rtw88: add deep power save support

Deep power save allows firmware/hardware to operate in a
lower power state. And the deep power save mode depends on
LPS mode. So, before entering deep PS, driver must first
enter LPS mode.

Under Deep PS, most of hardware functions are shutdown,
driver will not be able to read/write registers and transfer
data to the device. Hence TX path must be protected by each
interface. Take PCI for example, DMA engine should be idle,
and no nore activities on the PCI bus.

If driver wants to operate on the device, such as register
read/write, it must first acquire the mutex lock and wake
up from Deep PS, otherwise the behavior is undefined.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 95 insertions, 5 deletions

diff --git a/drivers/net/wireless/realtek/rtw88/ps.c b/drivers/net/wireless/realtek/rtw88/ps.c
index af5c7be2ef0f..4b5774687d21 100644
--- a/drivers/net/wireless/realtek/rtw88/ps.c
+++ b/drivers/net/wireless/realtek/rtw88/ps.c
@@ -3,6 +3,7 @@
  */
 
 #include "main.h"
+#include "reg.h"
 #include "fw.h"
 #include "ps.h"
 #include "mac.h"
@@ -61,6 +62,59 @@ int rtw_leave_ips(struct rtw_dev *rtwdev)
 	return 0;
 }
 
+void rtw_power_mode_change(struct rtw_dev *rtwdev, bool enter)
+{
+	u8 request, confirm, polling;
+	u8 polling_cnt;
+	u8 retry_cnt = 0;
+
+retry:
+	request = rtw_read8(rtwdev, rtwdev->hci.rpwm_addr);
+	confirm = rtw_read8(rtwdev, rtwdev->hci.cpwm_addr);
+
+	/* toggle to request power mode, others remain 0 */
+	request ^= request | BIT_RPWM_TOGGLE;
+	if (!enter)
+		request |= POWER_MODE_ACK;
+	else
+		request |= POWER_MODE_LCLK;
+
+	rtw_write8(rtwdev, rtwdev->hci.rpwm_addr, request);
+
+	/* check confirm power mode has left power save state */
+	if (!enter) {
+		for (polling_cnt = 0; polling_cnt < 3; polling_cnt++) {
+			polling = rtw_read8(rtwdev, rtwdev->hci.cpwm_addr);
+			if ((polling ^ confirm) & BIT_RPWM_TOGGLE)
+				return;
+			mdelay(20);
+		}
+
+		/* in case of fw/hw missed the request, retry 3 times */
+		if (retry_cnt < 3) {
+			rtw_warn(rtwdev, "failed to leave deep PS, retry=%d\n",
+				 retry_cnt);
+			retry_cnt++;
+			goto retry;
+		}
+
+		/* Hit here means that driver failed to change hardware
+		 * power mode to active state after retry 3 times.
+		 * If the power state is locked at Deep sleep, most of
+		 * the hardware circuits is not working, even register
+		 * read/write. It should be treated as fatal error and
+		 * requires an entire analysis about the firmware/hardware
+		 */
+		WARN_ON("Hardware power state locked\n");
+	}
+}
+EXPORT_SYMBOL(rtw_power_mode_change);
+
+static void __rtw_leave_lps_deep(struct rtw_dev *rtwdev)
+{
+	rtw_hci_deep_ps(rtwdev, false);
+}
+
 static void rtw_leave_lps_core(struct rtw_dev *rtwdev)
 {
 	struct rtw_lps_conf *conf = &rtwdev->lps_conf;
@@ -76,6 +130,17 @@ static void rtw_leave_lps_core(struct rtw_dev *rtwdev)
 	rtw_coex_lps_notify(rtwdev, COEX_LPS_DISABLE);
 }
 
+static void __rtw_enter_lps_deep(struct rtw_dev *rtwdev)
+{
+	if (!test_bit(RTW_FLAG_LEISURE_PS, rtwdev->flags)) {
+		rtw_dbg(rtwdev, RTW_DBG_PS,
+			"Should enter LPS before entering deep PS\n");
+		return;
+	}
+
+	rtw_hci_deep_ps(rtwdev, true);
+}
+
 static void rtw_enter_lps_core(struct rtw_dev *rtwdev)
 {
 	struct rtw_lps_conf *conf = &rtwdev->lps_conf;
@@ -91,12 +156,10 @@ static void rtw_enter_lps_core(struct rtw_dev *rtwdev)
 	set_bit(RTW_FLAG_LEISURE_PS, rtwdev->flags);
 }
 
-void rtw_enter_lps(struct rtw_dev *rtwdev, u8 port_id)
+static void __rtw_enter_lps(struct rtw_dev *rtwdev, u8 port_id)
 {
 	struct rtw_lps_conf *conf = &rtwdev->lps_conf;
 
-	lockdep_assert_held(&rtwdev->mutex);
-
 	if (test_bit(RTW_FLAG_LEISURE_PS, rtwdev->flags))
 		return;
 
@@ -106,11 +169,15 @@ void rtw_enter_lps(struct rtw_dev *rtwdev, u8 port_id)
 	rtw_enter_lps_core(rtwdev);
 }
 
-void rtw_leave_lps(struct rtw_dev *rtwdev)
+static void __rtw_leave_lps(struct rtw_dev *rtwdev)
 {
 	struct rtw_lps_conf *conf = &rtwdev->lps_conf;
 
-	lockdep_assert_held(&rtwdev->mutex);
+	if (test_and_clear_bit(RTW_FLAG_LEISURE_PS_DEEP, rtwdev->flags)) {
+		rtw_dbg(rtwdev, RTW_DBG_PS,
+			"Should leave deep PS before leaving LPS\n");
+		__rtw_leave_lps_deep(rtwdev);
+	}
 
 	if (!test_bit(RTW_FLAG_LEISURE_PS, rtwdev->flags))
 		return;
@@ -119,3 +186,26 @@ void rtw_leave_lps(struct rtw_dev *rtwdev)
 
 	rtw_leave_lps_core(rtwdev);
 }
+
+void rtw_enter_lps(struct rtw_dev *rtwdev, u8 port_id)
+{
+	lockdep_assert_held(&rtwdev->mutex);
+
+	__rtw_enter_lps(rtwdev, port_id);
+	__rtw_enter_lps_deep(rtwdev);
+}
+
+void rtw_leave_lps(struct rtw_dev *rtwdev)
+{
+	lockdep_assert_held(&rtwdev->mutex);
+
+	__rtw_leave_lps_deep(rtwdev);
+	__rtw_leave_lps(rtwdev);
+}
+
+void rtw_leave_lps_deep(struct rtw_dev *rtwdev)
+{
+	lockdep_assert_held(&rtwdev->mutex);
+
+	__rtw_leave_lps_deep(rtwdev);
+}