From 3d71746c420c1c1c27cf5c4e48f8fa0a6cfdc185 Mon Sep 17 00:00:00 2001
From: Baruch Siach <baruch@tkos.co.il>
Date: Wed, 3 Oct 2018 15:49:43 +0300
Subject: [PATCH] PCI: armada8k: Add support for gpio controlled reset signal
Add support for the gpio reset signal binding as described in the
designware-pcie.txt DT binding document. Both the documented
'reset-gpio' property name and the more standard 'reset-gpios' name are
supported.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
drivers/pci/controller/dwc/pcie-armada8k.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-armada8k.c b/drivers/pci/controller/dwc/pcie-armada8k.c
index 0c389a30ef5d3..b171b6bc15c84 100644
--- a/drivers/pci/controller/dwc/pcie-armada8k.c
+++ b/drivers/pci/controller/dwc/pcie-armada8k.c
@@ -22,6 +22,7 @@
#include <linux/resource.h>
#include <linux/of_pci.h>
#include <linux/of_irq.h>
+#include <linux/gpio/consumer.h>
#include "pcie-designware.h"
@@ -29,6 +30,7 @@ struct armada8k_pcie {
struct dw_pcie *pci;
struct clk *clk;
struct clk *clk_reg;
+ struct gpio_desc *reset_gpio;
};
#define PCIE_VENDOR_REGS_OFFSET 0x8000
@@ -137,6 +139,12 @@ static int armada8k_pcie_host_init(struct pcie_port *pp)
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct armada8k_pcie *pcie = to_armada8k_pcie(pci);
+ if (pcie->reset_gpio) {
+ /* assert and then deassert the reset signal */
+ gpiod_set_value_cansleep(pcie->reset_gpio, 1);
+ msleep(100);
+ gpiod_set_value_cansleep(pcie->reset_gpio, 0);
+ }
dw_pcie_setup_rc(pp);
armada8k_pcie_establish_link(pcie);
@@ -249,6 +257,14 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
goto fail_clkreg;
}
+ /* Get reset gpio signal and hold asserted (logically high) */
+ pcie->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(pcie->reset_gpio)) {
+ ret = PTR_ERR(pcie->reset_gpio);
+ goto fail_clkreg;
+ }
+
platform_set_drvdata(pdev, pcie);
ret = armada8k_add_pcie_port(pcie, pdev);
--
2.49.0