diff options
| author | Kishon Vijay Abraham I <kishon@ti.com> | 2015-07-28 16:39:09 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-08-11 23:57:34 +0300 |
| commit | 78bdcad05ea17fa1fe4644324b877162b1df4e16 (patch) | |
| tree | 0c8ec8fd142c406aa8f38ef56ffb0b80bbc695af | |
| parent | 389c7094ec241ee8ebe358ba10fe392018692c8c (diff) | |
| download | linux-78bdcad05ea17fa1fe4644324b877162b1df4e16.tar.xz | |
PCI: dra7xx: Add support to make GPIO drive PERST# line
The PERST# line in am57x-evm is connected to a GPIO line and PERST# should
be driven high to indicate the clocks are stable (As per Figure 2-10: Power
Up of the PCIe CEM spec 3.0).
Add support to make GPIO drive PERST# line.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| -rw-r--r-- | Documentation/devicetree/bindings/pci/ti-pci.txt | 3 | ||||
| -rw-r--r-- | drivers/pci/host/pci-dra7xx.c | 24 |
2 files changed, 25 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/pci/ti-pci.txt b/Documentation/devicetree/bindings/pci/ti-pci.txt index 3d217911b313..60e25161f351 100644 --- a/Documentation/devicetree/bindings/pci/ti-pci.txt +++ b/Documentation/devicetree/bindings/pci/ti-pci.txt @@ -23,6 +23,9 @@ PCIe Designware Controller interrupt-map-mask, interrupt-map : as specified in ../designware-pcie.txt +Optional Property: + - gpios : Should be added if a gpio line is required to drive PERST# line + Example: axi { compatible = "simple-bus"; diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c index 3772aff7df4f..abb85a157ce0 100644 --- a/drivers/pci/host/pci-dra7xx.c +++ b/drivers/pci/host/pci-dra7xx.c @@ -17,6 +17,7 @@ #include <linux/irqdomain.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of_gpio.h> #include <linux/pci.h> #include <linux/phy/phy.h> #include <linux/platform_device.h> @@ -336,6 +337,9 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; char name[10]; + int gpio_sel; + enum of_gpio_flags flags; + unsigned long gpio_flags; dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL); if (!dra7xx) @@ -398,6 +402,22 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) goto err_get_sync; } + gpio_sel = of_get_gpio_flags(dev->of_node, 0, &flags); + if (gpio_is_valid(gpio_sel)) { + gpio_flags = (flags & OF_GPIO_ACTIVE_LOW) ? + GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH; + ret = devm_gpio_request_one(dev, gpio_sel, gpio_flags, + "pcie_reset"); + if (ret) { + dev_err(&pdev->dev, "gpio%d request failed, ret %d\n", + gpio_sel, ret); + goto err_gpio; + } + } else if (gpio_sel == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto err_gpio; + } + reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD); reg &= ~LTSSM_EN; dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg); @@ -406,11 +426,11 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) ret = dra7xx_add_pcie_port(dra7xx, pdev); if (ret < 0) - goto err_add_port; + goto err_gpio; return 0; -err_add_port: +err_gpio: pm_runtime_put(dev); err_get_sync: |