pinctrl: rockchip：Add input schmitt support

To prevent external signal crosstalk, some pins need to
enable input schmitt, like i2c pins, 32k-input pin and so on.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/pinctrl-rockchip.c b/drivers/pinctrl/pinctrl-rockchip.c
index a838c8b..3723fd4 100644 (file)
--- a/drivers/pinctrl/pinctrl-rockchip.c
+++ b/drivers/pinctrl/pinctrl-rockchip.c
@@ -308,6 +308,9 @@ struct rockchip_pin_ctrl {
                                    int *reg, u8 *bit);
        void    (*iomux_recalc)(u8 bank_num, int pin, int *reg,
                                u8 *bit, int *mask);
+       int     (*schmitt_calc_reg)(struct rockchip_pin_bank *bank,
+                                   int pin_num, struct regmap **regmap,
+                                   int *reg, u8 *bit);
 };
 
 struct rockchip_pin_config {
@@ -1355,6 +1358,57 @@ static int rockchip_set_pull(struct rockchip_pin_bank *bank,
        return ret;
 }
 
+static int rockchip_get_schmitt(struct rockchip_pin_bank *bank, int pin_num)
+{
+       struct rockchip_pinctrl *info = bank->drvdata;
+       struct rockchip_pin_ctrl *ctrl = info->ctrl;
+       struct regmap *regmap;
+       int reg, ret;
+       u8 bit;
+       u32 data;
+
+       ret = ctrl->schmitt_calc_reg(bank, pin_num, &regmap, &reg, &bit);
+       if (ret)
+               return ret;
+
+       ret = regmap_read(regmap, reg, &data);
+       if (ret)
+               return ret;
+
+       data >>= bit;
+       return data & 0x1;
+}
+
+static int rockchip_set_schmitt(struct rockchip_pin_bank *bank,
+                               int pin_num, int enable)
+{
+       struct rockchip_pinctrl *info = bank->drvdata;
+       struct rockchip_pin_ctrl *ctrl = info->ctrl;
+       struct regmap *regmap;
+       int reg, ret;
+       unsigned long flags;
+       u8 bit;
+       u32 data, rmask;
+
+       dev_dbg(info->dev, "setting input schmitt of GPIO%d-%d to %d\n",
+               bank->bank_num, pin_num, enable);
+
+       ret = ctrl->schmitt_calc_reg(bank, pin_num, &regmap, &reg, &bit);
+       if (ret)
+               return ret;
+
+       spin_lock_irqsave(&bank->slock, flags);
+
+       /* enable the write to the equivalent lower bits */
+       data = BIT(bit + 16) | (enable << bit);
+       rmask = BIT(bit + 16) | BIT(bit);
+
+       ret = regmap_update_bits(regmap, reg, rmask, data);
+       spin_unlock_irqrestore(&bank->slock, flags);
+
+       return ret;
+}
+
 /*
  * Pinmux_ops handling
  */
@@ -1574,6 +1628,15 @@ static int rockchip_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
                        if (rc < 0)
                                return rc;
                        break;
+               case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+                       if (!info->ctrl->schmitt_calc_reg)
+                               return -ENOTSUPP;
+
+                       rc = rockchip_set_schmitt(bank,
+                                                 pin - bank->pin_base, arg);
+                       if (rc < 0)
+                               return rc;
+                       break;
                default:
                        return -ENOTSUPP;
                        break;
@@ -1634,6 +1697,16 @@ static int rockchip_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
 
                arg = rc;
                break;
+       case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+               if (!info->ctrl->schmitt_calc_reg)
+                       return -ENOTSUPP;
+
+               rc = rockchip_get_schmitt(bank, pin - bank->pin_base);
+               if (rc < 0)
+                       return rc;
+
+               arg = rc;
+               break;
        default:
                return -ENOTSUPP;
                break;