diff options
| author | Max Krummenacher <max.krummenacher@toradex.com> | 2014-11-21 18:58:02 +0100 |
|---|---|---|
| committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2017-12-21 14:29:10 +0100 |
| commit | e123320ed759113dec3a23df195a4d6c005d90ee (patch) | |
| tree | 1a2fd35d9568b5e3d0e92890044856478af8c77f | |
| parent | c5e23d1a2ccc046ff7e93af797f82456f360f5a8 (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.
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
(cherry picked from commit 94a60e7f645965b1e422e4e80aa8ccb9e0ec845c)
(cherry picked from commit f2bb337d37acd680404371d2530a486bfe821ce2)
Conflicts:
drivers/pci/host/pci-imx6.c
(cherry picked from commit 557f0276856f1731264492ad82fe2f13e2d64831)
| -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 1fb3ec9ecf71..bdd5685a91f8 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -62,6 +62,7 @@ struct imx6_pcie { int power_on_gpio; int reset_gpio; bool gpio_active_high; + int reset_ep_gpio; struct clk *pcie_bus; struct clk *pcie_inbound_axi; struct clk *pcie_phy; @@ -532,11 +533,16 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) /* 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_cansleep(imx6_pcie->reset_ep_gpio, 1); gpio_set_value_cansleep(imx6_pcie->reset_gpio, imx6_pcie->gpio_active_high); mdelay(20); gpio_set_value_cansleep(imx6_pcie->reset_gpio, !imx6_pcie->gpio_active_high); + mdelay(1); + if (gpio_is_valid(imx6_pcie->reset_ep_gpio)) + gpio_set_value_cansleep(imx6_pcie->reset_ep_gpio, 0); mdelay(20); } @@ -1224,6 +1230,17 @@ static int imx6_pcie_probe(struct platform_device *pdev) return ret; } } + imx6_pcie->reset_ep_gpio = of_get_named_gpio(node, "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(node, "power-on-gpio", 0); if (gpio_is_valid(imx6_pcie->power_on_gpio)) { |