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, 46 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
index a6f1bdb2083b..23688ca6d04e 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
@@ -17,6 +17,22 @@
 #define MTK_ENABLE     1
 #define MTK_PULLDOWN   0
 #define MTK_PULLUP     1
+#define MTK_PULL_PU_PD_TYPE		BIT(0)
+#define MTK_PULL_PULLSEL_TYPE		BIT(1)
+#define MTK_PULL_PUPD_R1R0_TYPE		BIT(2)
+/* MTK_PULL_RSEL_TYPE can select resistance and can be
+ * turned on/off itself. But it can't be selected pull up/down
+ */
+#define MTK_PULL_RSEL_TYPE		BIT(3)
+/* MTK_PULL_PU_PD_RSEL_TYPE is a type which is controlled by
+ * MTK_PULL_PU_PD_TYPE and MTK_PULL_RSEL_TYPE.
+ */
+#define MTK_PULL_PU_PD_RSEL_TYPE	(MTK_PULL_PU_PD_TYPE \
+					| MTK_PULL_RSEL_TYPE)
+#define MTK_PULL_TYPE_MASK	(MTK_PULL_PU_PD_TYPE |\
+				 MTK_PULL_PULLSEL_TYPE |\
+				 MTK_PULL_PUPD_R1R0_TYPE |\
+				 MTK_PULL_RSEL_TYPE)
 
 #define EINT_NA	U16_MAX
 #define NO_EINT_SUPPORT	EINT_NA
@@ -42,6 +58,14 @@
 	PIN_FIELD_CALC(_s_pin, _e_pin, 0, _s_addr, _x_addrs, _s_bit,	\
 		       _x_bits, 32, 1)
 
+#define PIN_RSEL(_s_pin, _e_pin, _rsel_index, _up_resl, _down_rsel) {	\
+		.s_pin = _s_pin,					\
+		.e_pin = _e_pin,					\
+		.rsel_index = _rsel_index,				\
+		.up_rsel = _up_resl,					\
+		.down_rsel = _down_rsel,				\
+	}
+
 /* List these attributes which could be modified for the pin */
 enum {
 	PINCTRL_PIN_REG_MODE,
@@ -67,6 +91,7 @@ enum {
 	PINCTRL_PIN_REG_DRV_E0,
 	PINCTRL_PIN_REG_DRV_E1,
 	PINCTRL_PIN_REG_DRV_ADV,
+	PINCTRL_PIN_REG_RSEL,
 	PINCTRL_PIN_REG_MAX,
 };
 
@@ -129,6 +154,22 @@ struct mtk_pin_field_calc {
 	u8  fixed;
 };
 
+/**
+ * struct mtk_pin_rsel - the structure that provides bias resistance selection.
+ * @s_pin:		the start pin within the rsel range
+ * @e_pin:		the end pin within the rsel range
+ * @rsel_index:	the rsel bias resistance index
+ * @up_rsel:	the pullup rsel bias resistance value
+ * @down_rsel:	the pulldown rsel bias resistance value
+ */
+struct mtk_pin_rsel {
+	u16 s_pin;
+	u16 e_pin;
+	u16 rsel_index;
+	u32 up_rsel;
+	u32 down_rsel;
+};
+
 /* struct mtk_pin_reg_calc - the structure that holds all ranges used to
  *			     determine which register the pin would make use of
  *			     for certain pin attribute.
@@ -206,6 +247,9 @@ struct mtk_pin_soc {
 	bool				ies_present;
 	const char * const		*base_names;
 	unsigned int			nbase_names;
+	const unsigned int		*pull_type;
+	const struct mtk_pin_rsel	*pin_rsel;
+	unsigned int			npin_rsel;
 
 	/* Specific pinconfig operations */
 	int (*bias_disable_set)(struct mtk_pinctrl *hw,
@@ -254,6 +298,8 @@ struct mtk_pinctrl {
 	const char          **grp_names;
 	/* lock pin's register resource to avoid multiple threads issue*/
 	spinlock_t lock;
+	/* identify rsel setting by si unit or rsel define in dts node */
+	bool rsel_si_unit;
 };
 
 void mtk_rmw(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 mask, u32 set);