Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[mirror_ubuntu-artful-kernel.git] / drivers / media / pci / cx25821 / cx25821-video-upstream.c

/*
 *  Driver for the Conexant CX25821 PCIe bridge
 *
 *  Copyright (C) 2009 Conexant Systems Inc.
 *  Authors  <hiep.huynh@conexant.com>, <shu.lin@conexant.com>
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "cx25821-video.h"
#include "cx25821-video-upstream.h"

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>

MODULE_DESCRIPTION("v4l2 driver module for cx25821 based TV cards");
MODULE_AUTHOR("Hiep Huynh <hiep.huynh@conexant.com>");
MODULE_LICENSE("GPL");

static int _intr_msk = FLD_VID_SRC_RISC1 | FLD_VID_SRC_UF | FLD_VID_SRC_SYNC |
                        FLD_VID_SRC_OPC_ERR;

int cx25821_sram_channel_setup_upstream(struct cx25821_dev *dev,
                                        const struct sram_channel *ch,
                                        unsigned int bpl, u32 risc)
{
        unsigned int i, lines;
        u32 cdt;

        if (ch->cmds_start == 0) {
                cx_write(ch->ptr1_reg, 0);
                cx_write(ch->ptr2_reg, 0);
                cx_write(ch->cnt2_reg, 0);
                cx_write(ch->cnt1_reg, 0);
                return 0;
        }

        bpl = (bpl + 7) & ~7;   /* alignment */
        cdt = ch->cdt;
        lines = ch->fifo_size / bpl;

        if (lines > 4)
                lines = 4;

        BUG_ON(lines < 2);

        /* write CDT */
        for (i = 0; i < lines; i++) {
                cx_write(cdt + 16 * i, ch->fifo_start + bpl * i);
                cx_write(cdt + 16 * i + 4, 0);
                cx_write(cdt + 16 * i + 8, 0);
                cx_write(cdt + 16 * i + 12, 0);
        }

        /* write CMDS */
        cx_write(ch->cmds_start + 0, risc);

        cx_write(ch->cmds_start + 4, 0);
        cx_write(ch->cmds_start + 8, cdt);
        cx_write(ch->cmds_start + 12, (lines * 16) >> 3);
        cx_write(ch->cmds_start + 16, ch->ctrl_start);

        cx_write(ch->cmds_start + 20, VID_IQ_SIZE_DW);

        for (i = 24; i < 80; i += 4)
                cx_write(ch->cmds_start + i, 0);

        /* fill registers */
        cx_write(ch->ptr1_reg, ch->fifo_start);
        cx_write(ch->ptr2_reg, cdt);
        cx_write(ch->cnt2_reg, (lines * 16) >> 3);
        cx_write(ch->cnt1_reg, (bpl >> 3) - 1);

        return 0;
}

static __le32 *cx25821_update_riscprogram(struct cx25821_channel *chan,
                                          __le32 *rp, unsigned int offset,
                                          unsigned int bpl, u32 sync_line,
                                          unsigned int lines, int fifo_enable,
                                          int field_type)
{
        struct cx25821_video_out_data *out = chan->out;
        unsigned int line, i;
        int dist_betwn_starts = bpl * 2;

        *(rp++) = cpu_to_le32(RISC_RESYNC | sync_line);

        if (USE_RISC_NOOP_VIDEO) {
                for (i = 0; i < NUM_NO_OPS; i++)
                        *(rp++) = cpu_to_le32(RISC_NOOP);
        }

        /* scan lines */
        for (line = 0; line < lines; line++) {
                *(rp++) = cpu_to_le32(RISC_READ | RISC_SOL | RISC_EOL | bpl);
                *(rp++) = cpu_to_le32(out->_data_buf_phys_addr + offset);
                *(rp++) = cpu_to_le32(0);       /* bits 63-32 */

                if ((lines <= NTSC_FIELD_HEIGHT)
                    || (line < (NTSC_FIELD_HEIGHT - 1)) || !(out->is_60hz)) {
                        offset += dist_betwn_starts;
                }
        }

        return rp;
}

static __le32 *cx25821_risc_field_upstream(struct cx25821_channel *chan, __le32 *rp,
                                           dma_addr_t databuf_phys_addr,
                                           unsigned int offset, u32 sync_line,
                                           unsigned int bpl, unsigned int lines,
                                           int fifo_enable, int field_type)
{
        struct cx25821_video_out_data *out = chan->out;
        unsigned int line, i;
        const struct sram_channel *sram_ch = chan->sram_channels;
        int dist_betwn_starts = bpl * 2;

        /* sync instruction */
        if (sync_line != NO_SYNC_LINE)
                *(rp++) = cpu_to_le32(RISC_RESYNC | sync_line);

        if (USE_RISC_NOOP_VIDEO) {
                for (i = 0; i < NUM_NO_OPS; i++)
                        *(rp++) = cpu_to_le32(RISC_NOOP);
        }

        /* scan lines */
        for (line = 0; line < lines; line++) {
                *(rp++) = cpu_to_le32(RISC_READ | RISC_SOL | RISC_EOL | bpl);
                *(rp++) = cpu_to_le32(databuf_phys_addr + offset);
                *(rp++) = cpu_to_le32(0);       /* bits 63-32 */

                if ((lines <= NTSC_FIELD_HEIGHT)
                    || (line < (NTSC_FIELD_HEIGHT - 1)) || !(out->is_60hz))
                        /* to skip the other field line */
                        offset += dist_betwn_starts;

                /* check if we need to enable the FIFO after the first 4 lines
                 * For the upstream video channel, the risc engine will enable
                 * the FIFO. */
                if (fifo_enable && line == 3) {
                        *(rp++) = cpu_to_le32(RISC_WRITECR);
                        *(rp++) = cpu_to_le32(sram_ch->dma_ctl);
                        *(rp++) = cpu_to_le32(FLD_VID_FIFO_EN);
                        *(rp++) = cpu_to_le32(0x00000001);
                }
        }

        return rp;
}

static int cx25821_risc_buffer_upstream(struct cx25821_channel *chan,
                                        struct pci_dev *pci,
                                        unsigned int top_offset,
                                        unsigned int bpl, unsigned int lines)
{
        struct cx25821_video_out_data *out = chan->out;
        __le32 *rp;
        int fifo_enable = 0;
        /* get line count for single field */
        int singlefield_lines = lines >> 1;
        int odd_num_lines = singlefield_lines;
        int frame = 0;
        int frame_size = 0;
        int databuf_offset = 0;
        int risc_program_size = 0;
        int risc_flag = RISC_CNT_RESET;
        unsigned int bottom_offset = bpl;
        dma_addr_t risc_phys_jump_addr;

        if (out->is_60hz) {
                odd_num_lines = singlefield_lines + 1;
                risc_program_size = FRAME1_VID_PROG_SIZE;
                frame_size = (bpl == Y411_LINE_SZ) ?
                        FRAME_SIZE_NTSC_Y411 : FRAME_SIZE_NTSC_Y422;
        } else {
                risc_program_size = PAL_VID_PROG_SIZE;
                frame_size = (bpl == Y411_LINE_SZ) ?
                        FRAME_SIZE_PAL_Y411 : FRAME_SIZE_PAL_Y422;
        }

        /* Virtual address of Risc buffer program */
        rp = out->_dma_virt_addr;

        for (frame = 0; frame < NUM_FRAMES; frame++) {
                databuf_offset = frame_size * frame;

                if (UNSET != top_offset) {
                        fifo_enable = (frame == 0) ? FIFO_ENABLE : FIFO_DISABLE;
                        rp = cx25821_risc_field_upstream(chan, rp,
                                        out->_data_buf_phys_addr +
                                        databuf_offset, top_offset, 0, bpl,
                                        odd_num_lines, fifo_enable, ODD_FIELD);
                }

                fifo_enable = FIFO_DISABLE;

                /* Even Field */
                rp = cx25821_risc_field_upstream(chan, rp,
                                                 out->_data_buf_phys_addr +
                                                 databuf_offset, bottom_offset,
                                                 0x200, bpl, singlefield_lines,
                                                 fifo_enable, EVEN_FIELD);

                if (frame == 0) {
                        risc_flag = RISC_CNT_RESET;
                        risc_phys_jump_addr = out->_dma_phys_start_addr +
                                risc_program_size;
                } else {
                        risc_phys_jump_addr = out->_dma_phys_start_addr;
                        risc_flag = RISC_CNT_INC;
                }

                /* Loop to 2ndFrameRISC or to Start of Risc
                 * program & generate IRQ
                 */
                *(rp++) = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | risc_flag);
                *(rp++) = cpu_to_le32(risc_phys_jump_addr);
                *(rp++) = cpu_to_le32(0);
        }

        return 0;
}

void cx25821_stop_upstream_video(struct cx25821_channel *chan)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        const struct sram_channel *sram_ch = chan->sram_channels;
        u32 tmp = 0;

        if (!out->_is_running) {
                pr_info("No video file is currently running so return!\n");
                return;
        }

        /* Set the interrupt mask register, disable irq. */
        cx_set(PCI_INT_MSK, cx_read(PCI_INT_MSK) & ~(1 << sram_ch->irq_bit));

        /* Disable RISC interrupts */
        tmp = cx_read(sram_ch->int_msk);
        cx_write(sram_ch->int_msk, tmp & ~_intr_msk);

        /* Turn OFF risc and fifo enable */
        tmp = cx_read(sram_ch->dma_ctl);
        cx_write(sram_ch->dma_ctl, tmp & ~(FLD_VID_FIFO_EN | FLD_VID_RISC_EN));

        free_irq(dev->pci->irq, chan);

        /* Clear data buffer memory */
        if (out->_data_buf_virt_addr)
                memset(out->_data_buf_virt_addr, 0, out->_data_buf_size);

        out->_is_running = 0;
        out->_is_first_frame = 0;
        out->_frame_count = 0;
        out->_file_status = END_OF_FILE;

        tmp = cx_read(VID_CH_MODE_SEL);
        cx_write(VID_CH_MODE_SEL, tmp & 0xFFFFFE00);
}

void cx25821_free_mem_upstream(struct cx25821_channel *chan)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;

        if (out->_is_running)
                cx25821_stop_upstream_video(chan);

        if (out->_dma_virt_addr) {
                pci_free_consistent(dev->pci, out->_risc_size,
                                    out->_dma_virt_addr, out->_dma_phys_addr);
                out->_dma_virt_addr = NULL;
        }

        if (out->_data_buf_virt_addr) {
                pci_free_consistent(dev->pci, out->_data_buf_size,
                                    out->_data_buf_virt_addr,
                                    out->_data_buf_phys_addr);
                out->_data_buf_virt_addr = NULL;
        }
}

int cx25821_write_frame(struct cx25821_channel *chan,
                const char __user *data, size_t count)
{
        struct cx25821_video_out_data *out = chan->out;
        int line_size = (out->_pixel_format == PIXEL_FRMT_411) ?
                Y411_LINE_SZ : Y422_LINE_SZ;
        int frame_size = 0;
        int frame_offset = 0;
        int curpos = out->curpos;

        if (out->is_60hz)
                frame_size = (line_size == Y411_LINE_SZ) ?
                        FRAME_SIZE_NTSC_Y411 : FRAME_SIZE_NTSC_Y422;
        else
                frame_size = (line_size == Y411_LINE_SZ) ?
                        FRAME_SIZE_PAL_Y411 : FRAME_SIZE_PAL_Y422;

        if (curpos == 0) {
                out->cur_frame_index = out->_frame_index;
                if (wait_event_interruptible(out->waitq, out->cur_frame_index != out->_frame_index))
                        return -EINTR;
                out->cur_frame_index = out->_frame_index;
        }

        frame_offset = out->cur_frame_index ? frame_size : 0;

        if (frame_size - curpos < count)
                count = frame_size - curpos;
        if (copy_from_user((__force char *)out->_data_buf_virt_addr + frame_offset + curpos,
                                data, count))
                return -EFAULT;
        curpos += count;
        if (curpos == frame_size) {
                out->_frame_count++;
                curpos = 0;
        }
        out->curpos = curpos;

        return count;
}

static int cx25821_upstream_buffer_prepare(struct cx25821_channel *chan,
                                           const struct sram_channel *sram_ch,
                                           int bpl)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        int ret = 0;
        dma_addr_t dma_addr;
        dma_addr_t data_dma_addr;

        if (out->_dma_virt_addr != NULL)
                pci_free_consistent(dev->pci, out->upstream_riscbuf_size,
                                out->_dma_virt_addr, out->_dma_phys_addr);

        out->_dma_virt_addr = pci_alloc_consistent(dev->pci,
                        out->upstream_riscbuf_size, &dma_addr);
        out->_dma_virt_start_addr = out->_dma_virt_addr;
        out->_dma_phys_start_addr = dma_addr;
        out->_dma_phys_addr = dma_addr;
        out->_risc_size = out->upstream_riscbuf_size;

        if (!out->_dma_virt_addr) {
                pr_err("FAILED to allocate memory for Risc buffer! Returning\n");
                return -ENOMEM;
        }

        /* Clear memory at address */
        memset(out->_dma_virt_addr, 0, out->_risc_size);

        if (out->_data_buf_virt_addr != NULL)
                pci_free_consistent(dev->pci, out->upstream_databuf_size,
                                out->_data_buf_virt_addr,
                                out->_data_buf_phys_addr);
        /* For Video Data buffer allocation */
        out->_data_buf_virt_addr = pci_alloc_consistent(dev->pci,
                        out->upstream_databuf_size, &data_dma_addr);
        out->_data_buf_phys_addr = data_dma_addr;
        out->_data_buf_size = out->upstream_databuf_size;

        if (!out->_data_buf_virt_addr) {
                pr_err("FAILED to allocate memory for data buffer! Returning\n");
                return -ENOMEM;
        }

        /* Clear memory at address */
        memset(out->_data_buf_virt_addr, 0, out->_data_buf_size);

        /* Create RISC programs */
        ret = cx25821_risc_buffer_upstream(chan, dev->pci, 0, bpl,
                        out->_lines_count);
        if (ret < 0) {
                pr_info("Failed creating Video Upstream Risc programs!\n");
                goto error;
        }

        return 0;

error:
        return ret;
}

static int cx25821_video_upstream_irq(struct cx25821_channel *chan, u32 status)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        u32 int_msk_tmp;
        const struct sram_channel *channel = chan->sram_channels;
        int singlefield_lines = NTSC_FIELD_HEIGHT;
        int line_size_in_bytes = Y422_LINE_SZ;
        int odd_risc_prog_size = 0;
        dma_addr_t risc_phys_jump_addr;
        __le32 *rp;

        if (status & FLD_VID_SRC_RISC1) {
                /* We should only process one program per call */
                u32 prog_cnt = cx_read(channel->gpcnt);

                /* Since we've identified our IRQ, clear our bits from the
                 * interrupt mask and interrupt status registers */
                int_msk_tmp = cx_read(channel->int_msk);
                cx_write(channel->int_msk, int_msk_tmp & ~_intr_msk);
                cx_write(channel->int_stat, _intr_msk);

                wake_up(&out->waitq);

                spin_lock(&dev->slock);

                out->_frame_index = prog_cnt;

                if (out->_is_first_frame) {
                        out->_is_first_frame = 0;

                        if (out->is_60hz) {
                                singlefield_lines += 1;
                                odd_risc_prog_size = ODD_FLD_NTSC_PROG_SIZE;
                        } else {
                                singlefield_lines = PAL_FIELD_HEIGHT;
                                odd_risc_prog_size = ODD_FLD_PAL_PROG_SIZE;
                        }

                        if (out->_dma_virt_start_addr != NULL) {
                                line_size_in_bytes =
                                    (out->_pixel_format ==
                                     PIXEL_FRMT_411) ? Y411_LINE_SZ :
                                    Y422_LINE_SZ;
                                risc_phys_jump_addr =
                                    out->_dma_phys_start_addr +
                                    odd_risc_prog_size;

                                rp = cx25821_update_riscprogram(chan,
                                        out->_dma_virt_start_addr, TOP_OFFSET,
                                        line_size_in_bytes, 0x0,
                                        singlefield_lines, FIFO_DISABLE,
                                        ODD_FIELD);

                                /* Jump to Even Risc program of 1st Frame */
                                *(rp++) = cpu_to_le32(RISC_JUMP);
                                *(rp++) = cpu_to_le32(risc_phys_jump_addr);
                                *(rp++) = cpu_to_le32(0);
                        }
                }

                spin_unlock(&dev->slock);
        } else {
                if (status & FLD_VID_SRC_UF)
                        pr_err("%s(): Video Received Underflow Error Interrupt!\n",
                               __func__);

                if (status & FLD_VID_SRC_SYNC)
                        pr_err("%s(): Video Received Sync Error Interrupt!\n",
                               __func__);

                if (status & FLD_VID_SRC_OPC_ERR)
                        pr_err("%s(): Video Received OpCode Error Interrupt!\n",
                               __func__);
        }

        if (out->_file_status == END_OF_FILE) {
                pr_err("EOF Channel 1 Framecount = %d\n", out->_frame_count);
                return -1;
        }
        /* ElSE, set the interrupt mask register, re-enable irq. */
        int_msk_tmp = cx_read(channel->int_msk);
        cx_write(channel->int_msk, int_msk_tmp |= _intr_msk);

        return 0;
}

static irqreturn_t cx25821_upstream_irq(int irq, void *dev_id)
{
        struct cx25821_channel *chan = dev_id;
        struct cx25821_dev *dev = chan->dev;
        u32 vid_status;
        int handled = 0;
        const struct sram_channel *sram_ch;

        if (!dev)
                return -1;

        sram_ch = chan->sram_channels;

        vid_status = cx_read(sram_ch->int_stat);

        /* Only deal with our interrupt */
        if (vid_status)
                handled = cx25821_video_upstream_irq(chan, vid_status);

        return IRQ_RETVAL(handled);
}

static void cx25821_set_pixelengine(struct cx25821_channel *chan,
                                    const struct sram_channel *ch,
                                    int pix_format)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        int width = WIDTH_D1;
        int height = out->_lines_count;
        int num_lines, odd_num_lines;
        u32 value;
        int vip_mode = OUTPUT_FRMT_656;

        value = ((pix_format & 0x3) << 12) | (vip_mode & 0x7);
        value &= 0xFFFFFFEF;
        value |= out->is_60hz ? 0 : 0x10;
        cx_write(ch->vid_fmt_ctl, value);

        /* set number of active pixels in each line.
         * Default is 720 pixels in both NTSC and PAL format */
        cx_write(ch->vid_active_ctl1, width);

        num_lines = (height / 2) & 0x3FF;
        odd_num_lines = num_lines;

        if (out->is_60hz)
                odd_num_lines += 1;

        value = (num_lines << 16) | odd_num_lines;

        /* set number of active lines in field 0 (top) and field 1 (bottom) */
        cx_write(ch->vid_active_ctl2, value);

        cx_write(ch->vid_cdt_size, VID_CDT_SIZE >> 3);
}

static int cx25821_start_video_dma_upstream(struct cx25821_channel *chan,
                                            const struct sram_channel *sram_ch)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        u32 tmp = 0;
        int err = 0;

        /* 656/VIP SRC Upstream Channel I & J and 7 - Host Bus Interface for
         * channel A-C
         */
        tmp = cx_read(VID_CH_MODE_SEL);
        cx_write(VID_CH_MODE_SEL, tmp | 0x1B0001FF);

        /* Set the physical start address of the RISC program in the initial
         * program counter(IPC) member of the cmds.
         */
        cx_write(sram_ch->cmds_start + 0, out->_dma_phys_addr);
        /* Risc IPC High 64 bits 63-32 */
        cx_write(sram_ch->cmds_start + 4, 0);

        /* reset counter */
        cx_write(sram_ch->gpcnt_ctl, 3);

        /* Clear our bits from the interrupt status register. */
        cx_write(sram_ch->int_stat, _intr_msk);

        /* Set the interrupt mask register, enable irq. */
        cx_set(PCI_INT_MSK, cx_read(PCI_INT_MSK) | (1 << sram_ch->irq_bit));
        tmp = cx_read(sram_ch->int_msk);
        cx_write(sram_ch->int_msk, tmp |= _intr_msk);

        err = request_irq(dev->pci->irq, cx25821_upstream_irq,
                        IRQF_SHARED, dev->name, chan);
        if (err < 0) {
                pr_err("%s: can't get upstream IRQ %d\n",
                       dev->name, dev->pci->irq);
                goto fail_irq;
        }

        /* Start the DMA  engine */
        tmp = cx_read(sram_ch->dma_ctl);
        cx_set(sram_ch->dma_ctl, tmp | FLD_VID_RISC_EN);

        out->_is_running = 1;
        out->_is_first_frame = 1;

        return 0;

fail_irq:
        cx25821_dev_unregister(dev);
        return err;
}

int cx25821_vidupstream_init(struct cx25821_channel *chan,
                                 int pixel_format)
{
        struct cx25821_video_out_data *out = chan->out;
        struct cx25821_dev *dev = chan->dev;
        const struct sram_channel *sram_ch;
        u32 tmp;
        int err = 0;
        int data_frame_size = 0;
        int risc_buffer_size = 0;

        if (out->_is_running) {
                pr_info("Video Channel is still running so return!\n");
                return 0;
        }

        sram_ch = chan->sram_channels;

        out->is_60hz = dev->tvnorm & V4L2_STD_525_60;

        /* 656/VIP SRC Upstream Channel I & J and 7 - Host Bus Interface for
         * channel A-C
         */
        tmp = cx_read(VID_CH_MODE_SEL);
        cx_write(VID_CH_MODE_SEL, tmp | 0x1B0001FF);

        out->_is_running = 0;
        out->_frame_count = 0;
        out->_file_status = RESET_STATUS;
        out->_lines_count = out->is_60hz ? 480 : 576;
        out->_pixel_format = pixel_format;
        out->_line_size = (out->_pixel_format == PIXEL_FRMT_422) ?
                (WIDTH_D1 * 2) : (WIDTH_D1 * 3) / 2;
        data_frame_size = out->is_60hz ? NTSC_DATA_BUF_SZ : PAL_DATA_BUF_SZ;
        risc_buffer_size = out->is_60hz ?
                NTSC_RISC_BUF_SIZE : PAL_RISC_BUF_SIZE;

        out->_is_running = 0;
        out->_frame_count = 0;
        out->_file_status = RESET_STATUS;
        out->_lines_count = out->is_60hz ? 480 : 576;
        out->_pixel_format = pixel_format;
        out->_line_size = (out->_pixel_format == PIXEL_FRMT_422) ?
                (WIDTH_D1 * 2) : (WIDTH_D1 * 3) / 2;
        out->curpos = 0;
        init_waitqueue_head(&out->waitq);

        err = cx25821_sram_channel_setup_upstream(dev, sram_ch,
                        out->_line_size, 0);

        /* setup fifo + format */
        cx25821_set_pixelengine(chan, sram_ch, out->_pixel_format);

        out->upstream_riscbuf_size = risc_buffer_size * 2;
        out->upstream_databuf_size = data_frame_size * 2;

        /* Allocating buffers and prepare RISC program */
        err = cx25821_upstream_buffer_prepare(chan, sram_ch, out->_line_size);
        if (err < 0) {
                pr_err("%s: Failed to set up Video upstream buffers!\n",
                       dev->name);
                goto error;
        }

        cx25821_start_video_dma_upstream(chan, sram_ch);

        return 0;

error:
        cx25821_dev_unregister(dev);

        return err;
}