soundwire: intel: move bus common sequences to different file

Now that the bus start/stop/clock_stop sequences use the ops, we can
move them to a different file to reuse them.

Note that we could in theory remove the abstraction for all those
sequences and directly call the functions in intel_auxdevice.c. To
allow for more flexibility and have means to special-case new
platforms, we decided to keep the abstraction. If in time it becomes
clear there is no benefit the abstraction will be simplified.

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/20230314015410.487311-9-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 210 insertions, 0 deletions

diff --git a/drivers/soundwire/intel_bus_common.c b/drivers/soundwire/intel_bus_common.c
new file mode 100644
index 000000000000..9a06ab58018b
--- /dev/null
+++ b/drivers/soundwire/intel_bus_common.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+// Copyright(c) 2015-2023 Intel Corporation. All rights reserved.
+
+#include <linux/acpi.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"
+
+int intel_start_bus(struct sdw_intel *sdw)
+{
+	struct device *dev = sdw->cdns.dev;
+	struct sdw_cdns *cdns = &sdw->cdns;
+	struct sdw_bus *bus = &cdns->bus;
+	int ret;
+
+	ret = sdw_cdns_enable_interrupt(cdns, true);
+	if (ret < 0) {
+		dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret);
+		return ret;
+	}
+
+	/*
+	 * follow recommended programming flows to avoid timeouts when
+	 * gsync is enabled
+	 */
+	if (bus->multi_link)
+		sdw_intel_sync_arm(sdw);
+
+	ret = sdw_cdns_init(cdns);
+	if (ret < 0) {
+		dev_err(dev, "%s: unable to initialize Cadence IP: %d\n", __func__, ret);
+		goto err_interrupt;
+	}
+
+	ret = sdw_cdns_exit_reset(cdns);
+	if (ret < 0) {
+		dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret);
+		goto err_interrupt;
+	}
+
+	if (bus->multi_link) {
+		ret = sdw_intel_sync_go(sdw);
+		if (ret < 0) {
+			dev_err(dev, "%s: sync go failed: %d\n", __func__, ret);
+			goto err_interrupt;
+		}
+	}
+	sdw_cdns_check_self_clearing_bits(cdns, __func__,
+					  true, INTEL_MASTER_RESET_ITERATIONS);
+
+	return 0;
+
+err_interrupt:
+	sdw_cdns_enable_interrupt(cdns, false);
+	return ret;
+}
+
+int intel_start_bus_after_reset(struct sdw_intel *sdw)
+{
+	struct device *dev = sdw->cdns.dev;
+	struct sdw_cdns *cdns = &sdw->cdns;
+	struct sdw_bus *bus = &cdns->bus;
+	bool clock_stop0;
+	int status;
+	int ret;
+
+	/*
+	 * An exception condition occurs for the CLK_STOP_BUS_RESET
+	 * case if one or more masters remain active. In this condition,
+	 * all the masters are powered on for they are in the same power
+	 * domain. Master can preserve its context for clock stop0, so
+	 * there is no need to clear slave status and reset bus.
+	 */
+	clock_stop0 = sdw_cdns_is_clock_stop(&sdw->cdns);
+
+	if (!clock_stop0) {
+
+		/*
+		 * make sure all Slaves are tagged as UNATTACHED and
+		 * provide reason for reinitialization
+		 */
+
+		status = SDW_UNATTACH_REQUEST_MASTER_RESET;
+		sdw_clear_slave_status(bus, status);
+
+		ret = sdw_cdns_enable_interrupt(cdns, true);
+		if (ret < 0) {
+			dev_err(dev, "cannot enable interrupts during resume\n");
+			return ret;
+		}
+
+		/*
+		 * follow recommended programming flows to avoid
+		 * timeouts when gsync is enabled
+		 */
+		if (bus->multi_link)
+			sdw_intel_sync_arm(sdw);
+
+		/*
+		 * Re-initialize the IP since it was powered-off
+		 */
+		sdw_cdns_init(&sdw->cdns);
+
+	} else {
+		ret = sdw_cdns_enable_interrupt(cdns, true);
+		if (ret < 0) {
+			dev_err(dev, "cannot enable interrupts during resume\n");
+			return ret;
+		}
+	}
+
+	ret = sdw_cdns_clock_restart(cdns, !clock_stop0);
+	if (ret < 0) {
+		dev_err(dev, "unable to restart clock during resume\n");
+		goto err_interrupt;
+	}
+
+	if (!clock_stop0) {
+		ret = sdw_cdns_exit_reset(cdns);
+		if (ret < 0) {
+			dev_err(dev, "unable to exit bus reset sequence during resume\n");
+			goto err_interrupt;
+		}
+
+		if (bus->multi_link) {
+			ret = sdw_intel_sync_go(sdw);
+			if (ret < 0) {
+				dev_err(sdw->cdns.dev, "sync go failed during resume\n");
+				goto err_interrupt;
+			}
+		}
+	}
+	sdw_cdns_check_self_clearing_bits(cdns, __func__, true, INTEL_MASTER_RESET_ITERATIONS);
+
+	return 0;
+
+err_interrupt:
+	sdw_cdns_enable_interrupt(cdns, false);
+	return ret;
+}
+
+void intel_check_clock_stop(struct sdw_intel *sdw)
+{
+	struct device *dev = sdw->cdns.dev;
+	bool clock_stop0;
+
+	clock_stop0 = sdw_cdns_is_clock_stop(&sdw->cdns);
+	if (!clock_stop0)
+		dev_err(dev, "%s: invalid configuration, clock was not stopped\n", __func__);
+}
+
+int intel_start_bus_after_clock_stop(struct sdw_intel *sdw)
+{
+	struct device *dev = sdw->cdns.dev;
+	struct sdw_cdns *cdns = &sdw->cdns;
+	int ret;
+
+	ret = sdw_cdns_enable_interrupt(cdns, true);
+	if (ret < 0) {
+		dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = sdw_cdns_clock_restart(cdns, false);
+	if (ret < 0) {
+		dev_err(dev, "%s: unable to restart clock: %d\n", __func__, ret);
+		sdw_cdns_enable_interrupt(cdns, false);
+		return ret;
+	}
+
+	sdw_cdns_check_self_clearing_bits(cdns, "intel_resume_runtime no_quirks",
+					  true, INTEL_MASTER_RESET_ITERATIONS);
+
+	return 0;
+}
+
+int intel_stop_bus(struct sdw_intel *sdw, bool clock_stop)
+{
+	struct device *dev = sdw->cdns.dev;
+	struct sdw_cdns *cdns = &sdw->cdns;
+	bool wake_enable = false;
+	int ret;
+
+	if (clock_stop) {
+		ret = sdw_cdns_clock_stop(cdns, true);
+		if (ret < 0)
+			dev_err(dev, "%s: cannot stop clock: %d\n", __func__, ret);
+		else
+			wake_enable = true;
+	}
+
+	ret = sdw_cdns_enable_interrupt(cdns, false);
+	if (ret < 0) {
+		dev_err(dev, "%s: cannot disable interrupts: %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = sdw_intel_link_power_down(sdw);
+	if (ret) {
+		dev_err(dev, "%s: Link power down failed: %d\n", __func__, ret);
+		return ret;
+	}
+
+	sdw_intel_shim_wake(sdw, wake_enable);
+
+	return 0;
+}