text: // SPDX-License-Identifier: GPL-2.0
  /*
   * nvec_ps2: mouse driver for a NVIDIA compliant embedded controller
   *
   * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
   *
   * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
   *           Ilya Petrov <ilya.muromec@gmail.com>
   *           Marc Dietrich <marvin24@gmx.de>
   */
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/serio.h>
  #include <linux/delay.h>
  #include <linux/platform_device.h>
  
  #include "nvec.h"
  
  #define PACKET_SIZE	6
  
  #define ENABLE_MOUSE	0xf4
  #define DISABLE_MOUSE	0xf5
  #define PSMOUSE_RST	0xff
  
  #ifdef NVEC_PS2_DEBUG
  #define NVEC_PHD(str, buf, len) \
  	print_hex_dump(KERN_DEBUG, str, DUMP_PREFIX_NONE, \
  			16, 1, buf, len, false)
  #else
  #define NVEC_PHD(str, buf, len) do { } while (0)
  #endif
  
  enum ps2_subcmds {
  	SEND_COMMAND = 1,
  	RECEIVE_N,
  	AUTO_RECEIVE_N,
  	CANCEL_AUTO_RECEIVE,
  };
  
  struct nvec_ps2 {
  	struct serio *ser_dev;
  	struct notifier_block notifier;
  	struct nvec_chip *nvec;
  };
  
  static struct nvec_ps2 ps2_dev;
  
  static int ps2_startstreaming(struct serio *ser_dev)
  {
  	unsigned char buf[] = { NVEC_PS2, AUTO_RECEIVE_N, PACKET_SIZE };
  
  	return nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
  }
  
  static void ps2_stopstreaming(struct serio *ser_dev)
  {
  	unsigned char buf[] = { NVEC_PS2, CANCEL_AUTO_RECEIVE };
  
  	nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
  }
  
  static int ps2_sendcommand(struct serio *ser_dev, unsigned char cmd)
  {
  	unsigned char buf[] = { NVEC_PS2, SEND_COMMAND, ENABLE_MOUSE, 1 };
  
  	buf[2] = cmd & 0xff;
  
  	dev_dbg(&ser_dev->dev, "Sending ps2 cmd %02x\n", cmd);
  	return nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
  }
  
  static int nvec_ps2_notifier(struct notifier_block *nb,
  			     unsigned long event_type, void *data)
  {
  	int i;
  	unsigned char *msg = data;
  
  	switch (event_type) {
  	case NVEC_PS2_EVT:
  		for (i = 0; i < msg[1]; i++)
  			serio_interrupt(ps2_dev.ser_dev, msg[2 + i], 0);
  		NVEC_PHD("ps/2 mouse event: ", &msg[2], msg[1]);
  		return NOTIFY_STOP;
  
  	case NVEC_PS2:
  		if (msg[2] == 1) {
  			for (i = 0; i < (msg[1] - 2); i++)
  				serio_interrupt(ps2_dev.ser_dev, msg[i + 4], 0);
  			NVEC_PHD("ps/2 mouse reply: ", &msg[4], msg[1] - 2);
  		}
  
  		else if (msg[1] != 2) /* !ack */
  			NVEC_PHD("unhandled mouse event: ", msg, msg[1] + 2);
  		return NOTIFY_STOP;
  	}
  
  	return NOTIFY_DONE;
  }
  
  static int nvec_mouse_probe(struct platform_device *pdev)
  {
  	struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
  	struct serio *ser_dev;
  
  	ser_dev = kzalloc(sizeof(*ser_dev), GFP_KERNEL);
  	if (!ser_dev)
  		return -ENOMEM;
  
  	ser_dev->id.type = SERIO_8042;
  	ser_dev->write = ps2_sendcommand;
  	ser_dev->start = ps2_startstreaming;
  	ser_dev->stop = ps2_stopstreaming;
  
  	strscpy(ser_dev->name, "nvec mouse", sizeof(ser_dev->name));
  	strscpy(ser_dev->phys, "nvec", sizeof(ser_dev->phys));
  
  	ps2_dev.ser_dev = ser_dev;
  	ps2_dev.notifier.notifier_call = nvec_ps2_notifier;
  	ps2_dev.nvec = nvec;
  	nvec_register_notifier(nvec, &ps2_dev.notifier, 0);
  
  	serio_register_port(ser_dev);
  
  	return 0;
  }
  
  static int nvec_mouse_remove(struct platform_device *pdev)
  {
  	struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
  
  	ps2_sendcommand(ps2_dev.ser_dev, DISABLE_MOUSE);
  	ps2_stopstreaming(ps2_dev.ser_dev);
  	nvec_unregister_notifier(nvec, &ps2_dev.notifier);
  	serio_unregister_port(ps2_dev.ser_dev);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int nvec_mouse_suspend(struct device *dev)
  {
  	/* disable mouse */
  	ps2_sendcommand(ps2_dev.ser_dev, DISABLE_MOUSE);
  
  	/* send cancel autoreceive */
  	ps2_stopstreaming(ps2_dev.ser_dev);
  
  	return 0;
  }
  
  static int nvec_mouse_resume(struct device *dev)
  {
  	/* start streaming */
  	ps2_startstreaming(ps2_dev.ser_dev);
  
  	/* enable mouse */
  	ps2_sendcommand(ps2_dev.ser_dev, ENABLE_MOUSE);
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(nvec_mouse_pm_ops, nvec_mouse_suspend,
  			 nvec_mouse_resume);
  
  static struct platform_driver nvec_mouse_driver = {
  	.probe  = nvec_mouse_probe,
  	.remove = nvec_mouse_remove,
  	.driver = {
  		.name = "nvec-mouse",
  		.pm = &nvec_mouse_pm_ops,
  	},
  };
  
  module_platform_driver(nvec_mouse_driver);
  
  MODULE_DESCRIPTION("NVEC mouse driver");
  MODULE_AUTHOR("Marc Dietrich <marvin24@gmx.de>");
  MODULE_ALIAS("platform:nvec-mouse");
  MODULE_LICENSE("GPL");
  