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| author | Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> | 2013-08-13 14:25:23 +0200 |
|---|---|---|
| committer | Jason Cooper <jason@lakedaemon.net> | 2013-09-30 14:58:43 +0000 |
| commit | 52ba992e201f47b878019f268391aa0e27592906 (patch) | |
| tree | 597d5361fc22a4680c6ca1bff45becbe4b95a423 | |
| parent | e5615c30c1c921dda957638ddf9c9437fcb7bb36 (diff) | |
| download | blackbird-op-linux-52ba992e201f47b878019f268391aa0e27592906.tar.gz blackbird-op-linux-52ba992e201f47b878019f268391aa0e27592906.zip | |
PCI: mvebu: add support for reset on GPIO
This patch adds a check for DT passed reset-gpios property and deasserts/
asserts reset pin on probe/remove with configurable delay. Corresponding
binding documentation is also updated.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
| -rw-r--r-- | Documentation/devicetree/bindings/pci/mvebu-pci.txt | 6 | ||||
| -rw-r--r-- | drivers/pci/host/pci-mvebu.c | 33 |
2 files changed, 38 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt index 638673aec306..8bb3245e1946 100644 --- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt +++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt @@ -76,6 +76,8 @@ and the following optional properties: - marvell,pcie-lane: the physical PCIe lane number, for ports having multiple lanes. If this property is not found, we assume that the value is 0. +- reset-gpios: optional gpio to PERST# +- reset-delay-us: delay in us to wait after reset de-assertion Example: @@ -138,6 +140,10 @@ pcie-controller { interrupt-map = <0 0 0 0 &mpic 58>; marvell,pcie-port = <0>; marvell,pcie-lane = <0>; + /* low-active PERST# reset on GPIO 25 */ + reset-gpios = <&gpio0 25 1>; + /* wait 20ms for device settle after reset deassertion */ + reset-delay-us = <20000>; clocks = <&gateclk 5>; status = "disabled"; }; diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c index af23038a52ac..2d5f414bc45a 100644 --- a/drivers/pci/host/pci-mvebu.c +++ b/drivers/pci/host/pci-mvebu.c @@ -9,14 +9,17 @@ #include <linux/kernel.h> #include <linux/pci.h> #include <linux/clk.h> +#include <linux/delay.h> +#include <linux/gpio.h> #include <linux/module.h> #include <linux/mbus.h> #include <linux/msi.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/of_address.h> -#include <linux/of_pci.h> #include <linux/of_irq.h> +#include <linux/of_gpio.h> +#include <linux/of_pci.h> #include <linux/of_platform.h> /* @@ -126,6 +129,9 @@ struct mvebu_pcie_port { unsigned int io_target; unsigned int io_attr; struct clk *clk; + int reset_gpio; + int reset_active_low; + char *reset_name; struct mvebu_sw_pci_bridge bridge; struct device_node *dn; struct mvebu_pcie *pcie; @@ -857,6 +863,7 @@ static int mvebu_pcie_probe(struct platform_device *pdev) i = 0; for_each_child_of_node(pdev->dev.of_node, child) { struct mvebu_pcie_port *port = &pcie->ports[i]; + enum of_gpio_flags flags; if (!of_device_is_available(child)) continue; @@ -897,6 +904,30 @@ static int mvebu_pcie_probe(struct platform_device *pdev) continue; } + port->reset_gpio = of_get_named_gpio_flags(child, + "reset-gpios", 0, &flags); + if (gpio_is_valid(port->reset_gpio)) { + u32 reset_udelay = 20000; + + port->reset_active_low = flags & OF_GPIO_ACTIVE_LOW; + port->reset_name = kasprintf(GFP_KERNEL, + "pcie%d.%d-reset", port->port, port->lane); + of_property_read_u32(child, "reset-delay-us", + &reset_udelay); + + ret = devm_gpio_request_one(&pdev->dev, + port->reset_gpio, GPIOF_DIR_OUT, port->reset_name); + if (ret) { + if (ret == -EPROBE_DEFER) + return ret; + continue; + } + + gpio_set_value(port->reset_gpio, + (port->reset_active_low) ? 1 : 0); + msleep(reset_udelay/1000); + } + port->clk = of_clk_get_by_name(child, NULL); if (IS_ERR(port->clk)) { dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n", |
