[PATCH 2/4] mfd: qca639x: add support for QCA639x powerup sequence

[Dmitry Baryshkov]

Qualcomm QCA639x 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. So add mfd device driver
handling power sequencing of QCA6390/1.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/mfd/Kconfig        |  12 +++
 drivers/mfd/Makefile       |   1 +
 drivers/mfd/qcom-qca639x.c | 168 +++++++++++++++++++++++++++++++++++++
 3 files changed, 181 insertions(+)
 create mode 100644 drivers/mfd/qcom-qca639x.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index bdfce7b15621..2fd6b9770ad0 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1036,6 +1036,18 @@ config MFD_PM8XXX
 	  Say M here if you want to include support for PM8xxx chips as a
 	  module. This will build a module called "pm8xxx-core".
 
+config MFD_QCOM_QCA639X
+	tristate "Qualcomm QCA639x WiFi/Bluetooth module support"
+	depends on REGULATOR && PM_GENERIC_DOMAINS
+	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.
+
+	  Say M here if you want to include support for QCA639x chips as a
+	  module. This will build a module called "qcom-qca639x".
+
 config MFD_QCOM_RPM
 	tristate "Qualcomm Resource Power Manager (RPM)"
 	depends on ARCH_QCOM && OF
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 14fdb188af02..da5747508faf 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -202,6 +202,7 @@ obj-$(CONFIG_MFD_SI476X_CORE)	+= si476x-core.o
 obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o omap-usb-tll.o
 obj-$(CONFIG_MFD_PM8XXX) 	+= qcom-pm8xxx.o ssbi.o
+obj-$(CONFIG_MFD_QCOM_QCA639X)	+= qcom-qca639x.o
 obj-$(CONFIG_MFD_QCOM_RPM)	+= qcom_rpm.o
 obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
diff --git a/drivers/mfd/qcom-qca639x.c b/drivers/mfd/qcom-qca639x.c
new file mode 100644
index 000000000000..1ecc2e2e5bfd
--- /dev/null
+++ b/drivers/mfd/qcom-qca639x.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020, Linaro Limited
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/devinfo.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regulator/consumer.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 qca639x_data {
+	struct regulator_bulk_data regulators[MAX_NUM_REGULATORS];
+	size_t num_vregs;
+	struct device *dev;
+	struct pinctrl_state *active_state;
+	struct generic_pm_domain pd;
+};
+
+#define domain_to_data(domain) container_of(domain, struct qca639x_data, pd)
+
+static int qca639x_power_on(struct generic_pm_domain *domain)
+{
+	struct qca639x_data *data = domain_to_data(domain);
+	int ret;
+
+	dev_warn(&domain->dev, "DUMMY POWER ON\n");
+
+	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);
+
+	ret = pinctrl_select_state(data->dev->pins->p, data->active_state);
+	if (ret) {
+		dev_err(data->dev, "Failed to select active state");
+		return ret;
+	}
+
+	/* Wait for all power levels to stabilize */
+	usleep_range(6000, 7000);
+
+	return 0;
+}
+
+static int qca639x_power_off(struct generic_pm_domain *domain)
+{
+	struct qca639x_data *data = domain_to_data(domain);
+
+	dev_warn(&domain->dev, "DUMMY POWER OFF\n");
+
+	pinctrl_select_default_state(data->dev);
+	regulator_bulk_disable(data->num_vregs, data->regulators);
+
+	return 0;
+}
+
+static int qca639x_probe(struct platform_device *pdev)
+{
+	struct qca639x_data *data;
+	struct device *dev = &pdev->dev;
+	int i, ret;
+
+	if (!dev->pins || IS_ERR_OR_NULL(dev->pins->default_state))
+		return -EINVAL;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->dev = dev;
+	data->num_vregs = ARRAY_SIZE(vregs);
+
+	data->active_state = pinctrl_lookup_state(dev->pins->p, "active");
+	if (IS_ERR(data->active_state)) {
+		ret = PTR_ERR(data->active_state);
+		dev_err(dev, "Failed to get active_state: %d\n", ret);
+		return ret;
+	}
+
+	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->pd.name = dev_name(dev);
+	data->pd.power_on = qca639x_power_on;
+	data->pd.power_off = qca639x_power_off;
+
+	ret = pm_genpd_init(&data->pd, NULL, true);
+	if (ret < 0)
+		return ret;
+
+	ret = of_genpd_add_provider_simple(dev->of_node, &data->pd);
+	if (ret < 0) {
+		pm_genpd_remove(&data->pd);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+}
+
+static int qca639x_remove(struct platform_device *pdev)
+{
+	struct qca639x_data *data = platform_get_drvdata(pdev);
+
+	pm_genpd_remove(&data->pd);
+
+	return 0;
+}
+
+static const struct of_device_id qca639x_of_match[] = {
+	{ .compatible = "qcom,qca639x" },
+};
+
+static struct platform_driver qca639x_driver = {
+	.probe = qca639x_probe,
+	.remove = qca639x_remove,
+	.driver = {
+		.name = "qca639x",
+		.of_match_table = qca639x_of_match,
+	},
+};
+
+module_platform_driver(qca639x_driver);
+MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Power control for Qualcomm QCA639x BT/WiFi chip");
+MODULE_LICENSE("GPL v2");
-- 
2.29.2