drivers/soundwire/intel_auxdevice.c - linux/kernel/git/bpf/bpf-next - Git at Google

 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
 // Copyright(c) 2015-22 Intel Corporation.

 /*
  * Soundwire Intel Manager Driver
  */

 #include <linux/acpi.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/auxiliary_bus.h>
 #include <sound/pcm_params.h>
 #include <linux/pm_runtime.h>
 #include <sound/soc.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_intel.h>
 #include "cadence_master.h"
 #include "bus.h"
 #include "intel.h"
 #include "intel_auxdevice.h"

 #define INTEL_MASTER_SUSPEND_DELAY_MS	3000

 /*
  * debug/config flags for the Intel SoundWire Master.
  *
  * Since we may have multiple masters active, we can have up to 8
  * flags reused in each byte, with master0 using the ls-byte, etc.
  */

 #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);
 MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off)");

 struct wake_capable_part {
 	const u16 mfg_id;
 	const u16 part_id;
 };

 static struct wake_capable_part wake_capable_list[] = {
 	{0x025d, 0x5682},
 	{0x025d, 0x700},
 	{0x025d, 0x711},
 	{0x025d, 0x1712},
 	{0x025d, 0x1713},
 	{0x025d, 0x1716},
 	{0x025d, 0x1717},
 	{0x025d, 0x712},
 	{0x025d, 0x713},
 	{0x025d, 0x714},
 	{0x025d, 0x715},
 	{0x025d, 0x716},
 	{0x025d, 0x717},
 	{0x025d, 0x722},
 };

 static bool is_wake_capable(struct sdw_slave *slave)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(wake_capable_list); i++)
 		if (slave->id.part_id == wake_capable_list[i].part_id &&
 		    slave->id.mfg_id == wake_capable_list[i].mfg_id)
 			return true;
 	return false;
 }

 static int generic_pre_bank_switch(struct sdw_bus *bus)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);

 	return sdw->link_res->hw_ops->pre_bank_switch(sdw);
 }

 static int generic_post_bank_switch(struct sdw_bus *bus)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);

 	return sdw->link_res->hw_ops->post_bank_switch(sdw);
 }

 static void generic_new_peripheral_assigned(struct sdw_bus *bus,
 					    struct sdw_slave *slave,
 					    int dev_num)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	int dev_num_min;
 	int dev_num_max;
 	bool wake_capable = slave->prop.wake_capable || is_wake_capable(slave);

 	if (wake_capable) {
 		dev_num_min = SDW_INTEL_DEV_NUM_IDA_MIN;
 		dev_num_max = SDW_MAX_DEVICES;
 	} else {
 		dev_num_min = 1;
 		dev_num_max = SDW_INTEL_DEV_NUM_IDA_MIN - 1;
 	}

 	/* paranoia check, this should never happen */
 	if (dev_num < dev_num_min || dev_num > dev_num_max)  {
 		dev_err(bus->dev, "%s: invalid dev_num %d, wake supported %d\n",
 			__func__, dev_num, slave->prop.wake_capable);
 		return;
 	}

 	if (sdw->link_res->hw_ops->program_sdi && wake_capable)
 		sdw->link_res->hw_ops->program_sdi(sdw, dev_num);
 }

 static int sdw_master_read_intel_prop(struct sdw_bus *bus)
 {
 	struct sdw_master_prop *prop = &bus->prop;
 	struct fwnode_handle *link;
 	char name[32];
 	u32 quirk_mask;

 	/* Find master handle */
 	snprintf(name, sizeof(name),
 		 "mipi-sdw-link-%d-subproperties", bus->link_id);

 	link = device_get_named_child_node(bus->dev, name);
 	if (!link) {
 		dev_err(bus->dev, "Master node %s not found\n", name);
 		return -EIO;
 	}

 	fwnode_property_read_u32(link,
 				 "intel-sdw-ip-clock",
 				 &prop->mclk_freq);

 	/* the values reported by BIOS are the 2x clock, not the bus clock */
 	prop->mclk_freq /= 2;

 	fwnode_property_read_u32(link,
 				 "intel-quirk-mask",
 				 &quirk_mask);

 	if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
 		prop->hw_disabled = true;

 	prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH |
 		SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY;

 	return 0;
 }

 static int intel_prop_read(struct sdw_bus *bus)
 {
 	/* Initialize with default handler to read all DisCo properties */
 	sdw_master_read_prop(bus);

 	/* read Intel-specific properties */
 	sdw_master_read_intel_prop(bus);

 	return 0;
 }

 static DEFINE_IDA(intel_peripheral_ida);

 static int intel_get_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
 {
 	int bit;

 	if (slave->prop.wake_capable || is_wake_capable(slave))
 		return ida_alloc_range(&intel_peripheral_ida,
 				       SDW_INTEL_DEV_NUM_IDA_MIN, SDW_MAX_DEVICES,
 				       GFP_KERNEL);

 	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
 	if (bit == SDW_MAX_DEVICES)
 		return -ENODEV;

 	return bit;
 }

 static void intel_put_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
 {
 	if (slave->prop.wake_capable || is_wake_capable(slave))
 		ida_free(&intel_peripheral_ida, slave->dev_num);
 }

 static struct sdw_master_ops sdw_intel_ops = {
 	.read_prop = intel_prop_read,
 	.override_adr = sdw_dmi_override_adr,
 	.xfer_msg = cdns_xfer_msg,
 	.xfer_msg_defer = cdns_xfer_msg_defer,
 	.set_bus_conf = cdns_bus_conf,
 	.pre_bank_switch = generic_pre_bank_switch,
 	.post_bank_switch = generic_post_bank_switch,
 	.read_ping_status = cdns_read_ping_status,
 	.get_device_num =  intel_get_device_num_ida,
 	.put_device_num = intel_put_device_num_ida,
 	.new_peripheral_assigned = generic_new_peripheral_assigned,
 };

 /*
  * probe and init (aux_dev_id argument is required by function prototype but not used)
  */
 static int intel_link_probe(struct auxiliary_device *auxdev,
 			    const struct auxiliary_device_id *aux_dev_id)

 {
 	struct device *dev = &auxdev->dev;
 	struct sdw_intel_link_dev *ldev = auxiliary_dev_to_sdw_intel_link_dev(auxdev);
 	struct sdw_intel *sdw;
 	struct sdw_cdns *cdns;
 	struct sdw_bus *bus;
 	int ret;

 	sdw = devm_kzalloc(dev, sizeof(*sdw), GFP_KERNEL);
 	if (!sdw)
 		return -ENOMEM;

 	cdns = &sdw->cdns;
 	bus = &cdns->bus;

 	sdw->instance = auxdev->id;
 	sdw->link_res = &ldev->link_res;
 	cdns->dev = dev;
 	cdns->registers = sdw->link_res->registers;
 	cdns->ip_offset = sdw->link_res->ip_offset;
 	cdns->instance = sdw->instance;
 	cdns->msg_count = 0;

 	/* single controller for all SoundWire links */
 	bus->controller_id = 0;

 	bus->link_id = auxdev->id;
 	bus->clk_stop_timeout = 1;

 	sdw_cdns_probe(cdns);

 	/* Set ops */
 	bus->ops = &sdw_intel_ops;

 	/* set driver data, accessed by snd_soc_dai_get_drvdata() */
 	auxiliary_set_drvdata(auxdev, cdns);

 	/* use generic bandwidth allocation algorithm */
 	sdw->cdns.bus.compute_params = sdw_compute_params;

 	/* avoid resuming from pm_runtime suspend if it's not required */
 	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);

 	ret = sdw_bus_master_add(bus, dev, dev->fwnode);
 	if (ret) {
 		dev_err(dev, "sdw_bus_master_add fail: %d\n", ret);
 		return ret;
 	}

 	if (bus->prop.hw_disabled)
 		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;
 }

 int intel_link_startup(struct auxiliary_device *auxdev)
 {
 	struct device *dev = &auxdev->dev;
 	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
 	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;

 	if (bus->prop.hw_disabled) {
 		dev_info(dev,
 			 "SoundWire master %d is disabled, ignoring\n",
 			 sdw->instance);
 		return 0;
 	}

 	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");
 	} 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->hw_sync_min_links = 1;
 	}
 	bus->multi_link = multi_link;

 	/* Initialize shim, controller */
 	ret = sdw_intel_link_power_up(sdw);
 	if (ret)
 		goto err_init;

 	/* Register DAIs */
 	ret = sdw_intel_register_dai(sdw);
 	if (ret) {
 		dev_err(dev, "DAI registration failed: %d\n", ret);
 		goto err_power_up;
 	}

 	sdw_intel_debugfs_init(sdw);

 	/* Enable runtime PM */
 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) {
 		pm_runtime_set_autosuspend_delay(dev,
 						 INTEL_MASTER_SUSPEND_DELAY_MS);
 		pm_runtime_use_autosuspend(dev);
 		pm_runtime_mark_last_busy(dev);

 		pm_runtime_set_active(dev);
 		pm_runtime_enable(dev);

 		pm_runtime_resume(bus->dev);
 	}

 	/* start bus */
 	ret = sdw_intel_start_bus(sdw);
 	if (ret) {
 		dev_err(dev, "bus start failed: %d\n", ret);
 		goto err_pm_runtime;
 	}

 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_NOT_ALLOWED) {
 		/*
 		 * To keep the clock running we need to prevent
 		 * pm_runtime suspend from happening by increasing the
 		 * reference count.
 		 * This quirk is specified by the parent PCI device in
 		 * case of specific latency requirements. It will have
 		 * no effect if pm_runtime is disabled by the user via
 		 * a module parameter for testing purposes.
 		 */
 		pm_runtime_get_noresume(dev);
 	}

 	/*
 	 * The runtime PM status of Slave devices is "Unsupported"
 	 * until they report as ATTACHED. If they don't, e.g. because
 	 * there are no Slave devices populated or if the power-on is
 	 * delayed or dependent on a power switch, the Master will
 	 * remain active and prevent its parent from suspending.
 	 *
 	 * Conditionally force the pm_runtime core to re-evaluate the
 	 * Master status in the absence of any Slave activity. A quirk
 	 * is provided to e.g. deal with Slaves that may be powered on
 	 * with a delay. A more complete solution would require the
 	 * definition of Master properties.
 	 */
 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE)) {
 		pm_runtime_mark_last_busy(bus->dev);
 		pm_runtime_mark_last_busy(dev);
 		pm_runtime_idle(dev);
 	}

 	sdw->startup_done = true;
 	return 0;

 err_pm_runtime:
 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME))
 		pm_runtime_disable(dev);
 err_power_up:
 	sdw_intel_link_power_down(sdw);
 err_init:
 	return ret;
 }

 static void intel_link_remove(struct auxiliary_device *auxdev)
 {
 	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;

 	/*
 	 * Since pm_runtime is already disabled, we don't decrease
 	 * the refcount when the clock_stop_quirk is
 	 * SDW_INTEL_CLK_STOP_NOT_ALLOWED
 	 */
 	if (!bus->prop.hw_disabled) {
 		sdw_intel_debugfs_exit(sdw);
 		sdw_cdns_enable_interrupt(cdns, false);
 	}
 	sdw_bus_master_delete(bus);
 }

 int intel_link_process_wakeen_event(struct auxiliary_device *auxdev)
 {
 	struct device *dev = &auxdev->dev;
 	struct sdw_intel *sdw;
 	struct sdw_bus *bus;

 	sdw = auxiliary_get_drvdata(auxdev);
 	bus = &sdw->cdns.bus;

 	if (bus->prop.hw_disabled || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	if (!sdw_intel_shim_check_wake(sdw))
 		return 0;

 	/* disable WAKEEN interrupt ASAP to prevent interrupt flood */
 	sdw_intel_shim_wake(sdw, false);

 	/*
 	 * resume the Master, which will generate a bus reset and result in
 	 * Slaves re-attaching and be re-enumerated. The SoundWire physical
 	 * device which generated the wake will trigger an interrupt, which
 	 * will in turn cause the corresponding Linux Slave device to be
 	 * resumed and the Slave codec driver to check the status.
 	 */
 	pm_request_resume(dev);

 	return 0;
 }

 /*
  * PM calls
  */

 static int intel_resume_child_device(struct device *dev, void *data)
 {
 	int ret;
 	struct sdw_slave *slave = dev_to_sdw_dev(dev);

 	if (!slave->probed) {
 		dev_dbg(dev, "skipping device, no probed driver\n");
 		return 0;
 	}
 	if (!slave->dev_num_sticky) {
 		dev_dbg(dev, "skipping device, never detected on bus\n");
 		return 0;
 	}

 	ret = pm_request_resume(dev);
 	if (ret < 0) {
 		dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
 		return ret;
 	}

 	return 0;
 }

 static int __maybe_unused intel_pm_prepare(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 || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

 	if (pm_runtime_suspended(dev) &&
 	    pm_runtime_suspended(dev->parent) &&
 	    ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
 	     !clock_stop_quirks)) {
 		/*
 		 * if we've enabled clock stop, and the parent is suspended, the SHIM registers
 		 * are not accessible and the shim wake cannot be disabled.
 		 * The only solution is to resume the entire bus to full power
 		 */

 		/*
 		 * If any operation in this block fails, we keep going since we don't want
 		 * to prevent system suspend from happening and errors should be recoverable
 		 * on resume.
 		 */

 		/*
 		 * first resume the device for this link. This will also by construction
 		 * resume the PCI parent device.
 		 */
 		ret = pm_request_resume(dev);
 		if (ret < 0) {
 			dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
 			return 0;
 		}

 		/*
 		 * Continue resuming the entire bus (parent + child devices) to exit
 		 * the clock stop mode. If there are no devices connected on this link
 		 * this is a no-op.
 		 * The resume to full power could have been implemented with a .prepare
 		 * step in SoundWire codec drivers. This would however require a lot
 		 * of code to handle an Intel-specific corner case. It is simpler in
 		 * practice to add a loop at the link level.
 		 */
 		ret = device_for_each_child(bus->dev, NULL, intel_resume_child_device);

 		if (ret < 0)
 			dev_err(dev, "%s: intel_resume_child_device failed: %d\n", __func__, ret);
 	}

 	return 0;
 }

 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 || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	if (pm_runtime_suspended(dev)) {
 		dev_dbg(dev, "pm_runtime status: suspended\n");

 		clock_stop_quirks = sdw->link_res->clock_stop_quirks;

 		if ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
 		    !clock_stop_quirks) {

 			if (pm_runtime_suspended(dev->parent)) {
 				/*
 				 * paranoia check: this should not happen with the .prepare
 				 * resume to full power
 				 */
 				dev_err(dev, "%s: invalid config: parent is suspended\n", __func__);
 			} else {
 				sdw_intel_shim_wake(sdw, false);
 			}
 		}

 		return 0;
 	}

 	ret = sdw_intel_stop_bus(sdw, false);
 	if (ret < 0) {
 		dev_err(dev, "%s: cannot stop bus: %d\n", __func__, ret);
 		return ret;
 	}

 	return 0;
 }

 static int __maybe_unused intel_suspend_runtime(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 || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
 		ret = sdw_intel_stop_bus(sdw, false);
 		if (ret < 0) {
 			dev_err(dev, "%s: cannot stop bus during teardown: %d\n",
 				__func__, ret);
 			return ret;
 		}
 	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET || !clock_stop_quirks) {
 		ret = sdw_intel_stop_bus(sdw, true);
 		if (ret < 0) {
 			dev_err(dev, "%s: cannot stop bus during clock_stop: %d\n",
 				__func__, ret);
 			return ret;
 		}
 	} else {
 		dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
 			__func__, clock_stop_quirks);
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static int __maybe_unused intel_resume(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;
 	int link_flags;
 	int ret;

 	if (bus->prop.hw_disabled || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	if (pm_runtime_suspended(dev)) {
 		dev_dbg(dev, "pm_runtime status was suspended, forcing active\n");

 		/* follow required sequence from runtime_pm.rst */
 		pm_runtime_disable(dev);
 		pm_runtime_set_active(dev);
 		pm_runtime_mark_last_busy(dev);
 		pm_runtime_enable(dev);

 		pm_runtime_resume(bus->dev);

 		link_flags = md_flags >> (bus->link_id * 8);

 		if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
 			pm_runtime_idle(dev);
 	}

 	ret = sdw_intel_link_power_up(sdw);
 	if (ret) {
 		dev_err(dev, "%s failed: %d\n", __func__, ret);
 		return ret;
 	}

 	/*
 	 * make sure all Slaves are tagged as UNATTACHED and provide
 	 * reason for reinitialization
 	 */
 	sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);

 	ret = sdw_intel_start_bus(sdw);
 	if (ret < 0) {
 		dev_err(dev, "cannot start bus during resume\n");
 		sdw_intel_link_power_down(sdw);
 		return ret;
 	}

 	/*
 	 * after system resume, the pm_runtime suspend() may kick in
 	 * during the enumeration, before any children device force the
 	 * master device to remain active.  Using pm_runtime_get()
 	 * routines is not really possible, since it'd prevent the
 	 * master from suspending.
 	 * A reasonable compromise is to update the pm_runtime
 	 * counters and delay the pm_runtime suspend by several
 	 * seconds, by when all enumeration should be complete.
 	 */
 	pm_runtime_mark_last_busy(bus->dev);
 	pm_runtime_mark_last_busy(dev);

 	return 0;
 }

 static int __maybe_unused intel_resume_runtime(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 || !sdw->startup_done) {
 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
 			bus->link_id);
 		return 0;
 	}

 	/* unconditionally disable WAKEEN interrupt */
 	sdw_intel_shim_wake(sdw, false);

 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
 		ret = sdw_intel_link_power_up(sdw);
 		if (ret) {
 			dev_err(dev, "%s: power_up failed after teardown: %d\n", __func__, ret);
 			return ret;
 		}

 		/*
 		 * make sure all Slaves are tagged as UNATTACHED and provide
 		 * reason for reinitialization
 		 */
 		sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);

 		ret = sdw_intel_start_bus(sdw);
 		if (ret < 0) {
 			dev_err(dev, "%s: cannot start bus after teardown: %d\n", __func__, ret);
 			sdw_intel_link_power_down(sdw);
 			return ret;
 		}

 	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
 		ret = sdw_intel_link_power_up(sdw);
 		if (ret) {
 			dev_err(dev, "%s: power_up failed after bus reset: %d\n", __func__, ret);
 			return ret;
 		}

 		ret = sdw_intel_start_bus_after_reset(sdw);
 		if (ret < 0) {
 			dev_err(dev, "%s: cannot start bus after reset: %d\n", __func__, ret);
 			sdw_intel_link_power_down(sdw);
 			return ret;
 		}
 	} else if (!clock_stop_quirks) {

 		sdw_intel_check_clock_stop(sdw);

 		ret = sdw_intel_link_power_up(sdw);
 		if (ret) {
 			dev_err(dev, "%s: power_up failed: %d\n", __func__, ret);
 			return ret;
 		}

 		ret = sdw_intel_start_bus_after_clock_stop(sdw);
 		if (ret < 0) {
 			dev_err(dev, "%s: cannot start bus after clock stop: %d\n", __func__, ret);
 			sdw_intel_link_power_down(sdw);
 			return ret;
 		}
 	} else {
 		dev_err(dev, "%s: clock_stop_quirks %x unsupported\n",
 			__func__, clock_stop_quirks);
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static const struct dev_pm_ops intel_pm = {
 	.prepare = intel_pm_prepare,
 	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
 	SET_RUNTIME_PM_OPS(intel_suspend_runtime, intel_resume_runtime, NULL)
 };

 static const struct auxiliary_device_id intel_link_id_table[] = {
 	{ .name = "soundwire_intel.link" },
 	{},
 };
 MODULE_DEVICE_TABLE(auxiliary, intel_link_id_table);

 static struct auxiliary_driver sdw_intel_drv = {
 	.probe = intel_link_probe,
 	.remove = intel_link_remove,
 	.driver = {
 		/* auxiliary_driver_register() sets .name to be the modname */
 		.pm = &intel_pm,
 	},
 	.id_table = intel_link_id_table
 };
 module_auxiliary_driver(sdw_intel_drv);

 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("Intel Soundwire Link Driver");
	// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
	// Copyright(c) 2015-22 Intel Corporation.

	/*
	* Soundwire Intel Manager Driver
	*/

	#include <linux/acpi.h>
	#include <linux/debugfs.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/auxiliary_bus.h>
	#include <sound/pcm_params.h>
	#include <linux/pm_runtime.h>
	#include <sound/soc.h>
	#include <linux/soundwire/sdw_registers.h>
	#include <linux/soundwire/sdw.h>
	#include <linux/soundwire/sdw_intel.h>
	#include "cadence_master.h"
	#include "bus.h"
	#include "intel.h"
	#include "intel_auxdevice.h"

	#define INTEL_MASTER_SUSPEND_DELAY_MS 3000

	/*
	* debug/config flags for the Intel SoundWire Master.
	*
	* Since we may have multiple masters active, we can have up to 8
	* flags reused in each byte, with master0 using the ls-byte, etc.
	*/

	#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);
	MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off)");

	struct wake_capable_part {
	const u16 mfg_id;
	const u16 part_id;
	};

	static struct wake_capable_part wake_capable_list[] = {
	{0x025d, 0x5682},
	{0x025d, 0x700},
	{0x025d, 0x711},
	{0x025d, 0x1712},
	{0x025d, 0x1713},
	{0x025d, 0x1716},
	{0x025d, 0x1717},
	{0x025d, 0x712},
	{0x025d, 0x713},
	{0x025d, 0x714},
	{0x025d, 0x715},
	{0x025d, 0x716},
	{0x025d, 0x717},
	{0x025d, 0x722},
	};

	static bool is_wake_capable(struct sdw_slave *slave)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(wake_capable_list); i++)
	if (slave->id.part_id == wake_capable_list[i].part_id &&
	slave->id.mfg_id == wake_capable_list[i].mfg_id)
	return true;
	return false;
	}

	static int generic_pre_bank_switch(struct sdw_bus *bus)
	{
	struct sdw_cdns *cdns = bus_to_cdns(bus);
	struct sdw_intel *sdw = cdns_to_intel(cdns);

	return sdw->link_res->hw_ops->pre_bank_switch(sdw);
	}

	static int generic_post_bank_switch(struct sdw_bus *bus)
	{
	struct sdw_cdns *cdns = bus_to_cdns(bus);
	struct sdw_intel *sdw = cdns_to_intel(cdns);

	return sdw->link_res->hw_ops->post_bank_switch(sdw);
	}

	static void generic_new_peripheral_assigned(struct sdw_bus *bus,
	struct sdw_slave *slave,
	int dev_num)
	{
	struct sdw_cdns *cdns = bus_to_cdns(bus);
	struct sdw_intel *sdw = cdns_to_intel(cdns);
	int dev_num_min;
	int dev_num_max;
	bool wake_capable = slave->prop.wake_capable \|\| is_wake_capable(slave);

	if (wake_capable) {
	dev_num_min = SDW_INTEL_DEV_NUM_IDA_MIN;
	dev_num_max = SDW_MAX_DEVICES;
	} else {
	dev_num_min = 1;
	dev_num_max = SDW_INTEL_DEV_NUM_IDA_MIN - 1;
	}

	/* paranoia check, this should never happen */
	if (dev_num < dev_num_min \|\| dev_num > dev_num_max) {
	dev_err(bus->dev, "%s: invalid dev_num %d, wake supported %d\n",
	__func__, dev_num, slave->prop.wake_capable);
	return;
	}

	if (sdw->link_res->hw_ops->program_sdi && wake_capable)
	sdw->link_res->hw_ops->program_sdi(sdw, dev_num);
	}

	static int sdw_master_read_intel_prop(struct sdw_bus *bus)
	{
	struct sdw_master_prop *prop = &bus->prop;
	struct fwnode_handle *link;
	char name[32];
	u32 quirk_mask;

	/* Find master handle */
	snprintf(name, sizeof(name),
	"mipi-sdw-link-%d-subproperties", bus->link_id);

	link = device_get_named_child_node(bus->dev, name);
	if (!link) {
	dev_err(bus->dev, "Master node %s not found\n", name);
	return -EIO;
	}

	fwnode_property_read_u32(link,
	"intel-sdw-ip-clock",
	&prop->mclk_freq);

	/* the values reported by BIOS are the 2x clock, not the bus clock */
	prop->mclk_freq /= 2;

	fwnode_property_read_u32(link,
	"intel-quirk-mask",
	&quirk_mask);

	if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
	prop->hw_disabled = true;

	prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH \|
	SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY;

	return 0;
	}

	static int intel_prop_read(struct sdw_bus *bus)
	{
	/* Initialize with default handler to read all DisCo properties */
	sdw_master_read_prop(bus);

	/* read Intel-specific properties */
	sdw_master_read_intel_prop(bus);

	return 0;
	}

	static DEFINE_IDA(intel_peripheral_ida);

	static int intel_get_device_num_ida(struct sdw_bus bus, struct sdw_slave slave)
	{
	int bit;

	if (slave->prop.wake_capable \|\| is_wake_capable(slave))
	return ida_alloc_range(&intel_peripheral_ida,
	SDW_INTEL_DEV_NUM_IDA_MIN, SDW_MAX_DEVICES,
	GFP_KERNEL);

	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
	if (bit == SDW_MAX_DEVICES)
	return -ENODEV;

	return bit;
	}

	static void intel_put_device_num_ida(struct sdw_bus bus, struct sdw_slave slave)
	{
	if (slave->prop.wake_capable \|\| is_wake_capable(slave))
	ida_free(&intel_peripheral_ida, slave->dev_num);
	}

	static struct sdw_master_ops sdw_intel_ops = {
	.read_prop = intel_prop_read,
	.override_adr = sdw_dmi_override_adr,
	.xfer_msg = cdns_xfer_msg,
	.xfer_msg_defer = cdns_xfer_msg_defer,
	.set_bus_conf = cdns_bus_conf,
	.pre_bank_switch = generic_pre_bank_switch,
	.post_bank_switch = generic_post_bank_switch,
	.read_ping_status = cdns_read_ping_status,
	.get_device_num = intel_get_device_num_ida,
	.put_device_num = intel_put_device_num_ida,
	.new_peripheral_assigned = generic_new_peripheral_assigned,
	};

	/*
	* probe and init (aux_dev_id argument is required by function prototype but not used)
	*/
	static int intel_link_probe(struct auxiliary_device *auxdev,
	const struct auxiliary_device_id *aux_dev_id)

	{
	struct device *dev = &auxdev->dev;
	struct sdw_intel_link_dev *ldev = auxiliary_dev_to_sdw_intel_link_dev(auxdev);
	struct sdw_intel *sdw;
	struct sdw_cdns *cdns;
	struct sdw_bus *bus;
	int ret;

	sdw = devm_kzalloc(dev, sizeof(*sdw), GFP_KERNEL);
	if (!sdw)
	return -ENOMEM;

	cdns = &sdw->cdns;
	bus = &cdns->bus;

	sdw->instance = auxdev->id;
	sdw->link_res = &ldev->link_res;
	cdns->dev = dev;
	cdns->registers = sdw->link_res->registers;
	cdns->ip_offset = sdw->link_res->ip_offset;
	cdns->instance = sdw->instance;
	cdns->msg_count = 0;

	/* single controller for all SoundWire links */
	bus->controller_id = 0;

	bus->link_id = auxdev->id;
	bus->clk_stop_timeout = 1;

	sdw_cdns_probe(cdns);

	/* Set ops */
	bus->ops = &sdw_intel_ops;

	/* set driver data, accessed by snd_soc_dai_get_drvdata() */
	auxiliary_set_drvdata(auxdev, cdns);

	/* use generic bandwidth allocation algorithm */
	sdw->cdns.bus.compute_params = sdw_compute_params;

	/* avoid resuming from pm_runtime suspend if it's not required */
	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);

	ret = sdw_bus_master_add(bus, dev, dev->fwnode);
	if (ret) {
	dev_err(dev, "sdw_bus_master_add fail: %d\n", ret);
	return ret;
	}

	if (bus->prop.hw_disabled)
	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;
	}

	int intel_link_startup(struct auxiliary_device *auxdev)
	{
	struct device *dev = &auxdev->dev;
	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
	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;

	if (bus->prop.hw_disabled) {
	dev_info(dev,
	"SoundWire master %d is disabled, ignoring\n",
	sdw->instance);
	return 0;
	}

	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");
	} 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->hw_sync_min_links = 1;
	}
	bus->multi_link = multi_link;

	/* Initialize shim, controller */
	ret = sdw_intel_link_power_up(sdw);
	if (ret)
	goto err_init;

	/* Register DAIs */
	ret = sdw_intel_register_dai(sdw);
	if (ret) {
	dev_err(dev, "DAI registration failed: %d\n", ret);
	goto err_power_up;
	}

	sdw_intel_debugfs_init(sdw);

	/* Enable runtime PM */
	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) {
	pm_runtime_set_autosuspend_delay(dev,
	INTEL_MASTER_SUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_mark_last_busy(dev);

	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	pm_runtime_resume(bus->dev);
	}

	/* start bus */
	ret = sdw_intel_start_bus(sdw);
	if (ret) {
	dev_err(dev, "bus start failed: %d\n", ret);
	goto err_pm_runtime;
	}

	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_NOT_ALLOWED) {
	/*
	* To keep the clock running we need to prevent
	* pm_runtime suspend from happening by increasing the
	* reference count.
	* This quirk is specified by the parent PCI device in
	* case of specific latency requirements. It will have
	* no effect if pm_runtime is disabled by the user via
	* a module parameter for testing purposes.
	*/
	pm_runtime_get_noresume(dev);
	}

	/*
	* The runtime PM status of Slave devices is "Unsupported"
	* until they report as ATTACHED. If they don't, e.g. because
	* there are no Slave devices populated or if the power-on is
	* delayed or dependent on a power switch, the Master will
	* remain active and prevent its parent from suspending.
	*
	* Conditionally force the pm_runtime core to re-evaluate the
	* Master status in the absence of any Slave activity. A quirk
	* is provided to e.g. deal with Slaves that may be powered on
	* with a delay. A more complete solution would require the
	* definition of Master properties.
	*/
	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE)) {
	pm_runtime_mark_last_busy(bus->dev);
	pm_runtime_mark_last_busy(dev);
	pm_runtime_idle(dev);
	}

	sdw->startup_done = true;
	return 0;

	err_pm_runtime:
	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME))
	pm_runtime_disable(dev);
	err_power_up:
	sdw_intel_link_power_down(sdw);
	err_init:
	return ret;
	}

	static void intel_link_remove(struct auxiliary_device *auxdev)
	{
	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
	struct sdw_intel *sdw = cdns_to_intel(cdns);
	struct sdw_bus *bus = &cdns->bus;

	/*
	* Since pm_runtime is already disabled, we don't decrease
	* the refcount when the clock_stop_quirk is
	* SDW_INTEL_CLK_STOP_NOT_ALLOWED
	*/
	if (!bus->prop.hw_disabled) {
	sdw_intel_debugfs_exit(sdw);
	sdw_cdns_enable_interrupt(cdns, false);
	}
	sdw_bus_master_delete(bus);
	}

	int intel_link_process_wakeen_event(struct auxiliary_device *auxdev)
	{
	struct device *dev = &auxdev->dev;
	struct sdw_intel *sdw;
	struct sdw_bus *bus;

	sdw = auxiliary_get_drvdata(auxdev);
	bus = &sdw->cdns.bus;

	if (bus->prop.hw_disabled \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	if (!sdw_intel_shim_check_wake(sdw))
	return 0;

	/* disable WAKEEN interrupt ASAP to prevent interrupt flood */
	sdw_intel_shim_wake(sdw, false);

	/*
	* resume the Master, which will generate a bus reset and result in
	* Slaves re-attaching and be re-enumerated. The SoundWire physical
	* device which generated the wake will trigger an interrupt, which
	* will in turn cause the corresponding Linux Slave device to be
	* resumed and the Slave codec driver to check the status.
	*/
	pm_request_resume(dev);

	return 0;
	}

	/*
	* PM calls
	*/

	static int intel_resume_child_device(struct device dev, void data)
	{
	int ret;
	struct sdw_slave *slave = dev_to_sdw_dev(dev);

	if (!slave->probed) {
	dev_dbg(dev, "skipping device, no probed driver\n");
	return 0;
	}
	if (!slave->dev_num_sticky) {
	dev_dbg(dev, "skipping device, never detected on bus\n");
	return 0;
	}

	ret = pm_request_resume(dev);
	if (ret < 0) {
	dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
	return ret;
	}

	return 0;
	}

	static int __maybe_unused intel_pm_prepare(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 \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

	if (pm_runtime_suspended(dev) &&
	pm_runtime_suspended(dev->parent) &&
	((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) \|\|
	!clock_stop_quirks)) {
	/*
	* if we've enabled clock stop, and the parent is suspended, the SHIM registers
	* are not accessible and the shim wake cannot be disabled.
	* The only solution is to resume the entire bus to full power
	*/

	/*
	* If any operation in this block fails, we keep going since we don't want
	* to prevent system suspend from happening and errors should be recoverable
	* on resume.
	*/

	/*
	* first resume the device for this link. This will also by construction
	* resume the PCI parent device.
	*/
	ret = pm_request_resume(dev);
	if (ret < 0) {
	dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
	return 0;
	}

	/*
	* Continue resuming the entire bus (parent + child devices) to exit
	* the clock stop mode. If there are no devices connected on this link
	* this is a no-op.
	* The resume to full power could have been implemented with a .prepare
	* step in SoundWire codec drivers. This would however require a lot
	* of code to handle an Intel-specific corner case. It is simpler in
	* practice to add a loop at the link level.
	*/
	ret = device_for_each_child(bus->dev, NULL, intel_resume_child_device);

	if (ret < 0)
	dev_err(dev, "%s: intel_resume_child_device failed: %d\n", __func__, ret);
	}

	return 0;
	}

	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 \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	if (pm_runtime_suspended(dev)) {
	dev_dbg(dev, "pm_runtime status: suspended\n");

	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

	if ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) \|\|
	!clock_stop_quirks) {

	if (pm_runtime_suspended(dev->parent)) {
	/*
	* paranoia check: this should not happen with the .prepare
	* resume to full power
	*/
	dev_err(dev, "%s: invalid config: parent is suspended\n", __func__);
	} else {
	sdw_intel_shim_wake(sdw, false);
	}
	}

	return 0;
	}

	ret = sdw_intel_stop_bus(sdw, false);
	if (ret < 0) {
	dev_err(dev, "%s: cannot stop bus: %d\n", __func__, ret);
	return ret;
	}

	return 0;
	}

	static int __maybe_unused intel_suspend_runtime(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 \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
	ret = sdw_intel_stop_bus(sdw, false);
	if (ret < 0) {
	dev_err(dev, "%s: cannot stop bus during teardown: %d\n",
	__func__, ret);
	return ret;
	}
	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET \|\| !clock_stop_quirks) {
	ret = sdw_intel_stop_bus(sdw, true);
	if (ret < 0) {
	dev_err(dev, "%s: cannot stop bus during clock_stop: %d\n",
	__func__, ret);
	return ret;
	}
	} else {
	dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
	__func__, clock_stop_quirks);
	ret = -EINVAL;
	}

	return ret;
	}

	static int __maybe_unused intel_resume(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;
	int link_flags;
	int ret;

	if (bus->prop.hw_disabled \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	if (pm_runtime_suspended(dev)) {
	dev_dbg(dev, "pm_runtime status was suspended, forcing active\n");

	/* follow required sequence from runtime_pm.rst */
	pm_runtime_disable(dev);
	pm_runtime_set_active(dev);
	pm_runtime_mark_last_busy(dev);
	pm_runtime_enable(dev);

	pm_runtime_resume(bus->dev);

	link_flags = md_flags >> (bus->link_id * 8);

	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
	pm_runtime_idle(dev);
	}

	ret = sdw_intel_link_power_up(sdw);
	if (ret) {
	dev_err(dev, "%s failed: %d\n", __func__, ret);
	return ret;
	}

	/*
	* make sure all Slaves are tagged as UNATTACHED and provide
	* reason for reinitialization
	*/
	sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);

	ret = sdw_intel_start_bus(sdw);
	if (ret < 0) {
	dev_err(dev, "cannot start bus during resume\n");
	sdw_intel_link_power_down(sdw);
	return ret;
	}

	/*
	* after system resume, the pm_runtime suspend() may kick in
	* during the enumeration, before any children device force the
	* master device to remain active. Using pm_runtime_get()
	* routines is not really possible, since it'd prevent the
	* master from suspending.
	* A reasonable compromise is to update the pm_runtime
	* counters and delay the pm_runtime suspend by several
	* seconds, by when all enumeration should be complete.
	*/
	pm_runtime_mark_last_busy(bus->dev);
	pm_runtime_mark_last_busy(dev);

	return 0;
	}

	static int __maybe_unused intel_resume_runtime(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 \|\| !sdw->startup_done) {
	dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
	bus->link_id);
	return 0;
	}

	/* unconditionally disable WAKEEN interrupt */
	sdw_intel_shim_wake(sdw, false);

	clock_stop_quirks = sdw->link_res->clock_stop_quirks;

	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
	ret = sdw_intel_link_power_up(sdw);
	if (ret) {
	dev_err(dev, "%s: power_up failed after teardown: %d\n", __func__, ret);
	return ret;
	}

	/*
	* make sure all Slaves are tagged as UNATTACHED and provide
	* reason for reinitialization
	*/
	sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);

	ret = sdw_intel_start_bus(sdw);
	if (ret < 0) {
	dev_err(dev, "%s: cannot start bus after teardown: %d\n", __func__, ret);
	sdw_intel_link_power_down(sdw);
	return ret;
	}

	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
	ret = sdw_intel_link_power_up(sdw);
	if (ret) {
	dev_err(dev, "%s: power_up failed after bus reset: %d\n", __func__, ret);
	return ret;
	}

	ret = sdw_intel_start_bus_after_reset(sdw);
	if (ret < 0) {
	dev_err(dev, "%s: cannot start bus after reset: %d\n", __func__, ret);
	sdw_intel_link_power_down(sdw);
	return ret;
	}
	} else if (!clock_stop_quirks) {

	sdw_intel_check_clock_stop(sdw);

	ret = sdw_intel_link_power_up(sdw);
	if (ret) {
	dev_err(dev, "%s: power_up failed: %d\n", __func__, ret);
	return ret;
	}

	ret = sdw_intel_start_bus_after_clock_stop(sdw);
	if (ret < 0) {
	dev_err(dev, "%s: cannot start bus after clock stop: %d\n", __func__, ret);
	sdw_intel_link_power_down(sdw);
	return ret;
	}
	} else {
	dev_err(dev, "%s: clock_stop_quirks %x unsupported\n",
	__func__, clock_stop_quirks);
	ret = -EINVAL;
	}

	return ret;
	}

	static const struct dev_pm_ops intel_pm = {
	.prepare = intel_pm_prepare,
	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
	SET_RUNTIME_PM_OPS(intel_suspend_runtime, intel_resume_runtime, NULL)
	};

	static const struct auxiliary_device_id intel_link_id_table[] = {
	{ .name = "soundwire_intel.link" },
	{},
	};
	MODULE_DEVICE_TABLE(auxiliary, intel_link_id_table);

	static struct auxiliary_driver sdw_intel_drv = {
	.probe = intel_link_probe,
	.remove = intel_link_remove,
	.driver = {
	/* auxiliary_driver_register() sets .name to be the modname */
	.pm = &intel_pm,
	},
	.id_table = intel_link_id_table
	};
	module_auxiliary_driver(sdw_intel_drv);

	MODULE_LICENSE("Dual BSD/GPL");
	MODULE_DESCRIPTION("Intel Soundwire Link Driver");