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Message-ID: <20130315124034.GF2989@localhost>
Date: Fri, 15 Mar 2013 09:40:35 -0300
From: Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>
To: Jon Arne Jørgensen <jonarne@...arne.no>
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
hverkuil@...all.nl, elezegarcia@...il.com
Subject: Re: [RFC V1 5/8] smi2021: Add smi2021_video.c
On Thu, Mar 14, 2013 at 03:07:01PM +0100, Jon Arne Jørgensen wrote:
> This file is responsible for all communication with the video hardware
> and also starting and stopping the capture.
>
> It also contains the setup and handling of the usb ISOCHRONOUS transfers.
>
> Signed-off-by: Jon Arne Jørgensen <jonarne@...arne.no>
> ---
> drivers/media/usb/smi2021/smi2021_video.c | 543 ++++++++++++++++++++++++++++++
> 1 file changed, 543 insertions(+)
> create mode 100644 drivers/media/usb/smi2021/smi2021_video.c
>
> diff --git a/drivers/media/usb/smi2021/smi2021_video.c b/drivers/media/usb/smi2021/smi2021_video.c
> new file mode 100644
> index 0000000..48f3e80
> --- /dev/null
> +++ b/drivers/media/usb/smi2021/smi2021_video.c
> @@ -0,0 +1,543 @@
> +/*******************************************************************************
> + * smi2021_video.c *
> + * *
> + * USB Driver for SMI2021 - EasyCAP *
> + * USB ID 1c88:003c *
> + * *
> + * *****************************************************************************
> + *
> + * Copyright 2011-2013 Jon Arne Jørgensen
> + * <jonjon.arnearne--a.t--gmail.com>
> + *
> + * Copyright 2011, 2012 Tony Brown, Michal Demin, Jeffry Johnston
> + *
> + * This file is part of SMI2021x
> + * http://code.google.com/p/easycap-somagic-linux/
> + *
> + * 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, see <http://www.gnu.org/licenses/>.
> + *
> + * This driver is heavily influensed by the STK1160 driver.
> + * Copyright (C) 2012 Ezequiel Garcia
> + * <elezegarcia--a.t--gmail.com>
> + *
> + */
> +
> +#include "smi2021.h"
> +
> +static void print_usb_err(struct smi2021_dev *dev, int packet, int status)
> +{
> + char *errmsg;
> +
> + switch (status) {
> + case -ENOENT:
> + errmsg = "unlinked synchronuously";
> + break;
> + case -ECONNRESET:
> + errmsg = "unlinked asynchronuously";
> + break;
> + case -ENOSR:
> + errmsg = "Buffer error (overrun)";
> + break;
> + case -EPIPE:
> + errmsg = "Stalled (device not responding)";
> + break;
> + case -EOVERFLOW:
> + errmsg = "Babble (bad cable?)";
> + break;
> + case -EPROTO:
> + errmsg = "Bit-stuff error (bad cable?)";
> + break;
> + case -EILSEQ:
> + errmsg = "CRC/Timeout (could be anything)";
> + break;
> + case -ETIME:
> + errmsg = "Device does not respond";
> + break;
> + default:
> + errmsg = "Unknown";
> + }
> +
> + if (packet < 0) {
> + printk_ratelimited(KERN_WARNING "Urb status %d [%s]\n",
> + status, errmsg);
> + } else {
> + printk_ratelimited(KERN_INFO "URB packet %d, status %d [%s]\n",
> + packet, status, errmsg);
> + }
> +}
> +
> +static struct smi2021_buffer *smi2021_next_buffer(struct smi2021_dev *dev)
> +{
> + struct smi2021_buffer *buf = NULL;
> + unsigned long flags = 0;
> +
> + BUG_ON(dev->isoc_ctl.buf);
> +
You should replace BUG_ON with WARN_ON. Linus' words:
http://permalink.gmane.org/gmane.linux.kernel/1347333
> + spin_lock_irqsave(&dev->buf_lock, flags);
> + if (!list_empty(&dev->avail_bufs)) {
> + buf = list_first_entry(&dev->avail_bufs, struct smi2021_buffer,
> + list);
> + list_del(&buf->list);
> + }
> + spin_unlock_irqrestore(&dev->buf_lock, flags);
> +
> + return buf;
> +}
> +
> +static void smi2021_buffer_done(struct smi2021_dev *dev)
> +{
> + struct smi2021_buffer *buf = dev->isoc_ctl.buf;
> +
> + dev->buf_count++;
> +
> + buf->vb.v4l2_buf.sequence = dev->buf_count >> 1;
> + buf->vb.v4l2_buf.field = V4L2_FIELD_INTERLACED;
> + buf->vb.v4l2_buf.bytesused = buf->pos;
> + do_gettimeofday(&buf->vb.v4l2_buf.timestamp);
> +
> + vb2_set_plane_payload(&buf->vb, 0, buf->pos);
> + vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
> +
> + dev->isoc_ctl.buf = NULL;
> +}
> +
> +static void copy_video(struct smi2021_dev *dev, u8 p)
> +{
> + struct smi2021_buffer *buf = dev->isoc_ctl.buf;
> +
> + int lines_per_field = dev->height / 2;
> + int line = 0;
> + int pos_in_line = 0;
> + unsigned int offset = 0;
> + u8 *dst;
> +
> + if (buf == NULL)
> + return;
> +
> + if (buf->in_blank)
> + return;
> +
> + if (buf->pos >= buf->length) {
> + if (buf->second_field == 0) {
> + /* We are probably trying to capture from
> + * a unconnected input
> + */
> + smi2021_buffer_done(dev);
> + } else {
> + printk_ratelimited(KERN_WARNING
> + "Buffer overflow!, max: %d bytes, av_lines_found: %d, second_field: %d\n",
> + buf->length, buf->trc_av,
> + buf->second_field);
> + }
> + return;
> + }
> +
> + pos_in_line = buf->pos % SMI2021_BYTES_PER_LINE;
> + line = buf->pos / SMI2021_BYTES_PER_LINE;
> + if (line >= lines_per_field)
> + line -= lines_per_field;
> +
> + if (line != buf->trc_av - 1) {
> + /* Keep video synchronized.
> + * The device will sometimes give us to many bytes
> + * for a line, before we get a new TRC.
> + * We just drop these bytes */
> + return;
> + }
> +
> + if (buf->second_field)
> + offset += SMI2021_BYTES_PER_LINE;
> +
> + offset += (SMI2021_BYTES_PER_LINE * line * 2) + pos_in_line;
> +
> + /* Will this ever happen? */
> + if (offset >= buf->length) {
> + printk_ratelimited(KERN_INFO
> + "Offset calculation error, field: %d, line: %d, pos_in_line: %d\n",
> + buf->second_field, line, pos_in_line);
> + return;
> + }
> +
> + dst = buf->mem + offset;
> + *dst = p;
> + buf->pos++;
> +}
> +
> +#define is_sav(trc) \
> + ((trc & SMI2021_TRC_EAV) == 0x00)
> +#define is_field2(trc) \
> + ((trc & SMI2021_TRC_FIELD_2) == SMI2021_TRC_FIELD_2)
> +#define is_active_video(trc) \
> + ((trc & SMI2021_TRC_VBI) == 0x00)
> +/*
> + * Parse the TRC.
> + * Grab a new buffer from the queue if don't have one
> + * and we are recieving the start of a video frame.
> + *
> + * Mark video buffers as done if we have one full frame.
> + */
> +static void parse_trc(struct smi2021_dev *dev, u8 trc)
> +{
> + struct smi2021_buffer *buf = dev->isoc_ctl.buf;
> + int lines_per_field = dev->height / 2;
> + int line = 0;
> +
> + if (buf == NULL) {
> + if (!is_sav(trc))
> + return;
> +
> + if (!is_active_video(trc))
> + return;
> +
> + if (is_field2(trc))
> + return;
> +
> + buf = smi2021_next_buffer(dev);
> + if (buf == NULL)
> + return;
> +
> + dev->isoc_ctl.buf = buf;
> + }
> +
> + if (is_sav(trc)) {
> + /* Start of VBI or ACTIVE VIDEO */
> + if (is_active_video(trc)) {
> + buf->in_blank = false;
> + buf->trc_av++;
> + } else {
> + /* VBI */
> + buf->in_blank = true;
> + }
> +
> + if (!buf->second_field && is_field2(trc)) {
> + line = buf->pos / SMI2021_BYTES_PER_LINE;
> + if (line < lines_per_field)
> + goto buf_done;
> +
> + buf->second_field = true;
> + buf->trc_av = 0;
> + }
> +
> + if (buf->second_field && !is_field2(trc))
> + goto buf_done;
> + } else {
> + /* End of VBI or ACTIVE VIDEO */
> + buf->in_blank = true;
> + }
> +
> + return;
> +
> +buf_done:
> + smi2021_buffer_done(dev);
> +}
> +
> +/*
> + * Scan the saa7113 Active video data.
> + * This data is:
> + * 4 bytes header (0xff 0x00 0x00 [TRC/SAV])
> + * 1440 bytes of UYUV Video data
> + * 4 bytes footer (0xff 0x00 0x00 [TRC/EAV])
> + *
> + * TRC = Time Reference Code.
> + * SAV = Start Active Video.
> + * EAV = End Active Video.
> + * This is described in the saa7113 datasheet.
> + */
> +static void parse_video(struct smi2021_dev *dev, u8 *p, int len)
> +{
> + int i;
> +
> + for (i = 0; i < len; i++) {
> + switch (dev->sync_state) {
> + case HSYNC:
> + if (p[i] == 0xff)
> + dev->sync_state = SYNCZ1;
> + else
> + copy_video(dev, p[i]);
> + break;
> + case SYNCZ1:
> + if (p[i] == 0x00) {
> + dev->sync_state = SYNCZ2;
> + } else {
> + dev->sync_state = HSYNC;
> + copy_video(dev, 0xff);
> + copy_video(dev, p[i]);
> + }
> + break;
> + case SYNCZ2:
> + if (p[i] == 0x00) {
> + dev->sync_state = TRC;
> + } else {
> + dev->sync_state = HSYNC;
> + copy_video(dev, 0xff);
> + copy_video(dev, 0x00);
> + copy_video(dev, p[i]);
> + }
> + break;
> + case TRC:
> + dev->sync_state = HSYNC;
> + parse_trc(dev, p[i]);
> + break;
> + }
> + }
> +
> +}
> +/*
> + *
> + * The device delivers data in chunks of 0x400 bytes.
> + * The four first bytes is a magic header to identify the chunks.
> + * 0xaa 0xaa 0x00 0x00 = saa7113 Active Video Data
> + * 0xaa 0xaa 0x00 0x01 = PCM - 24Bit 2 Channel audio data
> + */
> +static void process_packet(struct smi2021_dev *dev, u8 *p, int len)
> +{
> + int i;
> + u32 *header;
> +
> + if (len % 0x400 != 0) {
> + printk_ratelimited(KERN_INFO "smi2021::%s: len: %d\n",
> + __func__, len);
> + return;
> + }
> +
> + for (i = 0; i < len; i += 0x400) {
> + header = (u32 *)(p + i);
> + switch (__cpu_to_be32(*header)) {
> + case 0xaaaa0000: {
> + parse_video(dev, p+i+4, 0x400-4);
> + break;
> + }
> + case 0xaaaa0001: {
> + smi2021_audio(dev, p+i+4, 0x400-4);
> + break;
> + }
> + default: {
> + /* Nothing */
> + }
> + }
> + }
> +}
> +
> +/*
> + * Interrupt called by URB callback
> + */
> +static void smi2021_isoc_isr(struct urb *urb)
> +{
> + int i, rc, status, len;
> + struct smi2021_dev *dev = urb->context;
> + u8 *p;
> +
> + switch (urb->status) {
> + case 0:
> + break;
> + case -ECONNRESET: /* kill */
> + case -ENOENT:
> + case -ESHUTDOWN:
> + /* uvc driver frees the queue here */
> + return;
> + default:
> + smi2021_err("urb error! status %d\n", urb->status);
> + return;
> + }
> +
> + if (urb->status < 0)
> + print_usb_err(dev, -1, status);
> +
> + if (dev == NULL) {
> + smi2021_warn("called with null device\n");
> + return;
> + }
> +
> + for (i = 0; i < urb->number_of_packets; i++) {
> +
> + status = urb->iso_frame_desc[i].status;
> + if (status == -18) {
> + /* This seems to happen when the device
> + * trying to stream from an unconnected input
> + * */
> + continue;
> + }
> +
> + if (status < 0) {
> + print_usb_err(dev, i, status);
> + continue;
> + }
> +
> + p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
> + len = urb->iso_frame_desc[i].actual_length;
> + process_packet(dev, p, len);
> + }
> +
> + for (i = 0; i < urb->number_of_packets; i++) {
> + urb->iso_frame_desc[i].status = 0;
> + urb->iso_frame_desc[i].actual_length = 0;
> + }
> +
> + rc = usb_submit_urb(urb, GFP_ATOMIC);
> + if (rc)
> + smi2021_err("urb re-submit failed (%d)\n", rc);
> +}
> +
> +/*
> + * Cancel urbs
> + * This function can not be called in atomic context
> + */
> +void smi2021_cancel_isoc(struct smi2021_dev *dev)
> +{
> + int i, num_bufs = dev->isoc_ctl.num_bufs;
> + if (!num_bufs)
> + return;
> +
> + smi2021_dbg("killing %d urbs...\n", num_bufs);
> +
> + for (i = 0; i < num_bufs; i++)
> + usb_kill_urb(dev->isoc_ctl.urb[i]);
> +
> + smi2021_dbg("all urbs killed\n");
> +
> +}
> +
> +/*
> + * Releases urb and transfer buffers
> + * Obviously, associated urb must be killed before releasing it
> + */
> +void smi2021_free_isoc(struct smi2021_dev *dev)
> +{
> + struct urb *urb;
> + int i, num_bufs = dev->isoc_ctl.num_bufs;
> +
> + smi2021_dbg("freeing %d urb buffers...\n", num_bufs);
> +
> + for (i = 0; i < num_bufs; i++) {
> + urb = dev->isoc_ctl.urb[i];
> + if (urb) {
> + if (dev->isoc_ctl.transfer_buffer[i]) {
> +#ifndef CONFIG_DMA_NONCOHERENT
> + usb_free_coherent(dev->udev,
> + urb->transfer_buffer_length,
> + dev->isoc_ctl.transfer_buffer[i],
> + urb->transfer_dma);
> +#else
> + kfree(dev->isoc_ctl.transfer_buffer[i]);
> +#endif
> + }
> + usb_free_urb(urb);
> + dev->isoc_ctl.urb[i] = NULL;
> + }
> + dev->isoc_ctl.transfer_buffer[i] = NULL;
> + }
> +
> + kfree(dev->isoc_ctl.urb);
> + kfree(dev->isoc_ctl.transfer_buffer);
> +
> + dev->isoc_ctl.urb = NULL;
> + dev->isoc_ctl.transfer_buffer = NULL;
> + dev->isoc_ctl.num_bufs = 0;
> +
> + smi2021_dbg("all urb buffers freed\n");
> +}
> +
> +/*
> + * Helper for canceling and freeing urbs
> + * This function can not be called in atomic context
> + */
> +void smi2021_uninit_isoc(struct smi2021_dev *dev)
> +{
> + smi2021_cancel_isoc(dev);
> + smi2021_free_isoc(dev);
> +}
> +
> +
> +int smi2021_alloc_isoc(struct smi2021_dev *dev)
> +{
> + struct urb *urb;
> + int i, j, k, sb_size, max_packets, num_bufs;
> +
> + if (dev->isoc_ctl.num_bufs)
> + smi2021_uninit_isoc(dev);
> +
> + num_bufs = SMI2021_ISOC_BUFS;
> + max_packets = SMI2021_ISOC_PACKETS;
> + sb_size = max_packets * SMI2021_MAX_PKT_SIZE;
> +
> + dev->isoc_ctl.buf = NULL;
> + dev->isoc_ctl.max_pkt_size = SMI2021_MAX_PKT_SIZE;
> + dev->isoc_ctl.urb = kzalloc(sizeof(void *) * num_bufs, GFP_KERNEL);
> + if (!dev->isoc_ctl.urb) {
> + smi2021_err("out of memory for urb array\n");
> + return -ENOMEM;
> + }
> +
> + dev->isoc_ctl.transfer_buffer = kzalloc(sizeof(void *) * num_bufs,
> + GFP_KERNEL);
> + if (!dev->isoc_ctl.transfer_buffer) {
> + smi2021_err("out of memory for usb transfer\n");
> + kfree(dev->isoc_ctl.urb);
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < num_bufs; i++) {
> + urb = usb_alloc_urb(max_packets, GFP_KERNEL);
> + if (!urb) {
> + smi2021_err("connot allocate urb[%d]\n", i);
> + goto free_i_bufs;
> + }
> + dev->isoc_ctl.urb[i] = urb;
> +#ifndef CONFIG_DMA_NONCOHERENT
> + dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(
> + dev->udev, sb_size, GFP_KERNEL,
> + &urb->transfer_dma);
> +#else
> + dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size,
> + GFP_KERNEL);
> +#endif
> + if (!dev->isoc_ctl.transfer_buffer[i]) {
> + smi2021_err("cannot alloc %d bytes for tx[%d] buffer",
> + sb_size, i);
> + goto free_i_bufs;
> + }
> + /* Do not leak kernel data */
> + memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
> +
> + urb->dev = dev->udev;
> + urb->pipe = usb_rcvisocpipe(dev->udev, SMI2021_ISOC_EP);
> + urb->transfer_buffer = dev->isoc_ctl.transfer_buffer[i];
> + urb->transfer_buffer_length = sb_size;
> + urb->complete = smi2021_isoc_isr;
> + urb->context = dev;
> + urb->interval = 1;
> + urb->start_frame = 0;
> + urb->number_of_packets = max_packets;
> +#ifndef CONFIG_DMA_NONCOHERENT
> + urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
> +#else
> + urb->transfer_flags = URB_ISO_ASAP;
> +#endif
> + k = 0;
> + for (j = 0; j < max_packets; j++) {
> + urb->iso_frame_desc[j].offset = k;
> + urb->iso_frame_desc[j].length =
> + dev->isoc_ctl.max_pkt_size;
> + k += dev->isoc_ctl.max_pkt_size;
> + }
> + }
> + smi2021_dbg("urbs allocated\n");
> + dev->isoc_ctl.num_bufs = num_bufs;
> + return 0;
> +
> +free_i_bufs:
> + dev->isoc_ctl.num_bufs = i+1;
> + smi2021_free_isoc(dev);
> + return -ENOMEM;
> +}
> --
> 1.8.1.1
>
--
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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