pinctrl: mediatek: Backward compatible to previous Mediatek's bias-pull usage

Refine mtk_pinconf_set()/mtk_pinconf_get() for backward compatibility to
previous MediaTek's bias-pull usage.
In PINCTRL_MTK that use pinctrl-mtk-common.c, bias-pull setting for pins
with 2 pull resistors can be specified as value for bias-pull-up and
bias-pull-down. For example:
    bias-pull-up = <MTK_PUPD_SET_R1R0_00>;
    bias-pull-up = <MTK_PUPD_SET_R1R0_01>;
    bias-pull-up = <MTK_PUPD_SET_R1R0_10>;
    bias-pull-up = <MTK_PUPD_SET_R1R0_11>;
    bias-pull-down = <MTK_PUPD_SET_R1R0_00>;
    bias-pull-down = <MTK_PUPD_SET_R1R0_01>;
    bias-pull-down = <MTK_PUPD_SET_R1R0_10>;
    bias-pull-down = <MTK_PUPD_SET_R1R0_11>;

On the other hand, PINCTRL_MTK_PARIS use customized properties
"mediatek,pull-up-adv" and "mediatek,pull-down-adv" to specify bias-pull
setting for pins with 2 pull resistors.
This introduce in-compatibility in device tree and increase porting
effort to MediaTek's customer that had already used PINCTRL_MTK version.
Besides, if customers are not aware of this change and still write devicetree
for PINCTRL_MTK version, they may encounter runtime failure with pinctrl and
spent time to debug.

This patch adds backward compatible to previous MediaTek's bias-pull usage
so that Mediatek's customer need not use a new devicetree property name.
The rationale is that: changing driver implementation had better leave
interface unchanged.

Signed-off-by: Light Hsieh <light.hsieh@mediatek.com>
Link: https://lore.kernel.org/r/1579675994-7001-5-git-send-email-light.hsieh@mediatek.com
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 29 insertions, 20 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index d09a726beece..115ebc19fc44 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -78,7 +78,7 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev,
 {
 	struct mtk_pinctrl *hw = pinctrl_dev_get_drvdata(pctldev);
 	u32 param = pinconf_to_config_param(*config);
-	int err, reg, ret = 1;
+	int pullup, err, reg, ret = 1;
 	const struct mtk_pin_desc *desc;
 
 	if (pin >= hw->soc->npins) {
@@ -89,22 +89,31 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev,
 
 	switch (param) {
 	case PIN_CONFIG_BIAS_DISABLE:
-		if (hw->soc->bias_disable_get)
-			err = hw->soc->bias_disable_get(hw, desc, &ret);
-		else
-			err = -ENOTSUPP;
-		break;
 	case PIN_CONFIG_BIAS_PULL_UP:
-		if (hw->soc->bias_get)
-			err = hw->soc->bias_get(hw, desc, 1, &ret);
-		else
-			err = -ENOTSUPP;
-		break;
 	case PIN_CONFIG_BIAS_PULL_DOWN:
-		if (hw->soc->bias_get)
-			err = hw->soc->bias_get(hw, desc, 0, &ret);
-		else
+		if (hw->soc->bias_get_combo) {
+			err = hw->soc->bias_get_combo(hw, desc, &pullup, &ret);
+			if (err)
+				goto out;
+			if (param == PIN_CONFIG_BIAS_DISABLE) {
+				if (ret == MTK_PUPD_SET_R1R0_00)
+					ret = MTK_DISABLE;
+			} else if (param == PIN_CONFIG_BIAS_PULL_UP) {
+				/* When desire to get pull-up value, return
+				 *  error if current setting is pull-down
+				 */
+				if (!pullup)
+					err = -EINVAL;
+			} else if (param == PIN_CONFIG_BIAS_PULL_DOWN) {
+				/* When desire to get pull-down value, return
+				 *  error if current setting is pull-up
+				 */
+				if (pullup)
+					err = -EINVAL;
+			}
+		} else {
 			err = -ENOTSUPP;
+		}
 		break;
 	case PIN_CONFIG_SLEW_RATE:
 		err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_SR, &ret);
@@ -196,20 +205,20 @@ static int mtk_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
 
 	switch ((u32)param) {
 	case PIN_CONFIG_BIAS_DISABLE:
-		if (hw->soc->bias_disable_set)
-			err = hw->soc->bias_disable_set(hw, desc);
+		if (hw->soc->bias_set_combo)
+			err = hw->soc->bias_set_combo(hw, desc, 0, MTK_DISABLE);
 		else
 			err = -ENOTSUPP;
 		break;
 	case PIN_CONFIG_BIAS_PULL_UP:
-		if (hw->soc->bias_set)
-			err = hw->soc->bias_set(hw, desc, 1);
+		if (hw->soc->bias_set_combo)
+			err = hw->soc->bias_set_combo(hw, desc, 1, arg);
 		else
 			err = -ENOTSUPP;
 		break;
 	case PIN_CONFIG_BIAS_PULL_DOWN:
-		if (hw->soc->bias_set)
-			err = hw->soc->bias_set(hw, desc, 0);
+		if (hw->soc->bias_set_combo)
+			err = hw->soc->bias_set_combo(hw, desc, 0, arg);
 		else
 			err = -ENOTSUPP;
 		break;