diff options
| author | Max Krummenacher <max.krummenacher@toradex.com> | 2014-11-21 18:58:02 +0100 |
|---|---|---|
| committer | Max Krummenacher <max.krummenacher@toradex.com> | 2014-11-21 19:02:44 +0100 |
| commit | 94a60e7f645965b1e422e4e80aa8ccb9e0ec845c (patch) | |
| tree | 0b614a7e45d27d7651f4bbb2c3224e01b6e596a8 | |
| parent | f79675e581a4abda12db31cde3ee71d44016b981 (diff) | |
pcie-imx6: add reset function for reseting downstream EP
With the following dtb node one can define a gpio to reset
downstream endpoints.
reset-ep-gpio = <...>;
Currently the logic is 1 for reset asserted
and 0 for reset deasserted.
Some pcie switches require their downstream endpoints to be kept in reset
for an additonal millisecond after their reset has been deasserted.
| -rw-r--r-- | drivers/pci/host/pci-imx6.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index f201d8905100..485dc8689879 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -44,6 +44,7 @@ static u32 test_region_size = SZ_2M; struct imx6_pcie { int reset_gpio; + int reset_ep_gpio; int power_on_gpio; int wake_up_gpio; int disable_gpio; @@ -281,9 +282,14 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) /* Some boards don't have PCIe reset GPIO. */ if (gpio_is_valid(imx6_pcie->reset_gpio)) { + if (gpio_is_valid(imx6_pcie->reset_ep_gpio)) + gpio_set_value(imx6_pcie->reset_ep_gpio, 1); gpio_set_value(imx6_pcie->reset_gpio, 0); msleep(100); gpio_set_value(imx6_pcie->reset_gpio, 1); + msleep(1); + if (gpio_is_valid(imx6_pcie->reset_ep_gpio)) + gpio_set_value(imx6_pcie->reset_ep_gpio, 0); } return 0; @@ -755,6 +761,17 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) return ret; } } + imx6_pcie->reset_ep_gpio = of_get_named_gpio(np, "reset-ep-gpio", 0); + if (gpio_is_valid(imx6_pcie->reset_ep_gpio)) { + ret = devm_gpio_request_one(&pdev->dev, + imx6_pcie->reset_ep_gpio, + GPIOF_OUT_INIT_HIGH, + "PCIe EP reset"); + if (ret) { + dev_err(&pdev->dev, "unable to get reset end point gpio\n"); + return ret; + } + } imx6_pcie->power_on_gpio = of_get_named_gpio(np, "power-on-gpio", 0); if (gpio_is_valid(imx6_pcie->power_on_gpio)) { |