The eh bit is used for setting drive mode for i2c pins on recent SoCs.
Add support for it.

Signed-off-by: Igor Belwon <igor.belwon@mentallysanemainliners.org>
---
 drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 60 ++++++++++++++++++++++++
 drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h | 24 ++++++++++
 drivers/pinctrl/mediatek/pinctrl-paris.c         | 30 +++++++++---
 3 files changed, 108 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index 4918d38abfc29de1f27ee75bc6a51c32b3ca1ac5..51fbdbdf61c901bb7ee43405d36f2c1602b3616f 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -249,6 +249,58 @@ static int mtk_xt_find_eint_num(struct mtk_pinctrl *hw, unsigned long eint_n)
 	return EINT_NA;
 }
 
+/*
+ * The eh register determines the selection of the driving control
+ * for i2c pins.
+ * eh = 0: Non-i2c mode.
+ * eh = 1: i2c mode.
+ */
+int mtk_eh_ctrl(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
+		u16 mode)
+{
+	const struct mtk_eh_pin_pinmux *p = hw->soc->eh_pin_pinmux;
+	u32 eh_info_num = hw->soc->neh_pins;
+	u32 val = 0, on = 0, found = 0, i = 0;
+	int err;
+
+	while (i < eh_info_num) {
+		if (desc->number == p[i].pin) {
+			found = 1;
+			if (mode == p[i].pinmux) {
+				on = 1;
+				break;
+			}
+		}
+		/*
+		 * It is possible that one pin may have more than one pinmux
+		 *   that shall enable eh.
+		 * Besides, we assume that hw->soc->eh_pin_pinmux is sorted
+		 *   according to field 'pin'.
+		 * So when desc->number < p->pin, it mean no match will be
+		 *   found and we can leave.
+		 */
+		if (desc->number < p[i].pin)
+			break;
+
+		i++;
+	}
+
+	if (!found)
+		return 0;
+
+	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DRV_EH, &val);
+	if (err)
+		return err;
+
+	if (on)
+		val |= on;
+	else
+		val &= MTK_EH_ENABLE_MASK;
+
+	return mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DRV_EH, val);
+}
+EXPORT_SYMBOL_GPL(mtk_eh_ctrl);
+
 /*
  * Virtual GPIO only used inside SOC and not being exported to outside SOC.
  * Some modules use virtual GPIO as eint (e.g. pmif or usb).
@@ -1231,6 +1283,10 @@ int mtk_pinconf_adv_drive_set(struct mtk_pinctrl *hw,
 	int e0 = !!(arg & 2);
 	int e1 = !!(arg & 4);
 
+	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DRV_EH, arg);
+	if (!err)
+		return 0;
+
 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DRV_EN, en);
 	if (err)
 		return err;
@@ -1256,6 +1312,10 @@ int mtk_pinconf_adv_drive_get(struct mtk_pinctrl *hw,
 	u32 en, e0, e1;
 	int err;
 
+	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DRV_EH, val);
+	if (!err)
+		return 0;
+
 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DRV_EN, &en);
 	if (err)
 		return err;
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
index fa7c0ed49346486ba32ec615aa2b3483217f5077..a2ff8ae5ba43e5be87c8b478c07d9d4640c2e8ec 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
@@ -35,6 +35,8 @@
 				 MTK_PULL_PUPD_R1R0_TYPE |\
 				 MTK_PULL_RSEL_TYPE)
 
+#define MTK_EH_ENABLE_MASK	0xfffffffe
+
 #define EINT_NA	U16_MAX
 #define NO_EINT_SUPPORT	EINT_NA
 
@@ -67,6 +69,11 @@
 		.down_rsel = _down_rsel,				\
 	}
 
+#define PIN_MUX_EH(_pin, _pinmux) {						\
+		.pin = _pin,						\
+		.pinmux = _pinmux,					\
+	}
+
 /* List these attributes which could be modified for the pin */
 enum {
 	PINCTRL_PIN_REG_MODE,
@@ -88,6 +95,7 @@ enum {
 	PINCTRL_PIN_REG_IES,
 	PINCTRL_PIN_REG_PULLEN,
 	PINCTRL_PIN_REG_PULLSEL,
+	PINCTRL_PIN_REG_DRV_EH,
 	PINCTRL_PIN_REG_DRV_EN,
 	PINCTRL_PIN_REG_DRV_E0,
 	PINCTRL_PIN_REG_DRV_E1,
@@ -204,6 +212,17 @@ struct mtk_eint_desc {
 	u16 eint_n;
 };
 
+/**
+ * struct mtk_eh_pin_pinmux - entry recording (pin, pinmux) whose
+ *			      eh can be enabled
+ * @pin:                pin number
+ * @pinmux:             pinmux number
+ */
+struct mtk_eh_pin_pinmux {
+	u16 pin;
+	u16 pinmux;
+};
+
 /**
  * struct mtk_pin_desc - the structure that providing information
  *			       for each pin of chips
@@ -252,6 +271,8 @@ struct mtk_pin_soc {
 	const unsigned int		*pull_type;
 	const struct mtk_pin_rsel	*pin_rsel;
 	unsigned int			npin_rsel;
+	const struct mtk_eh_pin_pinmux  *eh_pin_pinmux;
+	unsigned int			neh_pins;
 
 	/* Specific pinconfig operations */
 	int (*bias_disable_set)(struct mtk_pinctrl *hw,
@@ -311,6 +332,9 @@ int mtk_hw_set_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
 int mtk_hw_get_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
 		     int field, int *value);
 
+int mtk_eh_ctrl(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
+		u16 mode);
+
 int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev);
 
 int mtk_pinconf_bias_disable_set(struct mtk_pinctrl *hw,
diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index 3e714554789d0e7e31ecce92388f53b906bdf122..f87447d6f879a3f7b57db44ed97cc91f8e93b425 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -104,13 +104,21 @@ static int mtk_pinmux_gpio_request_enable(struct pinctrl_dev *pctldev,
 					  struct pinctrl_gpio_range *range,
 					  unsigned int pin)
 {
+	int err;
 	struct mtk_pinctrl *hw = pinctrl_dev_get_drvdata(pctldev);
 	const struct mtk_pin_desc *desc;
 
 	desc = (const struct mtk_pin_desc *)&hw->soc->pins[pin];
 
-	return mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE,
-				hw->soc->gpio_m);
+	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE,
+			       hw->soc->gpio_m);
+	if (err)
+		return err;
+
+	if (hw->soc->eh_pin_pinmux)
+		err = mtk_eh_ctrl(hw, desc, hw->soc->gpio_m);
+
+	return err;
 }
 
 static int mtk_pinmux_gpio_set_direction(struct pinctrl_dev *pctldev,
@@ -749,10 +757,10 @@ static int mtk_pmx_set_mux(struct pinctrl_dev *pctldev,
 	struct mtk_pinctrl_group *grp = hw->groups + group;
 	const struct mtk_func_desc *desc_func;
 	const struct mtk_pin_desc *desc;
-	bool ret;
+	int err;
 
-	ret = mtk_pctrl_is_function_valid(hw, grp->pin, function);
-	if (!ret) {
+	err = mtk_pctrl_is_function_valid(hw, grp->pin, function);
+	if (!err) {
 		dev_err(hw->dev, "invalid function %d on group %d .\n",
 			function, group);
 		return -EINVAL;
@@ -763,7 +771,17 @@ static int mtk_pmx_set_mux(struct pinctrl_dev *pctldev,
 		return -EINVAL;
 
 	desc = (const struct mtk_pin_desc *)&hw->soc->pins[grp->pin];
-	return mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE, desc_func->muxval);
+
+	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE,
+			       desc_func->muxval);
+
+	if (!err)
+		return err;
+
+	if (hw->soc->eh_pin_pinmux)
+		err = mtk_eh_ctrl(hw, desc, desc_func->muxval);
+
+	return err;
 }
 
 static const struct pinmux_ops mtk_pmxops = {

-- 
2.51.0

Il 08/09/25 21:17, Igor Belwon ha scritto:
> The eh bit is used for setting drive mode for i2c pins on recent SoCs.
> Add support for it.
> 
> Signed-off-by: Igor Belwon <igor.belwon@mentallysanemainliners.org>

Noupe, this commit is not needed at all.

I get that this may be tricky to understand... but summarizing, what the
downstream calls "EH" in upstream is "DRV_ADV" :-)

Check the comments on patch [4/4] about how to change EH to DRV_ADV.

Cheers,
Angelo

On Tue Sep 9, 2025 at 9:57 AM CEST, AngeloGioacchino Del Regno wrote:
> Il 08/09/25 21:17, Igor Belwon ha scritto:
>> The eh bit is used for setting drive mode for i2c pins on recent SoCs.
>> Add support for it.
>> 
>> Signed-off-by: Igor Belwon <igor.belwon@mentallysanemainliners.org>
>
> Noupe, this commit is not needed at all.
>
> I get that this may be tricky to understand... but summarizing, what the
> downstream calls "EH" in upstream is "DRV_ADV" :-)
>
> Check the comments on patch [4/4] about how to change EH to DRV_ADV.
>
> Cheers,
> Angelo

Whoops, sorry, I don't know how I missed that.
Will change as in your comments and drop this commit.

Thanks,
Igor