regulator: Introduce tps68470-regulator driver

The TPS68470 PMIC provides Clocks, GPIOs and Regulators. At present in
the kernel the Regulators and Clocks are controlled by an OpRegion
driver designed to work with power control methods defined in ACPI, but
some platforms lack those methods, meaning drivers need to be able to
consume the resources of these chips through the usual frameworks.

This commit adds a driver for the regulators provided by the tps68470,
and is designed to bind to the platform_device registered by the
intel_skl_int3472 module.

This is based on this out of tree driver written by Intel:
https://github.com/intel/linux-intel-lts/blob/4.14/base/drivers/regulator/tps68470-regulator.c
with various cleanups added.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/regulator/Kconfig

@@ -1339,6 +1339,15 @@ config REGULATOR_TPS65912
 	help
 	    This driver supports TPS65912 voltage regulator chip.
 
+config REGULATOR_TPS68470
+	tristate "TI TPS68370 PMIC Regulators Driver"
+	depends on INTEL_SKL_INT3472 || COMPILE_TEST
+	help
+	  This driver adds support for the TPS68470 PMIC to register
+	  regulators against the usual framework.
+
+	  The module will be called "tps68470-regulator".
+
 config REGULATOR_TPS80031
 	tristate "TI TPS80031/TPS80032 power regulator driver"
 	depends on MFD_TPS80031

drivers/regulator/Makefile

@@ -158,6 +158,7 @@ obj-$(CONFIG_REGULATOR_TPS6524X) += tps6524x-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6586X) += tps6586x-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65910) += tps65910-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65912) += tps65912-regulator.o
+obj-$(CONFIG_REGULATOR_TPS68470) += tps68470-regulator.o
 obj-$(CONFIG_REGULATOR_TPS80031) += tps80031-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65132) += tps65132-regulator.o
 obj-$(CONFIG_REGULATOR_TWL4030) += twl-regulator.o twl6030-regulator.o

drivers/regulator/tps68470-regulator.c

@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Regulator driver for TPS68470 PMIC
+//
+// Copyright (c) 2021 Red Hat Inc.
+// Copyright (C) 2018 Intel Corporation
+//
+// Authors:
+//	Hans de Goede <hdegoede@redhat.com>
+//	Zaikuo Wang <zaikuo.wang@intel.com>
+//	Tianshu Qiu <tian.shu.qiu@intel.com>
+//	Jian Xu Zheng <jian.xu.zheng@intel.com>
+//	Yuning Pu <yuning.pu@intel.com>
+//	Rajmohan Mani <rajmohan.mani@intel.com>
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/tps68470.h>
+#include <linux/module.h>
+#include <linux/platform_data/tps68470.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+
+struct tps68470_regulator_data {
+	struct clk *clk;
+};
+
+#define TPS68470_REGULATOR(_name, _id, _ops, _n, _vr,			\
+			   _vm, _er, _em, _t, _lr, _nlr)		\
+	[TPS68470_ ## _name] = {					\
+		.name			= # _name,			\
+		.id			= _id,				\
+		.ops			= &_ops,			\
+		.n_voltages		= _n,				\
+		.type			= REGULATOR_VOLTAGE,		\
+		.owner			= THIS_MODULE,			\
+		.vsel_reg		= _vr,				\
+		.vsel_mask		= _vm,				\
+		.enable_reg		= _er,				\
+		.enable_mask		= _em,				\
+		.volt_table		= _t,				\
+		.linear_ranges		= _lr,				\
+		.n_linear_ranges	= _nlr,				\
+	}
+
+static const struct linear_range tps68470_ldo_ranges[] = {
+	REGULATOR_LINEAR_RANGE(875000, 0, 125, 17800),
+};
+
+static const struct linear_range tps68470_core_ranges[] = {
+	REGULATOR_LINEAR_RANGE(900000, 0, 42, 25000),
+};
+
+int tps68470_regulator_enable(struct regulator_dev *rdev)
+{
+	struct tps68470_regulator_data *data = rdev->reg_data;
+	int ret;
+
+	/* The Core buck regulator needs the PMIC's PLL to be enabled */
+	if (rdev->desc->id == TPS68470_CORE) {
+		ret = clk_prepare_enable(data->clk);
+		if (ret) {
+			dev_err(&rdev->dev, "Error enabling TPS68470 clock\n");
+			return ret;
+		}
+	}
+
+	return regulator_enable_regmap(rdev);
+}
+
+int tps68470_regulator_disable(struct regulator_dev *rdev)
+{
+	struct tps68470_regulator_data *data = rdev->reg_data;
+
+	if (rdev->desc->id == TPS68470_CORE)
+		clk_disable_unprepare(data->clk);
+
+	return regulator_disable_regmap(rdev);
+}
+
+/* Operations permitted on DCDCx, LDO2, LDO3 and LDO4 */
+static const struct regulator_ops tps68470_regulator_ops = {
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= tps68470_regulator_enable,
+	.disable		= tps68470_regulator_disable,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.map_voltage		= regulator_map_voltage_linear_range,
+};
+
+static const struct regulator_desc regulators[] = {
+	TPS68470_REGULATOR(CORE, TPS68470_CORE,
+			   tps68470_regulator_ops, 43, TPS68470_REG_VDVAL,
+			   TPS68470_VDVAL_DVOLT_MASK, TPS68470_REG_VDCTL,
+			   TPS68470_VDCTL_EN_MASK,
+			   NULL, tps68470_core_ranges,
+			   ARRAY_SIZE(tps68470_core_ranges)),
+	TPS68470_REGULATOR(ANA, TPS68470_ANA,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VAVAL,
+			   TPS68470_VAVAL_AVOLT_MASK, TPS68470_REG_VACTL,
+			   TPS68470_VACTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+	TPS68470_REGULATOR(VCM, TPS68470_VCM,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VCMVAL,
+			   TPS68470_VCMVAL_VCVOLT_MASK, TPS68470_REG_VCMCTL,
+			   TPS68470_VCMCTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+	TPS68470_REGULATOR(VIO, TPS68470_VIO,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VIOVAL,
+			   TPS68470_VIOVAL_IOVOLT_MASK, TPS68470_REG_S_I2C_CTL,
+			   TPS68470_S_I2C_CTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+
+/*
+ * (1) This register must have same setting as VIOVAL if S_IO LDO is used to
+ *     power daisy chained IOs in the receive side.
+ * (2) If there is no I2C daisy chain it can be set freely.
+ *
+ */
+	TPS68470_REGULATOR(VSIO, TPS68470_VSIO,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VSIOVAL,
+			   TPS68470_VSIOVAL_IOVOLT_MASK, TPS68470_REG_S_I2C_CTL,
+			   TPS68470_S_I2C_CTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+	TPS68470_REGULATOR(AUX1, TPS68470_AUX1,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VAUX1VAL,
+			   TPS68470_VAUX1VAL_AUX1VOLT_MASK,
+			   TPS68470_REG_VAUX1CTL,
+			   TPS68470_VAUX1CTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+	TPS68470_REGULATOR(AUX2, TPS68470_AUX2,
+			   tps68470_regulator_ops, 126, TPS68470_REG_VAUX2VAL,
+			   TPS68470_VAUX2VAL_AUX2VOLT_MASK,
+			   TPS68470_REG_VAUX2CTL,
+			   TPS68470_VAUX2CTL_EN_MASK,
+			   NULL, tps68470_ldo_ranges,
+			   ARRAY_SIZE(tps68470_ldo_ranges)),
+};
+
+static int tps68470_regulator_probe(struct platform_device *pdev)
+{
+	struct tps68470_regulator_platform_data *pdata = pdev->dev.platform_data;
+	struct tps68470_regulator_data *data;
+	struct regulator_config config = { };
+	struct regulator_dev *rdev;
+	int i;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk = devm_clk_get(&pdev->dev, "tps68470-clk");
+	if (IS_ERR(data->clk)) {
+		dev_err(&pdev->dev, "Error getting tps68470-clk\n");
+		return PTR_ERR(data->clk);
+	}
+
+	config.dev = pdev->dev.parent;
+	config.regmap = dev_get_drvdata(pdev->dev.parent);
+	config.driver_data = data;
+
+	for (i = 0; i < TPS68470_NUM_REGULATORS; i++) {
+		if (pdata)
+			config.init_data = pdata->reg_init_data[i];
+		else
+			config.init_data = NULL;
+
+		rdev = devm_regulator_register(&pdev->dev, &regulators[i], &config);
+		if (IS_ERR(rdev)) {
+			dev_err(&pdev->dev, "failed to register %s regulator\n",
+				regulators[i].name);
+			return PTR_ERR(rdev);
+		}
+	}
+
+	return 0;
+}
+
+static struct platform_driver tps68470_regulator_driver = {
+	.driver = {
+		.name = "tps68470-regulator",
+	},
+	.probe = tps68470_regulator_probe,
+};
+
+/*
+ * The ACPI tps68470 probe-ordering depends on the clk/gpio/regulator drivers
+ * registering before the drivers for the camera-sensors which use them bind.
+ * subsys_initcall() ensures this when the drivers are builtin.
+ */
+static int __init tps68470_regulator_init(void)
+{
+	return platform_driver_register(&tps68470_regulator_driver);
+}
+subsys_initcall(tps68470_regulator_init);
+
+static void __exit tps68470_regulator_exit(void)
+{
+	platform_driver_unregister(&tps68470_regulator_driver);
+}
+module_exit(tps68470_regulator_exit);
+
+MODULE_ALIAS("platform:tps68470-regulator");
+MODULE_DESCRIPTION("TPS68470 voltage regulator driver");
+MODULE_LICENSE("GPL v2");