// SPDX-License-Identifier: GPL-2.0+
//
// em28xx-core.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
//
// Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
//                    Markus Rechberger <mrechberger@gmail.com>
//                    Mauro Carvalho Chehab <mchehab@kernel.org>
//                    Sascha Sommer <saschasommer@freenet.de>
// Copyright (C) 2012 Frank Schäfer <fschaefer.oss@googlemail.com>

#include "em28xx.h"

#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/vmalloc.h>
#include <sound/ac97_codec.h>
#include <media/v4l2-common.h>

#define DRIVER_AUTHOR "Ludovico Cavedon <cavedon@sssup.it>, " \
                      "Markus Rechberger <mrechberger@gmail.com>, " \
                      "Mauro Carvalho Chehab <mchehab@kernel.org>, " \
                      "Sascha Sommer <saschasommer@freenet.de>"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL v2");
MODULE_VERSION(EM28XX_VERSION);

/* #define ENABLE_DEBUG_ISOC_FRAMES */

static unsigned int core_debug;
module_param(core_debug, int, 0644);
MODULE_PARM_DESC(core_debug, "enable debug messages [core and isoc]");

#define em28xx_coredbg(fmt, arg...) do {                                \
        if (core_debug)                                                 \
                dev_printk(KERN_DEBUG, &dev->intf->dev,                 \
                           "core: %s: " fmt, __func__, ## arg);         \
} while (0)

static unsigned int reg_debug;
module_param(reg_debug, int, 0644);
MODULE_PARM_DESC(reg_debug, "enable debug messages [URB reg]");

#define em28xx_regdbg(fmt, arg...) do {                         \
        if (reg_debug)                                                  \
                dev_printk(KERN_DEBUG, &dev->intf->dev,                 \
                           "reg: %s: " fmt, __func__, ## arg);          \
} while (0)

/* FIXME: don't abuse core_debug */
#define em28xx_isocdbg(fmt, arg...) do {                                \
        if (core_debug)                                                 \
                dev_printk(KERN_DEBUG, &dev->intf->dev,                 \
                           "core: %s: " fmt, __func__, ## arg);         \
} while (0)

/*
 * em28xx_read_reg_req()
 * reads data from the usb device specifying bRequest
 */
int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,
                            char *buf, int len)
{
        int ret;
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        int pipe = usb_rcvctrlpipe(udev, 0);

        if (dev->disconnected)
                return -ENODEV;

        if (len > URB_MAX_CTRL_SIZE)
                return -EINVAL;

        mutex_lock(&dev->ctrl_urb_lock);
        ret = usb_control_msg(udev, pipe, req,
                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                              0x0000, reg, dev->urb_buf, len, 1000);
        if (ret < 0) {
                em28xx_regdbg("(pipe 0x%08x): IN:  %02x %02x %02x %02x %02x %02x %02x %02x  failed with error %i\n",
                              pipe,
                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                              req, 0, 0,
                              reg & 0xff, reg >> 8,
                              len & 0xff, len >> 8, ret);
                mutex_unlock(&dev->ctrl_urb_lock);
                return usb_translate_errors(ret);
        }

        if (len)
                memcpy(buf, dev->urb_buf, len);

        mutex_unlock(&dev->ctrl_urb_lock);

        em28xx_regdbg("(pipe 0x%08x): IN:  %02x %02x %02x %02x %02x %02x %02x %02x <<< %*ph\n",
                      pipe, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                      req, 0, 0,
                      reg & 0xff, reg >> 8,
                      len & 0xff, len >> 8, len, buf);

        return ret;
}

/*
 * em28xx_read_reg_req()
 * reads data from the usb device specifying bRequest
 */
int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)
{
        int ret;
        u8 val;

        ret = em28xx_read_reg_req_len(dev, req, reg, &val, 1);
        if (ret < 0)
                return ret;

        return val;
}

int em28xx_read_reg(struct em28xx *dev, u16 reg)
{
        return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
}
EXPORT_SYMBOL_GPL(em28xx_read_reg);

/*
 * em28xx_write_regs_req()
 * sends data to the usb device, specifying bRequest
 */
int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
                          int len)
{
        int ret;
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        int pipe = usb_sndctrlpipe(udev, 0);

        if (dev->disconnected)
                return -ENODEV;

        if (len < 1 || len > URB_MAX_CTRL_SIZE)
                return -EINVAL;

        mutex_lock(&dev->ctrl_urb_lock);
        memcpy(dev->urb_buf, buf, len);
        ret = usb_control_msg(udev, pipe, req,
                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                              0x0000, reg, dev->urb_buf, len, 1000);
        mutex_unlock(&dev->ctrl_urb_lock);

        if (ret < 0) {
                em28xx_regdbg("(pipe 0x%08x): OUT:  %02x %02x %02x %02x %02x %02x %02x %02x >>> %*ph  failed with error %i\n",
                              pipe,
                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                              req, 0, 0,
                              reg & 0xff, reg >> 8,
                              len & 0xff, len >> 8, len, buf, ret);
                return usb_translate_errors(ret);
        }

        em28xx_regdbg("(pipe 0x%08x): OUT:  %02x %02x %02x %02x %02x %02x %02x %02x >>> %*ph\n",
                      pipe,
                      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                      req, 0, 0,
                      reg & 0xff, reg >> 8,
                      len & 0xff, len >> 8, len, buf);

        if (dev->wait_after_write)
                msleep(dev->wait_after_write);

        return ret;
}

int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
{
        return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
}
EXPORT_SYMBOL_GPL(em28xx_write_regs);

/* Write a single register */
int em28xx_write_reg(struct em28xx *dev, u16 reg, u8 val)
{
        return em28xx_write_regs(dev, reg, &val, 1);
}
EXPORT_SYMBOL_GPL(em28xx_write_reg);

/*
 * em28xx_write_reg_bits()
 * sets only some bits (specified by bitmask) of a register, by first reading
 * the actual value
 */
int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
                          u8 bitmask)
{
        int oldval;
        u8 newval;

        oldval = em28xx_read_reg(dev, reg);
        if (oldval < 0)
                return oldval;

        newval = (((u8)oldval) & ~bitmask) | (val & bitmask);

        return em28xx_write_regs(dev, reg, &newval, 1);
}
EXPORT_SYMBOL_GPL(em28xx_write_reg_bits);

/*
 * em28xx_toggle_reg_bits()
 * toggles/inverts the bits (specified by bitmask) of a register
 */
int em28xx_toggle_reg_bits(struct em28xx *dev, u16 reg, u8 bitmask)
{
        int oldval;
        u8 newval;

        oldval = em28xx_read_reg(dev, reg);
        if (oldval < 0)
                return oldval;

        newval = (~oldval & bitmask) | (oldval & ~bitmask);

        return em28xx_write_reg(dev, reg, newval);
}
EXPORT_SYMBOL_GPL(em28xx_toggle_reg_bits);

/*
 * em28xx_is_ac97_ready()
 * Checks if ac97 is ready
 */
static int em28xx_is_ac97_ready(struct em28xx *dev)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_AC97_XFER_TIMEOUT);
        int ret;

        /* Wait up to 50 ms for AC97 command to complete */
        while (time_is_after_jiffies(timeout)) {
                ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY);
                if (ret < 0)
                        return ret;

                if (!(ret & 0x01))
                        return 0;
                msleep(5);
        }

        dev_warn(&dev->intf->dev,
                 "AC97 command still being executed: not handled properly!\n");
        return -EBUSY;
}

/*
 * em28xx_read_ac97()
 * write a 16 bit value to the specified AC97 address (LSB first!)
 */
int em28xx_read_ac97(struct em28xx *dev, u8 reg)
{
        int ret;
        u8 addr = (reg & 0x7f) | 0x80;
        __le16 val;

        ret = em28xx_is_ac97_ready(dev);
        if (ret < 0)
                return ret;

        ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
        if (ret < 0)
                return ret;

        ret = dev->em28xx_read_reg_req_len(dev, 0, EM28XX_R40_AC97LSB,
                                           (u8 *)&val, sizeof(val));

        if (ret < 0)
                return ret;
        return le16_to_cpu(val);
}
EXPORT_SYMBOL_GPL(em28xx_read_ac97);

/*
 * em28xx_write_ac97()
 * write a 16 bit value to the specified AC97 address (LSB first!)
 */
int em28xx_write_ac97(struct em28xx *dev, u8 reg, u16 val)
{
        int ret;
        u8 addr = reg & 0x7f;
        __le16 value;

        value = cpu_to_le16(val);

        ret = em28xx_is_ac97_ready(dev);
        if (ret < 0)
                return ret;

        ret = em28xx_write_regs(dev, EM28XX_R40_AC97LSB, (u8 *)&value, 2);
        if (ret < 0)
                return ret;

        ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL_GPL(em28xx_write_ac97);

struct em28xx_vol_itable {
        enum em28xx_amux mux;
        u8               reg;
};

static struct em28xx_vol_itable inputs[] = {
        { EM28XX_AMUX_VIDEO,    AC97_VIDEO      },
        { EM28XX_AMUX_LINE_IN,  AC97_LINE       },
        { EM28XX_AMUX_PHONE,    AC97_PHONE      },
        { EM28XX_AMUX_MIC,      AC97_MIC        },
        { EM28XX_AMUX_CD,       AC97_CD         },
        { EM28XX_AMUX_AUX,      AC97_AUX        },
        { EM28XX_AMUX_PCM_OUT,  AC97_PCM        },
};

static int set_ac97_input(struct em28xx *dev)
{
        int ret, i;
        enum em28xx_amux amux = dev->ctl_ainput;

        /*
         * EM28XX_AMUX_VIDEO2 is a special case used to indicate that
         * em28xx should point to LINE IN, while AC97 should use VIDEO
         */
        if (amux == EM28XX_AMUX_VIDEO2)
                amux = EM28XX_AMUX_VIDEO;

        /* Mute all entres but the one that were selected */
        for (i = 0; i < ARRAY_SIZE(inputs); i++) {
                if (amux == inputs[i].mux)
                        ret = em28xx_write_ac97(dev, inputs[i].reg, 0x0808);
                else
                        ret = em28xx_write_ac97(dev, inputs[i].reg, 0x8000);

                if (ret < 0)
                        dev_warn(&dev->intf->dev,
                                 "couldn't setup AC97 register %d\n",
                                 inputs[i].reg);
        }
        return 0;
}

static int em28xx_set_audio_source(struct em28xx *dev)
{
        int ret;
        u8 input;

        if (dev->board.is_em2800) {
                if (dev->ctl_ainput == EM28XX_AMUX_VIDEO)
                        input = EM2800_AUDIO_SRC_TUNER;
                else
                        input = EM2800_AUDIO_SRC_LINE;

                ret = em28xx_write_regs(dev, EM2800_R08_AUDIOSRC, &input, 1);
                if (ret < 0)
                        return ret;
        }

        if (dev->has_msp34xx) {
                input = EM28XX_AUDIO_SRC_TUNER;
        } else {
                switch (dev->ctl_ainput) {
                case EM28XX_AMUX_VIDEO:
                        input = EM28XX_AUDIO_SRC_TUNER;
                        break;
                default:
                        input = EM28XX_AUDIO_SRC_LINE;
                        break;
                }
        }

        if (dev->board.mute_gpio && dev->mute)
                em28xx_gpio_set(dev, dev->board.mute_gpio);
        else
                em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);

        ret = em28xx_write_reg_bits(dev, EM28XX_R0E_AUDIOSRC, input, 0xc0);
        if (ret < 0)
                return ret;
        usleep_range(10000, 11000);

        switch (dev->audio_mode.ac97) {
        case EM28XX_NO_AC97:
                break;
        default:
                ret = set_ac97_input(dev);
        }

        return ret;
}

struct em28xx_vol_otable {
        enum em28xx_aout mux;
        u8               reg;
};

static const struct em28xx_vol_otable outputs[] = {
        { EM28XX_AOUT_MASTER, AC97_MASTER               },
        { EM28XX_AOUT_LINE,   AC97_HEADPHONE            },
        { EM28XX_AOUT_MONO,   AC97_MASTER_MONO          },
        { EM28XX_AOUT_LFE,    AC97_CENTER_LFE_MASTER    },
        { EM28XX_AOUT_SURR,   AC97_SURROUND_MASTER      },
};

int em28xx_audio_analog_set(struct em28xx *dev)
{
        int ret, i;
        u8 xclk;

        /* Set GPIOs here for boards without audio */
        if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE)
                return em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);

        /*
         * It is assumed that all devices use master volume for output.
         * It would be possible to use also line output.
         */
        if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
                /* Mute all outputs */
                for (i = 0; i < ARRAY_SIZE(outputs); i++) {
                        ret = em28xx_write_ac97(dev, outputs[i].reg, 0x8000);
                        if (ret < 0)
                                dev_warn(&dev->intf->dev,
                                         "couldn't setup AC97 register %d\n",
                                         outputs[i].reg);
                }
        }

        xclk = dev->board.xclk & 0x7f;
        if (!dev->mute)
                xclk |= EM28XX_XCLK_AUDIO_UNMUTE;

        ret = em28xx_write_reg(dev, EM28XX_R0F_XCLK, xclk);
        if (ret < 0)
                return ret;
        usleep_range(10000, 11000);

        /* Selects the proper audio input */
        ret = em28xx_set_audio_source(dev);

        /* Sets volume */
        if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
                int vol;

                em28xx_write_ac97(dev, AC97_POWERDOWN, 0x4200);
                em28xx_write_ac97(dev, AC97_EXTENDED_STATUS, 0x0031);
                em28xx_write_ac97(dev, AC97_PCM_LR_ADC_RATE, 0xbb80);

                /* LSB: left channel - both channels with the same level */
                vol = (0x1f - dev->volume) | ((0x1f - dev->volume) << 8);

                /* Mute device, if needed */
                if (dev->mute)
                        vol |= 0x8000;

                /* Sets volume */
                for (i = 0; i < ARRAY_SIZE(outputs); i++) {
                        if (dev->ctl_aoutput & outputs[i].mux)
                                ret = em28xx_write_ac97(dev, outputs[i].reg,
                                                        vol);
                        if (ret < 0)
                                dev_warn(&dev->intf->dev,
                                         "couldn't setup AC97 register %d\n",
                                         outputs[i].reg);
                }

                if (dev->ctl_aoutput & EM28XX_AOUT_PCM_IN) {
                        int sel = ac97_return_record_select(dev->ctl_aoutput);

                        /*
                         * Use the same input for both left and right
                         * channels
                         */
                        sel |= (sel << 8);

                        em28xx_write_ac97(dev, AC97_REC_SEL, sel);
                }
        }

        return ret;
}
EXPORT_SYMBOL_GPL(em28xx_audio_analog_set);

int em28xx_audio_setup(struct em28xx *dev)
{
        int vid1, vid2, feat, cfg;
        u32 vid = 0;
        u8 i2s_samplerates;

        if (dev->chip_id == CHIP_ID_EM2870 ||
            dev->chip_id == CHIP_ID_EM2874 ||
            dev->chip_id == CHIP_ID_EM28174 ||
            dev->chip_id == CHIP_ID_EM28178) {
                /* Digital only device - don't load any alsa module */
                dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
                dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
                return 0;
        }

        /* See how this device is configured */
        cfg = em28xx_read_reg(dev, EM28XX_R00_CHIPCFG);
        dev_info(&dev->intf->dev, "Config register raw data: 0x%02x\n", cfg);
        if (cfg < 0) { /* Register read error */
                /* Be conservative */
                dev->int_audio_type = EM28XX_INT_AUDIO_AC97;
        } else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) == 0x00) {
                /* The device doesn't have vendor audio at all */
                dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
                dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
                return 0;
        } else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) != EM28XX_CHIPCFG_AC97) {
                dev->int_audio_type = EM28XX_INT_AUDIO_I2S;
                if (dev->chip_id < CHIP_ID_EM2860 &&
                    (cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
                    EM2820_CHIPCFG_I2S_1_SAMPRATE)
                        i2s_samplerates = 1;
                else if (dev->chip_id >= CHIP_ID_EM2860 &&
                         (cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
                         EM2860_CHIPCFG_I2S_5_SAMPRATES)
                        i2s_samplerates = 5;
                else
                        i2s_samplerates = 3;
                dev_info(&dev->intf->dev, "I2S Audio (%d sample rate(s))\n",
                         i2s_samplerates);
                /* Skip the code that does AC97 vendor detection */
                dev->audio_mode.ac97 = EM28XX_NO_AC97;
                goto init_audio;
        } else {
                dev->int_audio_type = EM28XX_INT_AUDIO_AC97;
        }

        dev->audio_mode.ac97 = EM28XX_AC97_OTHER;

        vid1 = em28xx_read_ac97(dev, AC97_VENDOR_ID1);
        if (vid1 < 0) {
                /*
                 * Device likely doesn't support AC97
                 * Note: (some) em2800 devices without eeprom reports 0x91 on
                 *       CHIPCFG register, even not having an AC97 chip
                 */
                dev_warn(&dev->intf->dev,
                         "AC97 chip type couldn't be determined\n");
                dev->audio_mode.ac97 = EM28XX_NO_AC97;
                if (dev->usb_audio_type == EM28XX_USB_AUDIO_VENDOR)
                        dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
                dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
                goto init_audio;
        }

        vid2 = em28xx_read_ac97(dev, AC97_VENDOR_ID2);
        if (vid2 < 0)
                goto init_audio;

        vid = vid1 << 16 | vid2;
        dev_warn(&dev->intf->dev, "AC97 vendor ID = 0x%08x\n", vid);

        feat = em28xx_read_ac97(dev, AC97_RESET);
        if (feat < 0)
                goto init_audio;

        dev_warn(&dev->intf->dev, "AC97 features = 0x%04x\n", feat);

        /* Try to identify what audio processor we have */
        if ((vid == 0xffffffff || vid == 0x83847650) && feat == 0x6a90)
                dev->audio_mode.ac97 = EM28XX_AC97_EM202;
        else if ((vid >> 8) == 0x838476)
                dev->audio_mode.ac97 = EM28XX_AC97_SIGMATEL;

init_audio:
        /* Reports detected AC97 processor */
        switch (dev->audio_mode.ac97) {
        case EM28XX_NO_AC97:
                dev_info(&dev->intf->dev, "No AC97 audio processor\n");
                break;
        case EM28XX_AC97_EM202:
                dev_info(&dev->intf->dev,
                         "Empia 202 AC97 audio processor detected\n");
                break;
        case EM28XX_AC97_SIGMATEL:
                dev_info(&dev->intf->dev,
                         "Sigmatel audio processor detected (stac 97%02x)\n",
                         vid & 0xff);
                break;
        case EM28XX_AC97_OTHER:
                dev_warn(&dev->intf->dev,
                         "Unknown AC97 audio processor detected!\n");
                break;
        default:
                break;
        }

        return em28xx_audio_analog_set(dev);
}
EXPORT_SYMBOL_GPL(em28xx_audio_setup);

const struct em28xx_led *em28xx_find_led(struct em28xx *dev,
                                         enum em28xx_led_role role)
{
        if (dev->board.leds) {
                u8 k = 0;

                while (dev->board.leds[k].role >= 0 &&
                       dev->board.leds[k].role < EM28XX_NUM_LED_ROLES) {
                        if (dev->board.leds[k].role == role)
                                return &dev->board.leds[k];
                        k++;
                }
        }
        return NULL;
}
EXPORT_SYMBOL_GPL(em28xx_find_led);

int em28xx_capture_start(struct em28xx *dev, int start)
{
        int rc;
        const struct em28xx_led *led = NULL;

        if (dev->chip_id == CHIP_ID_EM2874 ||
            dev->chip_id == CHIP_ID_EM2884 ||
            dev->chip_id == CHIP_ID_EM28174 ||
            dev->chip_id == CHIP_ID_EM28178) {
                /* The Transport Stream Enable Register moved in em2874 */
                if (dev->dvb_xfer_bulk) {
                        /* Max Tx Size = 188 * 256 = 48128 - LCM(188,512) * 2 */
                        em28xx_write_reg(dev, (dev->ts == PRIMARY_TS) ?
                                         EM2874_R5D_TS1_PKT_SIZE :
                                         EM2874_R5E_TS2_PKT_SIZE,
                                         0xff);
                } else {
                        /* ISOC Maximum Transfer Size = 188 * 5 */
                        em28xx_write_reg(dev, (dev->ts == PRIMARY_TS) ?
                                         EM2874_R5D_TS1_PKT_SIZE :
                                         EM2874_R5E_TS2_PKT_SIZE,
                                         dev->dvb_max_pkt_size_isoc / 188);
                }
                if (dev->ts == PRIMARY_TS)
                        rc = em28xx_write_reg_bits(dev,
                                                   EM2874_R5F_TS_ENABLE,
                                                   start ? EM2874_TS1_CAPTURE_ENABLE : 0x00,
                                                   EM2874_TS1_CAPTURE_ENABLE | EM2874_TS1_FILTER_ENABLE | EM2874_TS1_NULL_DISCARD);
                else
                        rc = em28xx_write_reg_bits(dev,
                                                   EM2874_R5F_TS_ENABLE,
                                                   start ? EM2874_TS2_CAPTURE_ENABLE : 0x00,
                                                   EM2874_TS2_CAPTURE_ENABLE | EM2874_TS2_FILTER_ENABLE | EM2874_TS2_NULL_DISCARD);
        } else {
                /* FIXME: which is the best order? */
                /* video registers are sampled by VREF */
                rc = em28xx_write_reg_bits(dev, EM28XX_R0C_USBSUSP,
                                           start ? 0x10 : 0x00, 0x10);
                if (rc < 0)
                        return rc;

                if (start) {
                        if (dev->is_webcam)
                                rc = em28xx_write_reg(dev, 0x13, 0x0c);

                        /* Enable video capture */
                        rc = em28xx_write_reg(dev, 0x48, 0x00);
                        if (rc < 0)
                                return rc;

                        if (dev->mode == EM28XX_ANALOG_MODE)
                                rc = em28xx_write_reg(dev,
                                                      EM28XX_R12_VINENABLE,
                                                      0x67);
                        else
                                rc = em28xx_write_reg(dev,
                                                      EM28XX_R12_VINENABLE,
                                                      0x37);
                        if (rc < 0)
                                return rc;

                        usleep_range(10000, 11000);
                } else {
                        /* disable video capture */
                        rc = em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x27);
                }
        }

        if (dev->mode == EM28XX_ANALOG_MODE)
                led = em28xx_find_led(dev, EM28XX_LED_ANALOG_CAPTURING);
        else if (dev->ts == PRIMARY_TS)
                led = em28xx_find_led(dev, EM28XX_LED_DIGITAL_CAPTURING);
        else
                led = em28xx_find_led(dev, EM28XX_LED_DIGITAL_CAPTURING_TS2);

        if (led)
                em28xx_write_reg_bits(dev, led->gpio_reg,
                                      (!start ^ led->inverted) ?
                                      ~led->gpio_mask : led->gpio_mask,
                                      led->gpio_mask);

        return rc;
}

int em28xx_gpio_set(struct em28xx *dev, const struct em28xx_reg_seq *gpio)
{
        int rc = 0;

        if (!gpio)
                return rc;

        if (dev->mode != EM28XX_SUSPEND) {
                em28xx_write_reg(dev, 0x48, 0x00);
                if (dev->mode == EM28XX_ANALOG_MODE)
                        em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x67);
                else
                        em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x37);
                usleep_range(10000, 11000);
        }

        /* Send GPIO reset sequences specified at board entry */
        while (gpio->sleep >= 0) {
                if (gpio->reg >= 0) {
                        rc = em28xx_write_reg_bits(dev,
                                                   gpio->reg,
                                                   gpio->val,
                                                   gpio->mask);
                        if (rc < 0)
                                return rc;
                }
                if (gpio->sleep > 0)
                        msleep(gpio->sleep);

                gpio++;
        }
        return rc;
}
EXPORT_SYMBOL_GPL(em28xx_gpio_set);

int em28xx_set_mode(struct em28xx *dev, enum em28xx_mode set_mode)
{
        if (dev->mode == set_mode)
                return 0;

        if (set_mode == EM28XX_SUSPEND) {
                dev->mode = set_mode;

                /* FIXME: add suspend support for ac97 */

                return em28xx_gpio_set(dev, dev->board.suspend_gpio);
        }

        dev->mode = set_mode;

        if (dev->mode == EM28XX_DIGITAL_MODE)
                return em28xx_gpio_set(dev, dev->board.dvb_gpio);
        else
                return em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);
}
EXPORT_SYMBOL_GPL(em28xx_set_mode);

/*
 *URB control
 */

/*
 * URB completion handler for isoc/bulk transfers
 */
static void em28xx_irq_callback(struct urb *urb)
{
        struct em28xx *dev = urb->context;
        unsigned long flags;
        int i;

        switch (urb->status) {
        case 0:             /* success */
        case -ETIMEDOUT:    /* NAK */
                break;
        case -ECONNRESET:   /* kill */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        default:            /* error */
                em28xx_isocdbg("urb completion error %d.\n", urb->status);
                break;
        }

        /* Copy data from URB */
        spin_lock_irqsave(&dev->slock, flags);
        dev->usb_ctl.urb_data_copy(dev, urb);
        spin_unlock_irqrestore(&dev->slock, flags);

        /* Reset urb buffers */
        for (i = 0; i < urb->number_of_packets; i++) {
                /* isoc only (bulk: number_of_packets = 0) */
                urb->iso_frame_desc[i].status = 0;
                urb->iso_frame_desc[i].actual_length = 0;
        }
        urb->status = 0;

        urb->status = usb_submit_urb(urb, GFP_ATOMIC);
        if (urb->status) {
                em28xx_isocdbg("urb resubmit failed (error=%i)\n",
                               urb->status);
        }
}

/*
 * Stop and Deallocate URBs
 */
void em28xx_uninit_usb_xfer(struct em28xx *dev, enum em28xx_mode mode)
{
        struct urb *urb;
        struct em28xx_usb_bufs *usb_bufs;
        int i;

        em28xx_isocdbg("called %s in mode %d\n", __func__, mode);

        if (mode == EM28XX_DIGITAL_MODE)
                usb_bufs = &dev->usb_ctl.digital_bufs;
        else
                usb_bufs = &dev->usb_ctl.analog_bufs;

        for (i = 0; i < usb_bufs->num_bufs; i++) {
                urb = usb_bufs->urb[i];
                if (urb) {
                        if (!irqs_disabled())
                                usb_kill_urb(urb);
                        else
                                usb_unlink_urb(urb);

                        usb_free_urb(urb);
                        usb_bufs->urb[i] = NULL;
                }
        }

        kfree(usb_bufs->urb);
        kfree(usb_bufs->buf);

        usb_bufs->urb = NULL;
        usb_bufs->buf = NULL;
        usb_bufs->num_bufs = 0;

        em28xx_capture_start(dev, 0);
}
EXPORT_SYMBOL_GPL(em28xx_uninit_usb_xfer);

/*
 * Stop URBs
 */
void em28xx_stop_urbs(struct em28xx *dev)
{
        int i;
        struct urb *urb;
        struct em28xx_usb_bufs *isoc_bufs = &dev->usb_ctl.digital_bufs;

        em28xx_isocdbg("called %s\n", __func__);

        for (i = 0; i < isoc_bufs->num_bufs; i++) {
                urb = isoc_bufs->urb[i];
                if (urb) {
                        if (!irqs_disabled())
                                usb_kill_urb(urb);
                        else
                                usb_unlink_urb(urb);
                }
        }

        em28xx_capture_start(dev, 0);
}
EXPORT_SYMBOL_GPL(em28xx_stop_urbs);

/*
 * Allocate URBs
 */
int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,
                      int num_bufs, int max_pkt_size, int packet_multiplier)
{
        struct em28xx_usb_bufs *usb_bufs;
        struct urb *urb;
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        int i;
        int sb_size, pipe;
        int j, k;

        em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);

        /*
         * Check mode and if we have an endpoint for the selected
         * transfer type, select buffer
         */
        if (mode == EM28XX_DIGITAL_MODE) {
                if ((xfer_bulk && !dev->dvb_ep_bulk) ||
                    (!xfer_bulk && !dev->dvb_ep_isoc)) {
                        dev_err(&dev->intf->dev,
                                "no endpoint for DVB mode and transfer type %d\n",
                                xfer_bulk > 0);
                        return -EINVAL;
                }
                usb_bufs = &dev->usb_ctl.digital_bufs;
        } else if (mode == EM28XX_ANALOG_MODE) {
                if ((xfer_bulk && !dev->analog_ep_bulk) ||
                    (!xfer_bulk && !dev->analog_ep_isoc)) {
                        dev_err(&dev->intf->dev,
                                "no endpoint for analog mode and transfer type %d\n",
                                xfer_bulk > 0);
                        return -EINVAL;
                }
                usb_bufs = &dev->usb_ctl.analog_bufs;
        } else {
                dev_err(&dev->intf->dev, "invalid mode selected\n");
                return -EINVAL;
        }

        /* De-allocates all pending stuff */
        em28xx_uninit_usb_xfer(dev, mode);

        usb_bufs->num_bufs = num_bufs;

        usb_bufs->urb = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
        if (!usb_bufs->urb)
                return -ENOMEM;

        usb_bufs->buf = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
        if (!usb_bufs->buf) {
                kfree(usb_bufs->urb);
                return -ENOMEM;
        }

        usb_bufs->max_pkt_size = max_pkt_size;
        if (xfer_bulk)
                usb_bufs->num_packets = 0;
        else
                usb_bufs->num_packets = packet_multiplier;
        dev->usb_ctl.vid_buf = NULL;
        dev->usb_ctl.vbi_buf = NULL;

        sb_size = packet_multiplier * usb_bufs->max_pkt_size;

        /* allocate urbs and transfer buffers */
        for (i = 0; i < usb_bufs->num_bufs; i++) {
                urb = usb_alloc_urb(usb_bufs->num_packets, GFP_KERNEL);
                if (!urb) {
                        em28xx_uninit_usb_xfer(dev, mode);
                        return -ENOMEM;
                }
                usb_bufs->urb[i] = urb;

                usb_bufs->buf[i] = kzalloc(sb_size, GFP_KERNEL);
                if (!usb_bufs->buf[i]) {
                        for (i--; i >= 0; i--)
                                kfree(usb_bufs->buf[i]);

                        em28xx_uninit_usb_xfer(dev, mode);
                        return -ENOMEM;
                }

                urb->transfer_flags = URB_FREE_BUFFER;

                if (xfer_bulk) { /* bulk */
                        pipe = usb_rcvbulkpipe(udev,
                                               mode == EM28XX_ANALOG_MODE ?
                                               dev->analog_ep_bulk :
                                               dev->dvb_ep_bulk);
                        usb_fill_bulk_urb(urb, udev, pipe, usb_bufs->buf[i],
                                          sb_size, em28xx_irq_callback, dev);
                } else { /* isoc */
                        pipe = usb_rcvisocpipe(udev,
                                               mode == EM28XX_ANALOG_MODE ?
                                               dev->analog_ep_isoc :
                                               dev->dvb_ep_isoc);
                        usb_fill_int_urb(urb, udev, pipe, usb_bufs->buf[i],
                                         sb_size, em28xx_irq_callback, dev, 1);
                        urb->transfer_flags |= URB_ISO_ASAP;
                        k = 0;
                        for (j = 0; j < usb_bufs->num_packets; j++) {
                                urb->iso_frame_desc[j].offset = k;
                                urb->iso_frame_desc[j].length =
                                                        usb_bufs->max_pkt_size;
                                k += usb_bufs->max_pkt_size;
                        }
                }

                urb->number_of_packets = usb_bufs->num_packets;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(em28xx_alloc_urbs);

/*
 * Allocate URBs and start IRQ
 */
int em28xx_init_usb_xfer(struct em28xx *dev, enum em28xx_mode mode,
                         int xfer_bulk, int num_bufs, int max_pkt_size,
                    int packet_multiplier,
                    int (*urb_data_copy)(struct em28xx *dev, struct urb *urb))
{
        struct em28xx_dmaqueue *dma_q = &dev->vidq;
        struct em28xx_dmaqueue *vbi_dma_q = &dev->vbiq;
        struct em28xx_usb_bufs *usb_bufs;
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        int i;
        int rc;
        int alloc;

        em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);

        dev->usb_ctl.urb_data_copy = urb_data_copy;

        if (mode == EM28XX_DIGITAL_MODE) {
                usb_bufs = &dev->usb_ctl.digital_bufs;
                /* no need to free/alloc usb buffers in digital mode */
                alloc = 0;
        } else {
                usb_bufs = &dev->usb_ctl.analog_bufs;
                alloc = 1;
        }

        if (alloc) {
                rc = em28xx_alloc_urbs(dev, mode, xfer_bulk, num_bufs,
                                       max_pkt_size, packet_multiplier);
                if (rc)
                        return rc;
        }

        if (xfer_bulk) {
                rc = usb_clear_halt(udev, usb_bufs->urb[0]->pipe);
                if (rc < 0) {
                        dev_err(&dev->intf->dev,
                                "failed to clear USB bulk endpoint stall/halt condition (error=%i)\n",
                               rc);
                        em28xx_uninit_usb_xfer(dev, mode);
                        return rc;
                }
        }

        init_waitqueue_head(&dma_q->wq);
        init_waitqueue_head(&vbi_dma_q->wq);

        em28xx_capture_start(dev, 1);

        /* submit urbs and enables IRQ */
        for (i = 0; i < usb_bufs->num_bufs; i++) {
                rc = usb_submit_urb(usb_bufs->urb[i], GFP_KERNEL);
                if (rc) {
                        dev_err(&dev->intf->dev,
                                "submit of urb %i failed (error=%i)\n", i, rc);
                        em28xx_uninit_usb_xfer(dev, mode);
                        return rc;
                }
        }

        return 0;
}
EXPORT_SYMBOL_GPL(em28xx_init_usb_xfer);

/*
 * Device control list
 */

static LIST_HEAD(em28xx_devlist);
static DEFINE_MUTEX(em28xx_devlist_mutex);

/*
 * Extension interface
 */

static LIST_HEAD(em28xx_extension_devlist);

int em28xx_register_extension(struct em28xx_ops *ops)
{
        struct em28xx *dev = NULL;

        mutex_lock(&em28xx_devlist_mutex);
        list_add_tail(&ops->next, &em28xx_extension_devlist);
        list_for_each_entry(dev, &em28xx_devlist, devlist) {
                if (ops->init) {
                        ops->init(dev);
                        if (dev->dev_next)
                                ops->init(dev->dev_next);
                }
        }
        mutex_unlock(&em28xx_devlist_mutex);
        pr_info("em28xx: Registered (%s) extension\n", ops->name);
        return 0;
}
EXPORT_SYMBOL(em28xx_register_extension);

void em28xx_unregister_extension(struct em28xx_ops *ops)
{
        struct em28xx *dev = NULL;

        mutex_lock(&em28xx_devlist_mutex);
        list_for_each_entry(dev, &em28xx_devlist, devlist) {
                if (ops->fini) {
                        if (dev->dev_next)
                                ops->fini(dev->dev_next);
                        ops->fini(dev);
                }
        }
        list_del(&ops->next);
        mutex_unlock(&em28xx_devlist_mutex);
        pr_info("em28xx: Removed (%s) extension\n", ops->name);
}
EXPORT_SYMBOL(em28xx_unregister_extension);

void em28xx_init_extension(struct em28xx *dev)
{
        const struct em28xx_ops *ops = NULL;

        mutex_lock(&em28xx_devlist_mutex);
        list_add_tail(&dev->devlist, &em28xx_devlist);
        list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                if (ops->init) {
                        ops->init(dev);
                        if (dev->dev_next)
                                ops->init(dev->dev_next);
                }
        }
        mutex_unlock(&em28xx_devlist_mutex);
}

void em28xx_close_extension(struct em28xx *dev)
{
        const struct em28xx_ops *ops = NULL;

        mutex_lock(&em28xx_devlist_mutex);
        list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                if (ops->fini) {
                        if (dev->dev_next)
                                ops->fini(dev->dev_next);
                        ops->fini(dev);
                }
        }
        list_del(&dev->devlist);
        mutex_unlock(&em28xx_devlist_mutex);
}

int em28xx_suspend_extension(struct em28xx *dev)
{
        const struct em28xx_ops *ops = NULL;

        dev_info(&dev->intf->dev, "Suspending extensions\n");
        mutex_lock(&em28xx_devlist_mutex);
        list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                if (!ops->suspend)
                        continue;
                ops->suspend(dev);
                if (dev->dev_next)
                        ops->suspend(dev->dev_next);
        }
        mutex_unlock(&em28xx_devlist_mutex);
        return 0;
}

int em28xx_resume_extension(struct em28xx *dev)
{
        const struct em28xx_ops *ops = NULL;

        dev_info(&dev->intf->dev, "Resuming extensions\n");
        mutex_lock(&em28xx_devlist_mutex);
        list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                if (!ops->resume)
                        continue;
                ops->resume(dev);
                if (dev->dev_next)
                        ops->resume(dev->dev_next);
        }
        mutex_unlock(&em28xx_devlist_mutex);
        return 0;
}