Merge tag 'pci-v5.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:

 - Revert emulation of Marvell Armada A3720 expansion ROM because it
   doesn't work as expected (Marek Behún)

 - Assert PERST# in Apple M1 driver to fix initialization when booting
   from bootloaders using PCIe, such as U-Boot (Marc Zyngier)

 - Describe PERST# as active low in Apple T8103 DT and update driver to
   match (Marc Zyngier)

* tag 'pci-v5.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: apple: Fix PERST# polarity
  arm64: dts: apple: t8103: Mark PCIe PERST# polarity active low in DT
  PCI: apple: Follow the PCIe specifications when resetting the port
  Revert "PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge"

arch/arm64/boot/dts/apple/t8103.dtsi

@@ -7,6 +7,7 @@
  * Copyright The Asahi Linux Contributors
  */
 
+#include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/apple-aic.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 #include <dt-bindings/pinctrl/apple.h>
@@ -281,7 +282,7 @@ pcie0: pcie@690000000 {
 			port00: pci@0,0 {
 				device_type = "pci";
 				reg = <0x0 0x0 0x0 0x0 0x0>;
-				reset-gpios = <&pinctrl_ap 152 0>;
+				reset-gpios = <&pinctrl_ap 152 GPIO_ACTIVE_LOW>;
 				max-link-speed = <2>;
 
 				#address-cells = <3>;
@@ -301,7 +302,7 @@ port00: pci@0,0 {
 			port01: pci@1,0 {
 				device_type = "pci";
 				reg = <0x800 0x0 0x0 0x0 0x0>;
-				reset-gpios = <&pinctrl_ap 153 0>;
+				reset-gpios = <&pinctrl_ap 153 GPIO_ACTIVE_LOW>;
 				max-link-speed = <2>;
 
 				#address-cells = <3>;
@@ -321,7 +322,7 @@ port01: pci@1,0 {
 			port02: pci@2,0 {
 				device_type = "pci";
 				reg = <0x1000 0x0 0x0 0x0 0x0>;
-				reset-gpios = <&pinctrl_ap 33 0>;
+				reset-gpios = <&pinctrl_ap 33 GPIO_ACTIVE_LOW>;
 				max-link-speed = <1>;
 
 				#address-cells = <3>;

drivers/pci/controller/pci-aardvark.c

@@ -32,7 +32,6 @@
 #define PCIE_CORE_DEV_ID_REG					0x0
 #define PCIE_CORE_CMD_STATUS_REG				0x4
 #define PCIE_CORE_DEV_REV_REG					0x8
-#define PCIE_CORE_EXP_ROM_BAR_REG				0x30
 #define PCIE_CORE_PCIEXP_CAP					0xc0
 #define PCIE_CORE_ERR_CAPCTL_REG				0x118
 #define     PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX			BIT(5)
@@ -774,10 +773,6 @@ advk_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge,
 		*value = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG);
 		return PCI_BRIDGE_EMUL_HANDLED;
 
-	case PCI_ROM_ADDRESS1:
-		*value = advk_readl(pcie, PCIE_CORE_EXP_ROM_BAR_REG);
-		return PCI_BRIDGE_EMUL_HANDLED;
-
 	case PCI_INTERRUPT_LINE: {
 		/*
 		 * From the whole 32bit register we support reading from HW only
@@ -810,10 +805,6 @@ advk_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
 		advk_writel(pcie, new, PCIE_CORE_CMD_STATUS_REG);
 		break;
 
-	case PCI_ROM_ADDRESS1:
-		advk_writel(pcie, new, PCIE_CORE_EXP_ROM_BAR_REG);
-		break;
-
 	case PCI_INTERRUPT_LINE:
 		if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) {
 			u32 val = advk_readl(pcie, PCIE_CORE_CTRL1_REG);

drivers/pci/controller/pcie-apple.c

@@ -516,7 +516,7 @@ static int apple_pcie_setup_port(struct apple_pcie *pcie,
 	int ret, i;
 
 	reset = gpiod_get_from_of_node(np, "reset-gpios", 0,
-				       GPIOD_OUT_LOW, "#PERST");
+				       GPIOD_OUT_LOW, "PERST#");
 	if (IS_ERR(reset))
 		return PTR_ERR(reset);
 
@@ -539,12 +539,22 @@ static int apple_pcie_setup_port(struct apple_pcie *pcie,
 
 	rmw_set(PORT_APPCLK_EN, port->base + PORT_APPCLK);
 
+	/* Assert PERST# before setting up the clock */
+	gpiod_set_value(reset, 1);
+
 	ret = apple_pcie_setup_refclk(pcie, port);
 	if (ret < 0)
 		return ret;
 
+	/* The minimal Tperst-clk value is 100us (PCIe CEM r5.0, 2.9.2) */
+	usleep_range(100, 200);
+
+	/* Deassert PERST# */
 	rmw_set(PORT_PERST_OFF, port->base + PORT_PERST);
-	gpiod_set_value(reset, 1);
+	gpiod_set_value(reset, 0);
+
+	/* Wait for 100ms after PERST# deassertion (PCIe r5.0, 6.6.1) */
+	msleep(100);
 
 	ret = readl_relaxed_poll_timeout(port->base + PORT_STATUS, stat,
 					 stat & PORT_STATUS_READY, 100, 250000);