/**
 * Copyright (c) 2014 Redpine Signals Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include <linux/module.h>
#include "rsi_usb.h"

/**
 * rsi_usb_card_write() - This function writes to the USB Card.
 * @adapter: Pointer to the adapter structure.
 * @buf: Pointer to the buffer from where the data has to be taken.
 * @len: Length to be written.
 * @endpoint: Type of endpoint.
 *
 * Return: status: 0 on success, a negative error code on failure.
 */
static int rsi_usb_card_write(struct rsi_hw *adapter,
                              void *buf,
                              u16 len,
                              u8 endpoint)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
        int status;
        s32 transfer;

        status = usb_bulk_msg(dev->usbdev,
                              usb_sndbulkpipe(dev->usbdev,
                              dev->bulkout_endpoint_addr[endpoint - 1]),
                              buf,
                              len,
                              &transfer,
                              HZ * 5);

        if (status < 0) {
                rsi_dbg(ERR_ZONE,
                        "Card write failed with error code :%10d\n", status);
                dev->write_fail = 1;
        }
        return status;
}

/**
 * rsi_write_multiple() - This function writes multiple bytes of information
 *                        to the USB card.
 * @adapter: Pointer to the adapter structure.
 * @addr: Address of the register.
 * @data: Pointer to the data that has to be written.
 * @count: Number of multiple bytes to be written.
 *
 * Return: 0 on success, a negative error code on failure.
 */
static int rsi_write_multiple(struct rsi_hw *adapter,
                              u8 endpoint,
                              u8 *data,
                              u32 count)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
        u8 *seg = dev->tx_buffer;

        if (dev->write_fail)
                return 0;

        if (endpoint == MGMT_EP) {
                memset(seg, 0, RSI_USB_TX_HEAD_ROOM);
                memcpy(seg + RSI_USB_TX_HEAD_ROOM, data, count);
        } else {
                seg = ((u8 *)data - RSI_USB_TX_HEAD_ROOM);
        }

        return rsi_usb_card_write(adapter,
                                  seg,
                                  count + RSI_USB_TX_HEAD_ROOM,
                                  endpoint);
}

/**
 * rsi_find_bulk_in_and_out_endpoints() - This function initializes the bulk
 *                                        endpoints to the device.
 * @interface: Pointer to the USB interface structure.
 * @adapter: Pointer to the adapter structure.
 *
 * Return: ret_val: 0 on success, -ENOMEM on failure.
 */
static int rsi_find_bulk_in_and_out_endpoints(struct usb_interface *interface,
                                              struct rsi_hw *adapter)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
        struct usb_host_interface *iface_desc;
        struct usb_endpoint_descriptor *endpoint;
        __le16 buffer_size;
        int ii, bep_found = 0;

        iface_desc = &(interface->altsetting[0]);

        for (ii = 0; ii < iface_desc->desc.bNumEndpoints; ++ii) {
                endpoint = &(iface_desc->endpoint[ii].desc);

                if ((!(dev->bulkin_endpoint_addr)) &&
                    (endpoint->bEndpointAddress & USB_DIR_IN) &&
                    ((endpoint->bmAttributes &
                    USB_ENDPOINT_XFERTYPE_MASK) ==
                    USB_ENDPOINT_XFER_BULK)) {
                        buffer_size = endpoint->wMaxPacketSize;
                        dev->bulkin_size = buffer_size;
                        dev->bulkin_endpoint_addr =
                                endpoint->bEndpointAddress;
                }

                if (!dev->bulkout_endpoint_addr[bep_found] &&
                    !(endpoint->bEndpointAddress & USB_DIR_IN) &&
                    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
                      USB_ENDPOINT_XFER_BULK)) {
                        dev->bulkout_endpoint_addr[bep_found] =
                                endpoint->bEndpointAddress;
                        buffer_size = endpoint->wMaxPacketSize;
                        dev->bulkout_size[bep_found] = buffer_size;
                        bep_found++;
                }

                if (bep_found >= MAX_BULK_EP)
                        break;
        }

        if (!(dev->bulkin_endpoint_addr) &&
            (dev->bulkout_endpoint_addr[0]))
                return -EINVAL;

        return 0;
}

/* rsi_usb_reg_read() - This function reads data from given register address.
 * @usbdev: Pointer to the usb_device structure.
 * @reg: Address of the register to be read.
 * @value: Value to be read.
 * @len: length of data to be read.
 *
 * Return: status: 0 on success, a negative error code on failure.
 */
static int rsi_usb_reg_read(struct usb_device *usbdev,
                            u32 reg,
                            u16 *value,
                            u16 len)
{
        u8 *buf;
        int status = -ENOMEM;

        buf  = kmalloc(0x04, GFP_KERNEL);
        if (!buf)
                return status;

        status = usb_control_msg(usbdev,
                                 usb_rcvctrlpipe(usbdev, 0),
                                 USB_VENDOR_REGISTER_READ,
                                 USB_TYPE_VENDOR,
                                 ((reg & 0xffff0000) >> 16), (reg & 0xffff),
                                 (void *)buf,
                                 len,
                                 HZ * 5);

        *value = (buf[0] | (buf[1] << 8));
        if (status < 0) {
                rsi_dbg(ERR_ZONE,
                        "%s: Reg read failed with error code :%d\n",
                        __func__, status);
        }
        kfree(buf);

        return status;
}

/**
 * rsi_usb_reg_write() - This function writes the given data into the given
 *                       register address.
 * @usbdev: Pointer to the usb_device structure.
 * @reg: Address of the register.
 * @value: Value to write.
 * @len: Length of data to be written.
 *
 * Return: status: 0 on success, a negative error code on failure.
 */
static int rsi_usb_reg_write(struct usb_device *usbdev,
                             u32 reg,
                             u16 value,
                             u16 len)
{
        u8 *usb_reg_buf;
        int status = -ENOMEM;

        usb_reg_buf  = kmalloc(0x04, GFP_KERNEL);
        if (!usb_reg_buf)
                return status;

        usb_reg_buf[0] = (value & 0x00ff);
        usb_reg_buf[1] = (value & 0xff00) >> 8;
        usb_reg_buf[2] = 0x0;
        usb_reg_buf[3] = 0x0;

        status = usb_control_msg(usbdev,
                                 usb_sndctrlpipe(usbdev, 0),
                                 USB_VENDOR_REGISTER_WRITE,
                                 USB_TYPE_VENDOR,
                                 ((reg & 0xffff0000) >> 16),
                                 (reg & 0xffff),
                                 (void *)usb_reg_buf,
                                 len,
                                 HZ * 5);
        if (status < 0) {
                rsi_dbg(ERR_ZONE,
                        "%s: Reg write failed with error code :%d\n",
                        __func__, status);
        }
        kfree(usb_reg_buf);

        return status;
}

/**
 * rsi_rx_done_handler() - This function is called when a packet is received
 *                         from USB stack. This is callback to recieve done.
 * @urb: Received URB.
 *
 * Return: None.
 */
static void rsi_rx_done_handler(struct urb *urb)
{
        struct rsi_hw *adapter = urb->context;
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;

        if (urb->status)
                return;

        rsi_set_event(&dev->rx_thread.event);
}

/**
 * rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
 * @adapter: Pointer to the adapter structure.
 *
 * Return: 0 on success, a negative error code on failure.
 */
static int rsi_rx_urb_submit(struct rsi_hw *adapter)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
        struct urb *urb = dev->rx_usb_urb[0];
        int status;

        usb_fill_bulk_urb(urb,
                          dev->usbdev,
                          usb_rcvbulkpipe(dev->usbdev,
                                dev->bulkin_endpoint_addr),
                          urb->transfer_buffer,
                          3000,
                          rsi_rx_done_handler,
                          adapter);

        status = usb_submit_urb(urb, GFP_KERNEL);
        if (status)
                rsi_dbg(ERR_ZONE, "%s: Failed in urb submission\n", __func__);

        return status;
}

/**
 * rsi_usb_write_register_multiple() - This function writes multiple bytes of
 *                                     information to multiple registers.
 * @adapter: Pointer to the adapter structure.
 * @addr: Address of the register.
 * @data: Pointer to the data that has to be written.
 * @count: Number of multiple bytes to be written on to the registers.
 *
 * Return: status: 0 on success, a negative error code on failure.
 */
int rsi_usb_write_register_multiple(struct rsi_hw *adapter,
                                    u32 addr,
                                    u8 *data,
                                    u32 count)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
        u8 *buf;
        u8 transfer;
        int status = 0;

        buf = kzalloc(4096, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        while (count) {
                transfer = (u8)(min_t(u32, count, 4096));
                memcpy(buf, data, transfer);
                status = usb_control_msg(dev->usbdev,
                                         usb_sndctrlpipe(dev->usbdev, 0),
                                         USB_VENDOR_REGISTER_WRITE,
                                         USB_TYPE_VENDOR,
                                         ((addr & 0xffff0000) >> 16),
                                         (addr & 0xffff),
                                         (void *)buf,
                                         transfer,
                                         HZ * 5);
                if (status < 0) {
                        rsi_dbg(ERR_ZONE,
                                "Reg write failed with error code :%d\n",
                                status);
                } else {
                        count -= transfer;
                        data += transfer;
                        addr += transfer;
                }
        }

        kfree(buf);
        return 0;
}

/**
 *rsi_usb_host_intf_write_pkt() - This function writes the packet to the
 *                                 USB card.
 * @adapter: Pointer to the adapter structure.
 * @pkt: Pointer to the data to be written on to the card.
 * @len: Length of the data to be written on to the card.
 *
 * Return: 0 on success, a negative error code on failure.
 */
static int rsi_usb_host_intf_write_pkt(struct rsi_hw *adapter,
                                       u8 *pkt,
                                       u32 len)
{
        u32 queueno = ((pkt[1] >> 4) & 0xf);
        u8 endpoint;

        endpoint = ((queueno == RSI_WIFI_MGMT_Q) ? MGMT_EP : DATA_EP);

        return rsi_write_multiple(adapter,
                                  endpoint,
                                  (u8 *)pkt,
                                  len);
}

/**
 * rsi_deinit_usb_interface() - This function deinitializes the usb interface.
 * @adapter: Pointer to the adapter structure.
 *
 * Return: None.
 */
static void rsi_deinit_usb_interface(struct rsi_hw *adapter)
{
        struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;

        rsi_kill_thread(&dev->rx_thread);
        usb_free_urb(dev->rx_usb_urb[0]);
        kfree(adapter->priv->rx_data_pkt);
        kfree(dev->tx_buffer);
}

/**
 * rsi_init_usb_interface() - This function initializes the usb interface.
 * @adapter: Pointer to the adapter structure.
 * @pfunction: Pointer to USB interface structure.
 *
 * Return: 0 on success, a negative error code on failure.
 */
static int rsi_init_usb_interface(struct rsi_hw *adapter,
                                  struct usb_interface *pfunction)
{
        struct rsi_91x_usbdev *rsi_dev;
        struct rsi_common *common = adapter->priv;
        int status;

        rsi_dev = kzalloc(sizeof(*rsi_dev), GFP_KERNEL);
        if (!rsi_dev)
                return -ENOMEM;

        adapter->rsi_dev = rsi_dev;
        rsi_dev->usbdev = interface_to_usbdev(pfunction);

        if (rsi_find_bulk_in_and_out_endpoints(pfunction, adapter))
                return -EINVAL;

        adapter->device = &pfunction->dev;
        usb_set_intfdata(pfunction, adapter);

        common->rx_data_pkt = kmalloc(2048, GFP_KERNEL);
        if (!common->rx_data_pkt) {
                rsi_dbg(ERR_ZONE, "%s: Failed to allocate memory\n",
                        __func__);
                return -ENOMEM;
        }

        rsi_dev->tx_buffer = kmalloc(2048, GFP_KERNEL);
        if (!rsi_dev->tx_buffer) {
                status = -ENOMEM;
                goto fail_tx;
        }
        rsi_dev->rx_usb_urb[0] = usb_alloc_urb(0, GFP_KERNEL);
        if (!rsi_dev->rx_usb_urb[0]) {
                status = -ENOMEM;
                goto fail_rx;
        }
        rsi_dev->rx_usb_urb[0]->transfer_buffer = adapter->priv->rx_data_pkt;
        rsi_dev->tx_blk_size = 252;

        /* Initializing function callbacks */
        adapter->rx_urb_submit = rsi_rx_urb_submit;
        adapter->host_intf_write_pkt = rsi_usb_host_intf_write_pkt;
        adapter->check_hw_queue_status = rsi_usb_check_queue_status;
        adapter->determine_event_timeout = rsi_usb_event_timeout;

        rsi_init_event(&rsi_dev->rx_thread.event);
        status = rsi_create_kthread(common, &rsi_dev->rx_thread,
                                    rsi_usb_rx_thread, "RX-Thread");
        if (status) {
                rsi_dbg(ERR_ZONE, "%s: Unable to init rx thrd\n", __func__);
                goto fail_thread;
        }

#ifdef CONFIG_RSI_DEBUGFS
        /* In USB, one less than the MAX_DEBUGFS_ENTRIES entries is required */
        adapter->num_debugfs_entries = (MAX_DEBUGFS_ENTRIES - 1);
#endif

        rsi_dbg(INIT_ZONE, "%s: Enabled the interface\n", __func__);
        return 0;

fail_thread:
        usb_free_urb(rsi_dev->rx_usb_urb[0]);
fail_rx:
        kfree(rsi_dev->tx_buffer);
fail_tx:
        kfree(common->rx_data_pkt);
        return status;
}

/**
 * rsi_probe() - This function is called by kernel when the driver provided
 *               Vendor and device IDs are matched. All the initialization
 *               work is done here.
 * @pfunction: Pointer to the USB interface structure.
 * @id: Pointer to the usb_device_id structure.
 *
 * Return: 0 on success, a negative error code on failure.
 */
static int rsi_probe(struct usb_interface *pfunction,
                     const struct usb_device_id *id)
{
        struct rsi_hw *adapter;
        struct rsi_91x_usbdev *dev;
        u16 fw_status;
        int status;

        rsi_dbg(INIT_ZONE, "%s: Init function called\n", __func__);

        adapter = rsi_91x_init();
        if (!adapter) {
                rsi_dbg(ERR_ZONE, "%s: Failed to init os intf ops\n",
                        __func__);
                return -ENOMEM;
        }

        status = rsi_init_usb_interface(adapter, pfunction);
        if (status) {
                rsi_dbg(ERR_ZONE, "%s: Failed to init usb interface\n",
                        __func__);
                goto err;
        }

        rsi_dbg(ERR_ZONE, "%s: Initialized os intf ops\n", __func__);

        dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;

        status = rsi_usb_reg_read(dev->usbdev, FW_STATUS_REG, &fw_status, 2);
        if (status)
                goto err1;
        else
                fw_status &= 1;

        if (!fw_status) {
                status = rsi_usb_device_init(adapter->priv);
                if (status) {
                        rsi_dbg(ERR_ZONE, "%s: Failed in device init\n",
                                __func__);
                        goto err1;
                }

                status = rsi_usb_reg_write(dev->usbdev,
                                           USB_INTERNAL_REG_1,
                                           RSI_USB_READY_MAGIC_NUM, 1);
                if (status)
                        goto err1;
                rsi_dbg(INIT_ZONE, "%s: Performed device init\n", __func__);
        }

        status = rsi_rx_urb_submit(adapter);
        if (status)
                goto err1;

        return 0;
err1:
        rsi_deinit_usb_interface(adapter);
err:
        rsi_91x_deinit(adapter);
        rsi_dbg(ERR_ZONE, "%s: Failed in probe...Exiting\n", __func__);
        return status;
}

/**
 * rsi_disconnect() - This function performs the reverse of the probe function,
 *                    it deintialize the driver structure.
 * @pfunction: Pointer to the USB interface structure.
 *
 * Return: None.
 */
static void rsi_disconnect(struct usb_interface *pfunction)
{
        struct rsi_hw *adapter = usb_get_intfdata(pfunction);

        if (!adapter)
                return;

        rsi_mac80211_detach(adapter);
        rsi_deinit_usb_interface(adapter);
        rsi_91x_deinit(adapter);

        rsi_dbg(INFO_ZONE, "%s: Deinitialization completed\n", __func__);
}

#ifdef CONFIG_PM
static int rsi_suspend(struct usb_interface *intf, pm_message_t message)
{
        /* Not yet implemented */
        return -ENOSYS;
}

static int rsi_resume(struct usb_interface *intf)
{
        /* Not yet implemented */
        return -ENOSYS;
}
#endif

static const struct usb_device_id rsi_dev_table[] = {
        { USB_DEVICE(0x0303, 0x0100) },
        { USB_DEVICE(0x041B, 0x0301) },
        { USB_DEVICE(0x041B, 0x0201) },
        { USB_DEVICE(0x041B, 0x9330) },
        { /* Blank */},
};

static struct usb_driver rsi_driver = {
        .name       = "RSI-USB WLAN",
        .probe      = rsi_probe,
        .disconnect = rsi_disconnect,
        .id_table   = rsi_dev_table,
#ifdef CONFIG_PM
        .suspend    = rsi_suspend,
        .resume     = rsi_resume,
#endif
};

module_usb_driver(rsi_driver);

MODULE_AUTHOR("Redpine Signals Inc");
MODULE_DESCRIPTION("Common USB layer for RSI drivers");
MODULE_SUPPORTED_DEVICE("RSI-91x");
MODULE_DEVICE_TABLE(usb, rsi_dev_table);
MODULE_FIRMWARE(FIRMWARE_RSI9113);
MODULE_VERSION("0.1");
MODULE_LICENSE("Dual BSD/GPL");