1 files changed, 491 insertions, 46 deletions

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 6106577fb3ed..488c3c9e4947 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -2,6 +2,7 @@
 // Copyright(c) 2015-17 Intel Corporation.
 
 #include <linux/acpi.h>
+#include <linux/delay.h>
 #include <linux/mod_devicetable.h>
 #include <linux/pm_runtime.h>
 #include <linux/soundwire/sdw_registers.h>
@@ -113,6 +114,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 	struct sdw_bus *bus = slave->bus;
 
+	pm_runtime_disable(dev);
+
 	sdw_slave_debugfs_exit(slave);
 
 	mutex_lock(&bus->bus_lock);
@@ -317,6 +320,92 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
 	return 0;
 }
 
+/*
+ * Read/Write IO functions.
+ * no_pm versions can only be called by the bus, e.g. while enumerating or
+ * handling suspend-resume sequences.
+ * all clients need to use the pm versions
+ */
+
+static int
+sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+{
+	struct sdw_msg msg;
+	int ret;
+
+	ret = sdw_fill_msg(&msg, slave, addr, count,
+			   slave->dev_num, SDW_MSG_FLAG_READ, val);
+	if (ret < 0)
+		return ret;
+
+	return sdw_transfer(slave->bus, &msg);
+}
+
+static int
+sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+{
+	struct sdw_msg msg;
+	int ret;
+
+	ret = sdw_fill_msg(&msg, slave, addr, count,
+			   slave->dev_num, SDW_MSG_FLAG_WRITE, val);
+	if (ret < 0)
+		return ret;
+
+	return sdw_transfer(slave->bus, &msg);
+}
+
+static int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
+{
+	return sdw_nwrite_no_pm(slave, addr, 1, &value);
+}
+
+static int
+sdw_bread_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr)
+{
+	struct sdw_msg msg;
+	u8 buf;
+	int ret;
+
+	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
+			   SDW_MSG_FLAG_READ, &buf);
+	if (ret)
+		return ret;
+
+	ret = sdw_transfer(bus, &msg);
+	if (ret < 0)
+		return ret;
+	else
+		return buf;
+}
+
+static int
+sdw_bwrite_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
+{
+	struct sdw_msg msg;
+	int ret;
+
+	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
+			   SDW_MSG_FLAG_WRITE, &value);
+	if (ret)
+		return ret;
+
+	return sdw_transfer(bus, &msg);
+}
+
+static int
+sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
+{
+	u8 buf;
+	int ret;
+
+	ret = sdw_nread_no_pm(slave, addr, 1, &buf);
+	if (ret < 0)
+		return ret;
+	else
+		return buf;
+}
+
 /**
  * sdw_nread() - Read "n" contiguous SDW Slave registers
  * @slave: SDW Slave
@@ -326,19 +415,17 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
  */
 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 {
-	struct sdw_msg msg;
 	int ret;
 
-	ret = sdw_fill_msg(&msg, slave, addr, count,
-			   slave->dev_num, SDW_MSG_FLAG_READ, val);
-	if (ret < 0)
-		return ret;
-
 	ret = pm_runtime_get_sync(slave->bus->dev);
-	if (ret < 0)
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_noidle(slave->bus->dev);
 		return ret;
+	}
+
+	ret = sdw_nread_no_pm(slave, addr, count, val);
 
-	ret = sdw_transfer(slave->bus, &msg);
+	pm_runtime_mark_last_busy(slave->bus->dev);
 	pm_runtime_put(slave->bus->dev);
 
 	return ret;
@@ -354,19 +441,17 @@ EXPORT_SYMBOL(sdw_nread);
  */
 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 {
-	struct sdw_msg msg;
 	int ret;
 
-	ret = sdw_fill_msg(&msg, slave, addr, count,
-			   slave->dev_num, SDW_MSG_FLAG_WRITE, val);
-	if (ret < 0)
-		return ret;
-
 	ret = pm_runtime_get_sync(slave->bus->dev);
-	if (ret < 0)
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_noidle(slave->bus->dev);
 		return ret;
+	}
+
+	ret = sdw_nwrite_no_pm(slave, addr, count, val);
 
-	ret = sdw_transfer(slave->bus, &msg);
+	pm_runtime_mark_last_busy(slave->bus->dev);
 	pm_runtime_put(slave->bus->dev);
 
 	return ret;
@@ -486,7 +571,7 @@ static int sdw_assign_device_num(struct sdw_slave *slave)
 	dev_num = slave->dev_num;
 	slave->dev_num = 0;
 
-	ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
+	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
 	if (ret < 0) {
 		dev_err(&slave->dev, "Program device_num %d failed: %d\n",
 			dev_num, ret);
@@ -504,22 +589,11 @@ void sdw_extract_slave_id(struct sdw_bus *bus,
 {
 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
 
-	/*
-	 * Spec definition
-	 *   Register		Bit	Contents
-	 *   DevId_0 [7:4]	47:44	sdw_version
-	 *   DevId_0 [3:0]	43:40	unique_id
-	 *   DevId_1		39:32	mfg_id [15:8]
-	 *   DevId_2		31:24	mfg_id [7:0]
-	 *   DevId_3		23:16	part_id [15:8]
-	 *   DevId_4		15:08	part_id [7:0]
-	 *   DevId_5		07:00	class_id
-	 */
-	id->sdw_version = (addr >> 44) & GENMASK(3, 0);
-	id->unique_id = (addr >> 40) & GENMASK(3, 0);
-	id->mfg_id = (addr >> 24) & GENMASK(15, 0);
-	id->part_id = (addr >> 8) & GENMASK(15, 0);
-	id->class_id = addr & GENMASK(7, 0);
+	id->sdw_version = SDW_VERSION(addr);
+	id->unique_id = SDW_UNIQUE_ID(addr);
+	id->mfg_id = SDW_MFG_ID(addr);
+	id->part_id = SDW_PART_ID(addr);
+	id->class_id = SDW_CLASS_ID(addr);
 
 	dev_dbg(bus->dev,
 		"SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",
@@ -610,10 +684,320 @@ static void sdw_modify_slave_status(struct sdw_slave *slave,
 				    enum sdw_slave_status status)
 {
 	mutex_lock(&slave->bus->bus_lock);
+
+	dev_vdbg(&slave->dev,
+		 "%s: changing status slave %d status %d new status %d\n",
+		 __func__, slave->dev_num, slave->status, status);
+
+	if (status == SDW_SLAVE_UNATTACHED) {
+		dev_dbg(&slave->dev,
+			"%s: initializing completion for Slave %d\n",
+			__func__, slave->dev_num);
+
+		init_completion(&slave->enumeration_complete);
+		init_completion(&slave->initialization_complete);
+
+	} else if ((status == SDW_SLAVE_ATTACHED) &&
+		   (slave->status == SDW_SLAVE_UNATTACHED)) {
+		dev_dbg(&slave->dev,
+			"%s: signaling completion for Slave %d\n",
+			__func__, slave->dev_num);
+
+		complete(&slave->enumeration_complete);
+	}
 	slave->status = status;
 	mutex_unlock(&slave->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)
+{
+	int ret;
+
+	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);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
+				      enum sdw_clk_stop_mode mode,
+				      bool prepare)
+{
+	bool wake_en;
+	u32 val = 0;
+	int ret;
+
+	wake_en = slave->prop.wake_capable;
+
+	if (prepare) {
+		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
+
+		if (mode == SDW_CLK_STOP_MODE1)
+			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
+
+		if (wake_en)
+			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
+	} else {
+		val = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
+
+		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
+	}
+
+	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);
+
+	return ret;
+}
+
+static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
+{
+	int retry = bus->clk_stop_timeout;
+	int val;
+
+	do {
+		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT) &
+			SDW_SCP_STAT_CLK_STP_NF;
+		if (!val) {
+			dev_info(bus->dev, "clock stop prep/de-prep done slave:%d",
+				 dev_num);
+			return 0;
+		}
+
+		usleep_range(1000, 1500);
+		retry--;
+	} while (retry);
+
+	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d",
+		dev_num);
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
+ *
+ * @bus: SDW bus instance
+ *
+ * Query Slave for clock stop mode and prepare for that mode.
+ */
+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;
+	int ret = 0;
+
+	/*
+	 * In order to save on transition time, prepare
+	 * each Slave and then wait for all Slave(s) to be
+	 * prepared for clock stop.
+	 */
+	list_for_each_entry(slave, &bus->slaves, node) {
+		if (!slave->dev_num)
+			continue;
+
+		/* Identify if Slave(s) are available on Bus */
+		is_slave = true;
+
+		if (slave->status != SDW_SLAVE_ATTACHED &&
+		    slave->status != SDW_SLAVE_ALERT)
+			continue;
+
+		slave_mode = sdw_get_clk_stop_mode(slave);
+		slave->curr_clk_stop_mode = slave_mode;
+
+		ret = sdw_slave_clk_stop_callback(slave, slave_mode,
+						  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);
+			return ret;
+		}
+
+		if (slave_mode == SDW_CLK_STOP_MODE1)
+			simple_clk_stop = false;
+	}
+
+	if (is_slave && !simple_clk_stop) {
+		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
+						       SDW_BROADCAST_DEV_NUM);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Inform slaves that prep is done */
+	list_for_each_entry(slave, &bus->slaves, node) {
+		if (!slave->dev_num)
+			continue;
+
+		if (slave->status != SDW_SLAVE_ATTACHED &&
+		    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);
+
+			if (ret < 0) {
+				dev_err(&slave->dev,
+					"post-prepare failed:%d", ret);
+			}
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
+
+/**
+ * sdw_bus_clk_stop: stop bus clock
+ *
+ * @bus: SDW bus instance
+ *
+ * After preparing the Slaves for clock stop, stop the clock by broadcasting
+ * write to SCP_CTRL register.
+ */
+int sdw_bus_clk_stop(struct sdw_bus *bus)
+{
+	int ret;
+
+	/*
+	 * broadcast clock stop now, attached Slaves will ACK this,
+	 * unattached will ignore
+	 */
+	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);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_bus_clk_stop);
+
+/**
+ * sdw_bus_exit_clk_stop: Exit clock stop mode
+ *
+ * @bus: SDW bus instance
+ *
+ * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
+ * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
+ * back.
+ */
+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;
+	int ret;
+
+	/*
+	 * In order to save on transition time, de-prepare
+	 * each Slave and then wait for all Slave(s) to be
+	 * de-prepared after clock resume.
+	 */
+	list_for_each_entry(slave, &bus->slaves, node) {
+		if (!slave->dev_num)
+			continue;
+
+		/* Identify if Slave(s) are available on Bus */
+		is_slave = true;
+
+		if (slave->status != SDW_SLAVE_ATTACHED &&
+		    slave->status != SDW_SLAVE_ALERT)
+			continue;
+
+		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,
+						  SDW_CLK_PRE_DEPREPARE);
+		if (ret < 0)
+			dev_warn(&slave->dev,
+				 "clk stop deprep failed:%d", ret);
+
+		ret = sdw_slave_clk_stop_prepare(slave, mode,
+						 false);
+
+		if (ret < 0)
+			dev_warn(&slave->dev,
+				 "clk stop deprep failed:%d", ret);
+	}
+
+	if (is_slave && !simple_clk_stop)
+		sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
+
+	list_for_each_entry(slave, &bus->slaves, node) {
+		if (!slave->dev_num)
+			continue;
+
+		if (slave->status != SDW_SLAVE_ATTACHED &&
+		    slave->status != SDW_SLAVE_ALERT)
+			continue;
+
+		mode = slave->curr_clk_stop_mode;
+		sdw_slave_clk_stop_callback(slave, mode,
+					    SDW_CLK_POST_DEPREPARE);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
+
 int sdw_configure_dpn_intr(struct sdw_slave *slave,
 			   int port, bool enable, int mask)
 {
@@ -672,13 +1056,10 @@ static int sdw_initialize_slave(struct sdw_slave *slave)
 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
 
 	ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
-	if (ret < 0) {
+	if (ret < 0)
 		dev_err(slave->bus->dev,
 			"SDW_DP0_INTMASK read failed:%d\n", ret);
-		return val;
-	}
-
-	return 0;
+	return ret;
 }
 
 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
@@ -831,12 +1212,19 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 
 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 
+	ret = pm_runtime_get_sync(&slave->dev);
+	if (ret < 0 && ret != -EACCES) {
+		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
+		pm_runtime_put_noidle(slave->bus->dev);
+		return ret;
+	}
+
 	/* Read Instat 1, Instat 2 and Instat 3 registers */
 	ret = sdw_read(slave, SDW_SCP_INT1);
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 			"SDW_SCP_INT1 read failed:%d\n", ret);
-		return ret;
+		goto io_err;
 	}
 	buf = ret;
 
@@ -844,7 +1232,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
-		return ret;
+		goto io_err;
 	}
 
 	do {
@@ -924,7 +1312,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT1 write failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 
 		/*
@@ -935,7 +1323,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT1 read failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 		_buf = ret;
 
@@ -943,7 +1331,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT2/3 read failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 
 		/* Make sure no interrupts are pending */
@@ -964,16 +1352,39 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	if (count == SDW_READ_INTR_CLEAR_RETRY)
 		dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
 
+io_err:
+	pm_runtime_mark_last_busy(&slave->dev);
+	pm_runtime_put_autosuspend(&slave->dev);
+
 	return ret;
 }
 
 static int sdw_update_slave_status(struct sdw_slave *slave,
 				   enum sdw_slave_status status)
 {
-	if (slave->ops && slave->ops->update_status)
-		return slave->ops->update_status(slave, status);
+	unsigned long time;
 
-	return 0;
+	if (!slave->probed) {
+		/*
+		 * the slave status update is typically handled in an
+		 * interrupt thread, which can race with the driver
+		 * probe, e.g. when a module needs to be loaded.
+		 *
+		 * make sure the probe is complete before updating
+		 * status.
+		 */
+		time = wait_for_completion_timeout(&slave->probe_complete,
+				msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
+		if (!time) {
+			dev_err(&slave->dev, "Probe not complete, timed out\n");
+			return -ETIMEDOUT;
+		}
+	}
+
+	if (!slave->ops || !slave->ops->update_status)
+		return 0;
+
+	return slave->ops->update_status(slave, status);
 }
 
 /**
@@ -986,6 +1397,7 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 {
 	enum sdw_slave_status prev_status;
 	struct sdw_slave *slave;
+	bool attached_initializing;
 	int i, ret = 0;
 
 	/* first check if any Slaves fell off the bus */
@@ -1031,6 +1443,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 		if (!slave)
 			continue;
 
+		attached_initializing = false;
+
 		switch (status[i]) {
 		case SDW_SLAVE_UNATTACHED:
 			if (slave->status == SDW_SLAVE_UNATTACHED)
@@ -1057,6 +1471,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 			if (prev_status == SDW_SLAVE_ALERT)
 				break;
 
+			attached_initializing = true;
+
 			ret = sdw_initialize_slave(slave);
 			if (ret)
 				dev_err(bus->dev,
@@ -1075,8 +1491,37 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 		if (ret)
 			dev_err(slave->bus->dev,
 				"Update Slave status failed:%d\n", ret);
+		if (attached_initializing)
+			complete(&slave->initialization_complete);
 	}
 
 	return ret;
 }
 EXPORT_SYMBOL(sdw_handle_slave_status);
+
+void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
+{
+	struct sdw_slave *slave;
+	int i;
+
+	/* Check all non-zero devices */
+	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+		mutex_lock(&bus->bus_lock);
+		if (test_bit(i, bus->assigned) == false) {
+			mutex_unlock(&bus->bus_lock);
+			continue;
+		}
+		mutex_unlock(&bus->bus_lock);
+
+		slave = sdw_get_slave(bus, i);
+		if (!slave)
+			continue;
+
+		if (slave->status != SDW_SLAVE_UNATTACHED)
+			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+
+		/* keep track of request, used in pm_runtime resume */
+		slave->unattach_request = request;
+	}
+}
+EXPORT_SYMBOL(sdw_clear_slave_status);