soc: qcom: Add Snapshot of QSEE IPC irq driver

Qualcomm Technologies, Inc. Secure Execution Environment IPC Interrupt Bridge

[Root level node]

Required properties:

-compatible : should be "qcom,qsee-ipc-irq-bridge";

[Second level nodes]

qcom,qsee-ipc-irq-subsystem

Required properties:

-qcom,dev-name: the bridge device name

-interrupt: IPC interrupt line from remote subsystem to QSEE

-label : The name of this subsystem.

Required properties if interrupt type is IRQ_TYPE_LEVEL_HIGH[4]:

-qcom,rx-irq-clr : the register to clear the level triggered rx interrupt

-qcom,rx-irq-clr-mask : the bitmask to clear the rx interrupt

Example:

	qcom,qsee_ipc_irq_bridge {

		compatible = "qcom,qsee-ipc-irq-bridge";

		qcom,qsee-ipc-irq-spss {

			qcom,rx-irq-clr = <0x1d08008 0x4>;

			qcom,rx-irq-clr-mask = <0x2>;

			qcom,dev-name = "qsee_ipc_irq_spss";

			interrupts = <0 349 4>;

			label = "spss";

		};

	};

	  to Alway On processor using QMP transport.

source "drivers/soc/qcom/memshare/Kconfig"

config QSEE_IPC_IRQ_BRIDGE

	tristate "QSEE IPC Interrupt Bridge"

	help

	  This module enables bridging an Inter-Processor Communication(IPC)

	  interrupt from a remote subsystem directed towards Qualcomm

	  Technologies, Inc. Secure Execution Environment(QSEE).

obj-$(CONFIG_QTI_RPM_STATS_LOG) += rpm_stats.o

obj-$(CONFIG_QCOM_SMCINVOKE) += smcinvoke.o

obj-$(CONFIG_QMP_DEBUGFS_CLIENT) += qmp-debugfs-client.o

obj-$(CONFIG_QSEE_IPC_IRQ_BRIDGE) += qsee_ipc_irq_bridge.o

/* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <linux/cdev.h>

#include <linux/interrupt.h>

#include <linux/ipc_logging.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/platform_device.h>

#include <linux/poll.h>

#include <linux/slab.h>

#include <soc/qcom/subsystem_notif.h>

#include <soc/qcom/subsystem_restart.h>

#define MODULE_NAME "qsee_ipc_irq_bridge"

#define DEVICE_NAME MODULE_NAME

#define NUM_LOG_PAGES 4

#define QIIB_DBG(x...) do { \

	if (qiib_info->log_ctx) \

		ipc_log_string(qiib_info->log_ctx, x); \

	else \

		pr_debug(x); \

	} while (0)

#define QIIB_ERR(x...) do { \

	pr_err(x); \

	if (qiib_info->log_ctx) \

		ipc_log_string(qiib_info->log_ctx, x); \

	} while (0)

static void qiib_cleanup(void);

/**

 * qiib_dev - QSEE IPC IRQ bridge device

 * @dev_list:		qiib device list.

 * @i:			Index to this character device.

 * @dev_name:		Device node name used by the clients.

 * @cdev:		structure to the internal character device.

 * @devicep:		Pointer to the qiib class device structure.

 * @poll_wait_queue:	poll thread wait queue.

 * @irq_num:		IRQ number usd for this device.

 * @rx_irq_reset_reg:	Reference to the register to reset the rx irq

 *			line, if applicable.

 * @irq_mask:		Mask written to @rx_irq_reset_reg to clear the irq.

 * @irq_pending_count:	The number of IRQs pending.

 * @irq_pending_count_lock: Lock to protect @irq_pending_cont.

 * @ssr_name:		Name of the subsystem recognized by the SSR framework.

 * @nb:			SSR Notifier callback.

 * @notifier_handle:	SSR Notifier handle.

 * @in_reset:		Flag to check the SSR state.

 */

struct qiib_dev {

	struct list_head dev_list;

	uint32_t i;

	const char *dev_name;

	struct cdev cdev;

	struct device *devicep;

	wait_queue_head_t poll_wait_queue;

	uint32_t irq_line;

	void __iomem *rx_irq_reset_reg;

	uint32_t irq_mask;

	uint32_t irq_pending_count;

	spinlock_t irq_pending_count_lock;

	const char *ssr_name;

	struct notifier_block nb;

	void *notifier_handle;

	bool in_reset;

};

/**

 * qiib_driver_data - QSEE IPC IRQ bridge driver data

 * @list:		list of all nodes devices.

 * @list_lock:		lock to synchronize the @list access.

 * @nprots:		Number of device nodes.

 * @classp:		Pointer to the device class.

 * @dev_num:		qiib device number.

 * @log_ctx:		pointer to the ipc logging context.

 */

struct qiib_driver_data {

	struct list_head list;

	struct mutex list_lock;

	int nports;

	struct class *classp;

	dev_t dev_num;

	void *log_ctx;

};

static struct qiib_driver_data *qiib_info;

/**

 * qiib_driver_data_init() - Initialize the QIIB driver data.

 *

 * This function used to initialize the driver specific data

 * during the module init.

 *

 * Return:	0 for success, Standard Linux errors

 */

static int qiib_driver_data_init(void)

{

	qiib_info = kzalloc(sizeof(*qiib_info), GFP_KERNEL);

	if (!qiib_info)

		return -ENOMEM;

	INIT_LIST_HEAD(&qiib_info->list);

	mutex_init(&qiib_info->list_lock);

	qiib_info->log_ctx = ipc_log_context_create(NUM_LOG_PAGES,

						"qsee_ipc_irq_bridge", 0);

	if (!qiib_info->log_ctx)

		QIIB_ERR("%s: unable to create logging context\n", __func__);

	return 0;

}

/**

 * qiib_driver_data_deinit() - De-Initialize the QIIB driver data.

 *

 * This function used to de-initialize the driver specific data

 * during the module exit.

 */

static void qiib_driver_data_deinit(void)

{

	qiib_cleanup();

	if (!qiib_info->log_ctx)

		ipc_log_context_destroy(qiib_info->log_ctx);

	kfree(qiib_info);

	qiib_info = NULL;

}

/**

 * qiib_restart_notifier_cb() - SSR restart notifier callback function

 * @this:	Notifier block used by the SSR framework

 * @code:	The SSR code for which stage of restart is occurring

 * @data:	Structure containing private data - not used here.

 *

 * This function is a callback for the SSR framework. From here we initiate

 * our handling of SSR.

 *

 * Return: Status of SSR handling

 */

static int qiib_restart_notifier_cb(struct notifier_block *this,

				  unsigned long code,

				  void *data)

{

	struct qiib_dev *devp = container_of(this, struct qiib_dev, nb);

	if (code == SUBSYS_BEFORE_SHUTDOWN) {

		QIIB_DBG("%s: %s: subsystem restart for %s\n", __func__,

				"SUBSYS_BEFORE_SHUTDOWN",

				devp->ssr_name);

		devp->in_reset = true;

		wake_up_interruptible(&devp->poll_wait_queue);

	} else if (code == SUBSYS_AFTER_POWERUP) {

		QIIB_DBG("%s: %s: subsystem restart for %s\n", __func__,

				"SUBSYS_AFTER_POWERUP",

				devp->ssr_name);

		devp->in_reset = false;

	}

	return NOTIFY_DONE;

}

/**

 * qiib_poll() - poll() syscall for the qiib device

 * @file:	Pointer to the file structure.

 * @wait:	pointer to Poll table.

 *

 * This function is used to poll on the qiib device when

 * userspace client do a poll() system call. All input arguments are

 * validated by the virtual file system before calling this function.

 *

 * Return: POLLIN for interrupt intercepted case and POLLRDHUP for SSR.

 */

static unsigned int qiib_poll(struct file *file, poll_table *wait)

{

	struct qiib_dev *devp = file->private_data;

	unsigned int mask = 0;

	unsigned long flags;

	if (!devp) {

		QIIB_ERR("%s on NULL device\n", __func__);

		return POLLERR;

	}

	if (devp->in_reset)

		return POLLRDHUP;

	poll_wait(file, &devp->poll_wait_queue, wait);

	spin_lock_irqsave(&devp->irq_pending_count_lock, flags);

	if (devp->irq_pending_count) {

		mask |= POLLIN;

		QIIB_DBG("%s set POLLIN on [%s] count[%d]\n",

					__func__, devp->dev_name,

					devp->irq_pending_count);

		devp->irq_pending_count = 0;

	}

	spin_unlock_irqrestore(&devp->irq_pending_count_lock, flags);

	if (devp->in_reset) {

		mask |= POLLRDHUP;

		QIIB_DBG("%s set POLLRDHUP on [%s] count[%d]\n",

					__func__, devp->dev_name,

					devp->irq_pending_count);

	}

	return mask;

}

/**

 * qiib_open() - open() syscall for the qiib device

 * @inode:	Pointer to the inode structure.

 * @file:	Pointer to the file structure.

 *

 * This function is used to open the qiib device when

 * userspace client do a open() system call. All input arguments are

 * validated by the virtual file system before calling this function.

 *

 * Return:	0 for success, Standard Linux errors

 */

static int qiib_open(struct inode *inode, struct file *file)

{

	struct qiib_dev *devp = NULL;

	devp = container_of(inode->i_cdev, struct qiib_dev, cdev);

	if (!devp) {

		QIIB_ERR("%s on NULL device\n", __func__);

		return -EINVAL;

	}

	file->private_data = devp;

	QIIB_DBG("%s on [%s]\n", __func__, devp->dev_name);

	return 0;

}

/**

 * qiib_release() - release operation on qiibdevice

 * @inode:	Pointer to the inode structure.

 * @file:	Pointer to the file structure.

 *

 * This function is used to release the qiib device when

 * userspace client do a close() system call. All input arguments are

 * validated by the virtual file system before calling this function.

 */

static int qiib_release(struct inode *inode, struct file *file)

{

	struct qiib_dev *devp = file->private_data;

	if (!devp) {

		QIIB_ERR("%s on NULL device\n", __func__);

		return -EINVAL;

	}

	QIIB_DBG("%s on [%s]\n", __func__, devp->dev_name);

	return 0;

}

static const struct file_operations qiib_fops = {

	.owner = THIS_MODULE,

	.open = qiib_open,

	.release = qiib_release,

	.poll = qiib_poll,

};

/**

 * qiib_add_device() - Initialize qiib device and add cdev

 * @devp:	pointer to the qiib device.

 * @i:		index of the qiib device.

 *

 * Return:	0 for success, Standard Linux errors

 */

static int qiib_add_device(struct qiib_dev *devp, int i)

{

	int ret = 0;

	devp->i = i;

	init_waitqueue_head(&devp->poll_wait_queue);

	spin_lock_init(&devp->irq_pending_count_lock);

	cdev_init(&devp->cdev, &qiib_fops);

	devp->cdev.owner = THIS_MODULE;

	ret = cdev_add(&devp->cdev, qiib_info->dev_num + i, 1);

	if (IS_ERR_VALUE((unsigned long)ret)) {

		QIIB_ERR("%s: cdev_add() failed for dev [%s] ret:%i\n",

			__func__, devp->dev_name, ret);

		return ret;

	}

	devp->devicep = device_create(qiib_info->classp,

			      NULL,

			      (qiib_info->dev_num + i),

			      NULL,

			      devp->dev_name);

	if (IS_ERR_OR_NULL(devp->devicep)) {

		QIIB_ERR("%s: device_create() failed for dev [%s]\n",

			__func__, devp->dev_name);

		ret = -ENOMEM;

		cdev_del(&devp->cdev);

		return ret;

	}

	mutex_lock(&qiib_info->list_lock);

	list_add(&devp->dev_list, &qiib_info->list);

	mutex_unlock(&qiib_info->list_lock);

	return ret;

}

static irqreturn_t qiib_irq_handler(int irq, void *priv)

{

	struct qiib_dev *devp = priv;

	unsigned long flags;

	spin_lock_irqsave(&devp->irq_pending_count_lock, flags);

	devp->irq_pending_count++;

	spin_unlock_irqrestore(&devp->irq_pending_count_lock, flags);

	wake_up_interruptible(&devp->poll_wait_queue);

	if (devp->rx_irq_reset_reg)

		writel_relaxed(devp->irq_mask, devp->rx_irq_reset_reg);

	QIIB_DBG("%s name[%s] pend_count[%d]\n", __func__,

				devp->dev_name, devp->irq_pending_count);

	return IRQ_HANDLED;

}

/**

 * qiib_parse_node() - parse node from device tree binding

 * @node:	pointer to device tree node

 * @devp:	pointer to the qiib device

 *

 * Return:	0 on success, -ENODEV on failure.

 */

static int qiib_parse_node(struct device_node *node, struct qiib_dev *devp)

{

	char *key;

	const char *subsys_name;

	const char *dev_name;

	uint32_t irqtype;

	uint32_t irq_clear[2];

	struct irq_data *irqtype_data;

	int ret = -ENODEV;

	key = "qcom,dev-name";

	dev_name = of_get_property(node, key, NULL);

	if (!dev_name) {

		QIIB_ERR("%s: missing key: %s\n", __func__, key);

		goto missing_key;

	}

	QIIB_DBG("%s: %s = %s\n", __func__, key, dev_name);

	key = "interrupts";

	devp->irq_line = irq_of_parse_and_map(node, 0);

	if (!devp->irq_line) {

		QIIB_ERR("%s: missing key: %s\n", __func__, key);

		goto missing_key;

	}

	QIIB_DBG("%s: %s = %d\n", __func__, key, devp->irq_line);

	irqtype_data = irq_get_irq_data(devp->irq_line);

	if (!irqtype_data) {

		QIIB_ERR("%s: get irqdata fail:%d\n", __func__, devp->irq_line);

		goto missing_key;

	}

	irqtype = irqd_get_trigger_type(irqtype_data);

	QIIB_DBG("%s: irqtype = %d\n", __func__, irqtype);

	key = "label";

	subsys_name = of_get_property(node, key, NULL);

	if (!subsys_name) {

		QIIB_ERR("%s: missing key: %s\n", __func__, key);

		goto missing_key;

	}

	QIIB_DBG("%s: %s = %s\n", __func__, key, subsys_name);

	if (irqtype & IRQF_TRIGGER_HIGH) {

		key = "qcom,rx-irq-clr-mask";

		ret = of_property_read_u32(node, key, &devp->irq_mask);

		if (ret) {

			QIIB_ERR("%s: missing key: %s\n", __func__, key);

			ret = -ENODEV;

			goto missing_key;

		}

		QIIB_DBG("%s: %s = %d\n", __func__, key, devp->irq_mask);

		key = "qcom,rx-irq-clr";

		ret = of_property_read_u32_array(node, key, irq_clear,

							ARRAY_SIZE(irq_clear));

		if (ret) {

			QIIB_ERR("%s: missing key: %s\n", __func__, key);

			ret = -ENODEV;

			goto missing_key;

		}

		devp->rx_irq_reset_reg = ioremap_nocache(irq_clear[0],

								irq_clear[1]);

		if (!devp->rx_irq_reset_reg) {

			QIIB_ERR("%s: unable to map rx reset reg\n", __func__);

			ret = -ENOMEM;

			goto missing_key;

		}

	}

	devp->dev_name = dev_name;

	devp->ssr_name = subsys_name;

	devp->nb.notifier_call = qiib_restart_notifier_cb;

	devp->notifier_handle = subsys_notif_register_notifier(devp->ssr_name,

								&devp->nb);

	if (IS_ERR_OR_NULL(devp->notifier_handle)) {

		QIIB_ERR("%s: Could not register SSR notifier cb\n", __func__);

		ret = -EINVAL;

		goto ssr_reg_fail;

	}

	ret = request_irq(devp->irq_line, qiib_irq_handler,

			irqtype | IRQF_NO_SUSPEND,

			devp->dev_name, devp);

	if (ret < 0) {

		QIIB_ERR("%s: request_irq() failed on %d\n", __func__,

				devp->irq_line);

		goto req_irq_fail;

	} else {

		ret = enable_irq_wake(devp->irq_line);

		if (ret < 0)

			QIIB_ERR("%s: enable_irq_wake() failed on %d\n",

					__func__, devp->irq_line);

	}

	return ret;

req_irq_fail:

	subsys_notif_unregister_notifier(devp->notifier_handle,	&devp->nb);

ssr_reg_fail:

	if (devp->rx_irq_reset_reg) {

		iounmap(devp->rx_irq_reset_reg);

		devp->rx_irq_reset_reg = NULL;

	}

missing_key:

	return ret;

}

/**

 * qiib_cleanup - cleanup all the resources

 *

 * This function remove all the memory and unregister

 * the char device region.

 */

static void qiib_cleanup(void)

{

	struct qiib_dev *devp;

	struct qiib_dev *index;

	mutex_lock(&qiib_info->list_lock);

	list_for_each_entry_safe(devp, index, &qiib_info->list, dev_list) {

		cdev_del(&devp->cdev);

		list_del(&devp->dev_list);

		device_destroy(qiib_info->classp,

			       MKDEV(MAJOR(qiib_info->dev_num), devp->i));

		if (devp->notifier_handle)

			subsys_notif_unregister_notifier(devp->notifier_handle,

								&devp->nb);

		kfree(devp);

	}

	mutex_unlock(&qiib_info->list_lock);

	if (!IS_ERR_OR_NULL(qiib_info->classp))

		class_destroy(qiib_info->classp);

	unregister_chrdev_region(MAJOR(qiib_info->dev_num), qiib_info->nports);

}

/**

 * qiib_alloc_chrdev_region() - allocate the char device region

 *

 * This function allocate memory for qiib character-device region and

 * create the class.

 */

static int qiib_alloc_chrdev_region(void)

{

	int ret;

	ret = alloc_chrdev_region(&qiib_info->dev_num,

			       0,

			       qiib_info->nports,

			       DEVICE_NAME);

	if (IS_ERR_VALUE((unsigned long)ret)) {

		QIIB_ERR("%s: alloc_chrdev_region() failed ret:%i\n",

			__func__, ret);

		return ret;

	}

	qiib_info->classp = class_create(THIS_MODULE, DEVICE_NAME);

	if (IS_ERR(qiib_info->classp)) {

		QIIB_ERR("%s: class_create() failed ENOMEM\n", __func__);

		ret = -ENOMEM;

		unregister_chrdev_region(MAJOR(qiib_info->dev_num),

						qiib_info->nports);

		return ret;

	}

	return 0;

}

static int qsee_ipc_irq_bridge_probe(struct platform_device *pdev)

{

	int ret;

	struct device_node *node;

	struct qiib_dev *devp;

	int i = 0;

	qiib_info->nports = of_get_available_child_count(pdev->dev.of_node);

	if (!qiib_info->nports) {

		QIIB_ERR("%s:Fail nports = %d\n", __func__, qiib_info->nports);

		return -EINVAL;

	}

	ret = qiib_alloc_chrdev_region();

	if (ret) {

		QIIB_ERR("%s: chrdev_region allocation failed ret:%i\n",

			__func__, ret);

		return ret;

	}

	for_each_available_child_of_node(pdev->dev.of_node, node) {

		devp = kzalloc(sizeof(*devp), GFP_KERNEL);

		if (IS_ERR_OR_NULL(devp)) {

			QIIB_ERR("%s:Allocation failed id:%d\n", __func__, i);

			ret = -ENOMEM;

			goto error;

		}

		ret = qiib_parse_node(node, devp);

		if (ret) {

			QIIB_ERR("%s:qiib_parse_node failed %d\n", __func__, i);

			kfree(devp);

			goto error;

		}

		ret = qiib_add_device(devp, i);

		if (ret < 0) {

			QIIB_ERR("%s: add [%s] device failed ret=%d\n",

					__func__, devp->dev_name, ret);

			kfree(devp);

			goto error;

		}

		i++;

	}

	QIIB_DBG("%s: Driver Initialized.\n", __func__);

	return 0;

error:

	qiib_cleanup();

	return ret;

}

static int qsee_ipc_irq_bridge_remove(struct platform_device *pdev)

{

	qiib_cleanup();

	return 0;

}

static const struct of_device_id qsee_ipc_irq_bridge_match_table[] = {

	{ .compatible = "qcom,qsee-ipc-irq-bridge" },

	{},

};

static struct platform_driver qsee_ipc_irq_bridge_driver = {

	.probe = qsee_ipc_irq_bridge_probe,

	.remove = qsee_ipc_irq_bridge_remove,

	.driver = {

		.name = MODULE_NAME,

		.owner = THIS_MODULE,

		.of_match_table = qsee_ipc_irq_bridge_match_table,

	 },

};

static int __init qsee_ipc_irq_bridge_init(void)

{

	int ret;

	ret = qiib_driver_data_init();

	if (ret) {

		QIIB_ERR("%s: driver data init failed %d\n",

			__func__, ret);

		return ret;

	}

	ret = platform_driver_register(&qsee_ipc_irq_bridge_driver);

	if (ret) {

		QIIB_ERR("%s: platform driver register failed %d\n",

			__func__, ret);

		return ret;

	}

	return 0;

}

module_init(qsee_ipc_irq_bridge_init);

static void __exit qsee_ipc_irq_bridge_exit(void)

{

	platform_driver_unregister(&qsee_ipc_irq_bridge_driver);

	qiib_driver_data_deinit();

}

module_exit(qsee_ipc_irq_bridge_exit);

MODULE_DESCRIPTION("QSEE IPC interrupt bridge");

MODULE_LICENSE("GPL v2");