[PATCH] pinctrl: bcm63268: Add gpio function

[PATCH] pinctrl: bcm63268: Add gpio function

[Kyle Hendry]

There is no guarantee that the bootloader will leave the pin configuration
in a known default state, so pinctrl needs to be explicitly set in some
cases. This patch adds a gpio function for drivers that need it, i.e.
gpio-leds.

Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
---
 drivers/pinctrl/bcm/pinctrl-bcm63268.c | 68 ++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm63268.c b/drivers/pinctrl/bcm/pinctrl-bcm63268.c
index 80c2fc55ffa2..5ad86b40f0b3 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm63268.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm63268.c
@@ -38,6 +38,7 @@ enum bcm63268_pinctrl_reg {
 	BCM63268_MODE,
 	BCM63268_CTRL,
 	BCM63268_BASEMODE,
+	BCM63268_NOREG,
 };
 
 struct bcm63268_function {
@@ -242,6 +243,61 @@ static struct pingroup bcm63268_groups[] = {
 	BCM_PIN_GROUP(vdsl_phy3_grp),
 };
 
+static const char * const gpio_groups[] = {
+	"gpio0",
+	"gpio1",
+	"gpio2",
+	"gpio3",
+	"gpio4",
+	"gpio5",
+	"gpio6",
+	"gpio7",
+	"gpio8",
+	"gpio9",
+	"gpio10",
+	"gpio11",
+	"gpio12",
+	"gpio13",
+	"gpio14",
+	"gpio15",
+	"gpio16",
+	"gpio17",
+	"gpio18",
+	"gpio19",
+	"gpio20",
+	"gpio21",
+	"gpio22",
+	"gpio23",
+	"gpio24",
+	"gpio25",
+	"gpio26",
+	"gpio27",
+	"gpio28",
+	"gpio29",
+	"gpio30",
+	"gpio31",
+	"gpio32",
+	"gpio33",
+	"gpio34",
+	"gpio35",
+	"gpio36",
+	"gpio37",
+	"gpio38",
+	"gpio39",
+	"gpio40",
+	"gpio41",
+	"gpio42",
+	"gpio43",
+	"gpio44",
+	"gpio45",
+	"gpio46",
+	"gpio47",
+	"gpio48",
+	"gpio49",
+	"gpio50",
+	"gpio51",
+};
+
 static const char * const led_groups[] = {
 	"gpio0",
 	"gpio1",
@@ -427,7 +483,16 @@ static const char * const vdsl_phy_override_3_groups[] = {
 		.mask = val,				\
 	}
 
+#define BCM63268_NOMODE_FUN(n)			\
+	{						\
+		.name = #n,				\
+		.groups = n##_groups,			\
+		.num_groups = ARRAY_SIZE(n##_groups),	\
+		.reg = BCM63268_NOREG,			\
+	}
+
 static const struct bcm63268_function bcm63268_funcs[] = {
+	BCM63268_NOMODE_FUN(gpio),
 	BCM63268_LED_FUN(led),
 	BCM63268_MODE_FUN(serial_led_clk),
 	BCM63268_MODE_FUN(serial_led_data),
@@ -562,6 +627,9 @@ static int bcm63268_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 		mask = f->mask;
 		val = f->mask;
 		break;
+	case BCM63268_NOREG:
+		/*Do nothing, leave registers as default*/
+		break;
 	default:
 		WARN_ON(1);
 		return -EINVAL;
-- 
2.43.0

Re: [PATCH] pinctrl: bcm63268: Add gpio function

[kernel test robot]

Hi Kyle,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linusw-pinctrl/devel]
[also build test WARNING on linusw-pinctrl/for-next linus/master v6.13-rc1 next-20241206]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kyle-Hendry/pinctrl-bcm63268-Add-gpio-function/20241208-063718
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git devel
patch link:    https://lore.kernel.org/r/20241207223335.17535-1-kylehendrydev%40gmail.com
patch subject: [PATCH] pinctrl: bcm63268: Add gpio function
config: x86_64-buildonly-randconfig-005-20241208 (https://download.01.org/0day-ci/archive/20241208/202412081215.VyJuftPL-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241208/202412081215.VyJuftPL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412081215.VyJuftPL-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/pinctrl/bcm/pinctrl-bcm63268.c:630:7: warning: variable 'reg' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
     630 |         case BCM63268_NOREG:
         |              ^~~~~~~~~~~~~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:638:31: note: uninitialized use occurs here
     638 |         regmap_update_bits(pc->regs, reg, mask, val);
         |                                      ^~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:603:18: note: initialize the variable 'reg' to silence this warning
     603 |         unsigned int reg;
         |                         ^
         |                          = 0
>> drivers/pinctrl/bcm/pinctrl-bcm63268.c:630:7: warning: variable 'mask' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
     630 |         case BCM63268_NOREG:
         |              ^~~~~~~~~~~~~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:638:36: note: uninitialized use occurs here
     638 |         regmap_update_bits(pc->regs, reg, mask, val);
         |                                           ^~~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:604:24: note: initialize the variable 'mask' to silence this warning
     604 |         unsigned int val, mask;
         |                               ^
         |                                = 0
>> drivers/pinctrl/bcm/pinctrl-bcm63268.c:630:7: warning: variable 'val' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
     630 |         case BCM63268_NOREG:
         |              ^~~~~~~~~~~~~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:638:42: note: uninitialized use occurs here
     638 |         regmap_update_bits(pc->regs, reg, mask, val);
         |                                                 ^~~
   drivers/pinctrl/bcm/pinctrl-bcm63268.c:604:18: note: initialize the variable 'val' to silence this warning
     604 |         unsigned int val, mask;
         |                         ^
         |                          = 0
   3 warnings generated.


vim +/reg +630 drivers/pinctrl/bcm/pinctrl-bcm63268.c

   595	
   596	static int bcm63268_pinctrl_set_mux(struct pinctrl_dev *pctldev,
   597					    unsigned selector, unsigned group)
   598	{
   599		struct bcm63xx_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
   600		const struct pingroup *pg = &bcm63268_groups[group];
   601		const struct bcm63268_function *f = &bcm63268_funcs[selector];
   602		unsigned i;
   603		unsigned int reg;
   604		unsigned int val, mask;
   605	
   606		for (i = 0; i < pg->npins; i++)
   607			bcm63268_set_gpio(pc, pg->pins[i]);
   608	
   609		switch (f->reg) {
   610		case BCM63268_LEDCTRL:
   611			reg = BCM63268_LED_REG;
   612			mask = BIT(pg->pins[0]);
   613			val = BIT(pg->pins[0]);
   614			break;
   615		case BCM63268_MODE:
   616			reg = BCM63268_MODE_REG;
   617			mask = BIT(pg->pins[0]);
   618			val = BIT(pg->pins[0]);
   619			break;
   620		case BCM63268_CTRL:
   621			reg = BCM63268_CTRL_REG;
   622			mask = BIT(pg->pins[0]);
   623			val = 0;
   624			break;
   625		case BCM63268_BASEMODE:
   626			reg = BCM63268_BASEMODE_REG;
   627			mask = f->mask;
   628			val = f->mask;
   629			break;
 > 630		case BCM63268_NOREG:
   631			/*Do nothing, leave registers as default*/
   632			break;
   633		default:
   634			WARN_ON(1);
   635			return -EINVAL;
   636		}
   637	
   638		regmap_update_bits(pc->regs, reg, mask, val);
   639	
   640		return 0;
   641	}
   642	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v2] pinctrl: bcm63268: add gpio function

[Álvaro Fernández Rojas]

From: Kyle Hendry <kylehendrydev@gmail.com>

There is no guarantee that the bootloader will leave the pin configuration
in a known default state, so pinctrl needs to be explicitly set in some
cases. This patch adds a gpio function for drivers that need it, i.e.
gpio-leds.

Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 drivers/pinctrl/bcm/pinctrl-bcm63268.c | 71 +++++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm63268.c b/drivers/pinctrl/bcm/pinctrl-bcm63268.c
index 80c2fc55ffa2..a98f57e64d1e 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm63268.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm63268.c
@@ -34,6 +34,7 @@
 #define  BCM63268_BASEMODE_VDSL_PHY_3	BIT(9) /* GPIOs 26/27 */
 
 enum bcm63268_pinctrl_reg {
+	BCM63268_NONE,
 	BCM63268_LEDCTRL,
 	BCM63268_MODE,
 	BCM63268_CTRL,
@@ -242,6 +243,61 @@ static struct pingroup bcm63268_groups[] = {
 	BCM_PIN_GROUP(vdsl_phy3_grp),
 };
 
+static const char * const gpio_groups[] = {
+	"gpio0",
+	"gpio1",
+	"gpio2",
+	"gpio3",
+	"gpio4",
+	"gpio5",
+	"gpio6",
+	"gpio7",
+	"gpio8",
+	"gpio9",
+	"gpio10",
+	"gpio11",
+	"gpio12",
+	"gpio13",
+	"gpio14",
+	"gpio15",
+	"gpio16",
+	"gpio17",
+	"gpio18",
+	"gpio19",
+	"gpio20",
+	"gpio21",
+	"gpio22",
+	"gpio23",
+	"gpio24",
+	"gpio25",
+	"gpio26",
+	"gpio27",
+	"gpio28",
+	"gpio29",
+	"gpio30",
+	"gpio31",
+	"gpio32",
+	"gpio33",
+	"gpio34",
+	"gpio35",
+	"gpio36",
+	"gpio37",
+	"gpio38",
+	"gpio39",
+	"gpio40",
+	"gpio41",
+	"gpio42",
+	"gpio43",
+	"gpio44",
+	"gpio45",
+	"gpio46",
+	"gpio47",
+	"gpio48",
+	"gpio49",
+	"gpio50",
+	"gpio51",
+};
+
 static const char * const led_groups[] = {
 	"gpio0",
 	"gpio1",
@@ -394,6 +450,14 @@ static const char * const vdsl_phy_override_3_groups[] = {
 	"vdsl_phy_override_3_grp",
 };
 
+#define BCM63268_GPIO_FUN(n)				\
+	{						\
+		.name = #n,				\
+		.groups = n##_groups,			\
+		.num_groups = ARRAY_SIZE(n##_groups),	\
+		.reg = BCM63268_NONE,			\
+	}
+
 #define BCM63268_LED_FUN(n)				\
 	{						\
 		.name = #n,				\
@@ -428,6 +492,7 @@ static const char * const vdsl_phy_override_3_groups[] = {
 	}
 
 static const struct bcm63268_function bcm63268_funcs[] = {
+	BCM63268_GPIO_FUN(gpio),
 	BCM63268_LED_FUN(led),
 	BCM63268_MODE_FUN(serial_led_clk),
 	BCM63268_MODE_FUN(serial_led_data),
@@ -542,6 +607,9 @@ static int bcm63268_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 		bcm63268_set_gpio(pc, pg->pins[i]);
 
 	switch (f->reg) {
+	case BCM63268_NONE:
+		reg = 0;
+		break;
 	case BCM63268_LEDCTRL:
 		reg = BCM63268_LED_REG;
 		mask = BIT(pg->pins[0]);
@@ -567,7 +635,8 @@ static int bcm63268_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 		return -EINVAL;
 	}
 
-	regmap_update_bits(pc->regs, reg, mask, val);
+	if (reg)
+		regmap_update_bits(pc->regs, reg, mask, val);
 
 	return 0;
 }
-- 
2.39.5

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Linus Walleij]

On Tue, Dec 24, 2024 at 11:36 AM Álvaro Fernández Rojas
<noltari@gmail.com> wrote:

> From: Kyle Hendry <kylehendrydev@gmail.com>
>
> There is no guarantee that the bootloader will leave the pin configuration
> in a known default state, so pinctrl needs to be explicitly set in some
> cases. This patch adds a gpio function for drivers that need it, i.e.
> gpio-leds.
>
> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

This looks right to me, but can we get some review from some
of the Broadcom people? (Hm it's MIPS so I guess that means
Florian.)

Yours,
Linus Walleij

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Álvaro Fernández Rojas]

El vie, 27 dic 2024 a las 17:17, Linus Walleij
(<linus.walleij@linaro.org>) escribió:
>
> On Tue, Dec 24, 2024 at 11:36 AM Álvaro Fernández Rojas
> <noltari@gmail.com> wrote:
>
> > From: Kyle Hendry <kylehendrydev@gmail.com>
> >
> > There is no guarantee that the bootloader will leave the pin configuration
> > in a known default state, so pinctrl needs to be explicitly set in some
> > cases. This patch adds a gpio function for drivers that need it, i.e.
> > gpio-leds.
> >
> > Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> > Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
>
> This looks right to me, but can we get some review from some
> of the Broadcom people? (Hm it's MIPS so I guess that means
> Florian.)
>
> Yours,
> Linus Walleij

Thanks Linus :)

BTW, I think that other bcm63xx pinctrl drivers need that fix too (or
at least bcm6362).
Can anyone confirm it?

Best regards,
Álvaro.

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Jonas Gorski]

Hi,

On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
<noltari@gmail.com> wrote:
>
> From: Kyle Hendry <kylehendrydev@gmail.com>
>
> There is no guarantee that the bootloader will leave the pin configuration
> in a known default state, so pinctrl needs to be explicitly set in some
> cases. This patch adds a gpio function for drivers that need it, i.e.
> gpio-leds.
>
> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>


bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
should automatically set any requested GPIO pin to the GPIO function,
so explicitly requesting the gpio function for a pin should not be
needed. Is this not enough?

Best Regards,
Jonas

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Kyle Hendry]

On 2024-12-30 08:42, Jonas Gorski wrote:
> Hi,
>
> On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
> <noltari@gmail.com> wrote:
>> From: Kyle Hendry <kylehendrydev@gmail.com>
>>
>> There is no guarantee that the bootloader will leave the pin configuration
>> in a known default state, so pinctrl needs to be explicitly set in some
>> cases. This patch adds a gpio function for drivers that need it, i.e.
>> gpio-leds.
>>
>> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
>> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
>
> bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
> should automatically set any requested GPIO pin to the GPIO function,
> so explicitly requesting the gpio function for a pin should not be
> needed. Is this not enough?
>
> Best Regards,
> Jonas
>
>
I assumed that as well, but nothing I tried worked with gpio-leds.
gpiochip_generic_request() does call gpio_request_enable(), but gpio-leds
uses devm_fwnode_gpiod_get() which looks like a different code path. The
only place it seems to be configuring the gpio is in create_gpio_led()
where it needs a pinctl node in the device tree. That's just my reading
of the code, though. I haven't set up a ftrace to verify it.

Best Regards,
Kyle

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Álvaro Fernández Rojas]

El vie, 3 ene 2025 a las 4:04, Kyle Hendry (<kylehendrydev@gmail.com>) escribió:
>
> On 2024-12-30 08:42, Jonas Gorski wrote:
> > Hi,
> >
> > On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
> > <noltari@gmail.com> wrote:
> >> From: Kyle Hendry <kylehendrydev@gmail.com>
> >>
> >> There is no guarantee that the bootloader will leave the pin configuration
> >> in a known default state, so pinctrl needs to be explicitly set in some
> >> cases. This patch adds a gpio function for drivers that need it, i.e.
> >> gpio-leds.
> >>
> >> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> >> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> >
> > bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
> > should automatically set any requested GPIO pin to the GPIO function,
> > so explicitly requesting the gpio function for a pin should not be
> > needed. Is this not enough?
> >
> > Best Regards,
> > Jonas
> >
> >
> I assumed that as well, but nothing I tried worked with gpio-leds.
> gpiochip_generic_request() does call gpio_request_enable(), but gpio-leds
> uses devm_fwnode_gpiod_get() which looks like a different code path. The
> only place it seems to be configuring the gpio is in create_gpio_led()
> where it needs a pinctl node in the device tree. That's just my reading
> of the code, though. I haven't set up a ftrace to verify it.
>
> Best Regards,
> Kyle

As Kyle pointed out it's not enough and gpio_request_enable() doesn't
get called from gpio-leds.
I will try to investigate this and report back.

Best regards,
Álvaro.

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Álvaro Fernández Rojas]

El sáb, 4 ene 2025 a las 16:44, Álvaro Fernández Rojas
(<noltari@gmail.com>) escribió:
>
> El vie, 3 ene 2025 a las 4:04, Kyle Hendry (<kylehendrydev@gmail.com>) escribió:
> >
> > On 2024-12-30 08:42, Jonas Gorski wrote:
> > > Hi,
> > >
> > > On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
> > > <noltari@gmail.com> wrote:
> > >> From: Kyle Hendry <kylehendrydev@gmail.com>
> > >>
> > >> There is no guarantee that the bootloader will leave the pin configuration
> > >> in a known default state, so pinctrl needs to be explicitly set in some
> > >> cases. This patch adds a gpio function for drivers that need it, i.e.
> > >> gpio-leds.
> > >>
> > >> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> > >> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> > >
> > > bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
> > > should automatically set any requested GPIO pin to the GPIO function,
> > > so explicitly requesting the gpio function for a pin should not be
> > > needed. Is this not enough?
> > >
> > > Best Regards,
> > > Jonas
> > >
> > >
> > I assumed that as well, but nothing I tried worked with gpio-leds.
> > gpiochip_generic_request() does call gpio_request_enable(), but gpio-leds
> > uses devm_fwnode_gpiod_get() which looks like a different code path. The
> > only place it seems to be configuring the gpio is in create_gpio_led()
> > where it needs a pinctl node in the device tree. That's just my reading
> > of the code, though. I haven't set up a ftrace to verify it.
> >
> > Best Regards,
> > Kyle
>
> As Kyle pointed out it's not enough and gpio_request_enable() doesn't
> get called from gpio-leds.
> I will try to investigate this and report back.
>
> Best regards,
> Álvaro.

I've performed some tests and so far I haven't been able to get
bcm63268_gpio_request_enable() called.

Even exporting a gpio from userspace doesn't trigger that function,
which seems strange because in that case we won't have a "gpio"
function on the pinctrl for that gpio, even with this patch...

Best regards,
Álvaro.

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Jonas Gorski]

On Sat, Jan 4, 2025 at 6:02 PM Álvaro Fernández Rojas <noltari@gmail.com> wrote:
>
> El sáb, 4 ene 2025 a las 16:44, Álvaro Fernández Rojas
> (<noltari@gmail.com>) escribió:
> >
> > El vie, 3 ene 2025 a las 4:04, Kyle Hendry (<kylehendrydev@gmail.com>) escribió:
> > >
> > > On 2024-12-30 08:42, Jonas Gorski wrote:
> > > > Hi,
> > > >
> > > > On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
> > > > <noltari@gmail.com> wrote:
> > > >> From: Kyle Hendry <kylehendrydev@gmail.com>
> > > >>
> > > >> There is no guarantee that the bootloader will leave the pin configuration
> > > >> in a known default state, so pinctrl needs to be explicitly set in some
> > > >> cases. This patch adds a gpio function for drivers that need it, i.e.
> > > >> gpio-leds.
> > > >>
> > > >> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> > > >> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> > > >
> > > > bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
> > > > should automatically set any requested GPIO pin to the GPIO function,
> > > > so explicitly requesting the gpio function for a pin should not be
> > > > needed. Is this not enough?
> > > >
> > > > Best Regards,
> > > > Jonas
> > > >
> > > >
> > > I assumed that as well, but nothing I tried worked with gpio-leds.
> > > gpiochip_generic_request() does call gpio_request_enable(), but gpio-leds
> > > uses devm_fwnode_gpiod_get() which looks like a different code path. The
> > > only place it seems to be configuring the gpio is in create_gpio_led()
> > > where it needs a pinctl node in the device tree. That's just my reading
> > > of the code, though. I haven't set up a ftrace to verify it.
> > >
> > > Best Regards,
> > > Kyle
> >
> > As Kyle pointed out it's not enough and gpio_request_enable() doesn't
> > get called from gpio-leds.
> > I will try to investigate this and report back.
> >
> > Best regards,
> > Álvaro.
>
> I've performed some tests and so far I haven't been able to get
> bcm63268_gpio_request_enable() called.
>
> Even exporting a gpio from userspace doesn't trigger that function,
> which seems strange because in that case we won't have a "gpio"
> function on the pinctrl for that gpio, even with this patch...

On a first glance it looks like that regmap-gpio does not populate
gpio_chip::request and gpio_chip:free, so the gpio subsystem is not
aware that it needs to request anything. Not sure if just using
gpiolib_generic_request() / gpiolib_generic_free() is fine. Currently
on vacation, so no hardware to test anything at hand ;-)

Best Regards,
Jonas

Re: [PATCH v2] pinctrl: bcm63268: add gpio function

[Álvaro Fernández Rojas]

El sáb, 4 ene 2025 a las 20:32, Jonas Gorski
(<jonas.gorski@gmail.com>) escribió:
>
> On Sat, Jan 4, 2025 at 6:02 PM Álvaro Fernández Rojas <noltari@gmail.com> wrote:
> >
> > El sáb, 4 ene 2025 a las 16:44, Álvaro Fernández Rojas
> > (<noltari@gmail.com>) escribió:
> > >
> > > El vie, 3 ene 2025 a las 4:04, Kyle Hendry (<kylehendrydev@gmail.com>) escribió:
> > > >
> > > > On 2024-12-30 08:42, Jonas Gorski wrote:
> > > > > Hi,
> > > > >
> > > > > On Tue, Dec 24, 2024 at 11:41 AM Álvaro Fernández Rojas
> > > > > <noltari@gmail.com> wrote:
> > > > >> From: Kyle Hendry <kylehendrydev@gmail.com>
> > > > >>
> > > > >> There is no guarantee that the bootloader will leave the pin configuration
> > > > >> in a known default state, so pinctrl needs to be explicitly set in some
> > > > >> cases. This patch adds a gpio function for drivers that need it, i.e.
> > > > >> gpio-leds.
> > > > >>
> > > > >> Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
> > > > >> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> > > > >
> > > > > bcm63268-pinctrl implements pinmux_ops::gpio_request_enable(), which
> > > > > should automatically set any requested GPIO pin to the GPIO function,
> > > > > so explicitly requesting the gpio function for a pin should not be
> > > > > needed. Is this not enough?
> > > > >
> > > > > Best Regards,
> > > > > Jonas
> > > > >
> > > > >
> > > > I assumed that as well, but nothing I tried worked with gpio-leds.
> > > > gpiochip_generic_request() does call gpio_request_enable(), but gpio-leds
> > > > uses devm_fwnode_gpiod_get() which looks like a different code path. The
> > > > only place it seems to be configuring the gpio is in create_gpio_led()
> > > > where it needs a pinctl node in the device tree. That's just my reading
> > > > of the code, though. I haven't set up a ftrace to verify it.
> > > >
> > > > Best Regards,
> > > > Kyle
> > >
> > > As Kyle pointed out it's not enough and gpio_request_enable() doesn't
> > > get called from gpio-leds.
> > > I will try to investigate this and report back.
> > >
> > > Best regards,
> > > Álvaro.
> >
> > I've performed some tests and so far I haven't been able to get
> > bcm63268_gpio_request_enable() called.
> >
> > Even exporting a gpio from userspace doesn't trigger that function,
> > which seems strange because in that case we won't have a "gpio"
> > function on the pinctrl for that gpio, even with this patch...
>
> On a first glance it looks like that regmap-gpio does not populate
> gpio_chip::request and gpio_chip:free, so the gpio subsystem is not
> aware that it needs to request anything. Not sure if just using
> gpiolib_generic_request() / gpiolib_generic_free() is fine. Currently
> on vacation, so no hardware to test anything at hand ;-)
>
> Best Regards,
> Jonas

You're totally right, after adding request() and free() functions to
gpio-regmap it's now working without this patch because
bcm63268_gpio_request_enable() is now properly called:
1. gpio-keys-polled
[    4.052132] gpio_button_hotplug: loading out-of-tree module taints kernel.
[    4.060657] bcm63268-pinctrl 100000d0.pinctrl: request pin 34
(gpio34) for 100000d0.pinctrl:546
[    4.069704] bcm63268_gpio_request_enable: range=99a2e0ae offset=34
[    4.076158] bcm63268-pinctrl 100000d0.pinctrl: request pin 35
(gpio35) for 100000d0.pinctrl:547
[    4.085135] bcm63268_gpio_request_enable: range=99a2e0ae offset=35

2. gpio-leds
[    4.480190] bcm63268-pinctrl 100000d0.pinctrl: request pin 0
(gpio0) for 100000d0.pinctrl:512
[    4.489078] bcm63268_gpio_request_enable: range=99a2e0ae offset=0
[    4.495747] bcm63268-pinctrl 100000d0.pinctrl: request pin 1
(gpio1) for 100000d0.pinctrl:513
[    4.504600] bcm63268_gpio_request_enable: range=99a2e0ae offset=1

3. userspace gpio export
root@OpenWrt:~# cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 512-563, parent: platform/100000d0.pinctrl, 100000d0.pinctrl:
 gpio-512 (                    |red:mobile          ) out lo
 gpio-513 (                    |green:mobile        ) out lo
 gpio-546 (                    |wps                 ) in  hi ACTIVE LOW
 gpio-547 (                    |reset               ) in  hi ACTIVE LOW
root@OpenWrt:~# echo 545 > /sys/class/gpio/export
[   33.437477] bcm63268-pinctrl 100000d0.pinctrl: request pin 33
(gpio33) for 100000d0.pinctrl:545
[   33.446503] bcm63268_gpio_request_enable: range=99a2e0ae offset=33
root@OpenWrt:~# cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 512-563, parent: platform/100000d0.pinctrl, 100000d0.pinctrl:
 gpio-512 (                    |red:mobile          ) out lo
 gpio-513 (                    |green:mobile        ) out lo
 gpio-545 (                    |sysfs               ) in  hi
 gpio-546 (                    |wps                 ) in  hi ACTIVE LOW
 gpio-547 (                    |reset               ) in  hi ACTIVE LOW

OpenWrt test source code:
https://github.com/Noltari/openwrt/commits/bmips-gpio-tests
https://github.com/Noltari/openwrt/commit/d3bc7610c8fe8f713a3e47ed8368b6aa220ae763

Linux test source code:
https://github.com/Noltari/linux/commits/gpio-regmap-pinctrl-request-free
https://github.com/Noltari/linux/commit/2d0ebb8cad8084e932f40f3f69d4e931b2316aa4

@Linus I assume that adding those functions may cause issues to other
drivers and maybe we need to add some logic to add them dynamically
based on a new gpio_regmap_config parameter?

Best regards,
Álvaro.