From:   Hector Martin <marcan@marcan.st>
To:     Sven Peter <sven@svenpeter.dev>
Cc:     Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Janne Grunau <j@jannau.net>, asahi@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Hector Martin <marcan@marcan.st>
Subject: [PATCH] soc: apple: rtkit: Add apple_rtkit_idle() function
Date:   Mon, 23 Jan 2023 15:53:54 +0900
Message-Id: <20230123065354.28179-1-marcan@marcan.st>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This is yet another low power mode, used by DCP.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
 drivers/soc/apple/rtkit.c       | 21 +++++++++++++++++++++
 include/linux/soc/apple/rtkit.h |  5 +++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/soc/apple/rtkit.c b/drivers/soc/apple/rtkit.c
index ceb4516e442c..509b050cf040 100644
--- a/drivers/soc/apple/rtkit.c
+++ b/drivers/soc/apple/rtkit.c
@@ -9,6 +9,7 @@
 enum {
 	APPLE_RTKIT_PWR_STATE_OFF = 0x00, /* power off, cannot be restarted */
 	APPLE_RTKIT_PWR_STATE_SLEEP = 0x01, /* sleeping, can be restarted */
+	APPLE_RTKIT_PWR_STATE_IDLE = 0x201, /* sleeping, retain state */
 	APPLE_RTKIT_PWR_STATE_QUIESCED = 0x10, /* running but no communication */
 	APPLE_RTKIT_PWR_STATE_ON = 0x20, /* normal operating state */
 };
@@ -882,6 +883,26 @@ int apple_rtkit_shutdown(struct apple_rtkit *rtk)
 }
 EXPORT_SYMBOL_GPL(apple_rtkit_shutdown);
 
+int apple_rtkit_idle(struct apple_rtkit *rtk)
+{
+	int ret;
+
+	/* if OFF is used here the co-processor will not wake up again */
+	ret = apple_rtkit_set_ap_power_state(rtk,
+					     APPLE_RTKIT_PWR_STATE_IDLE);
+	if (ret)
+		return ret;
+
+	ret = apple_rtkit_set_iop_power_state(rtk, APPLE_RTKIT_PWR_STATE_IDLE);
+	if (ret)
+		return ret;
+
+	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_IDLE;
+	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_IDLE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(apple_rtkit_idle);
+
 int apple_rtkit_quiesce(struct apple_rtkit *rtk)
 {
 	int ret;
diff --git a/include/linux/soc/apple/rtkit.h b/include/linux/soc/apple/rtkit.h
index 2a0edb5fa6fe..f8d9cc0691de 100644
--- a/include/linux/soc/apple/rtkit.h
+++ b/include/linux/soc/apple/rtkit.h
@@ -132,6 +132,11 @@ int apple_rtkit_wake(struct apple_rtkit *rtk);
  */
 int apple_rtkit_shutdown(struct apple_rtkit *rtk);
 
+/*
+ * Put the co-processor into idle mode
+ */
+int apple_rtkit_idle(struct apple_rtkit *rtk);
+
 /*
  * Checks if RTKit is running and ready to handle messages.
  */
-- 
2.35.1