/*
 *  User Mode Init manager - For TI shared transport
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <poll.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/utsname.h>

#include <unistd.h>
#include <time.h>

#ifdef ANDROID
#include <private/android_filesystem_config.h>
#include <cutils/log.h>
#endif

#include "uim.h"

/* Maintains the exit state of UIM*/
static int exiting;

/* UART configuration parameters*/
int uart_flow_control;
int cust_baud_rate;
char uart_dev_name[15];
unsigned int uart_baud_rate;
struct termios ti;
int line_discipline;

/* BD address as string and a pointer to array of hex bytes */
char uim_bd_address[17];
bdaddr_t *bd_addr;

/* File descriptor for the UART device*/
int dev_fd;

/* Maintains the state of N_TI_WL line discipline installation*/
unsigned char st_state = INSTALL_N_TI_WL;
unsigned char prev_st_state = INSTALL_N_TI_WL;

/* from kernel's include/linux/rfkill.h
 * the header in itself not included because of the
 * version mismatch of android kernel headers project
 */

/**
 * enum rfkill_operation - operation types
 * @RFKILL_OP_ADD: a device was added
 * @RFKILL_OP_DEL: a device was removed
 * @RFKILL_OP_CHANGE: a device's state changed -- userspace changes one device
 * @RFKILL_OP_CHANGE_ALL: userspace changes all devices (of a type, or all)
 */
enum rfkill_operation {
        RFKILL_OP_ADD = 0,
        RFKILL_OP_DEL,
        RFKILL_OP_CHANGE,
        RFKILL_OP_CHANGE_ALL,
};

/**
 * struct rfkill_event - events for userspace on /dev/rfkill
 * @idx: index of dev rfkill
 * @type: type of the rfkill struct
 * @op: operation code
 * @hard: hard state (0/1)
 * @soft: soft state (0/1)
 *
 * Structure used for userspace communication on /dev/rfkill,
 * used for events from the kernel and control to the kernel.
 */

struct rfkill_event {
	uint32_t idx;
	uint8_t  type;
	uint8_t  op;
	uint8_t  soft, hard;
} __packed;

/* to read events and filter notifications for us */
struct rfkill_event rf_event;
int 	rfkill_idx;

/*****************************************************************************/
#ifdef UIM_DEBUG
/*  Function to Read the firmware version
 *  module into the system. Currently used for
 *  debugging purpose, whenever the baud rate is changed
 */
void read_firmware_version()
{
	int index = 0;
	char resp_buffer[20] = { 0 };
	unsigned char buffer[] = { 0x01, 0x01, 0x10, 0x00 };

	UIM_START_FUNC();
	UIM_VER(" wrote %d bytes", (int)write(dev_fd, buffer, 4));
	UIM_VER(" reading %d bytes", (int)read(dev_fd, resp_buffer, 15));

	for (index = 0; index < 15; index++)
		UIM_VER(" %x ", resp_buffer[index]);

	printf("\n");
}
#endif

/*****************************************************************************/
#ifdef ANDROID                 /* library for android to do insmod/rmmod  */

/* Function to insert the kernel module into the system*/
static int insmod(const char *filename, const char *args)
{
        void *module;
        unsigned int size;
        int ret = -1;

        UIM_START_FUNC();

        module = (void *)load_file(filename, &size);
        if (!module)
                return ret;

        ret = init_module(module, size, args);
        free(module);

        return ret;
}

/* Function to remove the kernel module from the system*/
static int rmmod(const char *modname)
{
        int ret = -1;
        int maxtry = MAX_TRY;

        UIM_START_FUNC();

        /* Retry MAX_TRY number of times in case of
 	 * failure
	 */
        while (maxtry-- > 0) {
                ret = delete_module(modname, O_NONBLOCK | O_EXCL);
                if (ret < 0 && errno == EAGAIN)
                        sleep(1);
                else
                        break;
        }

        /* Failed to remove the module
	*/
        if (ret != 0)
                UIM_ERR("Unable to unload driver module \"%s\": %s",
                                modname, strerror(errno));
        return ret;
}
#endif /*ANDROID*/

/*****************************************************************************/
/* Function to read the HCI event from the given file descriptor
 *
 * This will parse the response received and returns error
 * if the required response is not received
 */
int read_hci_event(int fd, unsigned char *buf, int size)
{
	int remain, rd;
	int count = 0;
	int reading = 1;
	int rd_retry_count = 0;
	struct timespec tm = {0, 50*1000*1000};

	UIM_START_FUNC();

	UIM_VER(" read_hci_event");
	if (size <= 0)
		return -1;

	/* The first byte identifies the packet type. For HCI event packets, it
	 * should be 0x04, so we read until we get to the 0x04. */
	while (reading) {
		rd = read(fd, buf, 1);
		if (rd <= 0 && rd_retry_count++ < 4) {
			nanosleep(&tm, NULL);
			continue;
		} else if (rd_retry_count >= 4) {
			return -1;
		}

		if (buf[0] == RESP_PREFIX) {
			break;
		}
	}
	count++;

	/* The next two bytes are the event code and parameter total length. */
	while (count < 3) {
		rd = read(fd, buf + count, 3 - count);
		if (rd <= 0)
			return -1;
		count += rd;
	}

	/* Now we read the parameters. */
	if (buf[2] < (size - 3))
		remain = buf[2];
	else
		remain = size - 3;

	while ((count - 3) < remain) {
		rd = read(fd, buf + count, remain - (count - 3));
		if (rd <= 0)
			return -1;
		count += rd;
	}

	return count;
}

/* Function to read the Command complete event
 *
 * This will read the response for the change speed
 * command that was sent to configure the UART speed
 * with the custom baud rate
 */
static int read_command_complete(int fd, unsigned short opcode)
{
	command_complete_t resp;

	UIM_START_FUNC();

	UIM_VER(" Command complete started");
	if (read_hci_event(fd, (unsigned char *)&resp, sizeof(resp)) < 0) {
		UIM_ERR(" Invalid response");
		return -1;
	}

	/* Response should be an event packet */
	if (resp.uart_prefix != HCI_EVENT_PKT) {
		UIM_ERR
			(" Error in response: not an event packet, but 0x%02x!",
			 resp.uart_prefix);
		return -1;
	}

	/* Response should be a command complete event */
	if (resp.hci_hdr.evt != EVT_CMD_COMPLETE) {
		/* event must be event-complete */
		UIM_ERR
			(" Error in response: not a cmd-complete event,but 0x%02x!",
			 resp.hci_hdr.evt);
		return -1;
	}

	if (resp.hci_hdr.plen < 4) {
		/* plen >= 4 for EVT_CMD_COMPLETE */
		UIM_ERR(" Error in response: plen is not >= 4, but 0x%02x!",
				resp.hci_hdr.plen);
		return -1;
	}

	if (resp.cmd_complete.opcode != (unsigned short)opcode) {
		UIM_ERR(" Error in response: opcode is 0x%04x, not 0x%04x!",
				resp.cmd_complete.opcode, opcode);
		return -1;
	}

	UIM_DBG(" Command complete done");
	return resp.status == 0 ? 0 : -1;
}

/* Function to set the default baud rate
 *
 * The default baud rate of 115200 is set to the UART from the host side
 * by making a call to this function.This function is also called before
 * making a call to set the custom baud rate
 */
static int set_baud_rate(void)
{
	UIM_START_FUNC();

	tcflush(dev_fd, TCIOFLUSH);

	/* Get the attributes of UART */
	if (tcgetattr(dev_fd, &ti) < 0) {
		UIM_ERR(" Can't get port settings");
		return -1;
	}

	/* Change the UART attributes before
	 * setting the default baud rate*/
	cfmakeraw(&ti);

	ti.c_cflag |= 1;
	ti.c_cflag |= CRTSCTS;

	/* Set the attributes of UART after making
	 * the above changes
	 */
	tcsetattr(dev_fd, TCSANOW, &ti);

	/* Set the actual default baud rate */
	cfsetospeed(&ti, B115200);
	cfsetispeed(&ti, B115200);
	tcsetattr(dev_fd, TCSANOW, &ti);

	tcflush(dev_fd, TCIOFLUSH);
	UIM_DBG(" set_baud_rate() done");

	return 0;
}

/* Function to set the UART custom baud rate.
 *
 * The UART baud rate has already been
 * set to default value 115200 before calling this function.
 * The baud rate is then changed to custom baud rate by this function*/
static int set_custom_baud_rate(void)
{
	UIM_START_FUNC();

	struct termios2 ti2;

	UIM_VER(" Changing baud rate to %u, flow control to %u",
			cust_baud_rate, uart_flow_control);

	/* Flush non-transmitted output data,
	 * non-read input data or both*/
	tcflush(dev_fd, TCIOFLUSH);

	/*Set the UART flow control */
	if (uart_flow_control)
		ti.c_cflag |= CRTSCTS;
	else
		ti.c_cflag &= ~CRTSCTS;

	/*
	 * Set the parameters associated with the UART
	 * The change will occur immediately by using TCSANOW
	 */
	if (tcsetattr(dev_fd, TCSANOW, &ti) < 0) {
		UIM_ERR(" Can't set port settings");
		return -1;
	}

	tcflush(dev_fd, TCIOFLUSH);

	/*Set the actual baud rate */
	ioctl(dev_fd, TCGETS2, &ti2);
	ti2.c_cflag &= ~CBAUD;
	ti2.c_cflag |= BOTHER;
	ti2.c_ospeed = cust_baud_rate;
	ioctl(dev_fd, TCSETS2, &ti2);

	UIM_DBG(" set_custom_baud_rate() done");
	return 0;
}

/*
 * After receiving the indication from rfkill subsystem, configure the
 * baud rate, flow control and Install the N_TI_WL line discipline
 */
int st_uart_config(void)
{
	int ldisc, len;
	uim_speed_change_cmd cmd;

	uim_bdaddr_change_cmd addr_cmd;	

	UIM_START_FUNC();

	/* Install the line discipline when the rfkill signal is received by UIM.
	 * Whenever the first protocol tries to register with the ST core, the
	 * ST KIM will inform the UIM through rfkill subsystem to install the N_TI_WL
	 * line discipline and do the host side UART configurations.
	 *
	 * On failure, ST KIM's line discipline installation times out, and the
	 * relevant protocol register fails
	 */
	if (st_state == INSTALL_N_TI_WL) {
		UIM_VER(" signal received, opening %s", uart_dev_name);
		dev_fd = open(uart_dev_name, O_RDWR);
		if (dev_fd < 0) {
			UIM_ERR(" Can't open %s", uart_dev_name);
			return -1;
		}
		/*
		 * Set only the default baud rate.
		 * This will set the baud rate to default 115200
		 */
		if (set_baud_rate() < 0) {
			UIM_ERR(" set_baudrate() failed");
			close(dev_fd);
			return -1;
		}

		fcntl(dev_fd, F_SETFL,fcntl(dev_fd, F_GETFL) | O_NONBLOCK);
		/* Set only thecustom baud rate */
		if (cust_baud_rate) {

			/* Forming the packet for Change speed command */
			cmd.uart_prefix = HCI_COMMAND_PKT;
			cmd.hci_hdr.opcode = HCI_HDR_OPCODE;
			cmd.hci_hdr.plen = sizeof(unsigned long);
			cmd.speed = cust_baud_rate;

			/* Writing the change speed command to the UART
			 * This will change the UART speed at the controller
			 * side
			 */
			UIM_VER(" Setting speed to %d", cust_baud_rate);
			len = write(dev_fd, &cmd, sizeof(cmd));
			if (len < 0) {
				UIM_ERR(" Failed to write speed-set command");
				close(dev_fd);
				return -1;
			}

			/* Read the response for the Change speed command */
			if (read_command_complete(dev_fd, HCI_HDR_OPCODE) < 0) {
				close(dev_fd);
				return -1;
			}

			UIM_VER(" Speed changed to %d", cust_baud_rate);

			/* Set the actual custom baud rate at the host side */
			if (set_custom_baud_rate() < 0) {
				UIM_ERR(" set_custom_baud_rate() failed");
				close(dev_fd);

				return -1;
			}
 			/* Set the uim BD address */
                        if (uim_bd_address[0] != 0) {

                                memset(&addr_cmd, 0, sizeof(addr_cmd));
                                /* Forming the packet for change BD address command*/
                                addr_cmd.uart_prefix = HCI_COMMAND_PKT;
                                addr_cmd.hci_hdr.opcode = WRITE_BD_ADDR_OPCODE;
                                addr_cmd.hci_hdr.plen = sizeof(bdaddr_t);
                                memcpy(&addr_cmd.addr, bd_addr, sizeof(bdaddr_t));

                                /* Writing the change BD address command to the UART
                                 * This will change the change BD address  at the controller
                                 * side
                                 */
                                len = write(dev_fd, &addr_cmd, sizeof(addr_cmd));
                                if (len < 0) {
                                        UIM_ERR(" Failed to write BD address command");
                                        close(dev_fd);
                                        return -1;
                                }

                                /* Read the response for the change BD address command */
                                if (read_command_complete(dev_fd, WRITE_BD_ADDR_OPCODE) < 0) {
                                        close(dev_fd);
                                        return -1;
                                }

                                UIM_VER(" BD address changed to %s", uim_bd_address);
                        }
#ifdef UIM_DEBUG
			read_firmware_version();
#endif
		}

		/* After the UART speed has been changed, the IOCTL is
		 * is called to set the line discipline to N_TI_WL
		 */
		ldisc = line_discipline;
		if (ioctl(dev_fd, TIOCSETD, &ldisc) < 0) {
			UIM_ERR(" Can't set line discipline");
			close(dev_fd);
			return -1;
		}

		UIM_DBG(" Installed N_TI_WL Line displine");
	}
	else {
		/* UNINSTALL_N_TI_WL - When the Signal is received from KIM */
		/* closing UART fd */
		close(dev_fd);
	}
	prev_st_state = st_state;
	return 0;
}

#ifdef ANDROID
int remove_modules(void)
{
	int err = 0;
        UIM_VER(" Removing gps_drv ");
        if (rmmod("gps_drv") != 0) {
                UIM_ERR(" Error removing gps_drv module");
                err = -1;
        } else {
                UIM_DBG(" Removed gps_drv module");
        }

        UIM_VER(" Removing fm_drv ");
        if (rmmod("fm_drv") != 0) {
                UIM_ERR(" Error removing fm_drv module");
                err = -1;
        } else {
                UIM_DBG(" Removed fm_drv module");
        }
        UIM_DBG(" Removed fm_drv module");

        UIM_VER(" Removing bt_drv ");

        if (rmmod("bt_drv") != 0) {
                UIM_ERR(" Error removing bt_drv module");
                err = -1;
        } else {
                UIM_DBG(" Removed bt_drv module");
        }
        UIM_DBG(" Removed bt_drv module");

        /*Remove the Shared Transport */
        UIM_VER(" Removing st_drv ");

        if (rmmod("st_drv") != 0) {
                UIM_ERR(" Error removing st_drv module");
                err = -1;
        } else {
                UIM_DBG(" Removed st_drv module ");
        }
        UIM_DBG(" Removed st_drv module ");
	return err;
}
#endif

int change_rfkill_perms(void)
{
	int fd, id, sz;
	char path[64];
	char buf[16];
	for (id = 0; id < 50; id++) {
		snprintf(path, sizeof(path), "/sys/class/rfkill/rfkill%d/name", id);
		fd = open(path, O_RDONLY);
		if (fd < 0) {
			UIM_DBG("open(%s) failed: %s (%d)\n", path, strerror(errno), errno);
			continue;
		}
		sz = read(fd, &buf, sizeof(buf));
		close(fd);
		if (sz >= 9 && memcmp(buf, "Bluetooth", 9) == 0) {
			UIM_DBG("found bluetooth rfkill entry @ %d\n", id);
			rfkill_idx = id;
			break;
		}
	}
	if (id == 50) {
		return -1;
	}

#ifdef ANDROID
	sprintf(path, "/sys/class/rfkill/rfkill%d/state", id);
	sz = chown(path, AID_BLUETOOTH, AID_BLUETOOTH);
	if (sz < 0) {
		UIM_ERR("change mode failed for %s (%d)\n", path, errno);
		return -1;
	}

	/*
	 * bluetooth group's user system needs write permission
	 */
	sz = chmod(path, 0660);
	if (sz < 0) {
		UIM_ERR("change mode failed for %s (%d)\n", path, errno);
		return -1;
	}
	UIM_DBG("changed permissions for %s(%d) \n", path, sz);
	/* end of change_perms */
#endif
	return 0;
}

void *bt_malloc(size_t size)
{
        return malloc(size);
}

/* Function to convert the BD address from ascii to hex value */
bdaddr_t *strtoba(const char *str)
{
        const char *ptr = str;
        int i;

        uint8_t *ba = bt_malloc(sizeof(bdaddr_t));
        if (!ba)
                return NULL;

        for (i = 0; i < 6; i++) {
                ba[i] = (uint8_t) strtol(ptr, NULL, 16);
                if (i != 5 && !(ptr = strchr(ptr, ':')))
                        ptr = ":00:00:00:00:00";
                ptr++;
        }

        return (bdaddr_t *) ba;
}

/*****************************************************************************/
int main(int argc, char *argv[])
{
	int st_fd,err;
#ifdef ANDROID
	struct stat file_stat;
#endif
#ifndef ANDROID
	struct utsname name;
#endif
	struct pollfd 	p;

	UIM_START_FUNC();
	err = 0;

	/* Parse the user input */
        if ((argc == 5) || (argc == 6)) {
                strcpy(uart_dev_name, argv[1]);
                uart_baud_rate = atoi(argv[2]);
                uart_flow_control = atoi(argv[3]);
                line_discipline = atoi(argv[4]);

                /* Depending upon the baud rate value, differentiate
                 * the custom baud rate and default baud rate
                 */
                switch (uart_baud_rate) {
                        case 115200:
                                UIM_VER(" Baudrate 115200");
                                break;
                        case 9600:
                        case 19200:
                        case 38400:
                        case 57600:
                        case 230400:
                        case 460800:
                        case 500000:
                        case 576000:
                        case 921600:
                        case 1000000:
                        case 1152000:
                        case 1500000:
                        case 2000000:
                        case 2500000:
                        case 3000000:
                        case 3500000:
                        case 3686400:
                        case 4000000:
                                cust_baud_rate = uart_baud_rate;
                                UIM_VER(" Baudrate %d", cust_baud_rate);
                                break;
                        default:
                                UIM_ERR(" Inavalid Baud Rate");
                                break;
                }

                memset(&uim_bd_address, 0, sizeof(uim_bd_address));
        } else {
                UIM_ERR(" Invalid arguements");
                UIM_ERR(" Usage: uim [Uart device] [Baud rate] [Flow control] [Line discipline] <bd address>");
                return -1;
        }

        if (argc == 6) {
                /* BD address passed as string in xx:xx:xx:xx:xx:xx format */
		strncpy(uim_bd_address, argv[5], sizeof(uim_bd_address));
                bd_addr = strtoba(uim_bd_address);
        }
#ifndef ANDROID
	if (uname (&name) == -1) {
	   UIM_ERR("cannot get kernel release name");
	   return -1;
	}
#else  /* if ANDROID */

        if (0 == lstat("/st_drv.ko", &file_stat)) {
                if (insmod("/st_drv.ko", "") < 0) {
                        UIM_ERR(" Error inserting st_drv module");
                        return -1;
                } else {
                        UIM_DBG(" Inserted st_drv module");
                }
        } else {
                if (0 == lstat("/dev/rfkill", &file_stat)) {
                        UIM_DBG("ST built into the kernel ?");
                } else {
                        UIM_ERR("BT/FM/GPS would be unavailable on system");
                        UIM_ERR(" rfkill device '/dev/rfkill' not found ");
                        return -1;
                }
        }

	if (change_rfkill_perms() < 0) {
		/* possible error condition */
		UIM_ERR("rfkill not enabled in st_drv - BT on from UI might fail\n");
	}

        if (0 == lstat("/bt_drv.ko", &file_stat)) {
                if (insmod("/bt_drv.ko", "") < 0) {
                        UIM_ERR(" Error inserting bt_drv module, NO BT? ");
                } else {
                        UIM_DBG(" Inserted bt_drv module");
                }
        } else {
                UIM_DBG("BT driver module un-available... ");
                UIM_DBG("BT driver built into the kernel ?");
        }

        if (0 == lstat("/fm_drv.ko", &file_stat)) {
                if (insmod("/fm_drv.ko", "") < 0) {
                        UIM_ERR(" Error inserting fm_drv module, NO FM? ");
                } else {
                        UIM_DBG(" Inserted fm_drv module");
                }
        } else {
                UIM_DBG("FM driver module un-available... ");
                UIM_DBG("FM driver built into the kernel ?");
        }

        if (0 == lstat("/gps_drv.ko", &file_stat)) {
                if (insmod("/gps_drv.ko", "") < 0) {
                        UIM_ERR(" Error inserting gps_drv module, NO GPS? ");
                } else {
                        UIM_DBG(" Inserted gps_drv module");
                }
        } else {
                UIM_DBG("GPS driver module un-available... ");
                UIM_DBG("GPS driver built into the kernel ?");
        }

        if (chmod("/dev/tifm", 0666) < 0) {
                UIM_ERR("unable to chmod /dev/tifm");
        }
#endif
	/* rfkill device's open/poll/read */
	st_fd = open("/dev/rfkill", O_RDONLY);

	p.fd = st_fd;
	p.events = POLLERR | POLLHUP | POLLOUT | POLLIN;

RE_POLL:
	while (!exiting) {
		p.revents = 0;
		err = poll(&p, 1, -1);
		if (err < 0 && errno == EINTR)
			continue;
                if (err)
                        break;
	}
	if (!exiting)
	{
		err = read(st_fd, &rf_event, sizeof(rf_event));
		UIM_DBG("rf_event: %d, %d, %d, %d, %d\n", rf_event.idx,
			rf_event.type, rf_event.op ,rf_event.hard,
			rf_event.soft);
		/* Since non-android/ubuntu solution for UIM doesn't insert
		 * modules, the rfkill entry relevant to TI ST can only be known
		 * by listening onto each of the RFKILL_OP_ADD event
		 */
#ifndef ANDROID
		if (rf_event.op == RFKILL_OP_ADD) {
			UIM_DBG("RFKILL_OP_ADD received\n");
			change_rfkill_perms();
			goto RE_POLL;
		}
#endif
		if ((rf_event.op == RFKILL_OP_CHANGE) &&
			(rf_event.idx == rfkill_idx)) {
			if (rf_event.hard == 1)
				st_state = UNINSTALL_N_TI_WL;
			else
				st_state = INSTALL_N_TI_WL;

			if (prev_st_state != st_state)
				st_uart_config();
		}
		goto RE_POLL;
	}

#ifdef ANDROID
	if(remove_modules() < 0) {
		UIM_ERR(" Error removing modules ");
		close(st_fd);
		return -1;
	}
#endif

	close(st_fd);
	return 0;
}