regulator: qcom: Add labibb driver

Qualcomm platforms have LAB(LCD AMOLED Boost)/IBB(Inverting Buck Boost)
regulators, labibb for short, which are used as power supply for
LCD Mode displays.

This patch adds labibb regulator driver for pmi8998 PMIC, found on
SDM845 platforms.

  [sumits: reworked the driver design as per upstream review]

Signed-off-by: Nisha Kumari <nishakumari@codeaurora.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20200622124110.20971-5-sumit.semwal@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -1223,5 +1223,15 @@ config REGULATOR_WM8994
 	  This driver provides support for the voltage regulators on the
 	  WM8994 CODEC.
 
+config REGULATOR_QCOM_LABIBB
+	tristate "QCOM LAB/IBB regulator support"
+	depends on SPMI || COMPILE_TEST
+	help
+	  This driver supports Qualcomm's LAB/IBB regulators present on the
+	  Qualcomm's PMIC chip pmi8998. QCOM LAB and IBB are SPMI
+	  based PMIC implementations. LAB can be used as positive
+	  boost regulator and IBB can be used as a negative boost regulator
+	  for LCD display panel.
+
 endif
 

drivers/regulator/Makefile

@@ -90,6 +90,7 @@ obj-$(CONFIG_REGULATOR_MT6323)	+= mt6323-regulator.o
 obj-$(CONFIG_REGULATOR_MT6358)	+= mt6358-regulator.o
 obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
 obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o

drivers/regulator/qcom-labibb-regulator.c

@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2020, The Linux Foundation. All rights reserved.
+
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define REG_PERPH_TYPE                  0x04
+
+#define QCOM_LAB_TYPE			0x24
+#define QCOM_IBB_TYPE			0x20
+
+#define PMI8998_LAB_REG_BASE		0xde00
+#define PMI8998_IBB_REG_BASE		0xdc00
+
+#define REG_LABIBB_STATUS1		0x08
+#define REG_LABIBB_ENABLE_CTL		0x46
+#define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
+#define LABIBB_CONTROL_ENABLE		BIT(7)
+
+#define LAB_ENABLE_CTL_MASK		BIT(7)
+#define IBB_ENABLE_CTL_MASK		(BIT(7) | BIT(6))
+
+#define LABIBB_OFF_ON_DELAY		1000
+#define LAB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 2)
+#define IBB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 10)
+#define LABIBB_POLL_ENABLED_TIME	1000
+
+struct labibb_regulator {
+	struct regulator_desc		desc;
+	struct device			*dev;
+	struct regmap			*regmap;
+	struct regulator_dev		*rdev;
+	u16				base;
+	u8				type;
+};
+
+struct labibb_regulator_data {
+	const char			*name;
+	u8				type;
+	u16				base;
+	struct regulator_desc		*desc;
+};
+
+static struct regulator_ops qcom_labibb_ops = {
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.is_enabled		= regulator_is_enabled_regmap,
+};
+
+static struct regulator_desc pmi8998_lab_desc = {
+	.enable_mask		= LAB_ENABLE_CTL_MASK,
+	.enable_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_ENABLE_CTL),
+	.enable_val		= LABIBB_CONTROL_ENABLE,
+	.enable_time		= LAB_ENABLE_TIME,
+	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
+	.off_on_delay		= LABIBB_OFF_ON_DELAY,
+	.owner			= THIS_MODULE,
+	.type			= REGULATOR_VOLTAGE,
+	.ops			= &qcom_labibb_ops,
+};
+
+static struct regulator_desc pmi8998_ibb_desc = {
+	.enable_mask		= IBB_ENABLE_CTL_MASK,
+	.enable_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_ENABLE_CTL),
+	.enable_val		= LABIBB_CONTROL_ENABLE,
+	.enable_time		= IBB_ENABLE_TIME,
+	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
+	.off_on_delay		= LABIBB_OFF_ON_DELAY,
+	.owner			= THIS_MODULE,
+	.type			= REGULATOR_VOLTAGE,
+	.ops			= &qcom_labibb_ops,
+};
+
+static const struct labibb_regulator_data pmi8998_labibb_data[] = {
+	{"lab", QCOM_LAB_TYPE, PMI8998_LAB_REG_BASE, &pmi8998_lab_desc},
+	{"ibb", QCOM_IBB_TYPE, PMI8998_IBB_REG_BASE, &pmi8998_ibb_desc},
+	{ },
+};
+
+static const struct of_device_id qcom_labibb_match[] = {
+	{ .compatible = "qcom,pmi8998-lab-ibb", .data = &pmi8998_labibb_data},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_labibb_match);
+
+static int qcom_labibb_regulator_probe(struct platform_device *pdev)
+{
+	struct labibb_regulator *vreg;
+	struct device *dev = &pdev->dev;
+	struct regulator_config cfg = {};
+
+	const struct of_device_id *match;
+	const struct labibb_regulator_data *reg_data;
+	struct regmap *reg_regmap;
+	unsigned int type;
+	int ret;
+
+	reg_regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!reg_regmap) {
+		dev_err(&pdev->dev, "Couldn't get parent's regmap\n");
+		return -ENODEV;
+	}
+
+	match = of_match_device(qcom_labibb_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
+
+	for (reg_data = match->data; reg_data->name; reg_data++) {
+
+		/* Validate if the type of regulator is indeed
+		 * what's mentioned in DT.
+		 */
+		ret = regmap_read(reg_regmap, reg_data->base + REG_PERPH_TYPE,
+				  &type);
+		if (ret < 0) {
+			dev_err(dev,
+				"Peripheral type read failed ret=%d\n",
+				ret);
+			return -EINVAL;
+		}
+
+		if (WARN_ON((type != QCOM_LAB_TYPE) && (type != QCOM_IBB_TYPE)) ||
+		    WARN_ON(type != reg_data->type))
+			return -EINVAL;
+
+		vreg  = devm_kzalloc(&pdev->dev, sizeof(*vreg),
+					   GFP_KERNEL);
+		if (!vreg)
+			return -ENOMEM;
+
+		vreg->regmap = reg_regmap;
+		vreg->dev = dev;
+		vreg->base = reg_data->base;
+		vreg->type = reg_data->type;
+
+		memcpy(&vreg->desc, reg_data->desc, sizeof(vreg->desc));
+		vreg->desc.of_match = reg_data->name;
+		vreg->desc.name = reg_data->name;
+
+		cfg.dev = vreg->dev;
+		cfg.driver_data = vreg;
+		cfg.regmap = vreg->regmap;
+
+		vreg->rdev = devm_regulator_register(vreg->dev, &vreg->desc,
+							&cfg);
+
+		if (IS_ERR(vreg->rdev)) {
+			dev_err(dev, "qcom_labibb: error registering %s : %d\n",
+					reg_data->name, ret);
+			return PTR_ERR(vreg->rdev);
+		}
+	}
+
+	return 0;
+}
+
+static struct platform_driver qcom_labibb_regulator_driver = {
+	.driver	= {
+		.name = "qcom-lab-ibb-regulator",
+		.of_match_table	= qcom_labibb_match,
+	},
+	.probe = qcom_labibb_regulator_probe,
+};
+module_platform_driver(qcom_labibb_regulator_driver);
+
+MODULE_DESCRIPTION("Qualcomm labibb driver");
+MODULE_AUTHOR("Nisha Kumari <nishakumari@codeaurora.org>");
+MODULE_AUTHOR("Sumit Semwal <sumit.semwal@linaro.org>");
+MODULE_LICENSE("GPL v2");