Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 344 insertions, 14 deletions

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index ccd59ddd76..85b27c42cf 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -66,6 +66,15 @@ config RESET_BRCMSTB_RESCAL
 	  This enables the RESCAL reset controller for SATA, PCIe0, or PCIe1 on
 	  BCM7216.
 
+config RESET_GPIO
+	tristate "GPIO reset controller"
+	help
+	  This enables a generic reset controller for resets attached via
+	  GPIOs.  Typically for OF platforms this driver expects "reset-gpios"
+	  property.
+
+	  If compiled as module, it will be called reset-gpio.
+
 config RESET_HSDK
 	bool "Synopsys HSDK Reset Driver"
 	depends on HAS_IOMEM
@@ -213,7 +222,7 @@ config RESET_SCMI
 
 config RESET_SIMPLE
 	bool "Simple Reset Controller Driver" if COMPILE_TEST || EXPERT
-	default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC
+	default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_SOPHGO || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC
 	depends on HAS_IOMEM
 	help
 	  This enables a simple reset controller driver for reset lines that
@@ -228,6 +237,7 @@ config RESET_SIMPLE
 	   - RCC reset controller in STM32 MCUs
 	   - Allwinner SoCs
 	   - SiFive FU740 SoCs
+	   - Sophgo SoCs
 
 config RESET_SOCFPGA
 	bool "SoCFPGA Reset Driver" if COMPILE_TEST && (!ARM || !ARCH_INTEL_SOCFPGA)
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 8270da8a4b..fd8b49fa46 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
 obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
 obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
 obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
+obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
 obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
 obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
 obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 4d5a78d3c0..dba74e857b 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -5,14 +5,19 @@
  * Copyright 2013 Philipp Zabel, Pengutronix
  */
 #include <linux/atomic.h>
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/machine.h>
+#include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/acpi.h>
+#include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/reset-controller.h>
 #include <linux/slab.h>
@@ -23,6 +28,11 @@ static LIST_HEAD(reset_controller_list);
 static DEFINE_MUTEX(reset_lookup_mutex);
 static LIST_HEAD(reset_lookup_list);
 
+/* Protects reset_gpio_lookup_list */
+static DEFINE_MUTEX(reset_gpio_lookup_mutex);
+static LIST_HEAD(reset_gpio_lookup_list);
+static DEFINE_IDA(reset_gpio_ida);
+
 /**
  * struct reset_control - a reset control
  * @rcdev: a pointer to the reset controller device
@@ -63,6 +73,16 @@ struct reset_control_array {
 	struct reset_control *rstc[] __counted_by(num_rstcs);
 };
 
+/**
+ * struct reset_gpio_lookup - lookup key for ad-hoc created reset-gpio devices
+ * @of_args: phandle to the reset controller with all the args like GPIO number
+ * @list: list entry for the reset_gpio_lookup_list
+ */
+struct reset_gpio_lookup {
+	struct of_phandle_args of_args;
+	struct list_head list;
+};
+
 static const char *rcdev_name(struct reset_controller_dev *rcdev)
 {
 	if (rcdev->dev)
@@ -71,6 +91,9 @@ static const char *rcdev_name(struct reset_controller_dev *rcdev)
 	if (rcdev->of_node)
 		return rcdev->of_node->full_name;
 
+	if (rcdev->of_args)
+		return rcdev->of_args->np->full_name;
+
 	return NULL;
 }
 
@@ -99,6 +122,9 @@ static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
  */
 int reset_controller_register(struct reset_controller_dev *rcdev)
 {
+	if (rcdev->of_node && rcdev->of_args)
+		return -EINVAL;
+
 	if (!rcdev->of_xlate) {
 		rcdev->of_reset_n_cells = 1;
 		rcdev->of_xlate = of_reset_simple_xlate;
@@ -813,12 +839,171 @@ static void __reset_control_put_internal(struct reset_control *rstc)
 	kref_put(&rstc->refcnt, __reset_control_release);
 }
 
+static int __reset_add_reset_gpio_lookup(int id, struct device_node *np,
+					 unsigned int gpio,
+					 unsigned int of_flags)
+{
+	const struct fwnode_handle *fwnode = of_fwnode_handle(np);
+	unsigned int lookup_flags;
+	const char *label_tmp;
+
+	/*
+	 * Later we map GPIO flags between OF and Linux, however not all
+	 * constants from include/dt-bindings/gpio/gpio.h and
+	 * include/linux/gpio/machine.h match each other.
+	 */
+	if (of_flags > GPIO_ACTIVE_LOW) {
+		pr_err("reset-gpio code does not support GPIO flags %u for GPIO %u\n",
+		       of_flags, gpio);
+		return -EINVAL;
+	}
+
+	struct gpio_device *gdev __free(gpio_device_put) = gpio_device_find_by_fwnode(fwnode);
+	if (!gdev)
+		return -EPROBE_DEFER;
+
+	label_tmp = gpio_device_get_label(gdev);
+	if (!label_tmp)
+		return -EINVAL;
+
+	char *label __free(kfree) = kstrdup(label_tmp, GFP_KERNEL);
+	if (!label)
+		return -ENOMEM;
+
+	/* Size: one lookup entry plus sentinel */
+	struct gpiod_lookup_table *lookup __free(kfree) = kzalloc(struct_size(lookup, table, 2),
+								  GFP_KERNEL);
+	if (!lookup)
+		return -ENOMEM;
+
+	lookup->dev_id = kasprintf(GFP_KERNEL, "reset-gpio.%d", id);
+	if (!lookup->dev_id)
+		return -ENOMEM;
+
+	lookup_flags = GPIO_PERSISTENT;
+	lookup_flags |= of_flags & GPIO_ACTIVE_LOW;
+	lookup->table[0] = GPIO_LOOKUP(no_free_ptr(label), gpio, "reset",
+				       lookup_flags);
+
+	/* Not freed on success, because it is persisent subsystem data. */
+	gpiod_add_lookup_table(no_free_ptr(lookup));
+
+	return 0;
+}
+
+/*
+ * @args:	phandle to the GPIO provider with all the args like GPIO number
+ */
+static int __reset_add_reset_gpio_device(const struct of_phandle_args *args)
+{
+	struct reset_gpio_lookup *rgpio_dev;
+	struct platform_device *pdev;
+	int id, ret;
+
+	/*
+	 * Currently only #gpio-cells=2 is supported with the meaning of:
+	 * args[0]: GPIO number
+	 * args[1]: GPIO flags
+	 * TODO: Handle other cases.
+	 */
+	if (args->args_count != 2)
+		return -ENOENT;
+
+	/*
+	 * Registering reset-gpio device might cause immediate
+	 * bind, resulting in its probe() registering new reset controller thus
+	 * taking reset_list_mutex lock via reset_controller_register().
+	 */
+	lockdep_assert_not_held(&reset_list_mutex);
+
+	mutex_lock(&reset_gpio_lookup_mutex);
+
+	list_for_each_entry(rgpio_dev, &reset_gpio_lookup_list, list) {
+		if (args->np == rgpio_dev->of_args.np) {
+			if (of_phandle_args_equal(args, &rgpio_dev->of_args))
+				goto out; /* Already on the list, done */
+		}
+	}
+
+	id = ida_alloc(&reset_gpio_ida, GFP_KERNEL);
+	if (id < 0) {
+		ret = id;
+		goto err_unlock;
+	}
+
+	/* Not freed on success, because it is persisent subsystem data. */
+	rgpio_dev = kzalloc(sizeof(*rgpio_dev), GFP_KERNEL);
+	if (!rgpio_dev) {
+		ret = -ENOMEM;
+		goto err_ida_free;
+	}
+
+	ret = __reset_add_reset_gpio_lookup(id, args->np, args->args[0],
+					    args->args[1]);
+	if (ret < 0)
+		goto err_kfree;
+
+	rgpio_dev->of_args = *args;
+	/*
+	 * We keep the device_node reference, but of_args.np is put at the end
+	 * of __of_reset_control_get(), so get it one more time.
+	 * Hold reference as long as rgpio_dev memory is valid.
+	 */
+	of_node_get(rgpio_dev->of_args.np);
+	pdev = platform_device_register_data(NULL, "reset-gpio", id,
+					     &rgpio_dev->of_args,
+					     sizeof(rgpio_dev->of_args));
+	ret = PTR_ERR_OR_ZERO(pdev);
+	if (ret)
+		goto err_put;
+
+	list_add(&rgpio_dev->list, &reset_gpio_lookup_list);
+
+out:
+	mutex_unlock(&reset_gpio_lookup_mutex);
+
+	return 0;
+
+err_put:
+	of_node_put(rgpio_dev->of_args.np);
+err_kfree:
+	kfree(rgpio_dev);
+err_ida_free:
+	ida_free(&reset_gpio_ida, id);
+err_unlock:
+	mutex_unlock(&reset_gpio_lookup_mutex);
+
+	return ret;
+}
+
+static struct reset_controller_dev *__reset_find_rcdev(const struct of_phandle_args *args,
+						       bool gpio_fallback)
+{
+	struct reset_controller_dev *rcdev;
+
+	lockdep_assert_held(&reset_list_mutex);
+
+	list_for_each_entry(rcdev, &reset_controller_list, list) {
+		if (gpio_fallback) {
+			if (rcdev->of_args && of_phandle_args_equal(args,
+								    rcdev->of_args))
+				return rcdev;
+		} else {
+			if (args->np == rcdev->of_node)
+				return rcdev;
+		}
+	}
+
+	return NULL;
+}
+
 struct reset_control *
 __of_reset_control_get(struct device_node *node, const char *id, int index,
 		       bool shared, bool optional, bool acquired)
 {
+	bool gpio_fallback = false;
 	struct reset_control *rstc;
-	struct reset_controller_dev *r, *rcdev;
+	struct reset_controller_dev *rcdev;
 	struct of_phandle_args args;
 	int rstc_id;
 	int ret;
@@ -839,39 +1024,52 @@ __of_reset_control_get(struct device_node *node, const char *id, int index,
 					 index, &args);
 	if (ret == -EINVAL)
 		return ERR_PTR(ret);
-	if (ret)
-		return optional ? NULL : ERR_PTR(ret);
+	if (ret) {
+		if (!IS_ENABLED(CONFIG_RESET_GPIO))
+			return optional ? NULL : ERR_PTR(ret);
 
-	mutex_lock(&reset_list_mutex);
-	rcdev = NULL;
-	list_for_each_entry(r, &reset_controller_list, list) {
-		if (args.np == r->of_node) {
-			rcdev = r;
-			break;
+		/*
+		 * There can be only one reset-gpio for regular devices, so
+		 * don't bother with the "reset-gpios" phandle index.
+		 */
+		ret = of_parse_phandle_with_args(node, "reset-gpios", "#gpio-cells",
+						 0, &args);
+		if (ret)
+			return optional ? NULL : ERR_PTR(ret);
+
+		gpio_fallback = true;
+
+		ret = __reset_add_reset_gpio_device(&args);
+		if (ret) {
+			rstc = ERR_PTR(ret);
+			goto out_put;
 		}
 	}
 
+	mutex_lock(&reset_list_mutex);
+	rcdev = __reset_find_rcdev(&args, gpio_fallback);
 	if (!rcdev) {
 		rstc = ERR_PTR(-EPROBE_DEFER);
-		goto out;
+		goto out_unlock;
 	}
 
 	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
 		rstc = ERR_PTR(-EINVAL);
-		goto out;
+		goto out_unlock;
 	}
 
 	rstc_id = rcdev->of_xlate(rcdev, &args);
 	if (rstc_id < 0) {
 		rstc = ERR_PTR(rstc_id);
-		goto out;
+		goto out_unlock;
 	}
 
 	/* reset_list_mutex also protects the rcdev's reset_control list */
 	rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);
 
-out:
+out_unlock:
 	mutex_unlock(&reset_list_mutex);
+out_put:
 	of_node_put(args.np);
 
 	return rstc;
diff --git a/drivers/reset/reset-gpio.c b/drivers/reset/reset-gpio.c
new file mode 100644
index 0000000000..2290b25b67
--- /dev/null
+++ b/drivers/reset/reset-gpio.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+struct reset_gpio_priv {
+	struct reset_controller_dev rc;
+	struct gpio_desc *reset;
+};
+
+static inline struct reset_gpio_priv
+*rc_to_reset_gpio(struct reset_controller_dev *rc)
+{
+	return container_of(rc, struct reset_gpio_priv, rc);
+}
+
+static int reset_gpio_assert(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	gpiod_set_value_cansleep(priv->reset, 1);
+
+	return 0;
+}
+
+static int reset_gpio_deassert(struct reset_controller_dev *rc,
+			       unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	gpiod_set_value_cansleep(priv->reset, 0);
+
+	return 0;
+}
+
+static int reset_gpio_status(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	return gpiod_get_value_cansleep(priv->reset);
+}
+
+static const struct reset_control_ops reset_gpio_ops = {
+	.assert = reset_gpio_assert,
+	.deassert = reset_gpio_deassert,
+	.status = reset_gpio_status,
+};
+
+static int reset_gpio_of_xlate(struct reset_controller_dev *rcdev,
+			       const struct of_phandle_args *reset_spec)
+{
+	return reset_spec->args[0];
+}
+
+static void reset_gpio_of_node_put(void *data)
+{
+	of_node_put(data);
+}
+
+static int reset_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct of_phandle_args *platdata = dev_get_platdata(dev);
+	struct reset_gpio_priv *priv;
+	int ret;
+
+	if (!platdata)
+		return -EINVAL;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, &priv->rc);
+
+	priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->reset))
+		return dev_err_probe(dev, PTR_ERR(priv->reset),
+				     "Could not get reset gpios\n");
+
+	priv->rc.ops = &reset_gpio_ops;
+	priv->rc.owner = THIS_MODULE;
+	priv->rc.dev = dev;
+	priv->rc.of_args = platdata;
+	ret = devm_add_action_or_reset(dev, reset_gpio_of_node_put,
+				       priv->rc.of_node);
+	if (ret)
+		return ret;
+
+	/* Cells to match GPIO specifier, but it's not really used */
+	priv->rc.of_reset_n_cells = 2;
+	priv->rc.of_xlate = reset_gpio_of_xlate;
+	priv->rc.nr_resets = 1;
+
+	return devm_reset_controller_register(dev, &priv->rc);
+}
+
+static const struct platform_device_id reset_gpio_ids[] = {
+	{ .name = "reset-gpio", },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, reset_gpio_ids);
+
+static struct platform_driver reset_gpio_driver = {
+	.probe		= reset_gpio_probe,
+	.id_table	= reset_gpio_ids,
+	.driver	= {
+		.name = "reset-gpio",
+	},
+};
+module_platform_driver(reset_gpio_driver);
+
+MODULE_AUTHOR("Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>");
+MODULE_DESCRIPTION("Generic GPIO reset driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
index 818cabcc9f..2760678398 100644
--- a/drivers/reset/reset-simple.c
+++ b/drivers/reset/reset-simple.c
@@ -151,6 +151,8 @@ static const struct of_device_id reset_simple_dt_ids[] = {
 	{ .compatible = "snps,dw-high-reset" },
 	{ .compatible = "snps,dw-low-reset",
 		.data = &reset_simple_active_low },
+	{ .compatible = "sophgo,sg2042-reset",
+		.data = &reset_simple_active_low },
 	{ /* sentinel */ },
 };