1 files changed, 690 insertions, 0 deletions
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
new file mode 100644
index 000000000..c66a04d24
--- /dev/null
+++ b/drivers/tty/serdev/core.c
@@ -0,0 +1,690 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
+ *
+ * Based on drivers/spmi/spmi.c:
+ * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/serdev.h>
+#include <linux/slab.h>
+
+static bool is_registered;
+static DEFINE_IDA(ctrl_ida);
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+	if (len != -ENODEV)
+		return len;
+
+	return of_device_modalias(dev, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *serdev_device_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(serdev_device);
+
+static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	int rc;
+
+	/* TODO: platform modalias */
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
+
+	return of_device_uevent_modalias(dev, env);
+}
+
+static void serdev_device_release(struct device *dev)
+{
+	struct serdev_device *serdev = to_serdev_device(dev);
+	kfree(serdev);
+}
+
+static const struct device_type serdev_device_type = {
+	.groups		= serdev_device_groups,
+	.uevent		= serdev_device_uevent,
+	.release	= serdev_device_release,
+};
+
+static bool is_serdev_device(const struct device *dev)
+{
+	return dev->type == &serdev_device_type;
+}
+
+static void serdev_ctrl_release(struct device *dev)
+{
+	struct serdev_controller *ctrl = to_serdev_controller(dev);
+	ida_simple_remove(&ctrl_ida, ctrl->nr);
+	kfree(ctrl);
+}
+
+static const struct device_type serdev_ctrl_type = {
+	.release	= serdev_ctrl_release,
+};
+
+static int serdev_device_match(struct device *dev, struct device_driver *drv)
+{
+	if (!is_serdev_device(dev))
+		return 0;
+
+	/* TODO: platform matching */
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
+	return of_driver_match_device(dev, drv);
+}
+
+/**
+ * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
+ * @serdev:	serdev_device to be added
+ */
+int serdev_device_add(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	struct device *parent = serdev->dev.parent;
+	int err;
+
+	dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
+
+	/* Only a single slave device is currently supported. */
+	if (ctrl->serdev) {
+		dev_err(&serdev->dev, "controller busy\n");
+		return -EBUSY;
+	}
+	ctrl->serdev = serdev;
+
+	err = device_add(&serdev->dev);
+	if (err < 0) {
+		dev_err(&serdev->dev, "Can't add %s, status %d\n",
+			dev_name(&serdev->dev), err);
+		goto err_clear_serdev;
+	}
+
+	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
+
+	return 0;
+
+err_clear_serdev:
+	ctrl->serdev = NULL;
+	return err;
+}
+EXPORT_SYMBOL_GPL(serdev_device_add);
+
+/**
+ * serdev_device_remove(): remove an serdev device
+ * @serdev:	serdev_device to be removed
+ */
+void serdev_device_remove(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	device_unregister(&serdev->dev);
+	ctrl->serdev = NULL;
+}
+EXPORT_SYMBOL_GPL(serdev_device_remove);
+
+int serdev_device_open(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	int ret;
+
+	if (!ctrl || !ctrl->ops->open)
+		return -EINVAL;
+
+	ret = ctrl->ops->open(ctrl);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_get_sync(&ctrl->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&ctrl->dev);
+		goto err_close;
+	}
+
+	return 0;
+
+err_close:
+	if (ctrl->ops->close)
+		ctrl->ops->close(ctrl);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(serdev_device_open);
+
+void serdev_device_close(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->close)
+		return;
+
+	pm_runtime_put(&ctrl->dev);
+
+	ctrl->ops->close(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_close);
+
+static void devm_serdev_device_release(struct device *dev, void *dr)
+{
+	serdev_device_close(*(struct serdev_device **)dr);
+}
+
+int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
+{
+	struct serdev_device **dr;
+	int ret;
+
+	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	*dr = serdev;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_serdev_device_open);
+
+void serdev_device_write_wakeup(struct serdev_device *serdev)
+{
+	complete(&serdev->write_comp);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
+
+int serdev_device_write_buf(struct serdev_device *serdev,
+			    const unsigned char *buf, size_t count)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_buf)
+		return -EINVAL;
+
+	return ctrl->ops->write_buf(ctrl, buf, count);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_buf);
+
+int serdev_device_write(struct serdev_device *serdev,
+			const unsigned char *buf, size_t count,
+			unsigned long timeout)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	int ret;
+
+	if (!ctrl || !ctrl->ops->write_buf ||
+	    (timeout && !serdev->ops->write_wakeup))
+		return -EINVAL;
+
+	mutex_lock(&serdev->write_lock);
+	do {
+		reinit_completion(&serdev->write_comp);
+
+		ret = ctrl->ops->write_buf(ctrl, buf, count);
+		if (ret < 0)
+			break;
+
+		buf += ret;
+		count -= ret;
+
+	} while (count &&
+		 (timeout = wait_for_completion_timeout(&serdev->write_comp,
+							timeout)));
+	mutex_unlock(&serdev->write_lock);
+	return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write);
+
+void serdev_device_write_flush(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_flush)
+		return;
+
+	ctrl->ops->write_flush(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_flush);
+
+int serdev_device_write_room(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_room)
+		return 0;
+
+	return serdev->ctrl->ops->write_room(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_room);
+
+unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_baudrate)
+		return 0;
+
+	return ctrl->ops->set_baudrate(ctrl, speed);
+
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
+
+void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_flow_control)
+		return;
+
+	ctrl->ops->set_flow_control(ctrl, enable);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
+
+int serdev_device_set_parity(struct serdev_device *serdev,
+			     enum serdev_parity parity)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_parity)
+		return -ENOTSUPP;
+
+	return ctrl->ops->set_parity(ctrl, parity);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_parity);
+
+void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->wait_until_sent)
+		return;
+
+	ctrl->ops->wait_until_sent(ctrl, timeout);
+}
+EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
+
+int serdev_device_get_tiocm(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->get_tiocm)
+		return -ENOTSUPP;
+
+	return ctrl->ops->get_tiocm(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
+
+int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_tiocm)
+		return -ENOTSUPP;
+
+	return ctrl->ops->set_tiocm(ctrl, set, clear);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
+
+static int serdev_drv_probe(struct device *dev)
+{
+	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+	int ret;
+
+	ret = dev_pm_domain_attach(dev, true);
+	if (ret)
+		return ret;
+
+	ret = sdrv->probe(to_serdev_device(dev));
+	if (ret)
+		dev_pm_domain_detach(dev, true);
+
+	return ret;
+}
+
+static int serdev_drv_remove(struct device *dev)
+{
+	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+	if (sdrv->remove)
+		sdrv->remove(to_serdev_device(dev));
+
+	dev_pm_domain_detach(dev, true);
+
+	return 0;
+}
+
+static struct bus_type serdev_bus_type = {
+	.name		= "serial",
+	.match		= serdev_device_match,
+	.probe		= serdev_drv_probe,
+	.remove		= serdev_drv_remove,
+};
+
+/**
+ * serdev_device_alloc() - Allocate a new serdev device
+ * @ctrl:	associated controller
+ *
+ * Caller is responsible for either calling serdev_device_add() to add the
+ * newly allocated controller, or calling serdev_device_put() to discard it.
+ */
+struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
+{
+	struct serdev_device *serdev;
+
+	serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
+	if (!serdev)
+		return NULL;
+
+	serdev->ctrl = ctrl;
+	device_initialize(&serdev->dev);
+	serdev->dev.parent = &ctrl->dev;
+	serdev->dev.bus = &serdev_bus_type;
+	serdev->dev.type = &serdev_device_type;
+	init_completion(&serdev->write_comp);
+	mutex_init(&serdev->write_lock);
+	return serdev;
+}
+EXPORT_SYMBOL_GPL(serdev_device_alloc);
+
+/**
+ * serdev_controller_alloc() - Allocate a new serdev controller
+ * @parent:	parent device
+ * @size:	size of private data
+ *
+ * Caller is responsible for either calling serdev_controller_add() to add the
+ * newly allocated controller, or calling serdev_controller_put() to discard it.
+ * The allocated private data region may be accessed via
+ * serdev_controller_get_drvdata()
+ */
+struct serdev_controller *serdev_controller_alloc(struct device *parent,
+					      size_t size)
+{
+	struct serdev_controller *ctrl;
+	int id;
+
+	if (WARN_ON(!parent))
+		return NULL;
+
+	ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
+	if (!ctrl)
+		return NULL;
+
+	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		dev_err(parent,
+			"unable to allocate serdev controller identifier.\n");
+		goto err_free;
+	}
+
+	ctrl->nr = id;
+
+	device_initialize(&ctrl->dev);
+	ctrl->dev.type = &serdev_ctrl_type;
+	ctrl->dev.bus = &serdev_bus_type;
+	ctrl->dev.parent = parent;
+	ctrl->dev.of_node = parent->of_node;
+	serdev_controller_set_drvdata(ctrl, &ctrl[1]);
+
+	dev_set_name(&ctrl->dev, "serial%d", id);
+
+	pm_runtime_no_callbacks(&ctrl->dev);
+	pm_suspend_ignore_children(&ctrl->dev, true);
+
+	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
+	return ctrl;
+
+err_free:
+	kfree(ctrl);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(serdev_controller_alloc);
+
+static int of_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	struct device_node *node;
+	struct serdev_device *serdev = NULL;
+	int err;
+	bool found = false;
+
+	for_each_available_child_of_node(ctrl->dev.of_node, node) {
+		if (!of_get_property(node, "compatible", NULL))
+			continue;
+
+		dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
+
+		serdev = serdev_device_alloc(ctrl);
+		if (!serdev)
+			continue;
+
+		serdev->dev.of_node = node;
+
+		err = serdev_device_add(serdev);
+		if (err) {
+			dev_err(&serdev->dev,
+				"failure adding device. status %d\n", err);
+			serdev_device_put(serdev);
+		} else
+			found = true;
+	}
+	if (!found)
+		return -ENODEV;
+
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
+					    struct acpi_device *adev)
+{
+	struct serdev_device *serdev = NULL;
+	int err;
+
+	if (acpi_bus_get_status(adev) || !adev->status.present ||
+	    acpi_device_enumerated(adev))
+		return AE_OK;
+
+	serdev = serdev_device_alloc(ctrl);
+	if (!serdev) {
+		dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
+			dev_name(&adev->dev));
+		return AE_NO_MEMORY;
+	}
+
+	ACPI_COMPANION_SET(&serdev->dev, adev);
+	acpi_device_set_enumerated(adev);
+
+	err = serdev_device_add(serdev);
+	if (err) {
+		dev_err(&serdev->dev,
+			"failure adding ACPI serdev device. status %d\n", err);
+		serdev_device_put(serdev);
+	}
+
+	return AE_OK;
+}
+
+static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
+	{ "INT3511", 0 },
+	{ "INT3512", 0 },
+	{ },
+};
+
+static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
+				       void *data, void **return_value)
+{
+	struct serdev_controller *ctrl = data;
+	struct acpi_device *adev;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+
+	/* Skip if black listed */
+	if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
+		return AE_OK;
+
+	return acpi_serdev_register_device(ctrl, adev);
+}
+
+static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	acpi_status status;
+	acpi_handle handle;
+
+	handle = ACPI_HANDLE(ctrl->dev.parent);
+	if (!handle)
+		return -ENODEV;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+				     acpi_serdev_add_device, NULL, ctrl, NULL);
+	if (ACPI_FAILURE(status))
+		dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");
+
+	if (!ctrl->serdev)
+		return -ENODEV;
+
+	return 0;
+}
+#else
+static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_ACPI */
+
+/**
+ * serdev_controller_add() - Add an serdev controller
+ * @ctrl:	controller to be registered.
+ *
+ * Register a controller previously allocated via serdev_controller_alloc() with
+ * the serdev core.
+ */
+int serdev_controller_add(struct serdev_controller *ctrl)
+{
+	int ret_of, ret_acpi, ret;
+
+	/* Can't register until after driver model init */
+	if (WARN_ON(!is_registered))
+		return -EAGAIN;
+
+	ret = device_add(&ctrl->dev);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&ctrl->dev);
+
+	ret_of = of_serdev_register_devices(ctrl);
+	ret_acpi = acpi_serdev_register_devices(ctrl);
+	if (ret_of && ret_acpi) {
+		dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
+			ret_of, ret_acpi);
+		ret = -ENODEV;
+		goto err_rpm_disable;
+	}
+
+	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
+		ctrl->nr, &ctrl->dev);
+	return 0;
+
+err_rpm_disable:
+	pm_runtime_disable(&ctrl->dev);
+	device_del(&ctrl->dev);
+	return ret;
+};
+EXPORT_SYMBOL_GPL(serdev_controller_add);
+
+/* Remove a device associated with a controller */
+static int serdev_remove_device(struct device *dev, void *data)
+{
+	struct serdev_device *serdev = to_serdev_device(dev);
+	if (dev->type == &serdev_device_type)
+		serdev_device_remove(serdev);
+	return 0;
+}
+
+/**
+ * serdev_controller_remove(): remove an serdev controller
+ * @ctrl:	controller to remove
+ *
+ * Remove a serdev controller.  Caller is responsible for calling
+ * serdev_controller_put() to discard the allocated controller.
+ */
+void serdev_controller_remove(struct serdev_controller *ctrl)
+{
+	int dummy;
+
+	if (!ctrl)
+		return;
+
+	dummy = device_for_each_child(&ctrl->dev, NULL,
+				      serdev_remove_device);
+	pm_runtime_disable(&ctrl->dev);
+	device_del(&ctrl->dev);
+}
+EXPORT_SYMBOL_GPL(serdev_controller_remove);
+
+/**
+ * serdev_driver_register() - Register client driver with serdev core
+ * @sdrv:	client driver to be associated with client-device.
+ *
+ * This API will register the client driver with the serdev framework.
+ * It is typically called from the driver's module-init function.
+ */
+int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
+{
+	sdrv->driver.bus = &serdev_bus_type;
+	sdrv->driver.owner = owner;
+
+	/* force drivers to async probe so I/O is possible in probe */
+        sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
+
+	return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
+
+static void __exit serdev_exit(void)
+{
+	bus_unregister(&serdev_bus_type);
+	ida_destroy(&ctrl_ida);
+}
+module_exit(serdev_exit);
+
+static int __init serdev_init(void)
+{
+	int ret;
+
+	ret = bus_register(&serdev_bus_type);
+	if (ret)
+		return ret;
+
+	is_registered = true;
+	return 0;
+}
+/* Must be before serial drivers register */
+postcore_initcall(serdev_init);
+
+MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Serial attached device bus");