diff options
| -rw-r--r-- | drivers/pci/controller/pci-tegra.c | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index 0fd1c1a8c1b9..6086c741cef7 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -17,6 +17,7 @@ #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/export.h> +#include <linux/gpio/consumer.h> #include <linux/interrupt.h> #include <linux/iopoll.h> #include <linux/irq.h> @@ -399,6 +400,8 @@ struct tegra_pcie_port { unsigned int lanes; struct phy **phys; + + struct gpio_desc *reset_gpio; }; struct tegra_pcie_bus { @@ -544,15 +547,23 @@ static void tegra_pcie_port_reset(struct tegra_pcie_port *port) unsigned long value; /* pulse reset signal */ - value = afi_readl(port->pcie, ctrl); - value &= ~AFI_PEX_CTRL_RST; - afi_writel(port->pcie, value, ctrl); + if (port->reset_gpio) { + gpiod_set_value(port->reset_gpio, 1); + } else { + value = afi_readl(port->pcie, ctrl); + value &= ~AFI_PEX_CTRL_RST; + afi_writel(port->pcie, value, ctrl); + } usleep_range(1000, 2000); - value = afi_readl(port->pcie, ctrl); - value |= AFI_PEX_CTRL_RST; - afi_writel(port->pcie, value, ctrl); + if (port->reset_gpio) { + gpiod_set_value(port->reset_gpio, 0); + } else { + value = afi_readl(port->pcie, ctrl); + value |= AFI_PEX_CTRL_RST; + afi_writel(port->pcie, value, ctrl); + } } static void tegra_pcie_enable_rp_features(struct tegra_pcie_port *port) @@ -2218,6 +2229,7 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie) struct tegra_pcie_port *rp; unsigned int index; u32 value; + char *label; err = of_pci_get_devfn(port); if (err < 0) { @@ -2276,6 +2288,31 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie) if (IS_ERR(rp->base)) return PTR_ERR(rp->base); + label = devm_kasprintf(dev, GFP_KERNEL, "pex-reset-%u", index); + if (!label) { + dev_err(dev, "failed to create reset GPIO label\n"); + return -ENOMEM; + } + + /* + * Returns -ENOENT if reset-gpios property is not populated + * and in this case fall back to using AFI per port register + * to toggle PERST# SFIO line. + */ + rp->reset_gpio = devm_gpiod_get_from_of_node(dev, port, + "reset-gpios", 0, + GPIOD_OUT_LOW, + label); + if (IS_ERR(rp->reset_gpio)) { + if (PTR_ERR(rp->reset_gpio) == -ENOENT) { + rp->reset_gpio = NULL; + } else { + dev_err(dev, "failed to get reset GPIO: %d\n", + err); + return PTR_ERR(rp->reset_gpio); + } + } + list_add_tail(&rp->list, &pcie->ports); } |