pinctrl: mediatek: support rsel feature

This patch supports rsel(resistance selection) feature for I2C pins.
It provides more resistance selection solution in different ICs.
It provides rsel define and si unit solution by identifying
"mediatek,rsel_resistance_in_si_unit" property in pio dtsi node.

Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20210924080632.28410-5-zhiyong.tao@mediatek.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 201 insertions, 30 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index 45ebdeba985a..91553b2fc160 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -661,6 +661,181 @@ out:
 	return err;
 }
 
+static int mtk_hw_pin_rsel_lookup(struct mtk_pinctrl *hw,
+				  const struct mtk_pin_desc *desc,
+				  u32 pullup, u32 arg, u32 *rsel_val)
+{
+	const struct mtk_pin_rsel *rsel;
+	int check;
+	bool found = false;
+
+	rsel = hw->soc->pin_rsel;
+
+	for (check = 0; check <= hw->soc->npin_rsel - 1; check++) {
+		if (desc->number >= rsel[check].s_pin &&
+		    desc->number <= rsel[check].e_pin) {
+			if (pullup) {
+				if (rsel[check].up_rsel == arg) {
+					found = true;
+					*rsel_val = rsel[check].rsel_index;
+					break;
+				}
+			} else {
+				if (rsel[check].down_rsel == arg) {
+					found = true;
+					*rsel_val = rsel[check].rsel_index;
+					break;
+				}
+			}
+		}
+	}
+
+	if (!found) {
+		dev_err(hw->dev, "Not support rsel value %d Ohm for pin = %d (%s)\n",
+			arg, desc->number, desc->name);
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static int mtk_pinconf_bias_set_rsel(struct mtk_pinctrl *hw,
+				     const struct mtk_pin_desc *desc,
+				     u32 pullup, u32 arg)
+{
+	int err, rsel_val;
+
+	if (hw->rsel_si_unit) {
+		/* find pin rsel_index from pin_rsel array*/
+		err = mtk_hw_pin_rsel_lookup(hw, desc, pullup, arg, &rsel_val);
+		if (err)
+			goto out;
+	} else {
+		if (arg < MTK_PULL_SET_RSEL_000 ||
+		    arg > MTK_PULL_SET_RSEL_111) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		rsel_val = arg - MTK_PULL_SET_RSEL_000;
+	}
+
+	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_RSEL, rsel_val);
+	if (err)
+		goto out;
+
+	err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, MTK_ENABLE);
+
+out:
+	return err;
+}
+
+int mtk_pinconf_bias_set_combo(struct mtk_pinctrl *hw,
+			       const struct mtk_pin_desc *desc,
+			       u32 pullup, u32 arg)
+{
+	int err = -ENOTSUPP;
+	u32 try_all_type;
+
+	if (hw->soc->pull_type)
+		try_all_type = hw->soc->pull_type[desc->number];
+	else
+		try_all_type = MTK_PULL_TYPE_MASK;
+
+	if (try_all_type & MTK_PULL_RSEL_TYPE) {
+		err = mtk_pinconf_bias_set_rsel(hw, desc, pullup, arg);
+		if (!err)
+			return err;
+	}
+
+	if (try_all_type & MTK_PULL_PU_PD_TYPE) {
+		err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, arg);
+		if (!err)
+			return err;
+	}
+
+	if (try_all_type & MTK_PULL_PULLSEL_TYPE) {
+		err = mtk_pinconf_bias_set_pullsel_pullen(hw, desc,
+							  pullup, arg);
+		if (!err)
+			return err;
+	}
+
+	if (try_all_type & MTK_PULL_PUPD_R1R0_TYPE)
+		err = mtk_pinconf_bias_set_pupd_r1_r0(hw, desc, pullup, arg);
+
+	if (err)
+		dev_err(hw->dev, "Invalid pull argument\n");
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(mtk_pinconf_bias_set_combo);
+
+static int mtk_rsel_get_si_unit(struct mtk_pinctrl *hw,
+				const struct mtk_pin_desc *desc,
+				u32 pullup, u32 rsel_val, u32 *si_unit)
+{
+	const struct mtk_pin_rsel *rsel;
+	int check;
+
+	rsel = hw->soc->pin_rsel;
+
+	for (check = 0; check <= hw->soc->npin_rsel - 1; check++) {
+		if (desc->number >= rsel[check].s_pin &&
+		    desc->number <= rsel[check].e_pin) {
+			if (rsel_val == rsel[check].rsel_index) {
+				if (pullup)
+					*si_unit = rsel[check].up_rsel;
+				else
+					*si_unit = rsel[check].down_rsel;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int mtk_pinconf_bias_get_rsel(struct mtk_pinctrl *hw,
+				     const struct mtk_pin_desc *desc,
+				     u32 *pullup, u32 *enable)
+{
+	int pu, pd, rsel, err;
+
+	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_RSEL, &rsel);
+	if (err)
+		goto out;
+
+	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PU, &pu);
+	if (err)
+		goto out;
+
+	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PD, &pd);
+
+	if (pu == 0 && pd == 0) {
+		*pullup = 0;
+		*enable = MTK_DISABLE;
+	} else if (pu == 1 && pd == 0) {
+		*pullup = 1;
+		if (hw->rsel_si_unit)
+			mtk_rsel_get_si_unit(hw, desc, *pullup, rsel, enable);
+		else
+			*enable = rsel + MTK_PULL_SET_RSEL_000;
+	} else if (pu == 0 && pd == 1) {
+		*pullup = 0;
+		if (hw->rsel_si_unit)
+			mtk_rsel_get_si_unit(hw, desc, *pullup, rsel, enable);
+		else
+			*enable = rsel + MTK_PULL_SET_RSEL_000;
+	} else {
+		err = -EINVAL;
+		goto out;
+	}
+
+out:
+	return err;
+}
+
 static int mtk_pinconf_bias_get_pu_pd(struct mtk_pinctrl *hw,
 				const struct mtk_pin_desc *desc,
 				u32 *pullup, u32 *enable)
@@ -742,44 +917,40 @@ out:
 	return err;
 }
 
-int mtk_pinconf_bias_set_combo(struct mtk_pinctrl *hw,
-				const struct mtk_pin_desc *desc,
-				u32 pullup, u32 arg)
-{
-	int err;
-
-	err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, arg);
-	if (!err)
-		goto out;
-
-	err = mtk_pinconf_bias_set_pullsel_pullen(hw, desc, pullup, arg);
-	if (!err)
-		goto out;
-
-	err = mtk_pinconf_bias_set_pupd_r1_r0(hw, desc, pullup, arg);
-
-out:
-	return err;
-}
-EXPORT_SYMBOL_GPL(mtk_pinconf_bias_set_combo);
-
 int mtk_pinconf_bias_get_combo(struct mtk_pinctrl *hw,
 			      const struct mtk_pin_desc *desc,
 			      u32 *pullup, u32 *enable)
 {
-	int err;
+	int err = -ENOTSUPP;
+	u32 try_all_type;
 
-	err = mtk_pinconf_bias_get_pu_pd(hw, desc, pullup, enable);
-	if (!err)
-		goto out;
+	if (hw->soc->pull_type)
+		try_all_type = hw->soc->pull_type[desc->number];
+	else
+		try_all_type = MTK_PULL_TYPE_MASK;
 
-	err = mtk_pinconf_bias_get_pullsel_pullen(hw, desc, pullup, enable);
-	if (!err)
-		goto out;
+	if (try_all_type & MTK_PULL_RSEL_TYPE) {
+		err = mtk_pinconf_bias_get_rsel(hw, desc, pullup, enable);
+		if (!err)
+			return err;
+	}
 
-	err = mtk_pinconf_bias_get_pupd_r1_r0(hw, desc, pullup, enable);
+	if (try_all_type & MTK_PULL_PU_PD_TYPE) {
+		err = mtk_pinconf_bias_get_pu_pd(hw, desc, pullup, enable);
+		if (!err)
+			return err;
+	}
+
+	if (try_all_type & MTK_PULL_PULLSEL_TYPE) {
+		err = mtk_pinconf_bias_get_pullsel_pullen(hw, desc,
+							  pullup, enable);
+		if (!err)
+			return err;
+	}
+
+	if (try_all_type & MTK_PULL_PUPD_R1R0_TYPE)
+		err = mtk_pinconf_bias_get_pupd_r1_r0(hw, desc, pullup, enable);
 
-out:
 	return err;
 }
 EXPORT_SYMBOL_GPL(mtk_pinconf_bias_get_combo);