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>
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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
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next prev 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
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