Merge branch 'pci/controller/mediatek-gen3'

- Deassert PCIE_PHY_RSTB so REFCLK is stable for at least 100ms
  (PCIE_T_PVPERL_MS) before deasserting PERST# (Jian Yang)

- Add .shutdown() to assert PERST# before powering down device (Jian Yang)

- Do full device power down on removal, including asserting PERST#, when
  removing driver (Chen-Yu Tsai)

- Fix a 'failed to create pwrctrl devices' error message that was
  inadvertently skipped (Chen-Yu Tsai)

* pci/controller/mediatek-gen3:
  PCI: mediatek-gen3: Fix incorrectly skipped pwrctrl error message
  PCI: mediatek-gen3: Do full device power down on removal
  PCI: mediatek-gen3: Add a .shutdown() callback to control PERST# signal
  PCI: mediatek-gen3: Fix PERST# control timing during system startup

1 files changed, 34 insertions, 5 deletions

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index b0accd828589..654e63f8fb57 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -63,6 +63,12 @@
 #define PCIE_BRG_RSTB			BIT(2)
 #define PCIE_PE_RSTB			BIT(3)
 
+/*
+ * As described in the datasheet of MediaTek PCIe Gen3 controller, wait 10ms
+ * after setting PCIE_BRG_RSTB, and before accessing PCIe internal registers.
+ */
+#define PCIE_BRG_RST_RDY_MS		10
+
 #define PCIE_LTSSM_STATUS_REG		0x150
 #define PCIE_LTSSM_STATE_MASK		GENMASK(28, 24)
 #define PCIE_LTSSM_STATE(val)		((val & PCIE_LTSSM_STATE_MASK) >> 24)
@@ -431,6 +437,21 @@ static int mtk_pcie_devices_power_up(struct mtk_gen3_pcie *pcie)
 	}
 
 	/*
+	 * Some of MediaTek's chips won't output REFCLK when PCIE_PHY_RSTB is
+	 * asserted, we have to de-assert MAC & PHY & BRG reset signals first
+	 * to allow the REFCLK to be stable. While PCIE_BRG_RSTB is asserted,
+	 * there is a short period during which the PCIe internal register
+	 * cannot be accessed, so we need to wait 10ms here.
+	 */
+	msleep(PCIE_BRG_RST_RDY_MS);
+
+	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
+		/* De-assert MAC, PHY and BRG reset signals */
+		val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_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)
@@ -439,9 +460,8 @@ static int mtk_pcie_devices_power_up(struct mtk_gen3_pcie *pcie)
 	msleep(PCIE_T_PVPERL_MS);
 
 	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
-		/* De-assert reset signals */
-		val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
-			 PCIE_PE_RSTB);
+		/* De-assert PERST# signal */
+		val &= ~PCIE_PE_RSTB;
 		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
 	}
 
@@ -1222,8 +1242,8 @@ static int mtk_pcie_probe(struct platform_device *pdev)
 
 	err = pci_pwrctrl_create_devices(pcie->dev);
 	if (err) {
-		goto err_tear_down_irq;
 		dev_err_probe(dev, err, "failed to create pwrctrl devices\n");
+		goto err_tear_down_irq;
 	}
 
 	err = mtk_pcie_setup(pcie);
@@ -1260,12 +1280,20 @@ static void mtk_pcie_remove(struct platform_device *pdev)
 	pci_remove_root_bus(host->bus);
 	pci_unlock_rescan_remove();
 
-	pci_pwrctrl_power_off_devices(pcie->dev);
+	mtk_pcie_devices_power_down(pcie);
 	mtk_pcie_power_down(pcie);
 	pci_pwrctrl_destroy_devices(pcie->dev);
 	mtk_pcie_irq_teardown(pcie);
 }
 
+static void mtk_pcie_shutdown(struct platform_device *pdev)
+{
+	struct mtk_gen3_pcie *pcie = platform_get_drvdata(pdev);
+
+	mtk_pcie_devices_power_down(pcie);
+	mtk_pcie_power_down(pcie);
+}
+
 static void mtk_pcie_irq_save(struct mtk_gen3_pcie *pcie)
 {
 	int i;
@@ -1404,6 +1432,7 @@ MODULE_DEVICE_TABLE(of, mtk_pcie_of_match);
 static struct platform_driver mtk_pcie_driver = {
 	.probe = mtk_pcie_probe,
 	.remove = mtk_pcie_remove,
+	.shutdown = mtk_pcie_shutdown,
 	.driver = {
 		.name = "mtk-pcie-gen3",
 		.of_match_table = mtk_pcie_of_match,