linux-kernel - [PATCH 7/7] soundwire: intel: introduce helper for link synchronization

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Message-Id: <20200311221026.18174-8-pierre-louis.bossart@linux.intel.com>
Date:   Wed, 11 Mar 2020 17:10:26 -0500
From:   Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
To:     alsa-devel@...a-project.org
Cc:     linux-kernel@...r.kernel.org, tiwai@...e.de, broonie@...nel.org,
        vkoul@...nel.org, gregkh@...uxfoundation.org, jank@...ence.com,
        srinivas.kandagatla@...aro.org, slawomir.blauciak@...el.com,
        Bard liao <yung-chuan.liao@...ux.intel.com>,
        Rander Wang <rander.wang@...ux.intel.com>,
        Ranjani Sridharan <ranjani.sridharan@...ux.intel.com>,
        Hui Wang <hui.wang@...onical.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Sanyog Kale <sanyog.r.kale@...el.com>
Subject: [PATCH 7/7] soundwire: intel: introduce helper for link synchronization

After arming the synchronization, the SYNCGO field controls the
hardware-based synchronization between links.

Move the programming and wait for clear of SYNCGO to dedicated helper.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
---
 drivers/soundwire/intel.c | 47 ++++++++++++++++++++++++++++++++-------
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 93d157d04eb9..e2dac2f0b343 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -524,6 +524,44 @@ static void intel_shim_sync_arm(struct sdw_intel *sdw)
 	mutex_unlock(sdw->link_res->shim_lock);
 }
 
+static int intel_shim_sync_go_unlocked(struct sdw_intel *sdw)
+{
+	void __iomem *shim = sdw->link_res->shim;
+	u32 sync_reg;
+	int ret;
+
+	/* Read SYNC register */
+	sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
+
+	/*
+	 * Set SyncGO bit to synchronously trigger a bank switch for
+	 * all the masters. A write to SYNCGO bit clears CMDSYNC bit for all
+	 * the Masters.
+	 */
+	sync_reg |= SDW_SHIM_SYNC_SYNCGO;
+
+	ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg,
+			      SDW_SHIM_SYNC_SYNCGO);
+
+	if (ret < 0)
+		dev_err(sdw->cdns.dev, "SyncGO clear failed: %d\n", ret);
+
+	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
  */
@@ -775,15 +813,8 @@ static int intel_post_bank_switch(struct sdw_bus *bus)
 		ret = 0;
 		goto unlock;
 	}
-	/*
-	 * Set SyncGO bit to synchronously trigger a bank switch for
-	 * all the masters. A write to SYNCGO bit clears CMDSYNC bit for all
-	 * the Masters.
-	 */
-	sync_reg |= SDW_SHIM_SYNC_SYNCGO;
 
-	ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg,
-			      SDW_SHIM_SYNC_SYNCGO);
+	ret = intel_shim_sync_go_unlocked(sdw);
 unlock:
 	mutex_unlock(sdw->link_res->shim_lock);
 
-- 
2.20.1