linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jim Quinlan <james.quinlan@broadcom.com>
To: linux-pci@vger.kernel.org,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
	bcm-kernel-feedback-list@broadcom.com,
	james.quinlan@broadcom.com
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Rob Herring <robh@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	linux-rpi-kernel@lists.infradead.org (moderated list:BROADCOM
	BCM2711/BCM2835 ARM ARCHITECTURE),
	linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM
	BCM2711/BCM2835 ARM ARCHITECTURE),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v1 3/6] PCI: brcmstb: Do not turn off regulators if EP can wake up
Date: Wed, 25 Nov 2020 14:24:20 -0500	[thread overview]
Message-ID: <20201125192424.14440-4-james.quinlan@broadcom.com> (raw)
In-Reply-To: <20201125192424.14440-1-james.quinlan@broadcom.com>

[-- Attachment #1: Type: text/plain, Size: 4107 bytes --]

If any downstream device may wake up during S2/S3 suspend, we do not want
to turn off its power when suspending.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 56 ++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 34d6bad07b66..9b888846f0bc 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -193,6 +193,7 @@ static inline void brcm_pcie_bridge_sw_init_set_7278(struct brcm_pcie *pcie, u32
 static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val);
 static inline void brcm_pcie_perst_set_7278(struct brcm_pcie *pcie, u32 val);
 static inline void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 val);
+static bool brcm_pcie_link_up(struct brcm_pcie *pcie);
 
 enum {
 	RGR1_SW_INIT_1,
@@ -302,6 +303,7 @@ struct brcm_pcie {
 	void			(*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
 	struct regulator	*regulators[PCIE_REGULATORS_MAX];
 	int			num_regulators;
+	bool			ep_wakeup_capable;
 };
 
 static int brcm_parse_regulators(struct brcm_pcie *pcie)
@@ -324,18 +326,60 @@ static int brcm_parse_regulators(struct brcm_pcie *pcie)
 	return 0;
 }
 
-static void brcm_set_regulators(struct brcm_pcie *pcie, bool on)
+static int pci_dev_may_wakeup(struct pci_dev *dev, void *data)
 {
+	bool *ret = data;
+
+	if (device_may_wakeup(&dev->dev)) {
+		*ret = true;
+		dev_dbg(&dev->dev, "disable cancelled for wake-up device\n");
+	}
+	return (int) *ret;
+}
+
+enum {
+	TURN_OFF,		/* Turn egulators off, unless an EP is wakeup-capable */
+	TURN_OFF_ALWAYS,	/* Turn Regulators off, no exceptions */
+	TURN_ON,		/* Turn regulators on, unless pcie->ep_wakeup_capable */
+};
+
+static void brcm_set_regulators(struct brcm_pcie *pcie, int how)
+{
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
 	struct device *dev = pcie->dev;
 	int ret, i;
 
 	if (pcie->num_regulators == 0)
 		return;
 
+	if (how == TURN_ON) {
+		if (pcie->ep_wakeup_capable) {
+			/*
+			 * We are resuming from a suspend.  In the
+			 * previous suspend we did not disable the power
+			 * supplies, so there is no need to enable them
+			 * (and falsely increase their usage count).
+			 */
+			pcie->ep_wakeup_capable = false;
+			return;
+		}
+	} else if (how == TURN_OFF) {
+		/*
+		 * If at least one device on this bus is enabled as a
+		 * wake-up source, do not turn off regulators.
+		 */
+		pcie->ep_wakeup_capable = false;
+		if (bridge->bus && brcm_pcie_link_up(pcie)) {
+			pci_walk_bus(bridge->bus, pci_dev_may_wakeup, &pcie->ep_wakeup_capable);
+			if (pcie->ep_wakeup_capable)
+				return;
+		}
+	}
+
 	for (i = 0; i < PCIE_REGULATORS_MAX; i++) {
 		if (!pcie->regulators[i])
 			continue;
-		if (on) {
+		if (how == TURN_ON) {
 			ret = regulator_enable(pcie->regulators[i]);
 			dev_dbg(dev, "enable regulator %s (%s)\n",
 				ep_regulator_names[i], ret ? "fail" : "pass");
@@ -1197,7 +1241,7 @@ static int brcm_pcie_suspend(struct device *dev)
 	brcm_pcie_turn_off(pcie);
 	ret = brcm_phy_stop(pcie);
 	clk_disable_unprepare(pcie->clk);
-	brcm_set_regulators(pcie, false);
+	brcm_set_regulators(pcie, TURN_OFF);
 
 	return ret;
 }
@@ -1210,7 +1254,7 @@ static int brcm_pcie_resume(struct device *dev)
 	int ret;
 
 	base = pcie->base;
-	brcm_set_regulators(pcie, true);
+	brcm_set_regulators(pcie, TURN_ON);
 	clk_prepare_enable(pcie->clk);
 
 	ret = brcm_phy_start(pcie);
@@ -1249,7 +1293,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
 	brcm_phy_stop(pcie);
 	reset_control_assert(pcie->rescal);
 	clk_disable_unprepare(pcie->clk);
-	brcm_set_regulators(pcie, false);
+	brcm_set_regulators(pcie, TURN_OFF_ALWAYS);
 }
 
 static int brcm_pcie_remove(struct platform_device *pdev)
@@ -1338,7 +1382,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	brcm_set_regulators(pcie, true);
+	brcm_set_regulators(pcie, TURN_ON);
 	ret = brcm_pcie_setup(pcie);
 	if (ret)
 		goto fail;
-- 
2.17.1


[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4167 bytes --]

  parent reply	other threads:[~2020-11-25 19:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-25 19:24 [PATCH v1 0/6] PCI: brcmstb: add EP regulators and panic handler Jim Quinlan
2020-11-25 19:24 ` [PATCH v1 1/6] dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators Jim Quinlan
2020-11-25 19:24 ` [PATCH v1 2/6] PCI: brcmstb: Add control of EP voltage regulator(s) Jim Quinlan
2020-11-26 11:49   ` Mark Brown
2020-11-27 20:26     ` Jim Quinlan
2020-11-30 12:06       ` Mark Brown
2020-11-25 19:24 ` Jim Quinlan [this message]
2020-11-25 19:24 ` [PATCH v1 4/6] PCI: brcmstb: Give 7216 SOCs their own config type Jim Quinlan
2020-11-25 19:24 ` [PATCH v1 5/6] PCI: brcmstb: Add panic/die handler to RC driver Jim Quinlan
2020-11-25 19:24 ` [PATCH v1 6/6] PCI: brcmstb: check return value of clk_prepare_enable() Jim Quinlan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201125192424.14440-4-james.quinlan@broadcom.com \
    --to=james.quinlan@broadcom.com \
    --cc=bcm-kernel-feedback-list@broadcom.com \
    --cc=bhelgaas@google.com \
    --cc=f.fainelli@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-rpi-kernel@lists.infradead.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=nsaenzjulienne@suse.de \
    --cc=robh@kernel.org \
    --subject='Re: [PATCH v1 3/6] PCI: brcmstb: Do not turn off regulators if EP can wake up' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).