[PATCH v2] PCI: imx6: Fix reset-gpio to work with active low GPIO
Lucas Stach
l.stach at pengutronix.de
Fri Nov 27 02:34:24 PST 2015
Am Freitag, den 27.11.2015, 11:01 +0100 schrieb Petr Štetiar:
> It's currently not possible to use reset-gpio on board where the GPIO is
> active low as the code incorrectly assumes, that reset-gpio will be
> always active high.
>
> In my case the broken behavior was observed on Toradex Apalis SoM with
> Ixora base board.
>
> Signed-off-by: Petr Štetiar <ynezz at true.cz>
> ---
>
> Changes since v1:
> * reworked to use descriptor based GPIO interface
>
> drivers/pci/host/pci-imx6.c | 20 ++++++--------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 22e8224..c0e121d 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -32,7 +32,7 @@
> #define to_imx6_pcie(x) container_of(x, struct imx6_pcie, pp)
>
> struct imx6_pcie {
> - int reset_gpio;
> + struct gpio_desc *reset_gpio;
> struct clk *pcie_bus;
> struct clk *pcie_phy;
> struct clk *pcie;
> @@ -287,10 +287,10 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
> usleep_range(200, 500);
>
> /* Some boards don't have PCIe reset GPIO. */
> - if (gpio_is_valid(imx6_pcie->reset_gpio)) {
> - gpio_set_value(imx6_pcie->reset_gpio, 0);
> + if (imx6_pcie->reset_gpio) {
> + gpiod_set_value(imx6_pcie->reset_gpio, 0);
This now collides with a fix from Fabio that allows this function to
sleep. So this should use gpiod_set_value_cansleep() and be rebased to
pci/host-imx6, or if Bjorn prefers to pull this in quickly, replace
Fabios commit.
Regards,
Lucas
> msleep(100);
> - gpio_set_value(imx6_pcie->reset_gpio, 1);
> + gpiod_set_value(imx6_pcie->reset_gpio, 1);
> }
> return 0;
>
> @@ -560,7 +560,6 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
> {
> struct imx6_pcie *imx6_pcie;
> struct pcie_port *pp;
> - struct device_node *np = pdev->dev.of_node;
> struct resource *dbi_base;
> int ret;
>
> @@ -581,15 +580,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
> return PTR_ERR(pp->dbi_base);
>
> /* Fetch GPIOs */
> - imx6_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
> - if (gpio_is_valid(imx6_pcie->reset_gpio)) {
> - ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio,
> - GPIOF_OUT_INIT_LOW, "PCIe reset");
> - if (ret) {
> - dev_err(&pdev->dev, "unable to get reset gpio\n");
> - return ret;
> - }
> - }
> + imx6_pcie->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
> + GPIOD_OUT_LOW);
>
> /* Fetch clocks */
> imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy");
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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