[RFC 8/9] PCI/pwrseq: add a pwrseq driver for QCA6390

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Add a PCIe power sequencing driver that's capable of correctly powering
up the ath11k module on QCA6390 using the PCIe pwrseq functionality.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/pci/pcie/pwrseq/Kconfig               |  11 +
 drivers/pci/pcie/pwrseq/Makefile              |   1 +
 drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c | 197 ++++++++++++++++++
 3 files changed, 209 insertions(+)
 create mode 100644 drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c

diff --git a/drivers/pci/pcie/pwrseq/Kconfig b/drivers/pci/pcie/pwrseq/Kconfig
index 010e31f432c9..f9fe555b8506 100644
--- a/drivers/pci/pcie/pwrseq/Kconfig
+++ b/drivers/pci/pcie/pwrseq/Kconfig
@@ -6,3 +6,14 @@ menuconfig PCIE_PWRSEQ
 	help
 	  Say yes here to enable support for PCIe power sequencing
 	  drivers.
+
+if PCIE_PWRSEQ
+
+config PCIE_PWRSEQ_QCA6390
+	tristate "PCIe Power Sequencing driver for QCA6390"
+	depends on ARCH_QCOM || COMPILE_TEST
+	help
+	  Enable support for the PCIe power sequencing driver for the
+	  ath11k module of the QCA6390 WLAN/BT chip.
+
+endif
diff --git a/drivers/pci/pcie/pwrseq/Makefile b/drivers/pci/pcie/pwrseq/Makefile
index da99566594f6..da3e02063404 100644
--- a/drivers/pci/pcie/pwrseq/Makefile
+++ b/drivers/pci/pcie/pwrseq/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_PCIE_PWRSEQ)		+= pwrseq.o
+obj-$(CONFIG_PCIE_PWRSEQ_QCA6390)	+= pcie-pwrseq-qca6390.o
diff --git a/drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c b/drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c
new file mode 100644
index 000000000000..e9fddbb642fe
--- /dev/null
+++ b/drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2023 Linaro Ltd.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pcie-pwrseq.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct pcie_pwrseq_qca6390_vreg {
+	const char *name;
+	unsigned int load_uA;
+};
+
+struct pcie_pwrseq_qca6390_pdata {
+	struct pcie_pwrseq_qca6390_vreg *vregs;
+	size_t num_vregs;
+	unsigned int delay_msec;
+};
+
+struct pcie_pwrseq_qca6390_ctx {
+	struct pcie_pwrseq pwrseq;
+	const struct pcie_pwrseq_qca6390_pdata *pdata;
+	struct regulator_bulk_data *regs;
+	struct gpio_descs *en_gpios;
+	unsigned long *en_gpios_values;
+};
+
+static struct pcie_pwrseq_qca6390_vreg pcie_pwrseq_qca6390_vregs[] = {
+	{
+		.name = "vddpmu",
+		.load_uA = 1250000,
+	},
+	{
+		.name = "vddpcie1",
+		.load_uA = 35000,
+	},
+	{
+		.name = "vddpcie2",
+		.load_uA = 15000,
+	},
+};
+
+static struct pcie_pwrseq_qca6390_pdata pcie_pwrseq_qca6390_of_data = {
+	.vregs = pcie_pwrseq_qca6390_vregs,
+	.num_vregs = ARRAY_SIZE(pcie_pwrseq_qca6390_vregs),
+	.delay_msec = 16,
+};
+
+static int pcie_pwrseq_qca6390_power_on(struct pcie_pwrseq_qca6390_ctx *ctx)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(ctx->pdata->num_vregs, ctx->regs);
+	if (ret)
+		return ret;
+
+	bitmap_fill(ctx->en_gpios_values, ctx->en_gpios->ndescs);
+
+	ret = gpiod_set_array_value_cansleep(ctx->en_gpios->ndescs,
+					     ctx->en_gpios->desc,
+					     ctx->en_gpios->info,
+					     ctx->en_gpios_values);
+	if (ret) {
+		regulator_bulk_disable(ctx->pdata->num_vregs, ctx->regs);
+		return ret;
+	}
+
+	if (ctx->pdata->delay_msec)
+		msleep(ctx->pdata->delay_msec);
+
+	return 0;
+}
+
+static int pcie_pwrseq_qca6390_power_off(struct pcie_pwrseq_qca6390_ctx *ctx)
+{
+	int ret;
+
+	bitmap_zero(ctx->en_gpios_values, ctx->en_gpios->ndescs);
+
+	ret = gpiod_set_array_value_cansleep(ctx->en_gpios->ndescs,
+					     ctx->en_gpios->desc,
+					     ctx->en_gpios->info,
+					     ctx->en_gpios_values);
+	if (ret)
+		return ret;
+
+	return regulator_bulk_disable(ctx->pdata->num_vregs, ctx->regs);
+}
+
+static void devm_pcie_pwrseq_qca6390_power_off(void *data)
+{
+	struct pcie_pwrseq_qca6390_ctx *ctx = data;
+
+	pcie_pwrseq_qca6390_power_off(ctx);
+}
+
+static int pcie_pwrseq_qca6309_probe(struct platform_device *pdev)
+{
+	struct pcie_pwrseq_qca6390_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++) {
+			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->en_gpios = devm_gpiod_get_array_optional(dev, "enable",
+						      GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->en_gpios))
+		return dev_err_probe(dev, PTR_ERR(ctx->en_gpios),
+				     "Failed to get enable GPIOs\n");
+
+	ctx->en_gpios_values = devm_bitmap_zalloc(dev, ctx->en_gpios->ndescs,
+						  GFP_KERNEL);
+	if (!ctx->en_gpios_values)
+		return -ENOMEM;
+
+	ret = pcie_pwrseq_qca6390_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_pcie_pwrseq_qca6390_power_off,
+				       ctx);
+	if (ret)
+		return ret;
+
+	ctx->pwrseq.dev = dev;
+
+	ret = devm_pcie_pwrseq_device_enable(dev, &ctx->pwrseq);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register the pwrseq wrapper\n");
+
+	return 0;
+}
+
+static const struct of_device_id pcie_pwrseq_qca6309_of_match[] = {
+	{
+		.compatible = "pci17cb,1101",
+		.data = &pcie_pwrseq_qca6390_of_data,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pcie_pwrseq_qca6309_of_match);
+
+static struct platform_driver pcie_pwrseq_qca6309_driver = {
+	.driver = {
+		.name = "pcie-pwrseq-qca6390",
+		.of_match_table = pcie_pwrseq_qca6309_of_match,
+	},
+	.probe = pcie_pwrseq_qca6309_probe,
+};
+module_platform_driver(pcie_pwrseq_qca6309_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
+MODULE_DESCRIPTION("PCIe Power Sequencing module for QCA6390");
+MODULE_LICENSE("GPL");
-- 
2.40.1