PCI/pwrctl: add a power control driver for WCN7850

Add a PCI power control driver that's capable of correctly powering up
the ath12k module on WCN7850 using the PCI pwrctl functionality.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/pci/pwrctl/Kconfig

@@ -5,4 +5,12 @@ menu "PCI Power control drivers"
 config PCI_PWRCTL
 	tristate
 
+config PCI_PWRCTL_WCN7850
+	tristate "PCI Power Control driver for WCN7850"
+	select PCI_PWRCTL
+	default m if (ATH12K && ARCH_QCOM)
+	help
+	  Enable support for the PCI power control driver for the ath12k
+	  module of the WCN7850 WLAN/BT chip.
+
 endmenu

drivers/pci/pwrctl/Makefile

@@ -2,3 +2,5 @@
 
 obj-$(CONFIG_PCI_PWRCTL)		+= pci-pwrctl-core.o
 pci-pwrctl-core-y			:= core.o
+
+obj-$(CONFIG_PCI_PWRCTL_WCN7850)	+= pci-pwrctl-wcn7850.o

drivers/pci/pwrctl/pci-pwrctl-wcn7850.c

@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 Linaro Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pci-pwrctl.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct pci_pwrctl_wcn7850_vreg {
+	const char *name;
+	unsigned int load_uA;
+};
+
+struct pci_pwrctl_wcn7850_pdata {
+	struct pci_pwrctl_wcn7850_vreg *vregs;
+	size_t num_vregs;
+	unsigned int delay_msec;
+};
+
+struct pci_pwrctl_wcn7850_ctx {
+	struct pci_pwrctl pwrctl;
+	const struct pci_pwrctl_wcn7850_pdata *pdata;
+	struct regulator_bulk_data *regs;
+	struct gpio_desc *en_gpio;
+	struct clk *clk;
+};
+
+static struct pci_pwrctl_wcn7850_vreg pci_pwrctl_wcn7850_vregs[] = {
+	{
+		.name = "vdd",
+		.load_uA = 16000,
+	},
+	{
+		.name = "vddio",
+		.load_uA = 5000,
+	},
+	{
+		.name = "vddio1p2",
+		.load_uA = 16000,
+	},
+	{
+		.name = "vddaon",
+		.load_uA = 26000,
+	},
+	{
+		.name = "vdddig",
+		.load_uA = 126000,
+	},
+	{
+		.name = "vddrfa1p2",
+		.load_uA = 257000,
+	},
+	{
+		.name = "vddrfa1p8",
+		.load_uA = 302000,
+	},
+};
+
+static struct pci_pwrctl_wcn7850_pdata pci_pwrctl_wcn7850_of_data = {
+	.vregs = pci_pwrctl_wcn7850_vregs,
+	.num_vregs = ARRAY_SIZE(pci_pwrctl_wcn7850_vregs),
+	.delay_msec = 50,
+};
+
+static int pci_pwrctl_wcn7850_power_on(struct pci_pwrctl_wcn7850_ctx *ctx)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(ctx->pdata->num_vregs, ctx->regs);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(ctx->clk);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(ctx->en_gpio, 1);
+
+	if (ctx->pdata->delay_msec)
+		msleep(ctx->pdata->delay_msec);
+
+	return 0;
+}
+
+static int pci_pwrctl_wcn7850_power_off(struct pci_pwrctl_wcn7850_ctx *ctx)
+{
+	gpiod_set_value_cansleep(ctx->en_gpio, 0);
+	clk_disable_unprepare(ctx->clk);
+
+	return regulator_bulk_disable(ctx->pdata->num_vregs, ctx->regs);
+}
+
+static void devm_pci_pwrctl_wcn7850_power_off(void *data)
+{
+	struct pci_pwrctl_wcn7850_ctx *ctx = data;
+
+	pci_pwrctl_wcn7850_power_off(ctx);
+}
+
+static int pci_pwrctl_wcn7850_probe(struct platform_device *pdev)
+{
+	struct pci_pwrctl_wcn7850_ctx *ctx;
+	struct device *dev = &pdev->dev;
+	int ret, i;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->pdata = of_device_get_match_data(dev);
+	if (!ctx->pdata)
+		return dev_err_probe(dev, -ENODEV,
+				     "Failed to obtain platform data\n");
+
+	if (ctx->pdata->vregs) {
+		ctx->regs = devm_kcalloc(dev, ctx->pdata->num_vregs,
+					 sizeof(*ctx->regs), GFP_KERNEL);
+		if (!ctx->regs)
+			return -ENOMEM;
+
+		for (i = 0; i < ctx->pdata->num_vregs; i++)
+			ctx->regs[i].supply = ctx->pdata->vregs[i].name;
+
+		ret = devm_regulator_bulk_get(dev, ctx->pdata->num_vregs,
+					      ctx->regs);
+		if (ret < 0)
+			return dev_err_probe(dev, ret,
+					     "Failed to get all regulators\n");
+
+		for (i = 0; i < ctx->pdata->num_vregs; i++) {
+			if (!ctx->pdata->vregs[1].load_uA)
+				continue;
+
+			ret = regulator_set_load(ctx->regs[i].consumer,
+						 ctx->pdata->vregs[i].load_uA);
+			if (ret)
+				return dev_err_probe(dev, ret,
+						     "Failed to set vreg load\n");
+		}
+	}
+
+	ctx->clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(ctx->clk))
+		return dev_err_probe(dev, PTR_ERR(ctx->clk),
+				     "Failed to get clock\n");
+
+	ctx->en_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->en_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->en_gpio),
+				     "Failed to get enable the GPIO\n");
+
+	ret = pci_pwrctl_wcn7850_power_on(ctx);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to power on the device\n");
+
+	ret = devm_add_action_or_reset(dev, devm_pci_pwrctl_wcn7850_power_off,
+				       ctx);
+	if (ret)
+		return ret;
+
+	ctx->pwrctl.dev = dev;
+
+	ret = devm_pci_pwrctl_device_set_ready(dev, &ctx->pwrctl);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register the pwrctl wrapper\n");
+
+	return 0;
+}
+
+static const struct of_device_id pci_pwrctl_wcn7850_of_match[] = {
+	{
+		.compatible = "pci17cb,1107",
+		.data = &pci_pwrctl_wcn7850_of_data,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pci_pwrctl_wcn7850_of_match);
+
+static struct platform_driver pci_pwrctl_wcn7850_driver = {
+	.driver = {
+		.name = "pci-pwrctl-wcn7850",
+		.of_match_table = pci_pwrctl_wcn7850_of_match,
+	},
+	.probe = pci_pwrctl_wcn7850_probe,
+};
+module_platform_driver(pci_pwrctl_wcn7850_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
+MODULE_DESCRIPTION("PCI Power Sequencing module for WCN7850");
+MODULE_LICENSE("GPL");