[PATCH v5 04/25] soundwire: amd: track full pad teardown across suspend/resume

[Vijendar Mukunda <Vijendar.Mukunda@amd.com>]

amd_sdw_pad_ctrl() performs a full pad teardown (keeper, pulldown, schmen
and OE) for system suspend, while amd_sdw_oe_ctrl() disables only OE for
wake-armed runtime suspend. amd_resume_runtime() must distinguish between
these two cases to restore pads correctly: a full teardown requires
amd_sdw_pad_ctrl(true) on resume; a wake-armed runtime suspend requires
only amd_sdw_oe_ctrl(true).

Introduce pad_fully_torn_down flag to track when a full pad teardown was
performed. Set the flag after amd_sdw_pad_ctrl(false) in amd_suspend()
using amd_sdw_pad_ctrl_supported() to gate the assignment to revisions
that support pad control. Clear it after the full restore in
amd_resume_runtime(). On resume, restore all pads if the flag is set,
otherwise restore OE only; both paths delegate revision gating to the
respective helpers.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
---
 drivers/soundwire/amd_manager.c   | 12 ++++++++++--
 include/linux/soundwire/sdw_amd.h |  7 +++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index b21691652490..28f5dbe131dc 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -1418,7 +1418,10 @@ static int __maybe_unused amd_suspend(struct device *dev)
 		if (ret)
 			return ret;
 		/* System suspend: tear down all pads */
-		amd_sdw_pad_ctrl(amd_manager, false);
+		if (amd_sdw_pad_ctrl_supported(amd_manager)) {
+			amd_sdw_pad_ctrl(amd_manager, false);
+			amd_manager->pad_fully_torn_down = true;
+		}
 	}
 	if (amd_manager->acp_rev >= ACP70_PCI_REV_ID) {
 		ret = amd_sdw_set_device_state(amd_manager, AMD_SDW_DEVICE_STATE_D3);
@@ -1510,7 +1513,12 @@ static int __maybe_unused amd_resume_runtime(struct device *dev)
 				return ret;
 		}
 	} else if (amd_manager->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
-		amd_sdw_pad_ctrl(amd_manager, true);
+		if (amd_manager->pad_fully_torn_down) {
+			amd_sdw_pad_ctrl(amd_manager, true);
+			amd_manager->pad_fully_torn_down = false;
+		} else {
+			amd_sdw_oe_ctrl(amd_manager, true);
+		}
 		writel(0x00, amd_manager->acp_mmio + ACP_SW_WAKE_EN(amd_manager->instance));
 		if (amd_manager->acp_rev >= ACP70_PCI_REV_ID) {
 			ret = amd_sdw_host_wake_enable(amd_manager, false);
diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
index 470360a2723c..c959d0fe2a39 100644
--- a/include/linux/soundwire/sdw_amd.h
+++ b/include/linux/soundwire/sdw_amd.h
@@ -75,6 +75,12 @@ struct sdw_amd_dai_runtime {
  * @wake_en_mask: wake enable mask per SoundWire manager
  * @acp_rev: acp pci device revision id
  * @clk_stopped: flag set to true when clock is stopped
+ * @pad_fully_torn_down: true when system suspend performed a full pad
+ *   teardown (keeper, schmen and OE cleared, pulldown asserted). Cleared after
+ *   all pads are restored in amd_resume_runtime(). False on initial probe
+ *   (zero-initialized) and after a wake-armed runtime suspend in which
+ *   only OE was disabled; in the latter case amd_resume_runtime() restores
+ *   OE only, leaving keeper and schmen untouched.
  * @power_mode_mask: flag interprets amd SoundWire manager power mode
  * @dai_runtime_array: dai runtime array
  */
@@ -106,6 +112,7 @@ struct amd_sdw_manager {
 	u32 power_mode_mask;
 	u32 acp_rev;
 	bool clk_stopped;
+	bool pad_fully_torn_down;
 
 	struct sdw_amd_dai_runtime **dai_runtime_array;
 };
-- 
2.53.0