soundwire: intel: add abstraction for cmdsync check

If we add one more callback, we can have common bank switch sequences
between old and new hardware: the only difference is where the CMDSYNC
register is located.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20230314015410.487311-10-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/intel.c

@@ -325,6 +325,15 @@ static void intel_shim_wake(struct sdw_intel *sdw, bool wake_enable)
 	mutex_unlock(sdw->link_res->shim_lock);
 }
 
+static bool intel_check_cmdsync_unlocked(struct sdw_intel *sdw)
+{
+	void __iomem *shim = sdw->link_res->shim;
+	int sync_reg;
+
+	sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
+	return !!(sync_reg & SDW_SHIM_SYNC_CMDSYNC_MASK);
+}
+
 static int intel_link_power_up(struct sdw_intel *sdw)
 {
 	unsigned int link_id = sdw->instance;
@@ -695,8 +704,7 @@ static int intel_post_bank_switch(struct sdw_intel *sdw)
 {
 	struct sdw_cdns *cdns = &sdw->cdns;
 	struct sdw_bus *bus = &cdns->bus;
-	void __iomem *shim = sdw->link_res->shim;
-	int sync_reg, ret;
+	int ret = 0;
 
 	/* Write to register only for multi-link */
 	if (!bus->multi_link)
@@ -704,9 +712,6 @@ static int intel_post_bank_switch(struct sdw_intel *sdw)
 
 	mutex_lock(sdw->link_res->shim_lock);
 
-	/* Read SYNC register */
-	sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
-
 	/*
 	 * post_bank_switch() ops is called from the bus in loop for
 	 * all the Masters in the steam with the expectation that
@@ -715,13 +720,9 @@ static int intel_post_bank_switch(struct sdw_intel *sdw)
 	 *
 	 * So, set the SYNCGO bit only if CMDSYNC bit is set for any Master.
 	 */
-	if (!(sync_reg & SDW_SHIM_SYNC_CMDSYNC_MASK)) {
-		ret = 0;
-		goto unlock;
-	}
+	if (sdw_intel_sync_check_cmdsync_unlocked(sdw))
+		ret = sdw_intel_sync_go_unlocked(sdw);
 
-	ret = sdw_intel_sync_go_unlocked(sdw);
-unlock:
 	mutex_unlock(sdw->link_res->shim_lock);
 
 	if (ret < 0)
@@ -1147,6 +1148,7 @@ const struct sdw_intel_hw_ops sdw_intel_cnl_hw_ops = {
 	.sync_arm = intel_shim_sync_arm,
 	.sync_go_unlocked = intel_shim_sync_go_unlocked,
 	.sync_go = intel_shim_sync_go,
+	.sync_check_cmdsync_unlocked = intel_check_cmdsync_unlocked,
 };
 EXPORT_SYMBOL_NS(sdw_intel_cnl_hw_ops, SOUNDWIRE_INTEL);
 

drivers/soundwire/intel.h

@@ -187,6 +187,13 @@ static inline int sdw_intel_sync_go(struct sdw_intel *sdw)
 	return -ENOTSUPP;
 }
 
+static inline bool sdw_intel_sync_check_cmdsync_unlocked(struct sdw_intel *sdw)
+{
+	if (SDW_INTEL_CHECK_OPS(sdw, sync_check_cmdsync_unlocked))
+		return SDW_INTEL_OPS(sdw, sync_check_cmdsync_unlocked)(sdw);
+	return false;
+}
+
 /* common bus management */
 int intel_start_bus(struct sdw_intel *sdw);
 int intel_start_bus_after_reset(struct sdw_intel *sdw);

include/linux/soundwire/sdw_intel.h

@@ -313,6 +313,8 @@ struct sdw_intel;
  * @sync_go_unlocked: helper for multi-link synchronization -
  * shim_lock is assumed to be locked at higher level
  * @sync_go: helper for multi-link synchronization
+ * @sync_check_cmdsync_unlocked: helper for multi-link synchronization
+ * and bank switch - shim_lock is assumed to be locked at higher level
  */
 struct sdw_intel_hw_ops {
 	void (*debugfs_init)(struct sdw_intel *sdw);
@@ -338,6 +340,7 @@ struct sdw_intel_hw_ops {
 	void (*sync_arm)(struct sdw_intel *sdw);
 	int (*sync_go_unlocked)(struct sdw_intel *sdw);
 	int (*sync_go)(struct sdw_intel *sdw);
+	bool (*sync_check_cmdsync_unlocked)(struct sdw_intel *sdw);
 };
 
 extern const struct sdw_intel_hw_ops sdw_intel_cnl_hw_ops;