[PATCH v9 4/9] PCI: dw-rockchip: Add helper function for enhanced LTSSM control mode

Sebastian Reichel sebastian.reichel at collabora.com
Thu Nov 5 05:33:12 PST 2026


Remove code duplication and improve readability by introducing a new
function to setup the enhanced LTSSM mode.

Reviewed-by: Shawn Lin <shawn.lin at rock-chips.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 28 ++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index a3b0fb918479..92154a790ac0 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -683,6 +683,18 @@ static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static void rockchip_pcie_enable_enhanced_ltssm_control_mode(struct rockchip_pcie *rockchip,
+							     bool delay_link_training_after_reset)
+{
+	u32 val;
+
+	/* Enable the enhanced control mode of signal app_ltssm_enable */
+	val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1);
+	if (delay_link_training_after_reset)
+		val |= FIELD_PREP_WM16(PCIE_LTSSM_APP_DLY2_EN, 1);
+	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+}
+
 static int rockchip_pcie_configure_rc(struct platform_device *pdev,
 				      struct rockchip_pcie *rockchip)
 {
@@ -706,9 +718,7 @@ static int rockchip_pcie_configure_rc(struct platform_device *pdev,
 		return ret;
 	}
 
-	/* LTSSM enable control mode */
-	val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1);
-	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+	rockchip_pcie_enable_enhanced_ltssm_control_mode(rockchip, false);
 
 	rockchip_pcie_writel_apb(rockchip,
 				 PCIE_CLIENT_SET_MODE(PCIE_CLIENT_MODE_RC),
@@ -765,13 +775,7 @@ static int rockchip_pcie_configure_ep(struct platform_device *pdev,
 		return ret;
 	}
 
-	/*
-	 * LTSSM enable control mode, and automatically delay link training on
-	 * hot reset/link-down reset.
-	 */
-	val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1) |
-	      FIELD_PREP_WM16(PCIE_LTSSM_APP_DLY2_EN, 1);
-	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+	rockchip_pcie_enable_enhanced_ltssm_control_mode(rockchip, true);
 
 	rockchip_pcie_writel_apb(rockchip,
 				 PCIE_CLIENT_SET_MODE(PCIE_CLIENT_MODE_EP),
@@ -940,9 +944,7 @@ static int rockchip_pcie_rc_reset_root_port(struct pci_host_bridge *bridge,
 		goto deinit_clk;
 	}
 
-	/* LTSSM enable control mode */
-	val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1);
-	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+	rockchip_pcie_enable_enhanced_ltssm_control_mode(rockchip, false);
 
 	rockchip_pcie_writel_apb(rockchip,
 				 PCIE_CLIENT_SET_MODE(PCIE_CLIENT_MODE_RC),

-- 
2.53.0




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