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: Ma?ra Canal <[email protected]>
---
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);
}
@@ -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");
--
2.31.1
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 <[email protected]>
> ---
> 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
<[email protected]> 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
>