linux-kernel - [PATCH 1/2] phy: usb: Turn off phy when port is in suspend

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Message-Id: <1686859578-45242-2-git-send-email-justin.chen@broadcom.com>
Date:   Thu, 15 Jun 2023 13:06:16 -0700
From:   Justin Chen <justin.chen@...adcom.com>
To:     linux-phy@...ts.infradead.org
Cc:     bcm-kernel-feedback-list@...adcom.com,
        florian.fainelli@...adcom.com,
        Justin Chen <justin.chen@...adcom.com>,
        Justin Chen <justinpopo6@...il.com>,
        Al Cooper <alcooperx@...il.com>, Vinod Koul <vkoul@...nel.org>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        linux-kernel@...r.kernel.org (open list:BROADCOM BRCMSTB USB2 and USB3
        PHY DRIVER)
Subject: [PATCH 1/2] phy: usb: Turn off phy when port is in suspend

The COMMONONN bit turns off the PHY when the host controller puts it
into suspend state. This can happen during the following...
- Nothing is connected to the port
- The host controller goes into low power mode whatever due to auto
  suspend or system suspend.

With COMMONONN we also must unset U2_FREECLK_EXISTS since the UTMI
clock is fed by the PHY.

With these changes we see a power savings of ~12mW when port is in
suspend.

Reviewed-by: Florian Fainelli <florian.fainelli@...adcom.com>
Signed-off-by: Justin Chen <justin.chen@...adcom.com>
---
 drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c | 15 +++++++++++++--
 drivers/phy/broadcom/phy-brcm-usb-init.h          |  8 ++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
index 76cf4280d7ed..4c10cafded4e 100644
--- a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
+++ b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
@@ -59,6 +59,8 @@
 #define   USB_CTLR_TP_DIAG1_wake_MASK			BIT(1)
 #define USB_CTRL_CTLR_CSHCR		0x50
 #define   USB_CTRL_CTLR_CSHCR_ctl_pme_en_MASK		BIT(18)
+#define USB_CTRL_P0_U2PHY_CFG1		0x68
+#define   USB_CTRL_P0_U2PHY_CFG1_COMMONONN_MASK		BIT(10)
 
 /* Register definitions for the USB_PHY block in 7211b0 */
 #define USB_PHY_PLL_CTL			0x00
@@ -90,6 +92,8 @@
 #define   BDC_EC_AXIRDA_RTS_MASK			GENMASK(31, 28)
 #define   BDC_EC_AXIRDA_RTS_SHIFT			28
 
+#define USB_XHCI_GBL_GUSB2PHYCFG	0x100
+#define   USB_XHCI_GBL_GUSB2PHYCFG_U2_FREECLK_EXISTS_MASK	BIT(30)
 
 static void usb_mdio_write_7211b0(struct brcm_usb_init_params *params,
 				  uint8_t addr, uint16_t data)
@@ -140,13 +144,17 @@ static void xhci_soft_reset(struct brcm_usb_init_params *params,
 			int on_off)
 {
 	void __iomem *ctrl = params->regs[BRCM_REGS_CTRL];
+	void __iomem *xhci_gbl = params->regs[BRCM_REGS_XHCI_GBL];
 
 	/* Assert reset */
-	if (on_off)
+	if (on_off) {
 		USB_CTRL_UNSET(ctrl, USB_PM, XHC_SOFT_RESETB);
 	/* De-assert reset */
-	else
+	} else {
 		USB_CTRL_SET(ctrl, USB_PM, XHC_SOFT_RESETB);
+		/* Required for COMMONONN to be set */
+		USB_XHCI_GBL_UNSET(xhci_gbl, GUSB2PHYCFG, U2_FREECLK_EXISTS);
+	}
 }
 
 static void usb_init_ipp(struct brcm_usb_init_params *params)
@@ -320,6 +328,9 @@ static void usb_init_common_7216(struct brcm_usb_init_params *params)
 	/* 1 millisecond - for USB clocks to settle down */
 	usleep_range(1000, 2000);
 
+	/* Disable PHY when port is suspended */
+	USB_CTRL_SET(ctrl, P0_U2PHY_CFG1, COMMONONN);
+
 	usb_wake_enable_7216(params, false);
 	usb_init_common(params);
 }
diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.h b/drivers/phy/broadcom/phy-brcm-usb-init.h
index f9fbf8fb80e5..c1a88f5cd4cd 100644
--- a/drivers/phy/broadcom/phy-brcm-usb-init.h
+++ b/drivers/phy/broadcom/phy-brcm-usb-init.h
@@ -34,6 +34,14 @@ enum brcmusb_reg_sel {
 	brcm_usb_ctrl_unset(USB_CTRL_REG(base, reg),		\
 			    USB_CTRL_##reg##_##field##_MASK)
 
+#define USB_XHCI_GBL_REG(base, reg) ((void __iomem *)base + USB_XHCI_GBL_##reg)
+#define USB_XHCI_GBL_SET(base, reg, field) \
+	brcm_usb_ctrl_set(USB_XHCI_GBL_REG(base, reg), \
+			  USB_XHCI_GBL_##reg##_##field##_MASK)
+#define USB_XHCI_GBL_UNSET(base, reg, field) \
+	brcm_usb_ctrl_unset(USB_XHCI_GBL_REG(base, reg), \
+			    USB_XHCI_GBL_##reg##_##field##_MASK)
+
 struct  brcm_usb_init_params;
 
 struct brcm_usb_init_ops {
-- 
2.7.4


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