pinctrl: mediatek: add driving strength related support to pinctrl-mtk-common-v2.c

Put driving strength support related functions to pinctrl-mtk-common-v2.c
as these operations might be different by chips and allow different type
of driver to reuse them.

Signed-off-by: Ryder.Lee <ryder.lee@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index 2a168043a6f0..886b40ec3b3f 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -13,6 +13,32 @@
 
 #include "pinctrl-mtk-common-v2.h"
 
+/**
+ * struct mtk_drive_desc - the structure that holds the information
+ *			    of the driving current
+ * @min:	the minimum current of this group
+ * @max:	the maximum current of this group
+ * @step:	the step current of this group
+ * @scal:	the weight factor
+ *
+ * formula: output = ((input) / step - 1) * scal
+ */
+struct mtk_drive_desc {
+	u8 min;
+	u8 max;
+	u8 step;
+	u8 scal;
+};
+
+/* The groups of drive strength */
+const struct mtk_drive_desc mtk_drive[] = {
+	[DRV_GRP0] = { 4, 16, 4, 1 },
+	[DRV_GRP1] = { 4, 16, 4, 2 },
+	[DRV_GRP2] = { 2, 8, 2, 1 },
+	[DRV_GRP3] = { 2, 8, 2, 2 },
+	[DRV_GRP4] = { 2, 16, 2, 1 },
+};
+
 static void mtk_w32(struct mtk_pinctrl *pctl, u32 reg, u32 val)
 {
 	writel_relaxed(val, pctl->base + reg);
@@ -163,3 +189,56 @@ int mtk_hw_get_value(struct mtk_pinctrl *hw, int pin, int field, int *value)
 
 	return 0;
 }
+
+/* Revision 0 */
+int mtk_pinconf_drive_set(struct mtk_pinctrl *hw,
+			  const struct mtk_pin_desc *desc, u32 arg)
+{
+	const struct mtk_drive_desc *tb;
+	int err = -ENOTSUPP;
+
+	tb = &mtk_drive[desc->drv_n];
+	/* 4mA when (e8, e4) = (0, 0)
+	 * 8mA when (e8, e4) = (0, 1)
+	 * 12mA when (e8, e4) = (1, 0)
+	 * 16mA when (e8, e4) = (1, 1)
+	 */
+	if ((arg >= tb->min && arg <= tb->max) && !(arg % tb->step)) {
+		arg = (arg / tb->step - 1) * tb->scal;
+		err = mtk_hw_set_value(hw, desc->number, PINCTRL_PIN_REG_E4,
+				       arg & 0x1);
+		if (err)
+			return err;
+
+		err = mtk_hw_set_value(hw, desc->number, PINCTRL_PIN_REG_E8,
+				       (arg & 0x2) >> 1);
+		if (err)
+			return err;
+	}
+
+	return err;
+}
+
+int mtk_pinconf_drive_get(struct mtk_pinctrl *hw,
+			  const struct mtk_pin_desc *desc, int *val)
+{
+	const struct mtk_drive_desc *tb;
+	int err, val1, val2;
+
+	tb = &mtk_drive[desc->drv_n];
+
+	err = mtk_hw_get_value(hw, desc->number, PINCTRL_PIN_REG_E4, &val1);
+	if (err)
+		return err;
+
+	err = mtk_hw_get_value(hw, desc->number, PINCTRL_PIN_REG_E8, &val2);
+	if (err)
+		return err;
+
+	/* 4mA when (e8, e4) = (0, 0); 8mA when (e8, e4) = (0, 1)
+	 * 12mA when (e8, e4) = (1, 0); 16mA when (e8, e4) = (1, 1)
+	 */
+	*val = (((val2 << 1) + val1) / tb->scal + 1) * tb->step;
+
+	return 0;
+}