pinctrl: Add pinconf support for BM1880 SoC

Add pinconf support for Bitmain BM1880 SoC. Pinconf support includes
pin bias, slew rate and schmitt trigger. Drive strength support will
be added later.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-bm1880.c

@@ -4,6 +4,8 @@
  *
  * Copyright (c) 2019 Linaro Ltd.
  * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ *
+ * TODO: Drive strength support
  */
 
 #include <linux/io.h>
@@ -872,6 +874,137 @@ static int bm1880_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
+#define BM1880_PINCONF(pin, idx) ((!((pin + 1) & 1) << 4) + idx)
+#define BM1880_PINCONF_PULLCTRL(pin)	BM1880_PINCONF(pin, 0)
+#define BM1880_PINCONF_PULLUP(pin)	BM1880_PINCONF(pin, 1)
+#define BM1880_PINCONF_PULLDOWN(pin)	BM1880_PINCONF(pin, 2)
+#define BM1880_PINCONF_SCHMITT(pin)	BM1880_PINCONF(pin, 9)
+#define BM1880_PINCONF_SLEW(pin)	BM1880_PINCONF(pin, 10)
+
+static int bm1880_pinconf_cfg_get(struct pinctrl_dev *pctldev,
+				  unsigned int pin,
+				  unsigned long *config)
+{
+	struct bm1880_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
+	unsigned int param = pinconf_to_config_param(*config);
+	unsigned int arg = 0;
+	u32 regval, offset, bit_offset;
+
+	offset = (pin >> 1) << 2;
+	regval = readl_relaxed(pctrl->base + BM1880_REG_MUX + offset);
+
+	switch (param) {
+	case PIN_CONFIG_BIAS_PULL_UP:
+		bit_offset = BM1880_PINCONF_PULLUP(pin);
+		arg = !!(regval & BIT(bit_offset));
+		break;
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		bit_offset = BM1880_PINCONF_PULLDOWN(pin);
+		arg = !!(regval & BIT(bit_offset));
+		break;
+	case PIN_CONFIG_BIAS_DISABLE:
+		bit_offset = BM1880_PINCONF_PULLCTRL(pin);
+		arg = !!(regval & BIT(bit_offset));
+		break;
+	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+		bit_offset = BM1880_PINCONF_SCHMITT(pin);
+		arg = !!(regval & BIT(bit_offset));
+		break;
+	case PIN_CONFIG_SLEW_RATE:
+		bit_offset = BM1880_PINCONF_SLEW(pin);
+		arg = !!(regval & BIT(bit_offset));
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	*config = pinconf_to_config_packed(param, arg);
+
+	return 0;
+}
+
+static int bm1880_pinconf_cfg_set(struct pinctrl_dev *pctldev,
+				  unsigned int pin,
+				  unsigned long *configs,
+				  unsigned int num_configs)
+{
+	struct bm1880_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
+	u32 regval, offset, bit_offset;
+	int i;
+
+	offset = (pin >> 1) << 2;
+	regval = readl_relaxed(pctrl->base + BM1880_REG_MUX + offset);
+
+	for (i = 0; i < num_configs; i++) {
+		unsigned int param = pinconf_to_config_param(configs[i]);
+		unsigned int arg = pinconf_to_config_argument(configs[i]);
+
+		switch (param) {
+		case PIN_CONFIG_BIAS_PULL_UP:
+			bit_offset = BM1880_PINCONF_PULLUP(pin);
+			regval |= BIT(bit_offset);
+			break;
+		case PIN_CONFIG_BIAS_PULL_DOWN:
+			bit_offset = BM1880_PINCONF_PULLDOWN(pin);
+			regval |= BIT(bit_offset);
+			break;
+		case PIN_CONFIG_BIAS_DISABLE:
+			bit_offset = BM1880_PINCONF_PULLCTRL(pin);
+			regval |= BIT(bit_offset);
+			break;
+		case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+			bit_offset = BM1880_PINCONF_SCHMITT(pin);
+			if (arg)
+				regval |= BIT(bit_offset);
+			else
+				regval &= ~BIT(bit_offset);
+			break;
+		case PIN_CONFIG_SLEW_RATE:
+			bit_offset = BM1880_PINCONF_SLEW(pin);
+			if (arg)
+				regval |= BIT(bit_offset);
+			else
+				regval &= ~BIT(bit_offset);
+			break;
+		default:
+			dev_warn(pctldev->dev,
+				 "unsupported configuration parameter '%u'\n",
+				 param);
+			continue;
+		}
+
+		writel_relaxed(regval, pctrl->base + BM1880_REG_MUX + offset);
+	}
+
+	return 0;
+}
+
+static int bm1880_pinconf_group_set(struct pinctrl_dev *pctldev,
+				    unsigned int selector,
+				    unsigned long *configs,
+				    unsigned int  num_configs)
+{
+	int i, ret;
+	struct bm1880_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
+	const struct bm1880_pctrl_group *pgrp = &pctrl->groups[selector];
+
+	for (i = 0; i < pgrp->npins; i++) {
+		ret = bm1880_pinconf_cfg_set(pctldev, pgrp->pins[i], configs,
+					     num_configs);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct pinconf_ops bm1880_pinconf_ops = {
+	.is_generic = true,
+	.pin_config_get = bm1880_pinconf_cfg_get,
+	.pin_config_set = bm1880_pinconf_cfg_set,
+	.pin_config_group_set = bm1880_pinconf_group_set,
+};
+
 static const struct pinmux_ops bm1880_pinmux_ops = {
 	.get_functions_count = bm1880_pmux_get_functions_count,
 	.get_function_name = bm1880_pmux_get_function_name,
@@ -885,6 +1018,7 @@ static struct pinctrl_desc bm1880_desc = {
 	.npins = ARRAY_SIZE(bm1880_pins),
 	.pctlops = &bm1880_pctrl_ops,
 	.pmxops = &bm1880_pinmux_ops,
+	.confops = &bm1880_pinconf_ops,
 	.owner = THIS_MODULE,
 };