Thread (36 messages) 36 messages, 5 authors, 2020-09-11

Re: [PATCH v11 04/11] PCI: brcmstb: Add suspend and resume pm_ops

From: Rob Herring <robh@kernel.org>
Date: 2020-09-10 16:00:51
Also in: linux-pci, lkml

On Mon, Aug 24, 2020 at 03:30:17PM -0400, Jim Quinlan wrote:
quoted hunk ↗ jump to hunk
From: Jim Quinlan <redacted>

Broadcom Set-top (BrcmSTB) boards typically support S2, S3, and S5 suspend
and resume.  Now the PCIe driver may do so as well.

Signed-off-by: Jim Quinlan <redacted>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 47 +++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index c2b3d2946a36..3d588ab7a6dd 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -978,6 +978,47 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
 	brcm_pcie_bridge_sw_init_set(pcie, 1);
 }
 
+static int brcm_pcie_suspend(struct device *dev)
+{
+	struct brcm_pcie *pcie = dev_get_drvdata(dev);
+
+	brcm_pcie_turn_off(pcie);
+	clk_disable_unprepare(pcie->clk);
+
+	return 0;
+}
+
+static int brcm_pcie_resume(struct device *dev)
+{
+	struct brcm_pcie *pcie = dev_get_drvdata(dev);
+	void __iomem *base;
+	u32 tmp;
+	int ret;
+
+	base = pcie->base;
+	clk_prepare_enable(pcie->clk);
+
+	/* Take bridge out of reset so we can access the SERDES reg */
+	brcm_pcie_bridge_sw_init_set(pcie, 0);
+
+	/* SERDES_IDDQ = 0 */
+	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+	u32p_replace_bits(&tmp, 0, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
+	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+
+	/* wait for serdes to be stable */
+	udelay(100);
Really needs to be a spinloop?
quoted hunk ↗ jump to hunk
+
+	ret = brcm_pcie_setup(pcie);
+	if (ret)
+		return ret;
+
+	if (pcie->msi)
+		brcm_msi_set_regs(pcie->msi);
+
+	return 0;
+}
+
 static void __brcm_pcie_remove(struct brcm_pcie *pcie)
 {
 	brcm_msi_remove(pcie);
@@ -1087,12 +1128,18 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 
 MODULE_DEVICE_TABLE(of, brcm_pcie_match);
 
+static const struct dev_pm_ops brcm_pcie_pm_ops = {
+	.suspend_noirq = brcm_pcie_suspend,
+	.resume_noirq = brcm_pcie_resume,
Why do you need interrupts disabled? There's 39 cases of .suspend_noirq 
and 1352 of .suspend in the tree.

Is doing a clk unprepare even safe in .suspend_noirq? IIRC, 
prepare/unprepare can sleep.
+};
+
 static struct platform_driver brcm_pcie_driver = {
 	.probe = brcm_pcie_probe,
 	.remove = brcm_pcie_remove,
 	.driver = {
 		.name = "brcm-pcie",
 		.of_match_table = brcm_pcie_match,
+		.pm = &brcm_pcie_pm_ops,
 	},
 };
 module_platform_driver(brcm_pcie_driver);
-- 
2.17.1
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