| Message ID | YX/zlRqmxbLRnTqT@fedora (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,RESEND] PCI: imx6: Replace legacy gpio interface for gpiod interface | expand |
Am Montag, dem 01.11.2021 um 11:03 -0300 schrieb Maíra Canal: > Considering the current transition of the GPIO subsystem, remove all > dependencies of the legacy GPIO interface (linux/gpio.h and linux > /of_gpio.h) and replace it with the descriptor-based GPIO approach. > > Signed-off-by: Maíra Canal <maira.canal@usp.br> > --- > V1 -> V2: Rewrite commit log and subject line to match PCI subsystem standard > --- > drivers/pci/controller/dwc/pci-imx6.c | 30 +++++++++------------------ > 1 file changed, 10 insertions(+), 20 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 80fc98acf097..589cbd600d17 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -11,13 +11,12 @@ > #include <linux/bitfield.h> > #include <linux/clk.h> > #include <linux/delay.h> > -#include <linux/gpio.h> > +#include <linux/gpio/consumer.h> > #include <linux/kernel.h> > #include <linux/mfd/syscon.h> > #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> > #include <linux/mfd/syscon/imx7-iomuxc-gpr.h> > #include <linux/module.h> > -#include <linux/of_gpio.h> > #include <linux/of_device.h> > #include <linux/of_address.h> > #include <linux/pci.h> > @@ -63,7 +62,7 @@ struct imx6_pcie_drvdata { > > struct imx6_pcie { > struct dw_pcie *pci; > - int reset_gpio; > + struct gpio_desc *reset_gpio; > bool gpio_active_high; > struct clk *pcie_bus; > struct clk *pcie_phy; > @@ -526,11 +525,11 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) > usleep_range(200, 500); > > /* Some boards don't have PCIe reset GPIO. */ > - if (gpio_is_valid(imx6_pcie->reset_gpio)) { > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > + if (imx6_pcie->reset_gpio) { > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > imx6_pcie->gpio_active_high); > msleep(100); > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > !imx6_pcie->gpio_active_high); I don't think this is correct. gpiod_set_value sets the logical line state, so if the GPIO is specified as active-low in the DT, the real line state will be negated. The only reason why the reset-gpio-active- high property even exists is that old DTs might specify the wrong GPIO polarity in the reset-gpio DT description. I think you need to use to gpiod_set_raw_value API here to get the expected real line state even with a broken DT description. Regards, Lucas > } > > @@ -1025,22 +1024,13 @@ static int imx6_pcie_probe(struct platform_device *pdev) > return PTR_ERR(pci->dbi_base); > > /* Fetch GPIOs */ > - imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0); > imx6_pcie->gpio_active_high = of_property_read_bool(node, > "reset-gpio-active-high"); > - if (gpio_is_valid(imx6_pcie->reset_gpio)) { > - ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio, > - imx6_pcie->gpio_active_high ? > - GPIOF_OUT_INIT_HIGH : > - GPIOF_OUT_INIT_LOW, > - "PCIe reset"); > - if (ret) { > - dev_err(dev, "unable to get reset gpio\n"); > - return ret; > - } > - } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) { > - return imx6_pcie->reset_gpio; > - } > + imx6_pcie->reset_gpio = devm_gpiod_get_optional(dev, "reset", > + imx6_pcie->gpio_active_high ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW); > + if (IS_ERR(imx6_pcie->reset_gpio)) > + return dev_err_probe(dev, PTR_ERR(imx6_pcie->reset_gpio), > + "unable to get reset gpio\n"); > > /* Fetch clocks */ > imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
? > > /* Some boards don't have PCIe reset GPIO. */ > > - if (gpio_is_valid(imx6_pcie->reset_gpio)) { > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > + if (imx6_pcie->reset_gpio) { > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > imx6_pcie->gpio_active_high); > > msleep(100); > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > !imx6_pcie->gpio_active_high); > > I don't think this is correct. gpiod_set_value sets the logical line > state, so if the GPIO is specified as active-low in the DT, the real > line state will be negated. The only reason why the reset-gpio-active- > high property even exists is that old DTs might specify the wrong GPIO > polarity in the reset-gpio DT description. I think you need to use to > gpiod_set_raw_value API here to get the expected real line state even > with a broken DT description. > > Regards, > Lucas > I'm a beginner in kernel development, so I'm sorry for the question. If I change gpiod_set_value_cansleep for gpiod_set_raw_value, wouldn't I change the behavior of the driver? I replaced gpio_set_value_cansleep for gpiod_set_value_cansleep because they have the same behavior and I didn't change the logic states. Thank you for the feedback! Regards, Maíra
Am Montag, dem 01.11.2021 um 11:44 -0300 schrieb Maíra Canal: > ? > > > /* Some boards don't have PCIe reset GPIO. */ > > > - if (gpio_is_valid(imx6_pcie->reset_gpio)) { > > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > > + if (imx6_pcie->reset_gpio) { > > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > > imx6_pcie->gpio_active_high); > > > msleep(100); > > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > > !imx6_pcie->gpio_active_high); > > > > I don't think this is correct. gpiod_set_value sets the logical line > > state, so if the GPIO is specified as active-low in the DT, the real > > line state will be negated. The only reason why the reset-gpio-active- > > high property even exists is that old DTs might specify the wrong GPIO > > polarity in the reset-gpio DT description. I think you need to use to > > gpiod_set_raw_value API here to get the expected real line state even > > with a broken DT description. > > > > Regards, > > Lucas > > > > I'm a beginner in kernel development, so I'm sorry for the question. > If I change gpiod_set_value_cansleep for gpiod_set_raw_value, wouldn't > I change the behavior of the driver? I replaced > gpio_set_value_cansleep for gpiod_set_value_cansleep because they have > the same behavior and I didn't change the logic states. Thank you for > the feedback! Yes, you need to use the _cansleep variant of the API to keep the context information. The point I was trying to make was that you probably (please double check, that's just an assumption on my side) need to use the _raw variant of the gpiod API to keep the current behavior of the driver, as we are setting the physical line state purely depending on the reset-gpio-active-high property presence, not the logical line state, which would take into account the polarity specified in the DT gpio descriptor. I guess the right API call here would be gpiod_set_raw_value_cansleep(). Regards, Lucas
Em seg., 1 de nov. de 2021 às 11:58, Lucas Stach <l.stach@pengutronix.de> escreveu: > > Am Montag, dem 01.11.2021 um 11:44 -0300 schrieb Maíra Canal: > > ? > > > > /* Some boards don't have PCIe reset GPIO. */ > > > > - if (gpio_is_valid(imx6_pcie->reset_gpio)) { > > > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > > > + if (imx6_pcie->reset_gpio) { > > > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > > > imx6_pcie->gpio_active_high); > > > > msleep(100); > > > > - gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > > > + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, > > > > !imx6_pcie->gpio_active_high); > > > > > > I don't think this is correct. gpiod_set_value sets the logical line > > > state, so if the GPIO is specified as active-low in the DT, the real > > > line state will be negated. The only reason why the reset-gpio-active- > > > high property even exists is that old DTs might specify the wrong GPIO > > > polarity in the reset-gpio DT description. I think you need to use to > > > gpiod_set_raw_value API here to get the expected real line state even > > > with a broken DT description. > > > > > > Regards, > > > Lucas > > > > > > > I'm a beginner in kernel development, so I'm sorry for the question. > > If I change gpiod_set_value_cansleep for gpiod_set_raw_value, wouldn't > > I change the behavior of the driver? I replaced > > gpio_set_value_cansleep for gpiod_set_value_cansleep because they have > > the same behavior and I didn't change the logic states. Thank you for > > the feedback! > > Yes, you need to use the _cansleep variant of the API to keep the > context information. The point I was trying to make was that you > probably (please double check, that's just an assumption on my side) > need to use the _raw variant of the gpiod API to keep the current > behavior of the driver, as we are setting the physical line state > purely depending on the reset-gpio-active-high property presence, not > the logical line state, which would take into account the polarity > specified in the DT gpio descriptor. > > I guess the right API call here would be > gpiod_set_raw_value_cansleep(). I got it now. Thank you for your attention! I will send the v3 with the correction. > > Regards, > Lucas >
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 80fc98acf097..589cbd600d17 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -11,13 +11,12 @@ #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/delay.h> -#include <linux/gpio.h> +#include <linux/gpio/consumer.h> #include <linux/kernel.h> #include <linux/mfd/syscon.h> #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> #include <linux/mfd/syscon/imx7-iomuxc-gpr.h> #include <linux/module.h> -#include <linux/of_gpio.h> #include <linux/of_device.h> #include <linux/of_address.h> #include <linux/pci.h> @@ -63,7 +62,7 @@ struct imx6_pcie_drvdata { struct imx6_pcie { struct dw_pcie *pci; - int reset_gpio; + struct gpio_desc *reset_gpio; bool gpio_active_high; struct clk *pcie_bus; struct clk *pcie_phy; @@ -526,11 +525,11 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) usleep_range(200, 500); /* Some boards don't have PCIe reset GPIO. */ - if (gpio_is_valid(imx6_pcie->reset_gpio)) { - gpio_set_value_cansleep(imx6_pcie->reset_gpio, + if (imx6_pcie->reset_gpio) { + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, imx6_pcie->gpio_active_high); msleep(100); - gpio_set_value_cansleep(imx6_pcie->reset_gpio, + gpiod_set_value_cansleep(imx6_pcie->reset_gpio, !imx6_pcie->gpio_active_high); } @@ -1025,22 +1024,13 @@ static int imx6_pcie_probe(struct platform_device *pdev) return PTR_ERR(pci->dbi_base); /* Fetch GPIOs */ - imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0); imx6_pcie->gpio_active_high = of_property_read_bool(node, "reset-gpio-active-high"); - if (gpio_is_valid(imx6_pcie->reset_gpio)) { - ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio, - imx6_pcie->gpio_active_high ? - GPIOF_OUT_INIT_HIGH : - GPIOF_OUT_INIT_LOW, - "PCIe reset"); - if (ret) { - dev_err(dev, "unable to get reset gpio\n"); - return ret; - } - } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) { - return imx6_pcie->reset_gpio; - } + imx6_pcie->reset_gpio = devm_gpiod_get_optional(dev, "reset", + imx6_pcie->gpio_active_high ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW); + if (IS_ERR(imx6_pcie->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(imx6_pcie->reset_gpio), + "unable to get reset gpio\n"); /* Fetch clocks */ imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
Considering the current transition of the GPIO subsystem, remove all dependencies of the legacy GPIO interface (linux/gpio.h and linux /of_gpio.h) and replace it with the descriptor-based GPIO approach. Signed-off-by: Maíra Canal <maira.canal@usp.br> --- V1 -> V2: Rewrite commit log and subject line to match PCI subsystem standard --- drivers/pci/controller/dwc/pci-imx6.c | 30 +++++++++------------------ 1 file changed, 10 insertions(+), 20 deletions(-)