[U-Boot] [PATCH 5/7] mvebu: pcie: Add support for GPIO reset for PCIe device

[kostap at marvell.com <kostap@marvell.com>]

From: Konstantin Porotchkin <kostap@marvell.com>

Add board init hook to mvebu DW PCIe device driver.
Add support for "marvell,reset-gpio" property to A8K
board init function.
This option is valid when CONFIG_DM_GPIO=y

Change-Id: Ic17c500449050c2fbb700731f1a9ca8b83298986
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Signed-off-by: Rabeeh Khoury <rabeeh@solid-run.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Neta Zur Hershkovits <neta@marvell.com>
Cc: Omri Itach <omrii@marvell.com>
Cc: Igal Liberman <igall@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
---
 board/Marvell/mvebu_armada-8k/board.c          | 22 ++++++++++++
 doc/device-tree-bindings/pci/armada8k-pcie.txt | 49 ++++++++++++++++++++++++++
 drivers/pci/pcie_dw_mvebu.c                    | 11 ++++++
 3 files changed, 82 insertions(+)
 create mode 100644 doc/device-tree-bindings/pci/armada8k-pcie.txt

diff --git a/board/Marvell/mvebu_armada-8k/board.c b/board/Marvell/mvebu_armada-8k/board.c
index aa6a6d7..7fca8ed 100644
--- a/board/Marvell/mvebu_armada-8k/board.c
+++ b/board/Marvell/mvebu_armada-8k/board.c
@@ -152,6 +152,28 @@ int board_xhci_enable(struct udevice *usb_dev)
 	return 0;
 }
 
+int board_pcie_init(struct udevice *pcie_dev)
+{
+#ifdef CONFIG_DM_GPIO
+	struct gpio_desc reset_gpio;
+
+	gpio_request_by_name(pcie_dev, "marvell,reset-gpio", 0,
+			     &reset_gpio, GPIOD_IS_OUT);
+	/*
+	 * Issue reset to add-in card trough the dedicated GPIO.
+	 * Some boards are connecting the card reset pin to common
+	 * system reset wire and others are using separate GPIO port.
+	 * In the last case we have to release a reset of the addon
+	 * card using this GPIO.
+	 */
+	if (dm_gpio_is_valid(&reset_gpio)) {
+		dm_gpio_set_value(&reset_gpio, 1);
+		mdelay(100);
+	}
+#endif /* CONFIG_DM_GPIO */
+	return 0;
+}
+
 int board_early_init_f(void)
 {
 	/* Nothing to do (yet), perhaps later some pin-muxing etc */
diff --git a/doc/device-tree-bindings/pci/armada8k-pcie.txt b/doc/device-tree-bindings/pci/armada8k-pcie.txt
new file mode 100644
index 0000000..7230f10
--- /dev/null
+++ b/doc/device-tree-bindings/pci/armada8k-pcie.txt
@@ -0,0 +1,49 @@
+Armada-8K PCIe DT details:
+==========================
+
+Armada-8k uses synopsis designware PCIe controller.
+
+Required properties:
+- compatible : should be "marvell,armada8k-pcie", "snps,dw-pcie".
+- reg: base addresses and lengths of the pcie control and global control registers.
+ "ctrl" registers points to the global control registers, while the "config" space
+ points to the pcie configuration registers as mentioned in dw-pcie dt bindings in the link below.
+- interrupt-map-mask and interrupt-map, standard PCI properties to
+  define the mapping of the PCIe interface to interrupt numbers.
+- All other definitions as per generic PCI bindings
+See Linux kernel documentation:
+"Documentation/devicetree/bindings/pci/designware-pcie.txt"
+
+Optional properties:
+PHY support is still not supported for armada-8k, once it will, the following parameters can be used:
+- phys		    : phandle to phy node associated with pcie controller.
+- phy-names	    : must be "pcie-phy"
+- marvell,reset-gpio :  specifies a gpio that needs to be activated for plug-in
+			card reset signal release.
+Example:
+
+cpm_pcie0: pcie at f2600000 {
+	compatible = "marvell,armada8k-pcie", "snps,dw-pcie";
+	reg = <0 0xf2600000 0 0x10000>,
+	      <0 0xf6f00000 0 0x80000>;
+	reg-names = "ctrl", "config";
+	#address-cells = <3>;
+	#size-cells = <2>;
+	#interrupt-cells = <1>;
+	device_type = "pci";
+	dma-coherent;
+
+	bus-range = <0 0xff>;
+	ranges =
+		/* downstream I/O */
+		<0x81000000 0 0xf9000000 0  0xf9000000 0 0x10000
+		/* non-prefetchable memory */
+		0x82000000 0 0xf6000000 0  0xf6000000 0 0xf00000>;
+	interrupt-map-mask = <0 0 0 0>;
+	interrupt-map = <0 0 0 0 &gic 0 GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+	interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+	num-lanes = <1>;
+	clocks = <&cpm_syscon0 1 13>;
+	marvell,reset-gpio = <&cpm_gpio1 20 GPIO_ACTIVE_HIGH>;
+	status = "disabled";
+};
diff --git a/drivers/pci/pcie_dw_mvebu.c b/drivers/pci/pcie_dw_mvebu.c
index 17fa024..26451b8 100644
--- a/drivers/pci/pcie_dw_mvebu.c
+++ b/drivers/pci/pcie_dw_mvebu.c
@@ -112,6 +112,15 @@ struct pcie_dw_mvebu {
 	int first_busno;
 };
 
+/*
+ * Dummy implementation that can be overwritten by a board
+ * specific function
+ */
+__weak int board_pcie_init(struct udevice *pcie_dev)
+{
+	return 0;
+}
+
 static int pcie_dw_get_link_speed(const void *regs_base)
 {
 	return (readl(regs_base + PCIE_LINK_STATUS_REG) &
@@ -464,6 +473,8 @@ static int pcie_dw_mvebu_probe(struct udevice *dev)
 
 	pcie->first_busno = dev->seq;
 
+	board_pcie_init(dev);
+
 	/* Don't register host if link is down */
 	if (!pcie_dw_mvebu_pcie_link_up(pcie->ctrl_base, LINK_SPEED_GEN_3)) {
 		printf("PCIE-%d: Link down\n", dev->seq);
-- 
2.7.4