/*
** =========================================================================
** File:
**     tspdrv.c
**
** Description:
**     TouchSense Kernel Module main entry-point.
**
** Portions Copyright (c) 2008-2010 Immersion Corporation. All Rights Reserved.
**
** This file contains Original Code and/or Modifications of Original Code
** as defined in and that are subject to the GNU Public License v2 -
** (the 'License'). You may not use this file except in compliance with the
** License. You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software Foundation, Inc.,
** 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or contact
** TouchSenseSales@immersion.com.
**
** The Original Code and all software distributed under the License are
** distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
** EXPRESS OR IMPLIED, AND IMMERSION HEREBY DISCLAIMS ALL SUCH WARRANTIES,
** INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
** FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see
** the License for the specific language governing rights and limitations
** under the License.
** =========================================================================
*/

#ifndef __KERNEL__
#define __KERNEL__
#endif

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/version.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/hrtimer.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/wakelock.h>
#include <linux/io.h>
#include <mach/map.h>

#if defined(CONFIG_MACH_GRANDE)
#include <linux/regulator/consumer.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#endif

#include "tspdrv.h"
#ifdef CONFIG_MOTOR_DRV_ISA1200
#include "ImmVibeSPI_isa1200.c"
#else
#include "ImmVibeSPI.c"
#endif
#if defined(VIBE_DEBUG) && defined(VIBE_RECORD)
#include <tspdrvRecorder.c>
#endif

/* Device name and version information */

/* DO NOT CHANGE - this is auto-generated */
#define VERSION_STR " v3.4.55.8\n"

/* account extra space for future extra digits in version number */
#define VERSION_STR_LEN 16

/* initialized in init_module */
static char g_szDeviceName[(VIBE_MAX_DEVICE_NAME_LENGTH
							+ VERSION_STR_LEN)
							* NUM_ACTUATORS];
/* initialized in init_module */
static size_t g_cchDeviceName;

static struct wake_lock vib_wake_lock;

/* Flag indicating whether the driver is in use */
static char g_bIsPlaying;

/* Buffer to store data sent to SPI */
#define SPI_BUFFER_SIZE (NUM_ACTUATORS * \
	(VIBE_OUTPUT_SAMPLE_SIZE + SPI_HEADER_SIZE))
static int g_bStopRequested;
static actuator_samples_buffer g_SamplesBuffer[NUM_ACTUATORS] = { {0} };
static char g_cWriteBuffer[SPI_BUFFER_SIZE];

/* #define VIBE_TUNING */
/* #define VIBE_ENABLE_SYSTEM_TIMER */
/* #define IMPLEMENT_AS_CHAR_DRIVER */

/* For QA purposes */
#ifdef QA_TEST
#define FORCE_LOG_BUFFER_SIZE   128
#define TIME_INCREMENT          5
static int g_nTime;
static int g_nForceLogIndex;
static VibeInt8 g_nForceLog[FORCE_LOG_BUFFER_SIZE];
#endif

#if ((LINUX_VERSION_CODE & 0xFFFF00) < KERNEL_VERSION(2, 6, 0))
#error Unsupported Kernel version
#endif

#ifdef IMPLEMENT_AS_CHAR_DRIVER
static int g_nMajor;
#endif

/* Needs to be included after the global variables because it uses them */
#ifdef CONFIG_HIGH_RES_TIMERS
#include "VibeOSKernelLinuxHRTime.c"
#else
#include "VibeOSKernelLinuxTime.c"
#endif

/* File IO */
static int open(struct inode *inode, struct file *file);
static int release(struct inode *inode, struct file *file);
static ssize_t read(struct file *file, char *buf, size_t count, loff_t *ppos);
static ssize_t write(struct file *file, const char *buf, size_t count,
	loff_t *ppos);
static long unlocked_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg);
static const struct file_operations fops = {
	.owner = THIS_MODULE,
	.read = read,
	.write = write,
	.unlocked_ioctl = unlocked_ioctl,
	.open = open,
	.release = release,
	.llseek =	default_llseek
};

#ifndef IMPLEMENT_AS_CHAR_DRIVER
static struct miscdevice miscdev = {
	.minor =    MISC_DYNAMIC_MINOR,
	.name =     MODULE_NAME,
	.fops =     &fops
};
#endif

static int suspend(struct platform_device *pdev, pm_message_t state);
static int resume(struct platform_device *pdev);
static struct platform_driver platdrv = {
	.suspend =  suspend,
	.resume =   resume,
	.driver = {
		.name = MODULE_NAME,
	},
};

static void platform_release(struct device *dev);
static struct platform_device platdev = {
	.name =     MODULE_NAME,
	/* means that there is only one device */
	.id =       -1,
	.dev = {
		.platform_data = NULL,
		/* a warning is thrown during rmmod if this is absent */
		.release = platform_release,
	},
};

/* Module info */
MODULE_AUTHOR("Immersion Corporation");
MODULE_DESCRIPTION("TouchSense Kernel Module");
MODULE_LICENSE("GPL v2");

#ifdef VIBE_ENABLE_SYSTEM_TIMER
int vibetonz_clk_on(struct device *dev)
{
	struct clk *vibetonz_clk = NULL;
    /*printk(KERN_ERR"[VIBRATOR]vibetonz_clk_on is called\n");*/
	vibetonz_clk = clk_get(dev, "timers");
	if (IS_ERR(vibetonz_clk)) {
		printk(KERN_ERR "tspdrv: failed to get clock for vibetonz\n");
		goto err_clk0;
	}
	clk_enable(vibetonz_clk);
	clk_put(vibetonz_clk);

	return 0;

err_clk0:
	clk_put(vibetonz_clk);
	return -EINVAL;
}

int vibetonz_clk_off(struct device *dev)
{
	struct clk *vibetonz_clk = NULL;

	vibetonz_clk = clk_get(dev, "timers");
	if (IS_ERR(vibetonz_clk)) {
		DbgOut((KERN_ERR "tspdrv: failed to get clock for vibetonz\n"));
		goto err_clk0;
	}
	clk_disable(vibetonz_clk);
	clk_put(vibetonz_clk);

	return 0;

err_clk0:
	clk_put(vibetonz_clk);

	return -EINVAL;
}
#else
int vibetonz_clk_on(struct device *dev)
{
	return -EINVAL;
}

int vibetonz_clk_off(struct device *dev)
{
	return -EINVAL;
}
#endif	/* VIBE_ENABLE_SYSTEM_TIMER */

int init_module(void)
{
	int nRet, i;   /* initialized below */
	nRet = 0;

#ifdef IMPLEMENT_AS_CHAR_DRIVER
	printk(KERN_ERR
		"[VIBRATOR]IMPLEMENT_AS_CHAR_DRIVER\n");
	g_nMajor = register_chrdev(0, MODULE_NAME, &fops);
	if (g_nMajor < 0) {
		printk(KERN_ERR"[VIBRATOR]tspdrv: can't get major number.\n");
		return g_nMajor;
	}
#else
	nRet = misc_register(&miscdev);
	if (nRet) {
		printk(KERN_ERR "[VIBRATOR]tspdrv: misc_register failed.\n");
		return nRet;
	}
#endif

	nRet = platform_device_register(&platdev);
	if (nRet) {
		printk(KERN_ERR "tspdrv: platform_device_register failed.\n");
		goto err_platform_dev_reg;
	}

	nRet = platform_driver_register(&platdrv);
	if (nRet) {
		printk(KERN_ERR "tspdrv: platform_driver_register failed.\n");
		goto err_platform_drv_reg;
	}

	DbgRecorderInit(());

	vibetonz_clk_on(&platdev.dev);

	ImmVibeSPI_ForceOut_Initialize();
	VibeOSKernelLinuxInitTimer();

	/* Get and concatenate device name and initialize data buffer */
	g_cchDeviceName = 0;
	for (i = 0; i < NUM_ACTUATORS; i++) {
		char *szName = g_szDeviceName + g_cchDeviceName;
		ImmVibeSPI_Device_GetName(i, szName,
			VIBE_MAX_DEVICE_NAME_LENGTH);

		/* Append version information and get buffer length */
		strcat(szName, VERSION_STR);
		g_cchDeviceName += strlen(szName);

		g_SamplesBuffer[i].nIndexPlayingBuffer = -1; /* Not playing */
		g_SamplesBuffer[i].actuatorSamples[0].nBufferSize = 0;
		g_SamplesBuffer[i].actuatorSamples[1].nBufferSize = 0;
	}

	wake_lock_init(&vib_wake_lock, WAKE_LOCK_SUSPEND, "vib_present");
	return 0;

err_platform_drv_reg:
	platform_device_unregister(&platdev);
err_platform_dev_reg:
#ifdef IMPLEMENT_AS_CHAR_DRIVER
	unregister_chrdev(g_nMajor, MODULE_NAME);
#else
	misc_deregister(&miscdev);
#endif
	return nRet;
}

void cleanup_module(void)
{
	DbgOut((KERN_INFO "tspdrv: cleanup_module.\n"));

	DbgRecorderTerminate(());

	VibeOSKernelLinuxTerminateTimer();
	ImmVibeSPI_ForceOut_Terminate();

	platform_driver_unregister(&platdrv);
	platform_device_unregister(&platdev);

#ifdef IMPLEMENT_AS_CHAR_DRIVER
	unregister_chrdev(g_nMajor, MODULE_NAME);
#else
	misc_deregister(&miscdev);
#endif
	wake_lock_destroy(&vib_wake_lock);
}

static int open(struct inode *inode, struct file *file)
{
	DbgOut((KERN_INFO "tspdrv: open.\n"));

	if (!try_module_get(THIS_MODULE))
		return -ENODEV;

	return 0;
}

static int release(struct inode *inode, struct file *file)
{
	DbgOut((KERN_INFO "tspdrv: release.\n"));

	/*
	** Reset force and stop timer when the driver is closed, to make sure
	** no dangling semaphore remains in the system, especially when the
	** driver is run outside of immvibed for testing purposes.
	*/
	VibeOSKernelLinuxStopTimer();

	/*
	** Clear the variable used to store the magic number to prevent
	** unauthorized caller to write data. TouchSense service is the only
	** valid caller.
	*/
	file->private_data = (void *)NULL;

	module_put(THIS_MODULE);

	return 0;
}

static ssize_t read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
	const size_t nBufSize = (g_cchDeviceName > (size_t)(*ppos)) ?
		min(count, g_cchDeviceName - (size_t)(*ppos)) : 0;

	/* End of buffer, exit */
	if (0 == nBufSize)
		return 0;

	if (0 != copy_to_user(buf, g_szDeviceName + (*ppos), nBufSize))	{
		/* Failed to copy all the data, exit */
		DbgOut((KERN_ERR "tspdrv: copy_to_user failed.\n"));
		return 0;
	}

	/* Update file position and return copied buffer size */
	*ppos += nBufSize;
	return nBufSize;
}

static ssize_t write(struct file *file, const char *buf, size_t count,
	loff_t *ppos)
{
	int i = 0;

	*ppos = 0;  /* file position not used, always set to 0 */

	/*
	** Prevent unauthorized caller to write data.
	** TouchSense service is the only valid caller.
	*/
	if (file->private_data != (void *)TSPDRV_MAGIC_NUMBER) {
		DbgOut((KERN_ERR "tspdrv: unauthorized write.\n"));
		return 0;
	}

	/* Check buffer size */
	if ((count <= SPI_HEADER_SIZE) || (count > SPI_BUFFER_SIZE)) {
		DbgOut((KERN_ERR "tspdrv: invalid write buffer size.\n"));
		return 0;
	}

	/* Copy immediately the input buffer */
	if (0 != copy_from_user(g_cWriteBuffer, buf, count)) {
		/* Failed to copy all the data, exit */
		DbgOut((KERN_ERR "tspdrv: copy_from_user failed.\n"));
		return 0;
	}

	while (i < count) {
		int nIndexFreeBuffer;   /* initialized below */

		samples_buffer* pInputBuffer =	(samples_buffer *)
			(&g_cWriteBuffer[i]);

		if ((i + SPI_HEADER_SIZE) >= count) {
			/*
			** Index is about to go beyond the buffer size.
			** (Should never happen).
			*/
			DbgOut((KERN_EMERG "tspdrv: invalid buffer index.\n"));
		}

		/* Check bit depth */
		if (8 != pInputBuffer->nBitDepth)
			DbgOut((KERN_WARNING
				"tspdrv: invalid bit depth."
				"Use default value (8)\n"));

		/* The above code not valid if SPI header size is not 3 */
#if (SPI_HEADER_SIZE != 3)
#error "SPI_HEADER_SIZE expected to be 3"
#endif

		/* Check buffer size */
		if ((i + SPI_HEADER_SIZE + pInputBuffer->nBufferSize) > count) {
			/*
			** Index is about to go beyond the buffer size.
			** (Should never happen).
			*/
			DbgOut((KERN_EMERG "tspdrv: invalid data size.\n"));
		}

		/* Check actuator index */
		if (NUM_ACTUATORS <= pInputBuffer->nActuatorIndex) {
			DbgOut((KERN_ERR "tspdrv: invalid actuator index.\n"));
			i += (SPI_HEADER_SIZE + pInputBuffer->nBufferSize);
			continue;
		}

		if (0 == g_SamplesBuffer[pInputBuffer->nActuatorIndex].
			actuatorSamples[0].nBufferSize) {
			nIndexFreeBuffer = 0;
		} else if (0 == g_SamplesBuffer[pInputBuffer->nActuatorIndex].
			actuatorSamples[1].nBufferSize) {
			nIndexFreeBuffer = 1;
		} else {
			/* No room to store new samples  */
			DbgOut((KERN_ERR
				"tspdrv: no room to store new samples.\n"));
			return 0;
		}

		/* Store the data in the free buffer of the given actuator */
		memcpy(&(g_SamplesBuffer[pInputBuffer->nActuatorIndex].
			actuatorSamples[nIndexFreeBuffer]), &g_cWriteBuffer[i],
			(SPI_HEADER_SIZE + pInputBuffer->nBufferSize));

		/* if the no buffer is playing, prepare to play
		  * g_SamplesBuffer[pInputBuffer->nActuatorIndex].
		  * actuatorSamples[nIndexFreeBuffer] */
		if (-1 == g_SamplesBuffer[pInputBuffer->
			nActuatorIndex].nIndexPlayingBuffer) {
			g_SamplesBuffer[pInputBuffer->nActuatorIndex].
				nIndexPlayingBuffer = nIndexFreeBuffer;
			g_SamplesBuffer[pInputBuffer->nActuatorIndex].
				nIndexOutputValue = 0;
		}

		/* Increment buffer index */
		i += (SPI_HEADER_SIZE + pInputBuffer->nBufferSize);
	}

#ifdef QA_TEST
	g_nForceLog[g_nForceLogIndex++] = g_cSPIBuffer[0];
	if (g_nForceLogIndex >= FORCE_LOG_BUFFER_SIZE) {
		for (i = 0; i < FORCE_LOG_BUFFER_SIZE; i++) {
			printk(KERN_DEBUG "<6>%d\t%d\n",
				g_nTime, g_nForceLog[i]);
			g_nTime += TIME_INCREMENT;
		}
		g_nForceLogIndex = 0;
	}
#endif

	/* Start the timer after receiving new output force */
	g_bIsPlaying = true;
	VibeOSKernelLinuxStartTimer();

	return count;
}

static long unlocked_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
#ifdef QA_TEST
	int i;
#endif
#if defined(CONFIG_MACH_GRANDE)
	struct regulator *regulator;
	regulator = regulator_get(NULL, "vmotor");
	if (IS_ERR(regulator))
		return 0;
#endif
	DbgOut((KERN_INFO "tspdrv: ioctl cmd[0x%x].\n", cmd));

	switch (cmd) {
	case TSPDRV_STOP_KERNEL_TIMER:
		/*
		  * As we send one sample ahead of time,
		  * we need to finish playing the last sample
		  * before stopping the timer. So we just set a flag here.
		  */
		if (true == g_bIsPlaying)
			g_bStopRequested = true;

#ifdef VIBEOSKERNELPROCESSDATA
		/* Last data processing to disable amp and stop timer */
		VibeOSKernelProcessData(NULL);
#endif

#ifdef QA_TEST
		if (g_nForceLogIndex) {
			for (i = 0; i < g_nForceLogIndex; i++) {
				printk(KERN_DEBUG "<6>%d\t%d\n",
					g_nTime, g_nForceLog[i]);
				g_nTime += TIME_INCREMENT;
			}
		}
		g_nTime = 0;
		g_nForceLogIndex = 0;
#endif
		break;

	case TSPDRV_MAGIC_NUMBER:
		file->private_data = (void *)TSPDRV_MAGIC_NUMBER;
		break;

	case TSPDRV_ENABLE_AMP:
		wake_lock(&vib_wake_lock);
                #if defined(CONFIG_MACH_GRANDE)
	        regulator_enable(regulator);
		printk(KERN_INFO "[TSPDRV] vmotor power on\n");
		regulator_put(regulator);
                #else
		ImmVibeSPI_ForceOut_AmpEnable(arg);
		DbgRecorderReset((arg));
		DbgRecord((arg, ";------- TSPDRV_ENABLE_AMP ---------\n"));
                #endif
		break;

	case TSPDRV_DISABLE_AMP:
		/* Small fix for now to handle proper combination of
		  * TSPDRV_STOP_KERNEL_TIMER and TSPDRV_DISABLE_AMP together
		  * If a stop was requested, ignore the request as the amp
		  * will be disabled by the timer proc when it's ready
		  */
                #if defined(CONFIG_MACH_GRANDE)
                regulator_disable(regulator);
		printk(KERN_INFO "[TSPDRV] vmotor power on\n");
		regulator_put(regulator);
                #else
		if (!g_bStopRequested)
			ImmVibeSPI_ForceOut_AmpDisable(arg);
                #endif
		wake_unlock(&vib_wake_lock);
		break;

	case TSPDRV_GET_NUM_ACTUATORS:
		return NUM_ACTUATORS;
	}

	return 0;
}

static int suspend(struct platform_device *pdev, pm_message_t state)
{
	int ret;

	if (g_bIsPlaying) {
		ret = -EBUSY;
	} else {
		/* Disable system timers */
		vibetonz_clk_off(&pdev->dev);

		ret = 0;
	}

	DbgOut((KERN_DEBUG "tspdrv: %s (%d).\n", __func__, ret));
	return ret;
}

static int resume(struct platform_device *pdev)
{
	u32 __iomem *pram;

	/* Restart system timers */
	vibetonz_clk_on(&pdev->dev);

	/* Restore system timers configuration */
	pram = ioremap(S5P_PA_TIMER, 4);
	writel(0x0F00, pram);
	iounmap(pram);

	DbgOut((KERN_DEBUG "tspdrv: %s.\n", __func__));
	return 0;
}

static void platform_release(struct device *dev)
{
	DbgOut((KERN_INFO "tspdrv: platform_release.\n"));
}

late_initcall(init_module);
module_exit(cleanup_module);