linux-kernel - [PATCH 01/13] soundwire: intel: Add basic power management support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200721203723.18305-2-yung-chuan.liao@linux.intel.com>
Date:   Wed, 22 Jul 2020 04:37:11 +0800
From:   Bard Liao <yung-chuan.liao@...ux.intel.com>
To:     alsa-devel@...a-project.org, vkoul@...nel.org
Cc:     vinod.koul@...aro.org, linux-kernel@...r.kernel.org, tiwai@...e.de,
        broonie@...nel.org, gregkh@...uxfoundation.org, jank@...ence.com,
        srinivas.kandagatla@...aro.org, rander.wang@...ux.intel.com,
        ranjani.sridharan@...ux.intel.com, hui.wang@...onical.com,
        pierre-louis.bossart@...ux.intel.com, sanyog.r.kale@...el.com,
        slawomir.blauciak@...el.com, mengdong.lin@...el.com,
        bard.liao@...el.com
Subject: [PATCH 01/13] soundwire: intel: Add basic power management support

From: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>

Implement suspend/resume capabilities (not runtime_pm for now)
The resume part is essentially a full-blown re-enumeration.

When S0ix is supported, we will select clock stop mode when the ACPI
target state is S0, and tear down the link for S3.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@...ux.intel.com>
---
 drivers/soundwire/intel.c | 81 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 79 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 23b66dcf9966..eb628f255cf5 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -463,7 +463,7 @@ static void intel_shim_wake(struct sdw_intel *sdw, bool wake_enable)
 	mutex_unlock(sdw->link_res->shim_lock);
 }
 
-static int __maybe_unused intel_link_power_down(struct sdw_intel *sdw)
+static int intel_link_power_down(struct sdw_intel *sdw)
 {
 	int link_control, spa_mask, cpa_mask;
 	unsigned int link_id = sdw->instance;
@@ -1375,12 +1375,89 @@ int intel_master_process_wakeen_event(struct platform_device *pdev)
 	return 0;
 }
 
+/*
+ * PM calls
+ */
+
+#ifdef CONFIG_PM
+
+static int 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;
+	int ret;
+
+	if (bus->prop.hw_disabled) {
+		dev_dbg(dev, "SoundWire master %d is disabled, ignoring\n",
+			bus->link_id);
+		return 0;
+	}
+
+	ret = sdw_cdns_enable_interrupt(cdns, false);
+	if (ret < 0) {
+		dev_err(dev, "cannot disable interrupts on suspend\n");
+		return ret;
+	}
+
+	ret = intel_link_power_down(sdw);
+	if (ret) {
+		dev_err(dev, "Link power down failed: %d", ret);
+		return ret;
+	}
+
+	intel_shim_wake(sdw, false);
+
+	return 0;
+}
+
+static int 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 ret;
+
+	if (bus->prop.hw_disabled) {
+		dev_dbg(dev, "SoundWire master %d is disabled, ignoring\n",
+			bus->link_id);
+		return 0;
+	}
+
+	ret = intel_init(sdw);
+	if (ret) {
+		dev_err(dev, "%s failed: %d", __func__, ret);
+		return ret;
+	}
+
+	ret = sdw_cdns_enable_interrupt(cdns, true);
+	if (ret < 0) {
+		dev_err(dev, "cannot enable interrupts during resume\n");
+		return ret;
+	}
+
+	ret = sdw_cdns_exit_reset(cdns);
+	if (ret < 0) {
+		dev_err(dev, "unable to exit bus reset sequence during resume\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+#endif
+
+static const struct dev_pm_ops intel_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
+};
+
 static struct platform_driver sdw_intel_drv = {
 	.probe = intel_master_probe,
 	.remove = intel_master_remove,
 	.driver = {
 		.name = "intel-sdw",
-	},
+		.pm = &intel_pm,
+	}
 };
 
 module_platform_driver(sdw_intel_drv);
-- 
2.17.1