| Message ID | 20210115210159.3090203-1-saravanak@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v1] of: property: Add fw_devlink support for "gpio" and "gpios" binding | expand |
On Fri, Jan 15, 2021 at 10:02 PM Saravana Kannan <saravanak@google.com> wrote: > To provide backward compatibility for boards that use deprecated DT > bindings, we need to add fw_devlink support for "gpio" and "gpios". > > Cc: linux-tegra <linux-tegra@vger.kernel.org> > Cc: Linus Walleij <linus.walleij@linaro.org> > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") > Tested-by: Jon Hunter <jonathanh@nvidia.com> > Signed-off-by: Saravana Kannan <saravanak@google.com> "gpios" is a valid non legacy property I think. Anyways: Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
On Mon, Jan 18, 2021 at 7:32 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > On Fri, Jan 15, 2021 at 10:02 PM Saravana Kannan <saravanak@google.com> wrote: > > > To provide backward compatibility for boards that use deprecated DT > > bindings, we need to add fw_devlink support for "gpio" and "gpios". > > > > Cc: linux-tegra <linux-tegra@vger.kernel.org> > > Cc: Linus Walleij <linus.walleij@linaro.org> > > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") > > Tested-by: Jon Hunter <jonathanh@nvidia.com> > > Signed-off-by: Saravana Kannan <saravanak@google.com> > > "gpios" is a valid non legacy property I think. I checked :) Quoting the documentation [1]: "While a non-existent <name> is considered valid for compatibility reasons (resolving to the "gpios" property), it is not allowed for new bindings." [1] - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/gpio/gpio.txt#n8 > Anyways: > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Thanks! Greg/Rob, Can we pull this into driver-core-next please? It fixes issues on some boards with fw_devlink=on. -Saravana
Hi Saravana, On Mon, Jan 18, 2021 at 11:14 PM Saravana Kannan <saravanak@google.com> wrote: > On Mon, Jan 18, 2021 at 7:32 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > On Fri, Jan 15, 2021 at 10:02 PM Saravana Kannan <saravanak@google.com> wrote: > > > To provide backward compatibility for boards that use deprecated DT > > > bindings, we need to add fw_devlink support for "gpio" and "gpios". > > > > > > Cc: linux-tegra <linux-tegra@vger.kernel.org> > > > Cc: Linus Walleij <linus.walleij@linaro.org> > > > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") > > > Tested-by: Jon Hunter <jonathanh@nvidia.com> > > > Signed-off-by: Saravana Kannan <saravanak@google.com> Thanks for your patch! > > "gpios" is a valid non legacy property I think. > > I checked :) Quoting the documentation [1]: > "While a non-existent <name> is considered valid for compatibility > reasons (resolving to the "gpios" property), it is not allowed for new > bindings." > > [1] - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/gpio/gpio.txt#n8 > > > Anyways: > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > > Thanks! > > Greg/Rob, > > Can we pull this into driver-core-next please? It fixes issues on some > boards with fw_devlink=on. On r8a77951-salvator-xs.dts, it introduces one more failure: OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get #gpio-cells for /cpus/cpu@102 Seems like it doesn't parse gpios properties in GPIO hogs correctly. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Can we pull this into driver-core-next please? It fixes issues on some > > boards with fw_devlink=on. > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > #gpio-cells for /cpus/cpu@102 > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. Could it be that the code assumes no self-referencing phandles? (Just guessing...) Yours, Linus Walleij
On Tue, Jan 19, 2021 at 11:20:24AM +0100, Linus Walleij wrote: > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > boards with fw_devlink=on. > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > #gpio-cells for /cpus/cpu@102 > > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > Could it be that the code assumes no self-referencing phandles? > (Just guessing...) Well, since this is scanning the DT and creating device links between producers and consumers, there's really no point in handling self- references, so I think that's fine. However, what this probably should do is skip the node if it's marked as a GPIO hog to avoid the error message. Thierry
On Tue, Jan 19, 2021 at 2:20 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > boards with fw_devlink=on. > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > #gpio-cells for /cpus/cpu@102 Geert, One good thing is that it's noticing this being weird and ignoring it in your particular board. I *think* it interprets the "7" as a phandle and that's cpu@102 and realizes it's not a gpio-controller. For at least in your case, it's a safe failure. > > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > Could it be that the code assumes no self-referencing phandles? > (Just guessing...) > Linus, Ok I tried to understand what gpio-hogs means. It's not fully clear to me. But it looks like if a gpio-controller has a gpio-hog, then it doesn't have/need gpio-cells? Is that right? So if a gpio-controller has a gpio-hog, can it ever be referred to by another consumer in DT using blah-gpios = ...? If so, I don't see any obvious code that's handling the missing gpio-cells in this case. Long story short, please help me understand gpio-hog in the context of finding dependencies in DT. Thanks, Saravana
Hi Saravana, On Tue, Jan 19, 2021 at 6:54 PM Saravana Kannan <saravanak@google.com> wrote: > On Tue, Jan 19, 2021 at 2:20 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > > boards with fw_devlink=on. > > > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > > #gpio-cells for /cpus/cpu@102 > > Geert, > > One good thing is that it's noticing this being weird and ignoring it > in your particular board. I *think* it interprets the "7" as a phandle > and that's cpu@102 and realizes it's not a gpio-controller. For at > least in your case, it's a safe failure. While 7 is the GPIO index, relative to the current GPIO controller, represented by the parent device node. > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > > > Could it be that the code assumes no self-referencing phandles? > > (Just guessing...) > > Ok I tried to understand what gpio-hogs means. It's not fully clear to > me. But it looks like if a gpio-controller has a gpio-hog, then it > doesn't have/need gpio-cells? Is that right? A GPIO hog is a way to fix (strap) a GPIO line to a specific value. Usually this is done to enable a piece of hardware on a board, or control a mux. The controller still needs gpio-cells. > So if a gpio-controller has a gpio-hog, can it ever be referred to by > another consumer in DT using blah-gpios = ...? If so, I don't see any > obvious code that's handling the missing gpio-cells in this case. Yes it can. > Long story short, please help me understand gpio-hog in the context of > finding dependencies in DT. The hog references a GPIO on the current controller. As this is always the parent device node, the hog's gpios properties lack the phandle. E.g. a normal reference to the first GPIO of gpio5 looks like: gpios = <&gpio5 0 GPIO_ACTIVE_LOW>; A hog on the first GPIO of gpio5 would be a subnode of gpio5, and would just use: gpios = <0 GPIO_ACTIVE_LOW>; instead. Hope this helps. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Jan 19, 2021 at 10:10 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Hi Saravana, > > On Tue, Jan 19, 2021 at 6:54 PM Saravana Kannan <saravanak@google.com> wrote: > > On Tue, Jan 19, 2021 at 2:20 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > > > boards with fw_devlink=on. > > > > > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > > > #gpio-cells for /cpus/cpu@102 > > > > Geert, > > > > One good thing is that it's noticing this being weird and ignoring it > > in your particular board. I *think* it interprets the "7" as a phandle > > and that's cpu@102 and realizes it's not a gpio-controller. For at > > least in your case, it's a safe failure. > > While 7 is the GPIO index, relative to the current GPIO controller, > represented by the parent device node. > > > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > > > > > Could it be that the code assumes no self-referencing phandles? > > > (Just guessing...) > > > > Ok I tried to understand what gpio-hogs means. It's not fully clear to > > me. But it looks like if a gpio-controller has a gpio-hog, then it > > doesn't have/need gpio-cells? Is that right? > > A GPIO hog is a way to fix (strap) a GPIO line to a specific value. > Usually this is done to enable a piece of hardware on a board, or > control a mux. > > The controller still needs gpio-cells. > > > So if a gpio-controller has a gpio-hog, can it ever be referred to by > > another consumer in DT using blah-gpios = ...? If so, I don't see any > > obvious code that's handling the missing gpio-cells in this case. > > Yes it can. > > > Long story short, please help me understand gpio-hog in the context of > > finding dependencies in DT. > > The hog references a GPIO on the current controller. As this is always > the parent device node, the hog's gpios properties lack the phandle. > > E.g. a normal reference to the first GPIO of gpio5 looks like: > > gpios = <&gpio5 0 GPIO_ACTIVE_LOW>; > > A hog on the first GPIO of gpio5 would be a subnode of gpio5, > and would just use: > > gpios = <0 GPIO_ACTIVE_LOW>; > > instead. > > Hope this helps. I'm still not sure if I've understood this fully, but does this just boil down to: Don't parse [name-]gpio[s] to find dependencies if the node has gpio-hog property? -Saravana
Hi Saravana, On Tue, Jan 19, 2021 at 7:19 PM Saravana Kannan <saravanak@google.com> wrote: > On Tue, Jan 19, 2021 at 10:10 AM Geert Uytterhoeven > <geert@linux-m68k.org> wrote: > > On Tue, Jan 19, 2021 at 6:54 PM Saravana Kannan <saravanak@google.com> wrote: > > > On Tue, Jan 19, 2021 at 2:20 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > > > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > > > > boards with fw_devlink=on. > > > > > > > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > > > > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > > > > #gpio-cells for /cpus/cpu@102 > > > > > > Geert, > > > > > > One good thing is that it's noticing this being weird and ignoring it > > > in your particular board. I *think* it interprets the "7" as a phandle > > > and that's cpu@102 and realizes it's not a gpio-controller. For at > > > least in your case, it's a safe failure. > > > > While 7 is the GPIO index, relative to the current GPIO controller, > > represented by the parent device node. > > > > > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > > > > > > > Could it be that the code assumes no self-referencing phandles? > > > > (Just guessing...) > > > > > > Ok I tried to understand what gpio-hogs means. It's not fully clear to > > > me. But it looks like if a gpio-controller has a gpio-hog, then it > > > doesn't have/need gpio-cells? Is that right? > > > > A GPIO hog is a way to fix (strap) a GPIO line to a specific value. > > Usually this is done to enable a piece of hardware on a board, or > > control a mux. > > > > The controller still needs gpio-cells. > > > > > So if a gpio-controller has a gpio-hog, can it ever be referred to by > > > another consumer in DT using blah-gpios = ...? If so, I don't see any > > > obvious code that's handling the missing gpio-cells in this case. > > > > Yes it can. > > > > > Long story short, please help me understand gpio-hog in the context of > > > finding dependencies in DT. > > > > The hog references a GPIO on the current controller. As this is always > > the parent device node, the hog's gpios properties lack the phandle. > > > > E.g. a normal reference to the first GPIO of gpio5 looks like: > > > > gpios = <&gpio5 0 GPIO_ACTIVE_LOW>; > > > > A hog on the first GPIO of gpio5 would be a subnode of gpio5, > > and would just use: > > > > gpios = <0 GPIO_ACTIVE_LOW>; > > > > instead. > > > > Hope this helps. > > I'm still not sure if I've understood this fully, but does this just > boil down to: > Don't parse [name-]gpio[s] to find dependencies if the node has > gpio-hog property? Indeed. You can just ignore all nodes with a gpio-hog property, as they're always handled by their parent. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Jan 19, 2021 at 10:33 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Hi Saravana, > > On Tue, Jan 19, 2021 at 7:19 PM Saravana Kannan <saravanak@google.com> wrote: > > On Tue, Jan 19, 2021 at 10:10 AM Geert Uytterhoeven > > <geert@linux-m68k.org> wrote: > > > On Tue, Jan 19, 2021 at 6:54 PM Saravana Kannan <saravanak@google.com> wrote: > > > > On Tue, Jan 19, 2021 at 2:20 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > > > > On Tue, Jan 19, 2021 at 9:50 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > > > > > Can we pull this into driver-core-next please? It fixes issues on some > > > > > > > boards with fw_devlink=on. > > > > > > > > > > > > On r8a77951-salvator-xs.dts, it introduces one more failure: > > > > > > > > > > > > OF: /soc/i2c@e66d8000/gpio@20/pcie-sata-switch-hog: could not get > > > > > > #gpio-cells for /cpus/cpu@102 > > > > > > > > Geert, > > > > > > > > One good thing is that it's noticing this being weird and ignoring it > > > > in your particular board. I *think* it interprets the "7" as a phandle > > > > and that's cpu@102 and realizes it's not a gpio-controller. For at > > > > least in your case, it's a safe failure. > > > > > > While 7 is the GPIO index, relative to the current GPIO controller, > > > represented by the parent device node. > > > > > > > > > Seems like it doesn't parse gpios properties in GPIO hogs correctly. > > > > > > > > > > Could it be that the code assumes no self-referencing phandles? > > > > > (Just guessing...) > > > > > > > > Ok I tried to understand what gpio-hogs means. It's not fully clear to > > > > me. But it looks like if a gpio-controller has a gpio-hog, then it > > > > doesn't have/need gpio-cells? Is that right? > > > > > > A GPIO hog is a way to fix (strap) a GPIO line to a specific value. > > > Usually this is done to enable a piece of hardware on a board, or > > > control a mux. > > > > > > The controller still needs gpio-cells. > > > > > > > So if a gpio-controller has a gpio-hog, can it ever be referred to by > > > > another consumer in DT using blah-gpios = ...? If so, I don't see any > > > > obvious code that's handling the missing gpio-cells in this case. > > > > > > Yes it can. > > > > > > > Long story short, please help me understand gpio-hog in the context of > > > > finding dependencies in DT. > > > > > > The hog references a GPIO on the current controller. As this is always > > > the parent device node, the hog's gpios properties lack the phandle. > > > > > > E.g. a normal reference to the first GPIO of gpio5 looks like: > > > > > > gpios = <&gpio5 0 GPIO_ACTIVE_LOW>; > > > > > > A hog on the first GPIO of gpio5 would be a subnode of gpio5, > > > and would just use: > > > > > > gpios = <0 GPIO_ACTIVE_LOW>; > > > > > > instead. > > > > > > Hope this helps. > > > > I'm still not sure if I've understood this fully, but does this just > > boil down to: > > Don't parse [name-]gpio[s] to find dependencies if the node has > > gpio-hog property? > > Indeed. You can just ignore all nodes with a gpio-hog property, as they're > always handled by their parent. Ok, I'll send out an updated patch later (next week probably). Or maybe we can merge this now and I can fix up gpio-hog handling later since I'd need to do it anyway for the name-gpios stuff anyway? Or will those never be combined with gpio-hog? -Saravana
diff --git a/drivers/of/property.c b/drivers/of/property.c index 5f9eed79a8aa..1c8c65c4a887 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1258,6 +1258,8 @@ DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL) DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL) DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL) DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL) +DEFINE_SIMPLE_PROP(gpio_compat, "gpio", "#gpio-cells") +DEFINE_SIMPLE_PROP(gpios_compat, "gpios", "#gpio-cells") DEFINE_SUFFIX_PROP(regulators, "-supply", NULL) DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells") DEFINE_SUFFIX_PROP(gpios, "-gpios", "#gpio-cells") @@ -1296,6 +1298,8 @@ static const struct supplier_bindings of_supplier_bindings[] = { { .parse_prop = parse_pinctrl6, }, { .parse_prop = parse_pinctrl7, }, { .parse_prop = parse_pinctrl8, }, + { .parse_prop = parse_gpio_compat, }, + { .parse_prop = parse_gpios_compat, }, { .parse_prop = parse_regulators, }, { .parse_prop = parse_gpio, }, { .parse_prop = parse_gpios, },
To provide backward compatibility for boards that use deprecated DT bindings, we need to add fw_devlink support for "gpio" and "gpios". Cc: linux-tegra <linux-tegra@vger.kernel.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Saravana Kannan <saravanak@google.com> --- drivers/of/property.c | 4 ++++ 1 file changed, 4 insertions(+)