[PATCH v2] power: regulator: Add support for NPCM8xx

[Jim Liu]

Add support for setting nuvoton BMC NPCM845 voltage supply.

Signed-off-by: Jim Liu <JJLIU0 at nuvoton.com>
---
Changes for v2:
   - modify Kconfig description
   - modify get_value function
---
 drivers/power/regulator/Kconfig             |   8 ++
 drivers/power/regulator/Makefile            |   1 +
 drivers/power/regulator/npcm8xx_regulator.c | 132 ++++++++++++++++++++
 3 files changed, 141 insertions(+)
 create mode 100644 drivers/power/regulator/npcm8xx_regulator.c

diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index c519e066ef..c02e6377d8 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -128,6 +128,14 @@ config DM_REGULATOR_MAX77686
 	features for REGULATOR MAX77686. The driver implements get/set api for:
 	value, enable and mode.
 
+config DM_REGULATOR_NPCM8XX
+	bool "Enable Driver Model for NPCM8xx voltage supply"
+	depends on DM_REGULATOR && ARCH_NPCM8XX
+	help
+	  Enable support for configuring voltage supply on NPCM8XX SoC. The
+	  voltage supplies support two voltage levels and the driver implements
+	  get/set api for setting the value.
+
 config DM_REGULATOR_FAN53555
 	bool "Enable Driver Model for REGULATOR FAN53555"
 	depends on DM_PMIC_FAN53555
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index bc736068bc..68e4c0f9dd 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_REGULATOR_ACT8846) += act8846.o
 obj-$(CONFIG_REGULATOR_AS3722)	+= as3722_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_DA9063) += da9063.o
 obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
+obj-$(CONFIG_DM_REGULATOR_NPCM8XX) += npcm8xx_regulator.o
 obj-$(CONFIG_$(SPL_)DM_PMIC_PFUZE100) += pfuze100.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_BD71837) += bd71837.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_PCA9450) += pca9450.o
diff --git a/drivers/power/regulator/npcm8xx_regulator.c b/drivers/power/regulator/npcm8xx_regulator.c
new file mode 100644
index 0000000000..fcd1058cdf
--- /dev/null
+++ b/drivers/power/regulator/npcm8xx_regulator.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Nuvoton Technology Corp.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <power/regulator.h>
+
+#define REG_VSRCR	0xf08000e8	/* Voltage Supply Control Register */
+
+/* Supported voltage levels (uV) */
+static const u32 volts_type1[] = { 3300000, 1800000 };
+static const u32 volts_type2[] = { 1000000, 1800000 };
+#define VOLT_LEV0	0
+#define VOLT_LEV1	1
+
+struct volt_supply {
+	char *name;
+	const u32 *volts;
+	u32 reg_shift;	/* Register bit offset for setting voltage */
+};
+
+static const struct volt_supply npcm8xx_volt_supps[] = {
+	{"v1", volts_type1, 0},
+	{"v2", volts_type1, 1},
+	{"v3", volts_type1, 2},
+	{"v4", volts_type1, 3},
+	{"v5", volts_type1, 4},
+	{"v6", volts_type1, 5},
+	{"v7", volts_type1, 6},
+	{"v8", volts_type1, 7},
+	{"v9", volts_type1, 8},
+	{"v10", volts_type1, 9},
+	{"v11", volts_type2, 10},
+	{"v12", volts_type1, 11},
+	{"v13", volts_type1, 12},
+	{"v14", volts_type2, 13},
+	{"vsif", volts_type1, 14},
+	{"vr2", volts_type1, 30},
+};
+
+static const struct volt_supply *npcm8xx_volt_supply_get(const char *name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(npcm8xx_volt_supps); i++) {
+		if (!strcmp(npcm8xx_volt_supps[i].name, name))
+			return &npcm8xx_volt_supps[i];
+	}
+
+	return NULL;
+}
+
+static int npcm8xx_regulator_set_value(struct udevice *dev, int uV)
+{
+	struct dm_regulator_uclass_plat *uc_pdata;
+	const struct volt_supply *supp;
+	u32 val, level;
+
+	uc_pdata = dev_get_uclass_plat(dev);
+	if (!uc_pdata)
+		return -ENXIO;
+
+	dev_dbg(dev, "%s set_value: %d\n", uc_pdata->name, uV);
+	supp = npcm8xx_volt_supply_get(uc_pdata->name);
+	if (!supp)
+		return -ENOENT;
+
+	if (uV == supp->volts[VOLT_LEV0])
+		level = VOLT_LEV0;
+	else if (uV == supp->volts[VOLT_LEV1])
+		level = VOLT_LEV1;
+	else
+		return -EINVAL;
+
+	/* Set voltage level */
+	val = readl(REG_VSRCR);
+	val &= ~BIT(supp->reg_shift);
+	val |= level << supp->reg_shift;
+	writel(val, REG_VSRCR);
+
+	return 0;
+}
+
+static int npcm8xx_regulator_get_value(struct udevice *dev)
+{
+	struct dm_regulator_uclass_plat *uc_pdata;
+	const struct volt_supply *supp;
+	u32 val;
+
+	uc_pdata = dev_get_uclass_plat(dev);
+	if (!uc_pdata)
+		return -ENXIO;
+
+	supp = npcm8xx_volt_supply_get(uc_pdata->name);
+	if (!supp)
+		return -ENOENT;
+
+	val = readl(REG_VSRCR) & BIT(supp->reg_shift);
+
+	dev_dbg(dev, "%s get_value: %d\n", uc_pdata->name,
+		val ? supp->volts[VOLT_LEV1] : supp->volts[VOLT_LEV0]);
+
+	return val ? supp->volts[VOLT_LEV1] : supp->volts[VOLT_LEV0];
+}
+
+static int npcm8xx_regulator_set_enable(struct udevice *dev, bool enable)
+{
+	/* Always on */
+	return 0;
+}
+
+static const struct dm_regulator_ops npcm8xx_regulator_ops = {
+	.set_value	= npcm8xx_regulator_set_value,
+	.get_value	= npcm8xx_regulator_get_value,
+	.set_enable	= npcm8xx_regulator_set_enable,
+};
+
+static const struct udevice_id npcm8xx_regulator_ids[] = {
+	{ .compatible = "regulator-npcm845" },
+	{ },
+};
+
+U_BOOT_DRIVER(regulator_npcm8xx) = {
+	.name = "regulator_npcm845",
+	.id = UCLASS_REGULATOR,
+	.ops = &npcm8xx_regulator_ops,
+	.of_match = npcm8xx_regulator_ids,
+};
-- 
2.17.1