regulator: add IPQ4019 SDHCI VQMMC LDO driver

This introduces the IPQ4019 VQMMC LDO driver needed for
the SD/EMMC driver I/O level operation.
This will enable introducing SD/EMMC support for the built-in controller.

Signed-off-by: Mantas Pucka <mantas@8devices.com>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Link: https://lore.kernel.org/r/20200112113003.11110-1-robert.marko@sartura.hr
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -1110,6 +1110,13 @@ config REGULATOR_VEXPRESS
 	  This driver provides support for voltage regulators available
 	  on the ARM Ltd's Versatile Express platform.
 
+config REGULATOR_VQMMC_IPQ4019
+	tristate "IPQ4019 VQMMC SD LDO regulator support"
+	depends on ARCH_QCOM
+	help
+	  This driver provides support for the VQMMC LDO I/0
+	  voltage regulator of the IPQ4019 SD/EMMC controller.
+
 config REGULATOR_WM831X
 	tristate "Wolfson Microelectronics WM831x PMIC regulators"
 	depends on MFD_WM831X

drivers/regulator/Makefile

@@ -135,6 +135,7 @@ obj-$(CONFIG_REGULATOR_TWL4030) += twl-regulator.o twl6030-regulator.o
 obj-$(CONFIG_REGULATOR_UNIPHIER) += uniphier-regulator.o
 obj-$(CONFIG_REGULATOR_VCTRL) += vctrl-regulator.o
 obj-$(CONFIG_REGULATOR_VEXPRESS) += vexpress-regulator.o
+obj-$(CONFIG_REGULATOR_VQMMC_IPQ4019) += vqmmc-ipq4019-regulator.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-dcdc.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-isink.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-ldo.o

drivers/regulator/vqmmc-ipq4019-regulator.c

@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright (c) 2019 Mantas Pucka <mantas@8devices.com>
+// Copyright (c) 2019 Robert Marko <robert.marko@sartura.hr>
+//
+// Driver for IPQ4019 SD/MMC controller's I/O LDO voltage regulator
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+
+static const unsigned int ipq4019_vmmc_voltages[] = {
+	1500000, 1800000, 2500000, 3000000,
+};
+
+static struct regulator_ops ipq4019_regulator_voltage_ops = {
+	.list_voltage = regulator_list_voltage_table,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+};
+
+static struct regulator_desc vmmc_regulator = {
+	.name		= "vmmcq",
+	.ops		= &ipq4019_regulator_voltage_ops,
+	.type		= REGULATOR_VOLTAGE,
+	.owner		= THIS_MODULE,
+	.volt_table	= ipq4019_vmmc_voltages,
+	.n_voltages	= ARRAY_SIZE(ipq4019_vmmc_voltages),
+	.vsel_reg	= 0,
+	.vsel_mask	= 0x3,
+};
+
+const struct regmap_config ipq4019_vmmcq_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+};
+
+static int ipq4019_regulator_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regulator_init_data *init_data;
+	struct regulator_config cfg = {};
+	struct regulator_dev *rdev;
+	struct resource *res;
+	struct regmap *rmap;
+	void __iomem *base;
+
+	init_data = of_get_regulator_init_data(dev, dev->of_node,
+					       &vmmc_regulator);
+	if (!init_data)
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rmap = devm_regmap_init_mmio(dev, base, &ipq4019_vmmcq_regmap_config);
+	if (IS_ERR(rmap))
+		return PTR_ERR(rmap);
+
+	cfg.dev = dev;
+	cfg.init_data = init_data;
+	cfg.of_node = dev->of_node;
+	cfg.regmap = rmap;
+
+	rdev = devm_regulator_register(dev, &vmmc_regulator, &cfg);
+	if (IS_ERR(rdev)) {
+		dev_err(dev, "Failed to register regulator: %ld\n",
+			PTR_ERR(rdev));
+		return PTR_ERR(rdev);
+	}
+	platform_set_drvdata(pdev, rdev);
+
+	return 0;
+}
+
+static int ipq4019_regulator_remove(struct platform_device *pdev)
+{
+	struct regulator_dev *rdev = platform_get_drvdata(pdev);
+
+	regulator_unregister(rdev);
+
+	return 0;
+}
+
+static const struct of_device_id regulator_ipq4019_of_match[] = {
+	{ .compatible = "qcom,vqmmc-ipq4019-regulator", },
+	{},
+};
+
+static struct platform_driver ipq4019_regulator_driver = {
+	.probe = ipq4019_regulator_probe,
+	.remove = ipq4019_regulator_remove,
+	.driver = {
+		.name = "vqmmc-ipq4019-regulator",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(regulator_ipq4019_of_match),
+	},
+};
+module_platform_driver(ipq4019_regulator_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mantas Pucka <mantas@8devices.com>");
+MODULE_DESCRIPTION("IPQ4019 VQMMC voltage regulator");