[PATCH 3/7] PCI: mediatek-gen3: Split out device power helpers

[Chen-Yu Tsai <wenst@chromium.org>]

Split out existing code that deals with device power sequencing into
into helpers to allow cleaning up the error paths and integrating the
new PCI pwrctrl API,

This change is purely code movement.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/pci/controller/pcie-mediatek-gen3.c | 87 ++++++++++++---------
 1 file changed, 52 insertions(+), 35 deletions(-)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index f2bf4afbdc2f..870d3b3db11d 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -403,6 +403,54 @@ static void mtk_pcie_enable_msi(struct mtk_gen3_pcie *pcie)
 	writel_relaxed(val, pcie->base + PCIE_INT_ENABLE_REG);
 }
 
+static int mtk_pcie_device_power_up(struct mtk_gen3_pcie *pcie)
+{
+	int err;
+	u32 val;
+
+	/*
+	 * Airoha EN7581 has a hw bug asserting/releasing PCIE_PE_RSTB signal
+	 * causing occasional PCIe link down. In order to overcome the issue,
+	 * PCIE_RSTB signals are not asserted/released at this stage and the
+	 * PCIe block is reset using en7523_reset_assert() and
+	 * en7581_pci_enable().
+	 */
+	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
+		/* Assert all reset signals */
+		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
+		val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
+		       PCIE_PE_RSTB;
+		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
+
+		/*
+		 * Described in PCIe CEM specification revision 6.0.
+		 *
+		 * The deassertion of PERST# should be delayed 100ms (TPVPERL)
+		 * for the power and clock to become stable.
+		 */
+		msleep(PCIE_T_PVPERL_MS);
+
+		/* De-assert reset signals */
+		val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
+			 PCIE_PE_RSTB);
+		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
+	}
+
+	return 0;
+}
+
+static void mtk_pcie_device_power_down(struct mtk_gen3_pcie *pcie)
+{
+	u32 val;
+
+	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
+		/* Assert the PERST# pin */
+		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
+		val |= PCIE_PE_RSTB;
+		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
+	}
+}
+
 static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie)
 {
 	struct resource_entry *entry;
@@ -464,33 +512,9 @@ static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie)
 	val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
 	writel_relaxed(val, pcie->base + PCIE_MISC_CTRL_REG);
 
-	/*
-	 * Airoha EN7581 has a hw bug asserting/releasing PCIE_PE_RSTB signal
-	 * causing occasional PCIe link down. In order to overcome the issue,
-	 * PCIE_RSTB signals are not asserted/released at this stage and the
-	 * PCIe block is reset using en7523_reset_assert() and
-	 * en7581_pci_enable().
-	 */
-	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
-		/* Assert all reset signals */
-		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
-		val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
-		       PCIE_PE_RSTB;
-		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
-
-		/*
-		 * Described in PCIe CEM specification revision 6.0.
-		 *
-		 * The deassertion of PERST# should be delayed 100ms (TPVPERL)
-		 * for the power and clock to become stable.
-		 */
-		msleep(PCIE_T_PVPERL_MS);
-
-		/* De-assert reset signals */
-		val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
-			 PCIE_PE_RSTB);
-		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
-	}
+	err = mtk_pcie_device_power_up(pcie);
+	if (err)
+		return err;
 
 	/* Check if the link is up or not */
 	err = readl_poll_timeout(pcie->base + PCIE_LINK_STATUS_REG, val,
@@ -1269,7 +1293,6 @@ static int mtk_pcie_suspend_noirq(struct device *dev)
 {
 	struct mtk_gen3_pcie *pcie = dev_get_drvdata(dev);
 	int err;
-	u32 val;
 
 	/* Trigger link to L2 state */
 	err = mtk_pcie_turn_off_link(pcie);
@@ -1278,13 +1301,7 @@ static int mtk_pcie_suspend_noirq(struct device *dev)
 		return err;
 	}
 
-	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
-		/* Assert the PERST# pin */
-		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
-		val |= PCIE_PE_RSTB;
-		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
-	}
-
+	mtk_pcie_device_power_down(pcie);
 	dev_dbg(pcie->dev, "entered L2 states successfully");
 
 	mtk_pcie_irq_save(pcie);
-- 
2.53.0.414.gf7e9f6c205-goog