[PATCH v3 2/7] regulator: qca6390: add support for QCA639x powerup sequence

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

Qualcomm QCA6390/1 is a family of WiFi + Bluetooth SoCs, with BT part
being controlled through the UART and WiFi being present on PCIe
bus. Both blocks share common power sources. Add device driver handling
power sequencing of QCA6390/1.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/regulator/Kconfig        |  13 +++
 drivers/regulator/Makefile       |   1 +
 drivers/regulator/qcom-qca639x.c | 157 +++++++++++++++++++++++++++++++
 3 files changed, 171 insertions(+)
 create mode 100644 drivers/regulator/qcom-qca639x.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 3e7a38525cb3..7a560cddea7a 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -909,6 +909,19 @@ config REGULATOR_PWM
 	  This driver supports PWM controlled voltage regulators. PWM
 	  duty cycle can increase or decrease the voltage.
 
+config REGULATOR_QCOM_QCA639X
+	tristate "Qualcomm QCA639x WiFi/Bluetooth module support"
+	help
+	  If you say yes to this option, support will be included for Qualcomm
+	  QCA639x family of WiFi and Bluetooth SoCs. Note, this driver supports
+	  only power control for this SoC, you still have to enable individual
+	  Bluetooth and WiFi drivers. This driver is only necessary on ARM
+	  platforms with this chip. PCIe cards handle power sequencing on their
+	  own.
+
+	  Say M here if you want to include support for QCA639x chips as a
+	  module. This will build a module called "qcom-qca639x".
+
 config REGULATOR_QCOM_RPM
 	tristate "Qualcomm RPM regulator driver"
 	depends on MFD_QCOM_RPM
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 580b015296ea..129c2110b78d 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -99,6 +99,7 @@ obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
 obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
 obj-$(CONFIG_REGULATOR_MTK_DVFSRC) += mtk-dvfsrc-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_QCA639X) += qcom-qca639x.o
 obj-$(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
diff --git a/drivers/regulator/qcom-qca639x.c b/drivers/regulator/qcom-qca639x.c
new file mode 100644
index 000000000000..a2c78c0f8baa
--- /dev/null
+++ b/drivers/regulator/qcom-qca639x.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, Linaro Limited
+ */
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+#define MAX_NUM_REGULATORS	8
+
+static struct vreg {
+	const char *name;
+	unsigned int load_uA;
+} vregs[MAX_NUM_REGULATORS] = {
+	/* 2.0 V */
+	{ "vddpcie2", 15000 },
+	{ "vddrfa3", 400000 },
+
+	/* 0.95 V */
+	{ "vddaon", 100000 },
+	{ "vddpmu", 1250000 },
+	{ "vddrfa1", 200000 },
+
+	/* 1.35 V */
+	{ "vddrfa2", 400000 },
+	{ "vddpcie1", 35000 },
+
+	/* 1.8 V */
+	{ "vddio", 20000 },
+};
+
+struct qca6390_data {
+	struct device *dev;
+	struct regulator_bulk_data regulators[MAX_NUM_REGULATORS];
+	size_t num_vregs;
+
+	struct regulator_desc desc;
+	struct regulator_dev *regulator_dev;
+	unsigned int enable_counter;
+};
+
+#define domain_to_data(domain) container_of(domain, struct qca6390_data, pd)
+
+static int qca6390_enable(struct regulator_dev *rdev)
+{
+	struct qca6390_data *data = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = regulator_bulk_enable(data->num_vregs, data->regulators);
+	if (ret) {
+		dev_err(data->dev, "Failed to enable regulators");
+		return ret;
+	}
+
+	/* Wait for 1ms before toggling enable pins. */
+	usleep_range(1000, 2000);
+
+	data->enable_counter++;
+
+	return 0;
+}
+
+static int qca6390_disable(struct regulator_dev *rdev)
+{
+	struct qca6390_data *data = rdev_get_drvdata(rdev);
+
+	regulator_bulk_disable(data->num_vregs, data->regulators);
+
+	data->enable_counter--;
+
+	return 0;
+}
+
+static int qca6390_is_enabled(struct regulator_dev *rdev)
+{
+	struct qca6390_data *data = rdev_get_drvdata(rdev);
+
+	return data->enable_counter > 0;
+}
+
+static const struct regulator_ops qca6390_ops = {
+	.enable = qca6390_enable,
+	.disable = qca6390_disable,
+	.is_enabled = qca6390_is_enabled,
+};
+
+static int qca6390_probe(struct platform_device *pdev)
+{
+	struct qca6390_data *data;
+	struct device *dev = &pdev->dev;
+	struct regulator_config cfg = { };
+	int i, ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->dev = dev;
+	data->num_vregs = ARRAY_SIZE(vregs);
+
+	for (i = 0; i < data->num_vregs; i++)
+		data->regulators[i].supply = vregs[i].name;
+
+	ret = devm_regulator_bulk_get(dev, data->num_vregs, data->regulators);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < data->num_vregs; i++) {
+		ret = regulator_set_load(data->regulators[i].consumer, vregs[i].load_uA);
+		if (ret)
+			return ret;
+	}
+
+	data->desc.name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
+	if (!data->desc.name)
+		return -ENOMEM;
+
+	data->desc.type = REGULATOR_VOLTAGE;
+	data->desc.owner = THIS_MODULE;
+	data->desc.ops = &qca6390_ops;
+
+	cfg.dev = dev;
+	cfg.of_node = dev->of_node;
+	cfg.driver_data = data;
+	cfg.init_data = of_get_regulator_init_data(dev, dev->of_node, &data->desc);
+
+	data->regulator_dev = devm_regulator_register(dev, &data->desc, &cfg);
+	if (IS_ERR(data->regulator_dev)) {
+		ret = PTR_ERR(data->regulator_dev);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+}
+
+static const struct of_device_id qca6390_of_match[] = {
+	{ .compatible = "qcom,qca6390" },
+};
+
+static struct platform_driver qca6390_driver = {
+	.probe = qca6390_probe,
+	.driver = {
+		.name = "qca6390",
+		.of_match_table = qca6390_of_match,
+	},
+};
+
+module_platform_driver(qca6390_driver);
+MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
+MODULE_DESCRIPTION("Power control for Qualcomm QCA6390/1 BT/WiFi chip");
+MODULE_LICENSE("GPL v2");
-- 
2.30.2