The IP supports a reset GPIO. When S2RAM will be added, we must ensure the reset line (if any) is deasserted when resuming. Add support for it.
Signed-off-by: Miquel Raynal <[email protected]> --- drivers/pci/controller/pci-aardvark.c | 57 +++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index b95eb2aa00bb..1d31d74ddab7 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -9,6 +9,7 @@ */ #include <linux/delay.h> +#include <linux/gpio.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/irqdomain.h> @@ -17,6 +18,7 @@ #include <linux/init.h> #include <linux/platform_device.h> #include <linux/of_address.h> +#include <linux/of_gpio.h> #include <linux/of_pci.h> #include "../pci.h" @@ -201,6 +203,7 @@ struct advk_pcie { u16 msi_msg; int root_bus_nr; struct pci_bridge_emul bridge; + struct gpio_desc *reset_gpio; }; static inline void advk_writel(struct advk_pcie *pcie, u32 val, u64 reg) @@ -973,6 +976,55 @@ static int advk_pcie_parse_request_of_pci_ranges(struct advk_pcie *pcie) return err; } +static int advk_pcie_hard_reset(struct advk_pcie *pcie) +{ + if (!pcie->reset_gpio) + return -EINVAL; + + gpiod_set_value_cansleep(pcie->reset_gpio, 0); + msleep(1); + gpiod_set_value_cansleep(pcie->reset_gpio, 1); + + return 0; +} + +static int advk_pcie_setup_reset_gpio(struct advk_pcie *pcie) +{ + struct device *dev = &pcie->pdev->dev; + enum of_gpio_flags of_flags; + unsigned long gpio_flags; + int gpio_nb; + int ret; + + gpio_nb = of_get_named_gpio_flags(dev->of_node, "reset-gpios", 0, + &of_flags); + if (gpio_nb == -EPROBE_DEFER) + return gpio_nb; + + /* Old bindings miss the reset GPIO handle */ + if (!gpio_is_valid(gpio_nb)) { + dev_warn(dev, "Reset GPIO unavailable\n"); + return 0; + } + + if (of_flags & OF_GPIO_ACTIVE_LOW) + gpio_flags = GPIOF_ACTIVE_LOW | + GPIOF_OUT_INIT_LOW; + else + gpio_flags = GPIOF_OUT_INIT_HIGH; + + ret = devm_gpio_request_one(dev, gpio_nb, gpio_flags, + "pcie-aardvark-reset"); + if (ret) { + dev_err(dev, "Failed to retrieve reset GPIO (%d)\n", ret); + return ret; + } + + pcie->reset_gpio = gpio_to_desc(gpio_nb); + + return 0; +} + static int advk_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1008,6 +1060,11 @@ static int advk_pcie_probe(struct platform_device *pdev) return ret; } + ret = advk_pcie_setup_reset_gpio(pcie); + if (ret) + return ret; + + advk_pcie_hard_reset(pcie); advk_pcie_setup_hw(pcie); advk_sw_pci_bridge_init(pcie); -- 2.19.1
