[PATCH V3 8/8] soundwire: amd: add pm_prepare callback and pm ops support

Vijendar Mukunda
2023-02-20T10:04:47Z

Add pm_prepare callback and System level pm ops support for
AMD SoundWire manager driver.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Signed-off-by: Mastan Katragadda <Mastan.Katragadda@amd.com>
---
drivers/soundwire/amd_manager.c | 89 +++++++++++++++++++++++++++++++++
1 file changed, 89 insertions(+)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index a7182aa78652..b974e52248da 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -1155,6 +1155,93 @@ static int amd_sdw_clock_stop_exit(struct amd_sdw_manager *amd_manager)
return 0;
}

+static int amd_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;
+ }
+ if (!pm_runtime_suspended(dev))
+ return 0;
+ ret = pm_request_resume(dev);
+ if (ret < 0)
+ dev_err(dev, "pm_request_resume failed: %d\n", ret);
+
+ return ret;
+}
+
+static int __maybe_unused amd_pm_prepare(struct device *dev)
+{
+ struct amd_sdw_manager *amd_manager = dev_get_drvdata(dev);
+ struct sdw_bus *bus = &amd_manager->bus;
+ int ret;
+
+ if (bus->prop.hw_disabled) {
+ dev_dbg(bus->dev, "SoundWire manager %d is disabled, ignoring\n",
+ bus->link_id);
+ return 0;
+ }
+ /*
+ * When multiple peripheral devices connected over the same link, if SoundWire manager
+ * device is not in runtime suspend state, observed that device alerts are missing
+ * without pm_prepare on AMD platforms in clockstop mode0.
+ */
+ if (pm_runtime_suspended(dev) && amd_manager->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
+ ret = pm_request_resume(dev);
+ if (ret < 0) {
+ dev_err(bus->dev, "pm_request_resume failed: %d\n", ret);
+ return 0;
+ }
+ }
+ /* To force peripheral devices to system level suspend state, resume the devices
+ * from runtime suspend state first. Without that unable to dispatch the alert
+ * status to peripheral driver during system level resume as they are in runtime
+ * suspend state.
+ */
+ ret = device_for_each_child(bus->dev, NULL, amd_resume_child_device);
+ if (ret < 0)
+ dev_err(dev, "amd_resume_child_device failed: %d\n", ret);
+ return 0;
+}
+
+static int __maybe_unused amd_suspend(struct device *dev)
+{
+ struct amd_sdw_manager *amd_manager = dev_get_drvdata(dev);
+ struct sdw_bus *bus = &amd_manager->bus;
+ int ret;
+
+ if (bus->prop.hw_disabled) {
+ dev_dbg(bus->dev, "SoundWire manager %d is disabled, ignoring\n",
+ bus->link_id);
+ return 0;
+ }
+
+ if (amd_manager->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
+ ret = amd_sdw_clock_stop(amd_manager);
+ if (ret)
+ return ret;
+ } else if (amd_manager->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
+ /*
+ * As per hardware programming sequence on AMD platforms,
+ * clock stop should be invoked first before powering-off
+ */
+ ret = amd_sdw_clock_stop(amd_manager);
+ if (ret)
+ return ret;
+ ret = amd_deinit_sdw_manager(amd_manager);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
static int __maybe_unused amd_suspend_runtime(struct device *dev)
{
struct amd_sdw_manager *amd_manager = dev_get_drvdata(dev);
@@ -1227,6 +1314,8 @@ static int __maybe_unused amd_resume_runtime(struct device *dev)
}

static const struct dev_pm_ops amd_pm = {
+ .prepare = amd_pm_prepare,
+ SET_SYSTEM_SLEEP_PM_OPS(amd_suspend, amd_resume_runtime)
SET_RUNTIME_PM_OPS(amd_suspend_runtime, amd_resume_runtime, NULL)
};

--
2.34.1