1 files changed, 73 insertions, 90 deletions

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 5d5b0bd59ae3..3e6d4addac2f 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -394,13 +394,13 @@ sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 }
 
 static int
-sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
 {
 	struct sdw_msg msg;
 	int ret;
 
 	ret = sdw_fill_msg(&msg, slave, addr, count,
-			   slave->dev_num, SDW_MSG_FLAG_WRITE, val);
+			   slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val);
 	if (ret < 0)
 		return ret;
 
@@ -550,9 +550,9 @@ EXPORT_SYMBOL(sdw_nread);
  * @slave: SDW Slave
  * @addr: Register address
  * @count: length
- * @val: Buffer for values to be read
+ * @val: Buffer for values to be written
  */
-int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
 {
 	int ret;
 
@@ -836,26 +836,6 @@ static void sdw_modify_slave_status(struct sdw_slave *slave,
 	mutex_unlock(&bus->bus_lock);
 }
 
-static enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave)
-{
-	enum sdw_clk_stop_mode mode;
-
-	/*
-	 * Query for clock stop mode if Slave implements
-	 * ops->get_clk_stop_mode, else read from property.
-	 */
-	if (slave->ops && slave->ops->get_clk_stop_mode) {
-		mode = slave->ops->get_clk_stop_mode(slave);
-	} else {
-		if (slave->prop.clk_stop_mode1)
-			mode = SDW_CLK_STOP_MODE1;
-		else
-			mode = SDW_CLK_STOP_MODE0;
-	}
-
-	return mode;
-}
-
 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
 				       enum sdw_clk_stop_mode mode,
 				       enum sdw_clk_stop_type type)
@@ -864,11 +844,8 @@ static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
 
 	if (slave->ops && slave->ops->clk_stop) {
 		ret = slave->ops->clk_stop(slave, mode, type);
-		if (ret < 0) {
-			dev_err(&slave->dev,
-				"Clk Stop type =%d failed: %d\n", type, ret);
+		if (ret < 0)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -895,7 +872,8 @@ static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
 	} else {
 		ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
 		if (ret < 0) {
-			dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
+			if (ret != -ENODATA)
+				dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
 			return ret;
 		}
 		val = ret;
@@ -904,9 +882,8 @@ static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
 
 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
 
-	if (ret < 0)
-		dev_err(&slave->dev,
-			"Clock Stop prepare failed for slave: %d", ret);
+	if (ret < 0 && ret != -ENODATA)
+		dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL write failed:%d\n", ret);
 
 	return ret;
 }
@@ -924,7 +901,7 @@ static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
 		}
 		val &= SDW_SCP_STAT_CLK_STP_NF;
 		if (!val) {
-			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d",
+			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d\n",
 				dev_num);
 			return 0;
 		}
@@ -933,7 +910,7 @@ static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
 		retry--;
 	} while (retry);
 
-	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d",
+	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d\n",
 		dev_num);
 
 	return -ETIMEDOUT;
@@ -948,7 +925,6 @@ static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
  */
 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 {
-	enum sdw_clk_stop_mode slave_mode;
 	bool simple_clk_stop = true;
 	struct sdw_slave *slave;
 	bool is_slave = false;
@@ -958,6 +934,9 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 	 * In order to save on transition time, prepare
 	 * each Slave and then wait for all Slave(s) to be
 	 * prepared for clock stop.
+	 * If one of the Slave devices has lost sync and
+	 * replies with Command Ignored/-ENODATA, we continue
+	 * the loop
 	 */
 	list_for_each_entry(slave, &bus->slaves, node) {
 		if (!slave->dev_num)
@@ -970,36 +949,45 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 		/* Identify if Slave(s) are available on Bus */
 		is_slave = true;
 
-		slave_mode = sdw_get_clk_stop_mode(slave);
-		slave->curr_clk_stop_mode = slave_mode;
-
-		ret = sdw_slave_clk_stop_callback(slave, slave_mode,
+		ret = sdw_slave_clk_stop_callback(slave,
+						  SDW_CLK_STOP_MODE0,
 						  SDW_CLK_PRE_PREPARE);
-		if (ret < 0) {
-			dev_err(&slave->dev,
-				"pre-prepare failed:%d", ret);
-			return ret;
-		}
-
-		ret = sdw_slave_clk_stop_prepare(slave,
-						 slave_mode, true);
-		if (ret < 0) {
-			dev_err(&slave->dev,
-				"pre-prepare failed:%d", ret);
+		if (ret < 0 && ret != -ENODATA) {
+			dev_err(&slave->dev, "clock stop pre-prepare cb failed:%d\n", ret);
 			return ret;
 		}
 
-		if (slave_mode == SDW_CLK_STOP_MODE1)
+		/* Only prepare a Slave device if needed */
+		if (!slave->prop.simple_clk_stop_capable) {
 			simple_clk_stop = false;
+
+			ret = sdw_slave_clk_stop_prepare(slave,
+							 SDW_CLK_STOP_MODE0,
+							 true);
+			if (ret < 0 && ret != -ENODATA) {
+				dev_err(&slave->dev, "clock stop prepare failed:%d\n", ret);
+				return ret;
+			}
+		}
 	}
 
 	/* Skip remaining clock stop preparation if no Slave is attached */
 	if (!is_slave)
-		return ret;
+		return 0;
 
+	/*
+	 * Don't wait for all Slaves to be ready if they follow the simple
+	 * state machine
+	 */
 	if (!simple_clk_stop) {
 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
 						       SDW_BROADCAST_DEV_NUM);
+		/*
+		 * if there are no Slave devices present and the reply is
+		 * Command_Ignored/-ENODATA, we don't need to continue with the
+		 * flow and can just return here. The error code is not modified
+		 * and its handling left as an exercise for the caller.
+		 */
 		if (ret < 0)
 			return ret;
 	}
@@ -1013,21 +1001,17 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 		    slave->status != SDW_SLAVE_ALERT)
 			continue;
 
-		slave_mode = slave->curr_clk_stop_mode;
-
-		if (slave_mode == SDW_CLK_STOP_MODE1) {
-			ret = sdw_slave_clk_stop_callback(slave,
-							  slave_mode,
-							  SDW_CLK_POST_PREPARE);
+		ret = sdw_slave_clk_stop_callback(slave,
+						  SDW_CLK_STOP_MODE0,
+						  SDW_CLK_POST_PREPARE);
 
-			if (ret < 0) {
-				dev_err(&slave->dev,
-					"post-prepare failed:%d", ret);
-			}
+		if (ret < 0 && ret != -ENODATA) {
+			dev_err(&slave->dev, "clock stop post-prepare cb failed:%d\n", ret);
+			return ret;
 		}
 	}
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
 
@@ -1050,12 +1034,8 @@ int sdw_bus_clk_stop(struct sdw_bus *bus)
 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
 	if (ret < 0) {
-		if (ret == -ENODATA)
-			dev_dbg(bus->dev,
-				"ClockStopNow Broadcast msg ignored %d", ret);
-		else
-			dev_err(bus->dev,
-				"ClockStopNow Broadcast msg failed %d", ret);
+		if (ret != -ENODATA)
+			dev_err(bus->dev, "ClockStopNow Broadcast msg failed %d\n", ret);
 		return ret;
 	}
 
@@ -1074,7 +1054,6 @@ EXPORT_SYMBOL(sdw_bus_clk_stop);
  */
 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
 {
-	enum sdw_clk_stop_mode mode;
 	bool simple_clk_stop = true;
 	struct sdw_slave *slave;
 	bool is_slave = false;
@@ -1096,33 +1075,36 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
 		/* Identify if Slave(s) are available on Bus */
 		is_slave = true;
 
-		mode = slave->curr_clk_stop_mode;
-
-		if (mode == SDW_CLK_STOP_MODE1) {
-			simple_clk_stop = false;
-			continue;
-		}
-
-		ret = sdw_slave_clk_stop_callback(slave, mode,
+		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
 						  SDW_CLK_PRE_DEPREPARE);
 		if (ret < 0)
-			dev_warn(&slave->dev,
-				 "clk stop deprep failed:%d", ret);
+			dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);
 
-		ret = sdw_slave_clk_stop_prepare(slave, mode,
-						 false);
+		/* Only de-prepare a Slave device if needed */
+		if (!slave->prop.simple_clk_stop_capable) {
+			simple_clk_stop = false;
 
-		if (ret < 0)
-			dev_warn(&slave->dev,
-				 "clk stop deprep failed:%d", ret);
+			ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
+							 false);
+
+			if (ret < 0)
+				dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret);
+		}
 	}
 
 	/* Skip remaining clock stop de-preparation if no Slave is attached */
 	if (!is_slave)
 		return 0;
 
-	if (!simple_clk_stop)
-		sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
+	/*
+	 * Don't wait for all Slaves to be ready if they follow the simple
+	 * state machine
+	 */
+	if (!simple_clk_stop) {
+		ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
+		if (ret < 0)
+			dev_warn(&slave->dev, "clock stop deprepare wait failed:%d\n", ret);
+	}
 
 	list_for_each_entry(slave, &bus->slaves, node) {
 		if (!slave->dev_num)
@@ -1132,9 +1114,10 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
 		    slave->status != SDW_SLAVE_ALERT)
 			continue;
 
-		mode = slave->curr_clk_stop_mode;
-		sdw_slave_clk_stop_callback(slave, mode,
-					    SDW_CLK_POST_DEPREPARE);
+		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
+						  SDW_CLK_POST_DEPREPARE);
+		if (ret < 0)
+			dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret);
 	}
 
 	return 0;