HID: intel-ish-hid: ipc layer

This layer is responsible for
- Enumerating over PCI bus
- Inform FW about host readiness
- Provide HW interface to transport layer for control and messages
- Interrupt handling and routing

Original-author: Daniel Drubin <daniel.drubin@intel.com>
Reviewed-and-tested-by: Ooi, Joyce <joyce.ooi@intel.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Rann Bar-On <rb6@duke.edu>
Tested-by: Atri Bhattacharya <badshah400@aim.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 333 insertions, 0 deletions

diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
new file mode 100644
index 000000000000..b14d6f4774b9
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -0,0 +1,333 @@
+/*
+ * PCI glue for ISHTP provider device (ISH) driver
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/miscdevice.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/intel_ish.h>
+#include "ishtp-dev.h"
+#include "hw-ish.h"
+
+static const struct pci_device_id ish_pci_tbl[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, CHV_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Bx_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, APL_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, SPT_Ax_DEVICE_ID)},
+	{0, }
+};
+MODULE_DEVICE_TABLE(pci, ish_pci_tbl);
+
+/**
+ * ish_event_tracer() - Callback function to dump trace messages
+ * @dev:	ishtp device
+ * @format:	printf style format
+ *
+ * Callback to direct log messages to Linux trace buffers
+ */
+static void ish_event_tracer(struct ishtp_device *dev, char *format, ...)
+{
+	if (trace_ishtp_dump_enabled()) {
+		va_list args;
+		char tmp_buf[100];
+
+		va_start(args, format);
+		vsnprintf(tmp_buf, sizeof(tmp_buf), format, args);
+		va_end(args);
+
+		trace_ishtp_dump(tmp_buf);
+	}
+}
+
+/**
+ * ish_init() - Init function
+ * @dev:	ishtp device
+ *
+ * This function initialize wait queues for suspend/resume and call
+ * calls hadware initialization function. This will initiate
+ * startup sequence
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_init(struct ishtp_device *dev)
+{
+	int ret;
+
+	/* Set the state of ISH HW to start */
+	ret = ish_hw_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISH: hw start failed.\n");
+		return ret;
+	}
+
+	/* Start the inter process communication to ISH processor */
+	ret = ishtp_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISHTP: Protocol init failed.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ish_probe() - PCI driver probe callback
+ * @pdev:	pci device
+ * @ent:	pci device id
+ *
+ * Initialize PCI function, setup interrupt and call for ISH initialization
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct ishtp_device *dev;
+	struct ish_hw *hw;
+	int	ret;
+
+	/* enable pci dev */
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to enable PCI device\n");
+		return ret;
+	}
+
+	/* set PCI host mastering */
+	pci_set_master(pdev);
+
+	/* pci request regions for ISH driver */
+	ret = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to get PCI regions\n");
+		goto disable_device;
+	}
+
+	/* allocates and initializes the ISH dev structure */
+	dev = ish_dev_init(pdev);
+	if (!dev) {
+		ret = -ENOMEM;
+		goto release_regions;
+	}
+	hw = to_ish_hw(dev);
+	dev->print_log = ish_event_tracer;
+
+	/* mapping IO device memory */
+	hw->mem_addr = pci_iomap(pdev, 0, 0);
+	if (!hw->mem_addr) {
+		dev_err(&pdev->dev, "ISH: mapping I/O range failure\n");
+		ret = -ENOMEM;
+		goto free_device;
+	}
+
+	dev->pdev = pdev;
+
+	pdev->dev_flags |= PCI_DEV_FLAGS_NO_D3;
+
+	/* request and enable interrupt */
+	ret = request_irq(pdev->irq, ish_irq_handler, IRQF_NO_SUSPEND,
+			  KBUILD_MODNAME, dev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: request IRQ failure (%d)\n",
+			pdev->irq);
+		goto free_device;
+	}
+
+	dev_set_drvdata(dev->devc, dev);
+
+	init_waitqueue_head(&dev->suspend_wait);
+	init_waitqueue_head(&dev->resume_wait);
+
+	ret = ish_init(dev);
+	if (ret)
+		goto free_irq;
+
+	return 0;
+
+free_irq:
+	free_irq(pdev->irq, dev);
+free_device:
+	pci_iounmap(pdev, hw->mem_addr);
+	kfree(dev);
+release_regions:
+	pci_release_regions(pdev);
+disable_device:
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	dev_err(&pdev->dev, "ISH: PCI driver initialization failed.\n");
+
+	return ret;
+}
+
+/**
+ * ish_remove() - PCI driver remove callback
+ * @pdev:	pci device
+ *
+ * This function does cleanup of ISH on pci remove callback
+ */
+static void ish_remove(struct pci_dev *pdev)
+{
+	struct ishtp_device *ishtp_dev = pci_get_drvdata(pdev);
+	struct ish_hw *hw = to_ish_hw(ishtp_dev);
+
+	ishtp_bus_remove_all_clients(ishtp_dev, false);
+	ish_device_disable(ishtp_dev);
+
+	free_irq(pdev->irq, ishtp_dev);
+	pci_iounmap(pdev, hw->mem_addr);
+	pci_release_regions(pdev);
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	kfree(ishtp_dev);
+}
+
+static struct device *ish_resume_device;
+
+/**
+ * ish_resume_handler() - Work function to complete resume
+ * @work:	work struct
+ *
+ * The resume work function to complete resume function asynchronously.
+ * There are two types of platforms, one where ISH is not powered off,
+ * in that case a simple resume message is enough, others we need
+ * a reset sequence.
+ */
+static void ish_resume_handler(struct work_struct *work)
+{
+	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+	int ret;
+
+	ishtp_send_resume(dev);
+
+	/* 50 ms to get resume response */
+	if (dev->resume_flag)
+		ret = wait_event_interruptible_timeout(dev->resume_wait,
+						       !dev->resume_flag,
+						       msecs_to_jiffies(50));
+
+	/*
+	 * If no resume response. This platform  is not S0ix compatible
+	 * So on resume full reboot of ISH processor will happen, so
+	 * need to go through init sequence again
+	 */
+	if (dev->resume_flag)
+		ish_init(dev);
+}
+
+/**
+ * ish_suspend() - ISH suspend callback
+ * @device:	device pointer
+ *
+ * ISH suspend callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_suspend(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	enable_irq_wake(pdev->irq);
+	/*
+	 * If previous suspend hasn't been asnwered then ISH is likely dead,
+	 * don't attempt nested notification
+	 */
+	if (dev->suspend_flag)
+		return	0;
+
+	dev->resume_flag = 0;
+	dev->suspend_flag = 1;
+	ishtp_send_suspend(dev);
+
+	/* 25 ms should be enough for live ISH to flush all IPC buf */
+	if (dev->suspend_flag)
+		wait_event_interruptible_timeout(dev->suspend_wait,
+						 !dev->suspend_flag,
+						  msecs_to_jiffies(25));
+
+	return 0;
+}
+
+static DECLARE_WORK(resume_work, ish_resume_handler);
+/**
+ * ish_resume() - ISH resume callback
+ * @device:	device pointer
+ *
+ * ISH resume callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_resume(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	ish_resume_device = device;
+	dev->resume_flag = 1;
+
+	disable_irq_wake(pdev->irq);
+	schedule_work(&resume_work);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static const struct dev_pm_ops ish_pm_ops = {
+	.suspend = ish_suspend,
+	.resume = ish_resume,
+};
+#define ISHTP_ISH_PM_OPS	(&ish_pm_ops)
+#else
+#define ISHTP_ISH_PM_OPS	NULL
+#endif
+
+static struct pci_driver ish_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = ish_pci_tbl,
+	.probe = ish_probe,
+	.remove = ish_remove,
+	.driver.pm = ISHTP_ISH_PM_OPS,
+};
+
+static int __init ish_driver_init(void)
+{
+	return pci_register_driver(&ish_driver);
+}
+
+static void __exit ish_driver_exit(void)
+{
+	pci_unregister_driver(&ish_driver);
+}
+
+module_init(ish_driver_init);
+module_exit(ish_driver_exit);
+
+/* Original author */
+MODULE_AUTHOR("Daniel Drubin <daniel.drubin@intel.com>");
+/* Adoption to upstream Linux kernel */
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+
+MODULE_DESCRIPTION("Intel(R) Integrated Sensor Hub PCI Device Driver");
+MODULE_LICENSE("GPL");