| Message ID | 1447687147-19436-1-git-send-email-ynezz@true.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Hi Petr, sorry for the delay in reviewing this. Am Montag, den 16.11.2015, 16:19 +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. > I see the need for this change, but I'm not completely happy with the implementation. > In my case the broken behavior was observed on Toradex Apalis SoM with > Ixora base board. > > Signed-off-by: Petr Štetiar <ynezz@true.cz> > --- > drivers/pci/host/pci-imx6.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index fdb9536..cd7ed71 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -293,9 +293,11 @@ 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)) { > - gpio_set_value(imx6_pcie->reset_gpio, 0); > + struct gpio_desc *gd = gpio_to_desc(imx6_pcie->reset_gpio); > + > + gpiod_set_value(gd, 0); > msleep(100); > - gpio_set_value(imx6_pcie->reset_gpio, 1); > + gpiod_set_value(gd, 1); > } > return 0; > > @@ -559,6 +561,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) > struct pcie_port *pp; > struct device_node *np = pdev->dev.of_node; > struct resource *dbi_base; > + enum of_gpio_flags of_flags; > + int flags = GPIOF_OUT_INIT_LOW; > int ret; > > imx6_pcie = devm_kzalloc(&pdev->dev, sizeof(*imx6_pcie), GFP_KERNEL); > @@ -578,10 +582,13 @@ 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); > + imx6_pcie->reset_gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, > + Rather than adding all this complexity to this function, this should really be switched over to the descriptor based GPIO interface as a whole. So the above should become a single call to "devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW)" and the dependent code changed accordingly. Regards, Lucas > &of_flags); > if (gpio_is_valid(imx6_pcie->reset_gpio)) { > + if (of_flags & OF_GPIO_ACTIVE_LOW) > + flags |= GPIOF_ACTIVE_LOW; > ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio, > - GPIOF_OUT_INIT_LOW, "PCIe reset"); > + flags, "PCIe reset"); > if (ret) { > dev_err(&pdev->dev, "unable to get reset gpio\n"); > return ret;
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index fdb9536..cd7ed71 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -293,9 +293,11 @@ 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)) { - gpio_set_value(imx6_pcie->reset_gpio, 0); + struct gpio_desc *gd = gpio_to_desc(imx6_pcie->reset_gpio); + + gpiod_set_value(gd, 0); msleep(100); - gpio_set_value(imx6_pcie->reset_gpio, 1); + gpiod_set_value(gd, 1); } return 0; @@ -559,6 +561,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) struct pcie_port *pp; struct device_node *np = pdev->dev.of_node; struct resource *dbi_base; + enum of_gpio_flags of_flags; + int flags = GPIOF_OUT_INIT_LOW; int ret; imx6_pcie = devm_kzalloc(&pdev->dev, sizeof(*imx6_pcie), GFP_KERNEL); @@ -578,10 +582,13 @@ 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); + imx6_pcie->reset_gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, + &of_flags); if (gpio_is_valid(imx6_pcie->reset_gpio)) { + if (of_flags & OF_GPIO_ACTIVE_LOW) + flags |= GPIOF_ACTIVE_LOW; ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio, - GPIOF_OUT_INIT_LOW, "PCIe reset"); + flags, "PCIe reset"); if (ret) { dev_err(&pdev->dev, "unable to get reset gpio\n"); return ret;
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@true.cz> --- drivers/pci/host/pci-imx6.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)