pinctrl: spmi-mpp: Fix pmic_mpp_config_get() to be compliant

[ Upstream commit 0d5b476f ]

If you look at "pinconf-groups" in debugfs for ssbi-mpp you'll notice
it looks like nonsense.

The problem is fairly well described in commit 1cf86bc2 ("pinctrl:
qcom: spmi-gpio: Fix pmic_gpio_config_get() to be compliant") and
commit 05e0c828 ("pinctrl: msm: Fix msm_config_group_get() to be
compliant"), but it was pointed out that ssbi-mpp has the same
problem.  Let's fix it there too.

NOTE: in case it's helpful to someone reading this, the way to tell
whether to do the -EINVAL or not is to look at the PCONFDUMP for a
given attribute.  If the last element (has_arg) is false then you need
to do the -EINVAL trick.

ALSO NOTE: it seems unlikely that the values returned when we try to
get PIN_CONFIG_BIAS_PULL_UP will actually be printed since "has_arg"
is false for that one, but I guess it's still fine to return different
values so I kept doing that.  It seems like another driver (ssbi-gpio)
uses a custom attribute (PM8XXX_QCOM_PULL_UP_STRENGTH) for something
similar so maybe a future change should do that here too.

Fixes: cfb24f6e ("pinctrl: Qualcomm SPMI PMIC MPP pin controller driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/pinctrl/qcom/pinctrl-spmi-mpp.c

@@ -345,13 +345,12 @@ static int pmic_mpp_config_get(struct pinctrl_dev *pctldev,
 
 	switch (param) {
 	case PIN_CONFIG_BIAS_DISABLE:
-		arg = pad->pullup == PMIC_MPP_PULL_UP_OPEN;
+		if (pad->pullup != PMIC_MPP_PULL_UP_OPEN)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_BIAS_PULL_UP:
 		switch (pad->pullup) {
-		case PMIC_MPP_PULL_UP_OPEN:
-			arg = 0;
-			break;
 		case PMIC_MPP_PULL_UP_0P6KOHM:
 			arg = 600;
 			break;
@@ -366,13 +365,17 @@ static int pmic_mpp_config_get(struct pinctrl_dev *pctldev,
 		}
 		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;
@@ -384,7 +387,9 @@ static int pmic_mpp_config_get(struct pinctrl_dev *pctldev,
 		arg = pad->amux_input;
 		break;
 	case PMIC_MPP_CONF_PAIRED:
-		arg = pad->paired;
+		if (!pad->paired)
+			return -EINVAL;
+		arg = 1;
 		break;
 	case PIN_CONFIG_DRIVE_STRENGTH:
 		arg = pad->drive_strength;