
+	u32 link_control, spa_mask, cpa_mask;
 	unsigned int link_id = sdw->instance;
 	void __iomem *shim = sdw->link_res->shim;
 	u32 *shim_mask = sdw->link_res->shim_mask;
@@ -493,24 +500,39 @@ static int intel_link_power_down(struct sdw_intel *sdw)
 
 	intel_shim_master_ip_to_glue(sdw);
 
-	/* Link power down sequence */
-	link_control = intel_readl(shim, SDW_SHIM_LCTL);
-	spa_mask = ~(SDW_SHIM_LCTL_SPA << link_id);
-	cpa_mask = (SDW_SHIM_LCTL_CPA << link_id);
-	link_control &=  spa_mask;
-
-	ret = intel_clear_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask);
-
 	if (!(*shim_mask & BIT(link_id)))
 		dev_err(sdw->cdns.dev,
 			"%s: Unbalanced power-up/down calls\n", __func__);
 
 	*shim_mask &= ~BIT(link_id);
 
+	if (!*shim_mask) {
+
+		dev_dbg(sdw->cdns.dev, "%s: powering down all links\n", __func__);
+
+		/* Link power down sequence */
+		link_control = intel_readl(shim, SDW_SHIM_LCTL);
+
+		/* only power-down enabled links */
+		spa_mask = (~sdw->link_res->link_mask) <<
+			SDW_REG_SHIFT(SDW_SHIM_LCTL_SPA_MASK);
+		cpa_mask = sdw->link_res->link_mask <<
+			SDW_REG_SHIFT(SDW_SHIM_LCTL_CPA_MASK);
+
+		link_control &=  spa_mask;
+
+		ret = intel_clear_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask);
+	}
+
+	link_control = intel_readl(shim, SDW_SHIM_LCTL);
+
 	mutex_unlock(sdw->link_res->shim_lock);
 
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(sdw->cdns.dev, "%s: could not power down link\n", __func__);
+
 		return ret;
+	}
 
 	sdw->cdns.link_up = false;
 	return 0;
-- 
2.17.1

Re: [PATCH v2 00/10] soundwire: intel: add multi-link support

[Vinod Koul]

On 01-09-20, 23:05, Bard Liao wrote:
> This series enables multi-link support for Intel platforms.

Applied all, thanks

> 
> Changes in v2:
> - Remove the "soundwire: intel: Only call sdw stream APIs for the first
>   cpu_dai" patch form this series. We will move the sounwdire stream
>   operations to machine driver in another series.
> - Update the commit message and title of "soundwire: intel: add error log
>   for clock-stop invalid configs"
> 
> Pierre-Louis Bossart (10):
>   soundwire: intel: disable shim wake on suspend
>   soundwire: intel: ignore software command retries
>   soundwire: intel: add multi-link support
>   soundwire: intel: add missing support for all clock stop modes
>   soundwire: bus: update multi-link definition with hw sync details
>   soundwire: intel: add multi-link hw_synchronization information
>   soundwire: stream: enable hw_sync as needed by hardware
>   soundwire: intel: add error log for clock-stop invalid configs
>   soundwire: intel: pass link_mask information to each master
>   soundwire: intel: don't manage link power individually
> 
>  drivers/soundwire/intel.c      | 264 ++++++++++++++++++++++++++++-----
>  drivers/soundwire/intel.h      |   2 +
>  drivers/soundwire/intel_init.c |   1 +
>  drivers/soundwire/stream.c     |  15 +-
>  include/linux/soundwire/sdw.h  |   6 +
>  5 files changed, 243 insertions(+), 45 deletions(-)
> 
> -- 
> 2.17.1

-- 
~Vinod