[PATCH v5 2/2] PCI: brcmstb: Use reset/rearm instead of deassert/assert
From: Jim Quinlan <jim2101024@gmail.com>
Date: 2021-03-12 20:47:25
Also in:
linux-pci, lkml
Subsystem:
broadcom bcm2711/bcm2835 arm architecture, broadcom bcm7xxx arm architecture, broadcom stb pcie driver, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Florian Fainelli, Jim Quinlan, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
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@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.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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