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-rw-r--r--drivers/reset/Kconfig12
-rw-r--r--drivers/reset/Makefile1
-rw-r--r--drivers/reset/core.c224
-rw-r--r--drivers/reset/reset-gpio.c119
-rw-r--r--drivers/reset/reset-simple.c2
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 */ },
};