[3/3] pinctrl: qcom: spmi-gpio: Fix pmic_gpio_config_get() to be compliant

Message ID 20180702225939.109169-3-dianders@chromium.org
State New
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Series
  • [1/3] pinctrl: Document pin_config_group_get() return codes like pin_config_get()
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Commit Message

Doug Anderson July 2, 2018, 10:59 p.m.
If you do this on an sdm845 board:
  grep "" /sys/kernel/debug/pinctrl/*spmi:pmic*/pinconf-groups

...it looks like nonsense.  For every pin you see listed:
  input bias disabled, input bias high impedance, input bias pull down, input bias pull up, ...

That's because pmic_gpio_config_get() isn't complying with the rules
that pinconf_generic_dump_one() expects.  Specifically for boolean
parameters (anything with a "struct pin_config_item" where has_arg is
false) the function expects that the function should return its value
not through the "config" parameter but should return "0" if the value
is set and "-EINVAL" if the value isn't set.

Let's fix this.

From a quick sample of other pinctrl drivers, it appears to be
tradition to also return 1 through the config parameter for these
boolean parameters when they exist.  I'm not one to knock tradition,
so I'll follow tradition and return 1 in these cases.  While I'm at
it, I'll also continue searching for four leaf clovers, kocking on
wood three times, and trying not to break mirrors.

NOTE: This also fixes an apparent typo for reading
PIN_CONFIG_BIAS_DISABLE where the old driver was accidentally
using "=" instead of "==" and thus was setting some internal
state when you tried to query PIN_CONFIG_BIAS_DISABLE.  Oops.

Fixes: eadff3024472 ("pinctrl: Qualcomm SPMI PMIC GPIO pin controller driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/pinctrl/qcom/pinctrl-spmi-gpio.c | 32 ++++++++++++++++++------
 1 file changed, 24 insertions(+), 8 deletions(-)

Comments

Stephen Boyd July 3, 2018, 6:09 a.m. | #1
Quoting Douglas Anderson (2018-07-02 15:59:39)
> If you do this on an sdm845 board:
>   grep "" /sys/kernel/debug/pinctrl/*spmi:pmic*/pinconf-groups
> 
> ...it looks like nonsense.  For every pin you see listed:
>   input bias disabled, input bias high impedance, input bias pull down, input bias pull up, ...
> 
> That's because pmic_gpio_config_get() isn't complying with the rules
> that pinconf_generic_dump_one() expects.  Specifically for boolean
> parameters (anything with a "struct pin_config_item" where has_arg is
> false) the function expects that the function should return its value
> not through the "config" parameter but should return "0" if the value
> is set and "-EINVAL" if the value isn't set.
> 
> Let's fix this.
> 
> From a quick sample of other pinctrl drivers, it appears to be
> tradition to also return 1 through the config parameter for these
> boolean parameters when they exist.  I'm not one to knock tradition,
> so I'll follow tradition and return 1 in these cases.  While I'm at
> it, I'll also continue searching for four leaf clovers, kocking on

Small typo here.

> wood three times, and trying not to break mirrors.
> 
> NOTE: This also fixes an apparent typo for reading
> PIN_CONFIG_BIAS_DISABLE where the old driver was accidentally
> using "=" instead of "==" and thus was setting some internal
> state when you tried to query PIN_CONFIG_BIAS_DISABLE.  Oops.

Awesome!

> 
> Fixes: eadff3024472 ("pinctrl: Qualcomm SPMI PMIC GPIO pin controller driver")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

We should fix the ssbi-gpio/mpp and spmi-mpp drivers too. All those
drivers are designed on the same buggy original driver.

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Linus Walleij July 9, 2018, 11:17 a.m. | #2
On Tue, Jul 3, 2018 at 1:00 AM Douglas Anderson <dianders@chromium.org> wrote:

> If you do this on an sdm845 board:
>   grep "" /sys/kernel/debug/pinctrl/*spmi:pmic*/pinconf-groups
>
> ...it looks like nonsense.  For every pin you see listed:
>   input bias disabled, input bias high impedance, input bias pull down, input bias pull up, ...
>
> That's because pmic_gpio_config_get() isn't complying with the rules
> that pinconf_generic_dump_one() expects.  Specifically for boolean
> parameters (anything with a "struct pin_config_item" where has_arg is
> false) the function expects that the function should return its value
> not through the "config" parameter but should return "0" if the value
> is set and "-EINVAL" if the value isn't set.
>
> Let's fix this.
>
> From a quick sample of other pinctrl drivers, it appears to be
> tradition to also return 1 through the config parameter for these
> boolean parameters when they exist.  I'm not one to knock tradition,
> so I'll follow tradition and return 1 in these cases.  While I'm at
> it, I'll also continue searching for four leaf clovers, kocking on
> wood three times, and trying not to break mirrors.
>
> NOTE: This also fixes an apparent typo for reading
> PIN_CONFIG_BIAS_DISABLE where the old driver was accidentally
> using "=" instead of "==" and thus was setting some internal
> state when you tried to query PIN_CONFIG_BIAS_DISABLE.  Oops.
>
> Fixes: eadff3024472 ("pinctrl: Qualcomm SPMI PMIC GPIO pin controller driver")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Patch applied, same thing. Stays in unless Bjorn has some
objections.

Yours,
Linus Walleij
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Linus Walleij July 9, 2018, 11:17 a.m. | #3
On Tue, Jul 3, 2018 at 8:09 AM Stephen Boyd <swboyd@chromium.org> wrote:

> > Fixes: eadff3024472 ("pinctrl: Qualcomm SPMI PMIC GPIO pin controller driver")
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
>
> We should fix the ssbi-gpio/mpp and spmi-mpp drivers too. All those
> drivers are designed on the same buggy original driver.

Agreed. Looking forward to the patches :D

Yours,
Linus Walleij
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Doug Anderson Aug. 30, 2018, 3:28 p.m. | #4
Hi,

On Mon, Jul 9, 2018 at 4:17 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Tue, Jul 3, 2018 at 8:09 AM Stephen Boyd <swboyd@chromium.org> wrote:
>
>> > Fixes: eadff3024472 ("pinctrl: Qualcomm SPMI PMIC GPIO pin controller driver")
>> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
>>
>> We should fix the ssbi-gpio/mpp and spmi-mpp drivers too. All those
>> drivers are designed on the same buggy original driver.
>
> Agreed. Looking forward to the patches :D

Well, it took a little while for me to get to it, but patches are
available at <http://lore.kernel.org/r/20180830152340.242249-1-dianders@chromium.org>.
I personally have no way to test them so I prefixed them with RFT.
Enjoy!

-Doug

Patch

diff --git a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
index 3e66e0d10010..cf82db78e69e 100644
--- a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
+++ b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
@@ -390,31 +390,47 @@  static int pmic_gpio_config_get(struct pinctrl_dev *pctldev,
 
 	switch (param) {
 	case PIN_CONFIG_DRIVE_PUSH_PULL:
-		arg = pad->buffer_type == PMIC_GPIO_OUT_BUF_CMOS;
+		if (pad->buffer_type != PMIC_GPIO_OUT_BUF_CMOS)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
-		arg = pad->buffer_type == PMIC_GPIO_OUT_BUF_OPEN_DRAIN_NMOS;
+		if (pad->buffer_type != PMIC_GPIO_OUT_BUF_OPEN_DRAIN_NMOS)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
-		arg = pad->buffer_type == PMIC_GPIO_OUT_BUF_OPEN_DRAIN_PMOS;
+		if (pad->buffer_type != PMIC_GPIO_OUT_BUF_OPEN_DRAIN_PMOS)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_BIAS_PULL_DOWN:
-		arg = pad->pullup == PMIC_GPIO_PULL_DOWN;
+		if (pad->pullup != PMIC_GPIO_PULL_DOWN)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_BIAS_DISABLE:
-		arg = pad->pullup = PMIC_GPIO_PULL_DISABLE;
+		if (pad->pullup != PMIC_GPIO_PULL_DISABLE)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_BIAS_PULL_UP:
-		arg = pad->pullup == PMIC_GPIO_PULL_UP_30;
+		if (pad->pullup != PMIC_GPIO_PULL_UP_30)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
-		arg = !pad->is_enabled;
+		if (pad->is_enabled)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_POWER_SOURCE:
 		arg = pad->power_source;
 		break;
 	case PIN_CONFIG_INPUT_ENABLE:
-		arg = pad->input_enabled;
+		if (!pad->input_enabled)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_OUTPUT:
 		arg = pad->out_value;