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Message-Id: <20210430152156.21162-4-jim2101024@gmail.com>
Date: Fri, 30 Apr 2021 11:21:56 -0400
From: Jim Quinlan <jim2101024@...il.com>
To: Bjorn Helgaas <helgaas@...nel.org>,
Amjad Ouled-Ameur <aouledameur@...libre.com>,
Philipp Zabel <p.zabel@...gutronix.de>,
linux-pci@...r.kernel.org,
Nicolas Saenz Julienne <nsaenzjulienne@...e.de>,
bcm-kernel-feedback-list@...adcom.com, james.quinlan@...adcom.com,
jim2101024@...il.com
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
Rob Herring <robh@...nel.org>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Florian Fainelli <f.fainelli@...il.com>,
Jim Quinlan <jquinlan@...adcom.com>,
linux-rpi-kernel@...ts.infradead.org (moderated list:BROADCOM
BCM2711/BCM2835 ARM ARCHITECTURE),
linux-arm-kernel@...ts.infradead.org (moderated list:BROADCOM
BCM2711/BCM2835 ARM ARCHITECTURE),
linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v6 3/3] PCI: brcmstb: Use reset/rearm instead of deassert/assert
The Broadcom STB PCIe RC uses a reset control "rescal" for certain chips.
The "rescal" implements a "pulse reset" so using assert/deassert is wrong
for this device. Instead, we use reset/rearm. We need to use rearm so
that we can reset it after a suspend/resume cycle; w/o using "rearm", the
"rescal" device will only ever fire once.
Of course for suspend/resume to work we also need to put the reset/rearm
calls in the suspend and resume routines.
Fixes: 740d6c3708a9 ("PCI: brcmstb: Add control of rescal reset")
Signed-off-by: Jim Quinlan <jim2101024@...il.com>
Acked-by: Florian Fainelli <f.fainelli@...il.com>
---
drivers/pci/controller/pcie-brcmstb.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index e330e6811f0b..3b35d629035e 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1148,6 +1148,7 @@ static int brcm_pcie_suspend(struct device *dev)
brcm_pcie_turn_off(pcie);
ret = brcm_phy_stop(pcie);
+ reset_control_rearm(pcie->rescal);
clk_disable_unprepare(pcie->clk);
return ret;
@@ -1163,9 +1164,13 @@ static int brcm_pcie_resume(struct device *dev)
base = pcie->base;
clk_prepare_enable(pcie->clk);
+ ret = reset_control_reset(pcie->rescal);
+ if (ret)
+ goto err_disable_clk;
+
ret = brcm_phy_start(pcie);
if (ret)
- goto err;
+ goto err_reset;
/* Take bridge out of reset so we can access the SERDES reg */
pcie->bridge_sw_init_set(pcie, 0);
@@ -1180,14 +1185,16 @@ static int brcm_pcie_resume(struct device *dev)
ret = brcm_pcie_setup(pcie);
if (ret)
- goto err;
+ goto err_reset;
if (pcie->msi)
brcm_msi_set_regs(pcie->msi);
return 0;
-err:
+err_reset:
+ reset_control_rearm(pcie->rescal);
+err_disable_clk:
clk_disable_unprepare(pcie->clk);
return ret;
}
@@ -1197,7 +1204,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
brcm_msi_remove(pcie);
brcm_pcie_turn_off(pcie);
brcm_phy_stop(pcie);
- reset_control_assert(pcie->rescal);
+ reset_control_rearm(pcie->rescal);
clk_disable_unprepare(pcie->clk);
}
@@ -1278,13 +1285,13 @@ static int brcm_pcie_probe(struct platform_device *pdev)
return PTR_ERR(pcie->perst_reset);
}
- ret = reset_control_deassert(pcie->rescal);
+ ret = reset_control_reset(pcie->rescal);
if (ret)
dev_err(&pdev->dev, "failed to deassert 'rescal'\n");
ret = brcm_phy_start(pcie);
if (ret) {
- reset_control_assert(pcie->rescal);
+ reset_control_rearm(pcie->rescal);
clk_disable_unprepare(pcie->clk);
return ret;
}
--
2.17.1
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