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From: Michael Hunold <hunold@linuxtv.org>
To: hunold@linuxtv.org, torvalds@osdl.org, akpm@osdl.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4/9] DVB: Add EN50221 cam support to dvb-core
Date: Mon, 26 Apr 2004 09:42:04 -0400	[thread overview]
Message-ID: <1082986832779@convergence.de> (raw)
In-Reply-To: <10829867862196@convergence.de>

- [DVB] add generic functions for EN50221 CAM interfaces
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ca_en50221.c linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ca_en50221.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ca_en50221.c	2004-04-23 21:51:15.000000000 +0200
@@ -0,0 +1,1628 @@
+/*
+ * dvb_ca.c: generic DVB functions for EN50221 CAM interfaces
+ *
+ * Copyright (C) 2004 Andrew de Quincey
+ *
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2003 Ralph Metzler <rjkm@metzlerbros.de>
+ *
+ * based on code:
+ *
+ * Copyright (C) 1999-2002 Ralph  Metzler
+ *                       & Marcus Metzler for convergence integrated media GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * Or, point your browser to http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <asm/semaphore.h>
+#include <asm/atomic.h>
+
+#include "dvb_ca_en50221.h"
+#include "dvb_functions.h"
+#include "dvb_ringbuffer.h"
+
+static int dvb_ca_en50221_debug = 0;
+#define dprintk if (dvb_ca_en50221_debug) printk
+
+#define INIT_TIMEOUT_SECS 5
+
+#define HOST_LINK_BUF_SIZE 0x200
+
+#define RX_BUFFER_SIZE 65535
+
+#define MAX_RX_PACKETS_PER_ITERATION 10
+
+#define CTRLIF_DATA      0
+#define CTRLIF_COMMAND   1
+#define CTRLIF_STATUS    1
+#define CTRLIF_SIZE_LOW  2
+#define CTRLIF_SIZE_HIGH 3
+
+#define CMDREG_HC        1 /* Host control */
+#define CMDREG_SW        2 /* Size write */
+#define CMDREG_SR        4 /* Size read */
+#define CMDREG_RS        8 /* Reset interface */
+#define CMDREG_FRIE   0x40 /* Enable FR interrupt */
+#define CMDREG_DAIE   0x80 /* Enable DA interrupt */
+#define IRQEN (CMDREG_DAIE)
+
+#define STATUSREG_RE     1 /* read error */
+#define STATUSREG_WE     2 /* write error */
+#define STATUSREG_FR  0x40 /* module free */
+#define STATUSREG_DA  0x80 /* data available */
+#define STATUSREG_TXERR (STATUSREG_RE|STATUSREG_WE) /* general transfer error */
+
+
+#define DVB_CA_SLOTSTATE_NONE           0
+#define DVB_CA_SLOTSTATE_UNINITIALISED  1
+#define DVB_CA_SLOTSTATE_RUNNING        2
+#define DVB_CA_SLOTSTATE_INVALID        3
+#define DVB_CA_SLOTSTATE_WAITREADY      4
+#define DVB_CA_SLOTSTATE_VALIDATE       5
+#define DVB_CA_SLOTSTATE_WAITFR         6
+#define DVB_CA_SLOTSTATE_LINKINIT       7
+
+
+/* Information on a CA slot */
+struct dvb_ca_slot {
+
+        /* current state of the CAM */
+        int slot_state;
+
+        /* Number of CAMCHANGES that have occurred since last processing */
+        atomic_t camchange_count;
+
+        /* Type of last CAMCHANGE */
+        int camchange_type;
+
+        /* base address of CAM config */
+        u32 config_base;
+
+        /* value to write into Config Control register */
+        u8 config_option;
+
+        /* if 1, the CAM supports DA IRQs */
+        u8 da_irq_supported:1;
+
+        /* size of the buffer to use when talking to the CAM */
+        int link_buf_size;
+
+        /* semaphore for syncing access to slot structure */
+        struct semaphore sem;
+
+        /* buffer for incoming packets */
+        struct dvb_ringbuffer rx_buffer;
+
+        /* timer used during various states of the slot */
+        unsigned long timeout;
+};
+
+/* Private CA-interface information */
+struct dvb_ca_private {
+
+        /* pointer back to the public data structure */
+        struct dvb_ca_en50221* pub;
+
+        /* the DVB device */
+        struct dvb_device *dvbdev;
+
+        /* Flags describing the interface (DVB_CA_FLAG_*) */
+        u32 flags;
+
+        /* number of slots supported by this CA interface */
+        unsigned int slot_count;
+
+        /* information on each slot */
+        struct dvb_ca_slot* slot_info;
+
+        /* wait queues for read() and write() operations */
+        wait_queue_head_t wait_queue;
+
+        /* PID of the monitoring thread */
+        pid_t thread_pid;
+
+        /* Wait queue used when shutting thread down */
+        wait_queue_head_t thread_queue;
+
+        /* Flag indicating when thread should exit */
+        int exit:1;
+
+        /* Flag indicating if the CA device is open */
+        int open:1;
+
+        /* Flag indicating the thread should wake up now */
+        int wakeup:1;
+
+        /* Delay the main thread should use */
+        unsigned long delay;
+
+        /* Slot to start looking for data to read from in the next user-space read operation */
+        int next_read_slot;
+};
+
+static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private* ca);
+static int dvb_ca_en50221_read_data(struct dvb_ca_private* ca, int slot, u8* ebuf, int ecount);
+static int dvb_ca_en50221_write_data(struct dvb_ca_private* ca, int slot, u8* ebuf, int ecount);
+
+
+/**
+ * Safely find needle in haystack.
+ *
+ * @param haystack Buffer to look in.
+ * @param hlen Number of bytes in haystack.
+ * @param needle Buffer to find.
+ * @param nlen Number of bytes in needle.
+ * @return Pointer into haystack needle was found at, or NULL if not found.
+ */
+static u8* findstr(u8* haystack, int hlen, u8* needle, int nlen)
+{
+        int i;
+
+        if (hlen < nlen) return NULL;
+
+        for(i=0; i<= hlen - nlen; i++) {
+                  if (!strncmp(haystack+i, needle, nlen)) return haystack+i;
+        }
+
+        return NULL;
+}
+
+
+
+/* ******************************************************************************** */
+/* EN50221 physical interface functions */
+
+
+/**
+ * Check CAM status.
+ */
+static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private* ca, int slot)
+{
+        int slot_status;
+        int status;
+        int cam_present_now;
+        int cam_changed;
+
+        /* IRQ mode */
+        if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE) {
+                return (atomic_read(&ca->slot_info[slot].camchange_count) != 0);
+        }
+
+        /* poll mode */
+        if ((status = down_interruptible(&ca->slot_info[slot].sem)) != 0) return status;
+        slot_status = ca->pub->poll_slot_status(ca->pub, slot);
+        up(&ca->slot_info[slot].sem);
+
+        cam_present_now = (slot_status & DVB_CA_EN50221_POLL_CAM_PRESENT) ? 1: 0;
+        cam_changed = (slot_status & DVB_CA_EN50221_POLL_CAM_CHANGED) ? 1: 0;
+        if (!cam_changed) {
+                int cam_present_old = (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE);
+                cam_changed = (cam_present_now != cam_present_old);
+        }
+
+        if (cam_changed) {
+                if (!cam_present_now) {
+                        ca->slot_info[slot].camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
+                } else {
+                        ca->slot_info[slot].camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
+                }
+                atomic_set(&ca->slot_info[slot].camchange_count, 1);
+        } else {
+                if ((ca->slot_info[slot].slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
+                    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
+                        // move to validate state if reset is completed
+                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+                }
+        }
+
+        return cam_changed;
+}
+
+
+/**
+ * Wait for flags to become set on the STATUS register on a CAM interface,
+ * checking for errors and timeout.
+ *
+ * @param ca CA instance.
+ * @param slot Slot on interface.
+ * @param waitfor Flags to wait for.
+ * @param timeout_ms Timeout in milliseconds.
+ *
+ * @return 0 on success, nonzero on error.
+ */
+static int dvb_ca_en50221_wait_if_status(struct dvb_ca_private* ca, int slot, u8 waitfor, int timeout_hz)
+{
+        unsigned long timeout;
+        unsigned long start;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* loop until timeout elapsed */
+        start = jiffies;
+        timeout = jiffies + timeout_hz;
+        while(1) {
+                /* read the status and check for error */
+                int res = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+                if (res < 0) return -EIO;
+
+                /* if we got the flags, it was successful! */
+                if (res & waitfor) {
+                        dprintk("%s succeeded timeout:%lu\n", __FUNCTION__, jiffies - start);
+                        return 0;
+                }
+
+                /* check for timeout */
+                if (time_after(jiffies, timeout)) {
+                        break;
+                }
+
+                /* wait for a bit */
+                dvb_delay(1);
+        }
+
+        dprintk("%s failed timeout:%lu\n", __FUNCTION__, jiffies - start);
+
+        /* if we get here, we've timed out */
+        return -ETIMEDOUT;
+}
+
+
+/**
+ * Initialise the link layer connection to a CAM.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ *
+ * @return 0 on success, nonzero on failure.
+ */
+static int dvb_ca_en50221_link_init(struct dvb_ca_private* ca, int slot)
+{
+        int ret;
+        int buf_size;
+        u8 buf[2];
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* we'll be determining these during this function */
+        ca->slot_info[slot].da_irq_supported = 0;
+
+        /* reset the link interface. Note CAM IRQs are disabled */
+        if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, CMDREG_RS)) != 0) return ret;
+        if ((ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ/10)) != 0) return ret;
+
+        /* set the host link buffer size temporarily. it will be overwritten with the
+         * real negotiated size later. */
+        ca->slot_info[slot].link_buf_size = 2;
+
+        /* read the buffer size from the CAM */
+        if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN | CMDREG_SR)) != 0) return ret;
+        if ((ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ/10)) != 0) return ret;
+        if ((ret = dvb_ca_en50221_read_data(ca, slot, buf, 2)) != 2) return -EIO;
+        if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN)) != 0) return ret;
+
+        /* store it, and choose the minimum of our buffer and the CAM's buffer size */
+        buf_size = (buf[0] << 8) | buf[1];
+        if (buf_size > HOST_LINK_BUF_SIZE) buf_size = HOST_LINK_BUF_SIZE;
+        ca->slot_info[slot].link_buf_size = buf_size;
+        buf[0] = buf_size >> 8;
+        buf[1] = buf_size & 0xff;
+        dprintk("Chosen link buffer size of %i\n", buf_size);
+
+        /* write the buffer size to the CAM */
+        if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN | CMDREG_SW)) != 0) return ret;
+        if ((ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ/10)) != 0) return ret;
+        if ((ret = dvb_ca_en50221_write_data(ca, slot, buf, 2)) != 2) return -EIO;
+        if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN)) != 0) return ret;
+
+        /* success */
+        return 0;
+}
+
+/**
+ * Read a tuple from attribute memory.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ * @param address Address to read from. Updated.
+ * @param tupleType Tuple id byte. Updated.
+ * @param tupleLength Tuple length. Updated.
+ * @param tuple Dest buffer for tuple (must be 256 bytes). Updated.
+ *
+ * @return 0 on success, nonzero on error.
+ */
+static int dvb_ca_en50221_read_tuple(struct dvb_ca_private* ca, int slot,
+                                     int* address, int* tupleType, int* tupleLength, u8* tuple)
+{
+        int i;
+        int _tupleType;
+        int _tupleLength;
+        int _address = *address;
+
+        /* grab the next tuple length and type */
+        if ((_tupleType = ca->pub->read_attribute_mem(ca->pub, slot, _address)) < 0) return _tupleType;
+        if ((_tupleLength = ca->pub->read_attribute_mem(ca->pub, slot, _address+2)) < 0) return _tupleLength;
+        _address += 4;
+
+        dprintk("TUPLE type:0x%x length:%i\n", _tupleType, _tupleLength);
+
+        /* read in the whole tuple */
+        for(i=0; i< _tupleLength; i++) {
+                tuple[i] = ca->pub->read_attribute_mem(ca->pub, slot, _address + (i*2));
+                dprintk("  0x%02x: 0x%02x %c\n", i, tuple[i] & 0xff, ((tuple[i] > 31) && (tuple[i] < 127)) ? tuple[i] : '.');
+        }
+        _address += (_tupleLength*2);
+
+        // success
+        *tupleType = _tupleType;
+        *tupleLength = _tupleLength;
+        *address = _address;
+        return 0;
+}
+
+
+/**
+ * Parse attribute memory of a CAM module, extracting Config register, and checking
+ * it is a DVB CAM module.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ *
+ * @return 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private* ca, int slot)
+{
+        int address = 0;
+        int tupleLength;
+        int tupleType;
+        u8 tuple[257];
+        char* dvb_str;
+        int rasz;
+        int status;
+        int got_cftableentry = 0;
+        int end_chain = 0;
+        int i;
+        u16 manfid = 0;
+        u16 devid = 0;
+
+
+        // CISTPL_DEVICE_0A
+        if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+        if (tupleType != 0x1D) return -EINVAL;
+
+
+
+        // CISTPL_DEVICE_0C
+        if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+        if (tupleType != 0x1C) return -EINVAL;
+
+
+
+        // CISTPL_VERS_1
+        if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+        if (tupleType != 0x15) return -EINVAL;
+
+
+
+        // CISTPL_MANFID
+        if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+        if (tupleType != 0x20) return -EINVAL;
+        if (tupleLength != 4) return -EINVAL;
+        manfid = (tuple[1] << 8) | tuple[0];
+        devid = (tuple[3] << 8) | tuple[2];
+
+
+
+        // CISTPL_CONFIG
+        if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+        if (tupleType != 0x1A) return -EINVAL;
+        if (tupleLength < 3) return -EINVAL;
+
+        /* extract the configbase */
+        rasz = tuple[0] & 3;
+        if (tupleLength < (3 + rasz + 14)) return -EINVAL;
+        ca->slot_info[slot].config_base = 0;
+        for(i=0; i< rasz+1; i++) {
+                ca->slot_info[slot].config_base |= (tuple[2+i] << (8*i));
+        }
+
+        /* check it contains the correct DVB string */
+        dvb_str = findstr(tuple, tupleLength, "DVB_CI_V", 8);
+        if (dvb_str == NULL) return -EINVAL;
+        if (tupleLength < ((dvb_str - (char*) tuple) + 12)) return -EINVAL;
+
+        /* is it a version we support? */
+        if (strncmp(dvb_str + 8, "1.00", 4)) {
+                printk("dvb_ca: Unsupported DVB CAM module version %c%c%c%c\n",
+                        dvb_str[8], dvb_str[9], dvb_str[10], dvb_str[11]);
+                return -EINVAL;
+        }
+
+        /* process the CFTABLE_ENTRY tuples, and any after those */
+        while((!end_chain) && (address < 0x1000)) {
+                if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0) return status;
+                switch(tupleType) {
+                case 0x1B: // CISTPL_CFTABLE_ENTRY
+                        if (tupleLength < (2+11+17)) break;
+
+                        /* if we've already parsed one, just use it */
+                        if (got_cftableentry) break;
+
+                        /* get the config option */
+                        ca->slot_info[slot].config_option = tuple[0] & 0x3f;
+
+                        /* OK, check it contains the correct strings */
+                        if ((findstr(tuple, tupleLength, "DVB_HOST", 8) == NULL) ||
+                            (findstr(tuple, tupleLength, "DVB_CI_MODULE", 13) == NULL)) break;
+
+                        got_cftableentry = 1;
+                        break;
+
+                case 0x14: // CISTPL_NO_LINK
+                        break;
+
+                case 0xFF: // CISTPL_END
+                        end_chain = 1;
+                        break;
+
+                default: /* Unknown tuple type - just skip this tuple and move to the next one */
+                        dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n", tupleType, tupleLength);
+                        break;
+                }
+        }
+
+        if ((address > 0x1000) || (!got_cftableentry)) return -EINVAL;
+
+        dprintk("Valid DVB CAM detected MANID:%x DEVID:%x CONFIGBASE:0x%x CONFIGOPTION:0x%x\n",
+                manfid, devid,
+                ca->slot_info[slot].config_base,
+                ca->slot_info[slot].config_option);
+
+        // success!
+        return 0;
+}
+
+
+/**
+ * Set CAM's configoption correctly.
+ *
+ * @param ca CA instance.
+ * @param slot Slot containing the CAM.
+ */
+static int dvb_ca_en50221_set_configoption(struct dvb_ca_private* ca, int slot)
+{
+        int configoption;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* set the config option */
+        ca->pub->write_attribute_mem(ca->pub, slot, ca->slot_info[slot].config_base, ca->slot_info[slot].config_option);
+
+        /* check it */
+        configoption = ca->pub->read_attribute_mem(ca->pub, slot, ca->slot_info[slot].config_base);
+        dprintk("Set configoption 0x%x, read configoption 0x%x\n", 
+		ca->slot_info[slot].config_option, configoption & 0x3f);
+
+        /* fine! */
+        return 0;
+
+}
+
+
+/**
+ * This function talks to an EN50221 CAM control interface. It reads a buffer of
+ * data from the CAM. The data can either be stored in a supplied buffer, or
+ * automatically be added to the slot's rx_buffer.
+ *
+ * @param ca CA instance.
+ * @param slot Slot to read from.
+ * @param ebuf If non-NULL, the data will be written to this buffer. If NULL,
+ * the data will be added into the buffering system as a normal fragment.
+ * @param ecount Size of ebuf. Ignored if ebuf is NULL.
+ *
+ * @return Number of bytes read, or < 0 on error
+ */
+static int dvb_ca_en50221_read_data(struct dvb_ca_private* ca, int slot, u8* ebuf, int ecount)
+{
+        int bytes_read;
+        int status;
+        u8 buf[HOST_LINK_BUF_SIZE];
+        int i;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* acquire the slot */
+        if ((status = down_interruptible(&ca->slot_info[slot].sem)) != 0) return status;
+
+        /* check if we have space for a link buf in the rx_buffer */
+        if (ebuf == NULL) {
+                if (dvb_ringbuffer_free(&ca->slot_info[slot].rx_buffer) <
+                    (ca->slot_info[slot].link_buf_size + DVB_RINGBUFFER_PKTHDRSIZE)) {
+                        status = -EAGAIN;
+                        goto exit;
+                }
+        }
+
+        /* reset the interface if there's been a tx error */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exit;
+        if (status & STATUSREG_TXERR) {
+                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+                status = -EIO;
+                goto exit;
+        }
+        if (!(status & STATUSREG_DA)) {
+                /* no data */
+                status = 0;
+                goto exit;
+        }
+
+        /* read the amount of data */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH)) < 0) goto exit;
+        bytes_read = status << 8;
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW)) < 0) goto exit;
+        bytes_read |= status;
+
+        /* check it will fit */
+        if (ebuf == NULL) {
+                if (bytes_read > ca->slot_info[slot].link_buf_size) {
+                        printk("dvb_ca: CAM tried to send a buffer larger than the link buffer size!\n");
+                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+                        status = -EIO;
+                        goto exit;
+                }
+                if (bytes_read < 2) {
+                        printk("dvb_ca: CAM sent a buffer that was less than 2 bytes!\n");
+                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+                        status = -EIO;
+                        goto exit;
+                }
+        } else {
+                if (bytes_read > ecount) {
+                        printk("dvb_ca: CAM tried to send a buffer larger than the ecount size!\n");
+                        status = -EIO;
+                        goto exit;
+                }
+        }
+
+        /* fill the buffer */
+        for(i=0; i < bytes_read; i++) {
+                /* read byte and check */
+                if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_DATA)) < 0) goto exit;
+
+                /* OK, store it in the buffer */
+                buf[i] = status;
+        }
+
+        /* check for read error (RE should now go to 0) */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exit;
+        if (status & STATUSREG_RE) {
+                status = -EIO;
+                goto exit;
+        }
+
+        /* OK, add it to the receive buffer, or copy into external buffer if supplied */
+        if (ebuf == NULL) {
+                dvb_ringbuffer_pkt_write(&ca->slot_info[slot].rx_buffer, buf, bytes_read, 0);
+        } else {
+                memcpy(ebuf, buf, bytes_read);
+        }
+
+        /* wake up readers when a last_fragment is received */
+        if ((buf[1] & 0x80) == 0x00) {
+                wake_up_interruptible(&ca->wait_queue);
+        }
+
+        status = bytes_read;
+
+exit:
+        up(&ca->slot_info[slot].sem);
+        return status;
+}
+
+
+/**
+ * This function talks to an EN50221 CAM control interface. It writes a buffer of data
+ * to a CAM.
+ *
+ * @param ca CA instance.
+ * @param slot Slot to write to.
+ * @param ebuf The data in this buffer is treated as a complete link-level packet to
+ * be written.
+ * @param count Size of ebuf.
+ *
+ * @return Number of bytes written, or < 0 on error.
+ */
+static int dvb_ca_en50221_write_data(struct dvb_ca_private* ca, int slot, u8* buf, int bytes_write)
+{
+        int status;
+        int i;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+
+        // sanity check
+        if (bytes_write > ca->slot_info[slot].link_buf_size) return -EINVAL;
+
+        /* acquire the slot */
+        if ((status = down_interruptible(&ca->slot_info[slot].sem)) != 0) return status;
+
+        /* reset the interface if there's been a tx error */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exitnowrite;
+        if (status & STATUSREG_TXERR) {
+                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+                status = -EIO;
+                goto exitnowrite;
+        }
+
+        /* check if interface is actually waiting for us to read from it */
+        if (status & STATUSREG_DA) {
+                status = -EAGAIN;
+                goto exitnowrite;
+        }
+
+        /* OK, set HC bit */
+        if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN | CMDREG_HC)) != 0) goto exit;
+
+        /* check if interface is still free */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exit;
+        if (!(status & STATUSREG_FR)) {
+                /* it wasn't free => try again later */
+                status = -EAGAIN;
+                goto exit;
+        }
+
+        /* send the amount of data */
+        if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH, bytes_write >> 8)) != 0) goto exit;
+        if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW, bytes_write & 0xff)) != 0) goto exit;
+
+        /* send the buffer */
+        for(i=0; i < bytes_write; i++) {
+                if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA, buf[i])) != 0) goto exit;
+        }
+
+        /* check for write error (WE should now be 0) */
+        if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exit;
+        if (status & STATUSREG_WE) {
+                status = -EIO;
+                goto exit;
+        }
+        status = bytes_write;
+
+exit:
+        ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
+
+exitnowrite:
+        up(&ca->slot_info[slot].sem);
+        return status;
+}
+
+
+
+/* ******************************************************************************** */
+/* EN50221 higher level functions */
+
+
+/**
+ * A CAM has been removed => shut it down.
+ *
+ * @param ca CA instance.
+ * @param slot Slot to shut down.
+ */
+static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private* ca, int slot)
+{
+        int status;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        if ((status = down_interruptible(&ca->slot_info[slot].sem)) != 0) return status;
+        ca->pub->slot_shutdown(ca->pub, slot);
+        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
+        if (ca->slot_info[slot].rx_buffer.data) vfree(ca->slot_info[slot].rx_buffer.data);
+        ca->slot_info[slot].rx_buffer.data = NULL;
+        up(&ca->slot_info[slot].sem);
+
+        /* need to wake up all processes to check if they're now
+           trying to write to a defunct CAM */
+        wake_up_interruptible(&ca->wait_queue);
+
+        dprintk("Slot %i shutdown\n", slot);
+
+        /* success */
+        return 0;
+}
+
+
+/**
+ * A CAMCHANGE IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ * @param change_type One of the DVB_CA_CAMCHANGE_* values.
+ */
+void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221* pubca, int slot, int change_type)
+{
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) pubca->private;
+
+        dprintk("CAMCHANGE IRQ slot:%i change_type:%i\n", slot, change_type);
+
+        switch(change_type) {
+        case DVB_CA_EN50221_CAMCHANGE_REMOVED:
+        case DVB_CA_EN50221_CAMCHANGE_INSERTED:
+                break;
+
+        default:
+                return;
+        }
+
+        ca->slot_info[slot].camchange_type = change_type;
+        atomic_inc(&ca->slot_info[slot].camchange_count);
+        dvb_ca_en50221_thread_wakeup(ca);
+}
+
+
+/**
+ * A CAMREADY IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221* pubca, int slot)
+{
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) pubca->private;
+
+        dprintk("CAMREADY IRQ slot:%i\n", slot);
+
+        if (ca->slot_info[slot].slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
+                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+                dvb_ca_en50221_thread_wakeup(ca);
+        }
+}
+
+
+/**
+ * An FR or DA IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221* pubca, int slot)
+{
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) pubca->private;
+        int flags;
+
+        dprintk("FR/DA IRQ slot:%i\n", slot);
+
+        switch(ca->slot_info[slot].slot_state) {
+        case DVB_CA_SLOTSTATE_LINKINIT:
+                flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
+                if (flags & STATUSREG_DA) {
+                        dprintk("CAM supports DA IRQ\n");
+                        ca->slot_info[slot].da_irq_supported = 1;
+		}
+                break;
+
+        case DVB_CA_SLOTSTATE_RUNNING:
+                flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
+                if (flags & STATUSREG_DA) {
+                        dvb_ca_en50221_thread_wakeup(ca);
+                }
+                break;
+        }
+}
+
+
+
+/* ******************************************************************************** */
+/* EN50221 thread functions */
+
+/**
+ * Wake up the DVB CA thread
+ *
+ * @param ca CA instance.
+ */
+static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private* ca)
+{
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        ca->wakeup = 1;
+        mb();
+        wake_up_interruptible(&ca->thread_queue);
+}
+
+/**
+ * Used by the CA thread to determine if an early wakeup is necessary
+ *
+ * @param ca CA instance.
+ */
+static int dvb_ca_en50221_thread_should_wakeup(struct dvb_ca_private* ca)
+{
+        if (ca->wakeup) {
+                ca->wakeup = 0;
+                return 1;
+        }
+        if (ca->exit) return 1;
+   
+        return 0;
+}
+
+
+/**
+ * Update the delay used by the thread.
+ *
+ * @param ca CA instance.
+ */
+static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private* ca)
+{
+        int delay;
+        int curdelay = 100000000;
+        int slot;
+
+        for(slot=0; slot < ca->slot_count; slot++) {
+                switch(ca->slot_info[slot].slot_state) {
+                default:
+                case DVB_CA_SLOTSTATE_NONE:
+                case DVB_CA_SLOTSTATE_INVALID:
+                        delay = HZ*60;
+                        if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) {
+                                delay = HZ/10;
+                        }
+                        break;
+
+                case DVB_CA_SLOTSTATE_UNINITIALISED:
+                case DVB_CA_SLOTSTATE_WAITREADY:
+                case DVB_CA_SLOTSTATE_VALIDATE:
+                case DVB_CA_SLOTSTATE_WAITFR:
+                case DVB_CA_SLOTSTATE_LINKINIT:
+                        delay = HZ/10;
+                        break;
+
+                case DVB_CA_SLOTSTATE_RUNNING:
+                        delay = HZ*60;
+                        if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) {
+                                delay = HZ/10;
+                        }
+                        if (ca->open) {
+                                if ((!ca->slot_info[slot].da_irq_supported) ||
+                                    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA))) {
+                                        delay = HZ/100;
+                                }
+                        }
+                        break;
+                }
+
+                if (delay < curdelay) curdelay = delay;
+        }
+
+        ca->delay = curdelay;
+}
+
+
+
+/**
+ * Kernel thread which monitors CA slots for CAM changes, and performs data transfers.
+ */
+static int dvb_ca_en50221_thread(void* data)
+{
+        struct dvb_ca_private *ca = (struct dvb_ca_private*) data;
+        char name[15];
+        int slot;
+        int flags;
+        int pktcount;
+        void* rxbuf;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* setup kernel thread */
+        snprintf(name, sizeof(name), "kdvb-ca-%i:%i", ca->dvbdev->adapter->num, ca->dvbdev->id);
+        dvb_kernel_thread_setup(name);
+
+        /* choose the correct initial delay */
+        dvb_ca_en50221_thread_update_delay(ca);
+
+        /* main loop */
+        while(!ca->exit) {
+                /* sleep for a bit */
+                if (!ca->wakeup) {
+                        flags = wait_event_interruptible_timeout(ca->thread_queue, dvb_ca_en50221_thread_should_wakeup(ca), ca->delay);
+                        if ((flags == -ERESTARTSYS) || ca->exit) {
+                                /* got signal or quitting */
+                                break;
+                        }
+                }
+                ca->wakeup = 0;
+
+                /* go through all the slots processing them */
+                for(slot=0; slot < ca->slot_count; slot++) {
+
+                        // check the cam status + deal with CAMCHANGEs
+                        while(dvb_ca_en50221_check_camstatus(ca, slot)) {
+                                /* clear down an old CI slot if necessary */
+                                if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE) dvb_ca_en50221_slot_shutdown(ca, slot);
+
+                                /* if a CAM is NOW present, initialise it */
+                                if (ca->slot_info[slot].camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED) {
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
+                                }
+
+                                /* we've handled one CAMCHANGE */
+                                dvb_ca_en50221_thread_update_delay(ca);
+                                atomic_dec(&ca->slot_info[slot].camchange_count);
+                        }
+
+                        // CAM state machine
+                        switch(ca->slot_info[slot].slot_state) {
+                        case DVB_CA_SLOTSTATE_NONE:
+                        case DVB_CA_SLOTSTATE_INVALID:
+                                // no action needed
+                                break;
+
+                        case DVB_CA_SLOTSTATE_UNINITIALISED:
+                                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_WAITREADY;
+                                ca->pub->slot_reset(ca->pub, slot);
+                                ca->slot_info[slot].timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+                                break;
+
+                        case DVB_CA_SLOTSTATE_WAITREADY:
+                                if (time_after(jiffies, ca->slot_info[slot].timeout)) {
+                                        printk("dvb_ca: PC card did not respond :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+				        dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+                                // no other action needed; will automatically change state when ready
+                                break;
+
+                        case DVB_CA_SLOTSTATE_VALIDATE:
+                                if (dvb_ca_en50221_parse_attributes(ca, slot) != 0) {
+                                        printk("dvb_ca: Invalid PC card inserted :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+				        dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+                                if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
+                                        printk("dvb_ca: Unable to initialise CAM :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+				        dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+
+                                dprintk("DVB CAM validated successfully\n");
+
+                                ca->slot_info[slot].timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+                                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_WAITFR;
+                                ca->wakeup = 1;
+                                break;
+
+                        case DVB_CA_SLOTSTATE_WAITFR:
+                                if (time_after(jiffies, ca->slot_info[slot].timeout)) {
+                                        printk("dvb_ca: DVB CAM did not respond :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+				        dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+
+                                flags = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+                                if (flags & STATUSREG_FR) {
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+                                        ca->wakeup = 1;
+                                }
+                                break;
+
+                        case DVB_CA_SLOTSTATE_LINKINIT:
+                                if (dvb_ca_en50221_link_init(ca, slot) != 0) {
+                                        printk("dvb_ca: DVB CAM link initialisation failed :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+			                dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+
+                                rxbuf = vmalloc(RX_BUFFER_SIZE);
+                                if (rxbuf == NULL) {
+                                        printk("dvb_ca: Unable to allocate CAM rx buffer :(\n");
+                                        ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+				        dvb_ca_en50221_thread_update_delay(ca);
+                                        break;
+                                }
+                                dvb_ringbuffer_init(&ca->slot_info[slot].rx_buffer, rxbuf, RX_BUFFER_SIZE);
+
+                                ca->pub->slot_ts_enable(ca->pub, slot);
+                                ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_RUNNING;
+                                dvb_ca_en50221_thread_update_delay(ca);
+                                printk("dvb_ca: DVB CAM detected and initialised successfully\n");
+                                break;
+
+                        case DVB_CA_SLOTSTATE_RUNNING:
+                                if (!ca->open) break;
+
+                                pktcount = 0;
+                                while(dvb_ca_en50221_read_data(ca, slot, NULL, 0) > 0) {
+                                        if (!ca->open) break;
+
+                                        /* if a CAMCHANGE occurred at some point, do not do any more processing of this slot */
+                                        if (dvb_ca_en50221_check_camstatus(ca, slot)) {
+                                                // we dont want to sleep on the next iteration so we can handle the cam change
+                                                ca->wakeup = 1;
+                                                break;
+                                        }
+
+                                        /* check if we've hit our limit this time */
+                                        if (++pktcount >= MAX_RX_PACKETS_PER_ITERATION) {
+                                                // dont sleep; there is likely to be more data to read
+                                                ca->wakeup = 1;
+                                                break;
+                                        }
+                                }
+                                break;
+                        }
+                }
+        }
+
+        /* completed */
+        ca->thread_pid = 0;
+        mb();
+        wake_up_interruptible (&ca->thread_queue);
+        return 0;
+}
+
+
+
+/* ******************************************************************************** */
+/* EN50221 IO interface functions */
+
+/**
+ * Real ioctl implementation.
+ * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
+ *
+ * @param inode Inode concerned.
+ * @param file File concerned.
+ * @param cmd IOCTL command.
+ * @param arg Associated argument.
+ *
+ * @return 0 on success, <0 on error.
+ */
+static int dvb_ca_en50221_io_do_ioctl(struct inode *inode, struct file *file, unsigned int cmd, void *parg)
+{
+        struct dvb_device* dvbdev=(struct dvb_device*) file->private_data;
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) dvbdev->priv;
+        int err=0;
+        int slot;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        switch (cmd) {
+        case CA_RESET:
+                for(slot = 0; slot < ca->slot_count; slot++) {
+                        if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE) {
+                                dvb_ca_en50221_slot_shutdown(ca, slot);
+                                if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
+                                        dvb_ca_en50221_camchange_irq(ca->pub, slot, DVB_CA_EN50221_CAMCHANGE_INSERTED);
+                        }
+                }
+                ca->next_read_slot = 0;
+                dvb_ca_en50221_thread_wakeup(ca);
+                break;
+
+        case CA_GET_CAP:
+        {
+                struct ca_caps *caps = (struct ca_caps*) parg;
+
+                caps->slot_num=ca->slot_count;
+                caps->slot_type=CA_CI_LINK;
+                caps->descr_num=0;
+                caps->descr_type=0;
+                break;
+        }
+
+
+        case CA_GET_SLOT_INFO:
+        {
+                struct ca_slot_info *info=(struct ca_slot_info *)parg;
+
+                if ((info->num > ca->slot_count) || (info->num < 0))
+                        return -EINVAL;
+
+                info->type = CA_CI_LINK;
+                info->flags = 0;
+                if ((ca->slot_info[info->num].slot_state != DVB_CA_SLOTSTATE_NONE) &&
+                    (ca->slot_info[info->num].slot_state != DVB_CA_SLOTSTATE_INVALID)) {
+                        info->flags = CA_CI_MODULE_PRESENT;
+                }
+                if (ca->slot_info[info->num].slot_state == DVB_CA_SLOTSTATE_RUNNING) {
+                        info->flags |= CA_CI_MODULE_READY;
+                }
+                break;
+        }
+
+        default:
+                err=-EINVAL;
+                break;
+        }
+
+        return err;
+}
+
+
+/**
+ * Wrapper for ioctl implementation.
+ *
+ * @param inode Inode concerned.
+ * @param file File concerned.
+ * @param cmd IOCTL command.
+ * @param arg Associated argument.
+ *
+ * @return 0 on success, <0 on error.
+ */
+static int dvb_ca_en50221_io_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+        return dvb_usercopy(inode, file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
+}
+
+
+/**
+ * Implementation of write() syscall.
+ *
+ * @param file File structure.
+ * @param buf Source buffer.
+ * @param count Size of source buffer.
+ * @param ppos Position in file (ignored).
+ *
+ * @return Number of bytes read, or <0 on error.
+ */
+static ssize_t dvb_ca_en50221_io_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+        struct dvb_device *dvbdev=(struct dvb_device *) file->private_data;
+        struct dvb_ca_private *ca=(struct dvb_ca_private*) dvbdev->priv;
+        u8 slot, connection_id;
+        int status;
+        char fragbuf[HOST_LINK_BUF_SIZE];
+        int fragpos = 0;
+        int fraglen;
+        unsigned long timeout;
+        int written;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* Incoming packet has a 2 byte header. hdr[0] = slot_id, hdr[1] = connection_id */
+        if (count < 2) return -EINVAL;
+
+        /* extract slot & connection id */
+        if (copy_from_user(&slot, buf, 1)) return -EFAULT;
+        if (copy_from_user(&connection_id, buf+1, 1)) return -EFAULT;
+        buf+=2;
+        count-=2;
+
+        /* check if the slot is actually running */
+        if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING) return -EINVAL;
+
+        /* fragment the packets & store in the buffer */
+        while(fragpos < count) {
+                fraglen = ca->slot_info[slot].link_buf_size - 2;
+                if ((count - fragpos) < fraglen) fraglen = count - fragpos;
+
+                fragbuf[0] = connection_id;
+                fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
+                if ((status = copy_from_user(fragbuf+2, buf+fragpos, fraglen)) != 0) goto exit;
+
+		timeout = jiffies + HZ/2;
+	        written = 0;
+                while(!time_after(jiffies, timeout)) {
+                        status = dvb_ca_en50221_write_data(ca, slot, fragbuf, fraglen+2);
+		        if (status == (fraglen+2)) {
+			       written = 1;
+			       break;
+			}
+                        if (status != -EAGAIN) goto exit;
+
+                        dvb_delay(1);
+                }
+	        if (!written) {
+		        status = -EIO;
+		        goto exit;
+		}
+
+                fragpos += fraglen;
+        }
+        status = count + 2;
+
+exit:
+        return status;
+}
+
+
+/**
+ * Condition for waking up in dvb_ca_en50221_io_read_condition
+ */
+static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private* ca, int* result, int* _slot)
+{
+        int slot;
+        int slot_count = 0;
+        int idx;
+        int fraglen;
+        int connection_id = -1;
+        int found = 0;
+        u8 hdr[2];
+
+        slot = ca->next_read_slot;
+        while((slot_count < ca->slot_count) && (!found)) {
+                if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING) goto nextslot;
+
+                if ((*result = down_interruptible(&ca->slot_info[slot].sem)) != 0) return 1;
+
+                idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, -1, &fraglen);
+                while(idx != -1) {
+                        dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 0, hdr, 2, 0);
+                        if (connection_id == -1) connection_id = hdr[0];
+                        if ((hdr[0] == connection_id) && ((hdr[1] & 0x80) == 0)) {
+                                *_slot = slot;
+                                found = 1;
+                                break;
+                        }
+
+                        idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, idx, &fraglen);
+                }
+
+                if (!found) up(&ca->slot_info[slot].sem);
+
+nextslot:
+                slot = (slot + 1) % ca->slot_count;
+                slot_count++;
+        }
+
+        ca->next_read_slot = slot;
+        return found;
+}
+
+
+/**
+ * Implementation of read() syscall.
+ *
+ * @param file File structure.
+ * @param buf Destination buffer.
+ * @param count Size of destination buffer.
+ * @param ppos Position in file (ignored).
+ *
+ * @return Number of bytes read, or <0 on error.
+ */
+static ssize_t dvb_ca_en50221_io_read(struct file *file, char *buf, size_t count, loff_t *ppos)
+{
+        struct dvb_device *dvbdev=(struct dvb_device *) file->private_data;
+        struct dvb_ca_private *ca=(struct dvb_ca_private*) dvbdev->priv;
+        int status;
+        int result = 0;
+        u8 hdr[2];
+        int slot;
+        int connection_id = -1;
+        size_t idx, idx2;
+        int last_fragment = 0;
+        size_t fraglen;
+        int pktlen;
+        int dispose = 0;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* Outgoing packet has a 2 byte header. hdr[0] = slot_id, hdr[1] = connection_id */
+        if (count < 2) return -EINVAL;
+
+        /* wait for some data */
+        if ((status = dvb_ca_en50221_io_read_condition(ca, &result, &slot)) == 0) {
+
+                /* if we're in nonblocking mode, exit immediately */
+                if (file->f_flags & O_NONBLOCK) return -EWOULDBLOCK;
+
+                /* wait for some data */
+                status = wait_event_interruptible(ca->wait_queue, dvb_ca_en50221_io_read_condition(ca, &result, &slot));
+        }
+        if ((status < 0) || (result < 0)) {
+                if (result) return result;
+                return status;
+        }
+
+        idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, -1, &fraglen);
+        pktlen = 2;
+        do {
+                if (idx == -1) {
+                        printk("dvb_ca: BUG: read packet ended before last_fragment encountered\n");
+                        status = -EIO;
+                        goto exit;
+                }
+
+                dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 0, hdr, 2, 0);
+                if (connection_id == -1) connection_id = hdr[0];
+                if (hdr[0] == connection_id) {
+                        if (pktlen < count) {
+                                if ((pktlen + fraglen - 2) > count) {
+                                        fraglen = count - pktlen;
+                                } else {
+                                        fraglen -= 2;
+                                }
+
+			        if ((status = dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 2, buf + pktlen, fraglen, 1)) < 0) {
+                                        goto exit;
+                                }
+                                pktlen += fraglen;
+                        }
+
+                        if ((hdr[1] & 0x80) == 0) last_fragment = 1;
+                        dispose = 1;
+                }
+
+                idx2 = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, idx, &fraglen);
+                if (dispose) dvb_ringbuffer_pkt_dispose(&ca->slot_info[slot].rx_buffer, idx);
+                idx = idx2;
+                dispose = 0;
+        } while (!last_fragment);
+
+        hdr[0] = slot;
+        hdr[1] = connection_id;
+        if ((status = copy_to_user(buf, hdr, 2)) != 0) goto exit;
+        status = pktlen;
+
+exit:
+        up(&ca->slot_info[slot].sem);
+        return status;
+}
+
+
+/**
+ * Implementation of file open syscall.
+ *
+ * @param inode Inode concerned.
+ * @param file File concerned.
+ *
+ * @return 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
+{
+        struct dvb_device *dvbdev = (struct dvb_device *) file->private_data;
+        struct dvb_ca_private *ca = (struct dvb_ca_private*) dvbdev->priv;
+        int err;
+        int i;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        err=dvb_generic_open(inode, file);
+        if (err<0)
+                return err;
+
+        for(i=0; i< ca->slot_count; i++) {
+                if (ca->slot_info[i].slot_state == DVB_CA_SLOTSTATE_RUNNING) {
+                        dvb_ringbuffer_flush(&ca->slot_info[i].rx_buffer);
+                }
+        }
+
+        ca->open = 1;
+        dvb_ca_en50221_thread_update_delay(ca);
+        dvb_ca_en50221_thread_wakeup(ca);
+
+        return 0;
+}
+
+
+/**
+ * Implementation of file close syscall.
+ *
+ * @param inode Inode concerned.
+ * @param file File concerned.
+ *
+ * @return 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
+{
+        struct dvb_device *dvbdev=(struct dvb_device *) file->private_data;
+        struct dvb_ca_private *ca=(struct dvb_ca_private*) dvbdev->priv;
+        int err;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* mark the CA device as closed */
+        ca->open = 0;
+        dvb_ca_en50221_thread_update_delay(ca);
+
+        err=dvb_generic_release(inode, file);
+        if (err<0)
+                return err;
+        return 0;
+}
+
+
+/**
+ * Implementation of poll() syscall.
+ *
+ * @param file File concerned.
+ * @param wait poll wait table.
+ *
+ * @return Standard poll mask.
+ */
+static unsigned int dvb_ca_en50221_io_poll(struct file *file, poll_table *wait)
+{
+        struct dvb_device* dvbdev = (struct dvb_device*) file->private_data;
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) dvbdev->priv;
+        unsigned int mask=0;
+        int slot;
+        int result = 0;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
+                up(&ca->slot_info[slot].sem);
+                mask |= POLLIN;
+        }
+
+        /* if there is something, return now */
+        if (mask) return mask;
+
+        /* wait for something to happen */
+        poll_wait(file, &ca->wait_queue, wait);
+
+        if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
+                up(&ca->slot_info[slot].sem);
+                mask |= POLLIN;
+        }
+
+        return mask;
+}
+
+
+static struct file_operations dvb_ca_fops = {
+        owner: THIS_MODULE,
+        read: dvb_ca_en50221_io_read,
+        write: dvb_ca_en50221_io_write,
+        ioctl: dvb_ca_en50221_io_ioctl,
+        open: dvb_ca_en50221_io_open,
+        release: dvb_ca_en50221_io_release,
+        poll: dvb_ca_en50221_io_poll,
+};
+
+static struct dvb_device dvbdev_ca = {
+        priv: 0,
+        users: 1,
+        readers: 1,
+        writers: 1,
+        fops: &dvb_ca_fops,
+};
+
+
+/* ******************************************************************************** */
+/* Initialisation/shutdown functions */
+
+
+/**
+ * Initialise a new DVB CA EN50221 interface device.
+ *
+ * @param dvb_adapter DVB adapter to attach the new CA device to.
+ * @param ca The dvb_ca instance.
+ * @param flags Flags describing the CA device (DVB_CA_FLAG_*).
+ * @param slot_count Number of slots supported.
+ *
+ * @return 0 on success, nonzero on failure
+ */
+int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter, struct dvb_ca_en50221* pubca, int flags, int slot_count)
+{
+        int ret;
+        struct dvb_ca_private* ca = NULL;
+        int i;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        if (slot_count < 1) return -EINVAL;
+
+        /* initialise the system data */
+        if ((ca = (struct dvb_ca_private*) kmalloc(sizeof(struct dvb_ca_private), GFP_KERNEL)) == NULL) {
+                ret = -ENOMEM;
+                goto error;
+        }
+        memset(ca, 0, sizeof(struct dvb_ca_private));
+        ca->pub = pubca;
+        ca->flags = flags;
+        ca->slot_count = slot_count;
+        if ((ca->slot_info = kmalloc(sizeof(struct dvb_ca_slot) * slot_count, GFP_KERNEL)) == NULL) {
+                ret = -ENOMEM;
+                goto error;
+        }
+        memset(ca->slot_info, 0, sizeof(struct dvb_ca_slot) * slot_count);
+        init_waitqueue_head(&ca->wait_queue);
+        ca->thread_pid = 0;
+        init_waitqueue_head(&ca->thread_queue);
+        ca->exit = 0;
+        ca->open = 0;
+        ca->wakeup = 0;
+        ca->next_read_slot = 0;
+        pubca->private = ca;
+
+        /* register the DVB device */
+        ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca, DVB_DEVICE_CA);
+        if (ret) goto error;
+
+        /* now initialise each slot */
+        for(i=0; i< slot_count; i++) {
+                memset(&ca->slot_info[i], 0, sizeof(struct dvb_ca_slot));
+                ca->slot_info[i].slot_state = DVB_CA_SLOTSTATE_NONE;
+                atomic_set(&ca->slot_info[i].camchange_count, 0);
+                ca->slot_info[i].camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
+                init_MUTEX(&ca->slot_info[i].sem);
+        }
+
+        if (signal_pending(current)) {
+                ret = -EINTR;
+                goto error;
+        }
+        mb();
+
+        /* create a kthread for monitoring this CA device */
+        ret = kernel_thread (dvb_ca_en50221_thread, ca, 0);
+        if (ret < 0) {
+                printk("dvb_ca_init: failed to start kernel_thread (%d)\n", ret);
+                goto error;
+        }
+        ca->thread_pid = ret;
+        return 0;
+
+error:
+        if (ca != NULL) {
+                if (ca->dvbdev != NULL) dvb_unregister_device(ca->dvbdev);
+                if (ca->slot_info != NULL) kfree(ca->slot_info);
+                kfree(ca);
+        }
+        pubca->private = NULL;
+        return ret;
+}
+
+
+
+/**
+ * Release a DVB CA EN50221 interface device.
+ *
+ * @param ca_dev The dvb_device_t instance for the CA device.
+ * @param ca The associated dvb_ca instance.
+ */
+void dvb_ca_en50221_release(struct dvb_ca_en50221* pubca)
+{
+        struct dvb_ca_private* ca = (struct dvb_ca_private*) pubca->private;
+        int i;
+
+        dprintk ("%s\n", __FUNCTION__);
+
+        /* shutdown the thread if there was one */
+        if (ca->thread_pid) {
+                if (kill_proc(ca->thread_pid, 0, 1) == -ESRCH) {
+                        printk("dvb_ca_release: thread PID %d already died\n", ca->thread_pid);
+                } else {
+                        ca->exit = 1;
+                        mb();
+                        dvb_ca_en50221_thread_wakeup(ca);
+                        wait_event_interruptible(ca->thread_queue, ca->thread_pid == 0);
+                }
+        }
+
+        for(i=0; i< ca->slot_count; i++) {
+                dvb_ca_en50221_slot_shutdown(ca, i);
+        }
+        kfree(ca->slot_info);
+        dvb_unregister_device(ca->dvbdev);
+        kfree(ca);
+        pubca->private = NULL;
+}
+
+MODULE_PARM(dvb_ca_en50221_debug,"i");
+
+MODULE_PARM_DESC(dvb_ca_en50221_debug, "enable verbose debug messages");
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ca_en50221.h linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ca_en50221.h
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ca_en50221.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ca_en50221.h	2004-04-05 14:17:33.000000000 +0200
@@ -0,0 +1,128 @@
+/*
+ * dvb_ca.h: generic DVB functions for EN50221 CA interfaces
+ *
+ * Copyright (C) 2004 Andrew de Quincey
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * 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 Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _DVB_CA_EN50221_H_
+#define _DVB_CA_EN50221_H_
+
+#include <linux/list.h>
+#include <linux/dvb/ca.h>
+
+#include "dvbdev.h"
+
+#define DVB_CA_EN50221_POLL_CAM_PRESENT	1
+#define DVB_CA_EN50221_POLL_CAM_CHANGED	2
+#define DVB_CA_EN50221_POLL_CAM_READY		4
+
+#define DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE	1
+#define DVB_CA_EN50221_FLAG_IRQ_FR		2
+#define DVB_CA_EN50221_FLAG_IRQ_DA		4
+
+#define DVB_CA_EN50221_CAMCHANGE_REMOVED		0
+#define DVB_CA_EN50221_CAMCHANGE_INSERTED		1
+
+
+
+/* Structure describing a CA interface */
+struct dvb_ca_en50221 {
+
+	/* functions for accessing attribute memory on the CAM */
+	int (*read_attribute_mem)(struct dvb_ca_en50221* ca, int slot, int address);
+	int (*write_attribute_mem)(struct dvb_ca_en50221* ca, int slot, int address, u8 value);
+
+	/* functions for accessing the control interface on the CAM */
+	int (*read_cam_control)(struct dvb_ca_en50221* ca, int slot, u8 address);
+	int (*write_cam_control)(struct dvb_ca_en50221* ca, int slot, u8 address, u8 value);
+
+	/* Functions for controlling slots */
+	int (*slot_reset)(struct dvb_ca_en50221* ca, int slot);
+	int (*slot_shutdown)(struct dvb_ca_en50221* ca, int slot);
+	int (*slot_ts_enable)(struct dvb_ca_en50221* ca, int slot);
+
+	/*
+	* Poll slot status.
+	* Only necessary if DVB_CA_FLAG_EN50221_IRQ_CAMCHANGE is not set
+	*/
+	int (*poll_slot_status)(struct dvb_ca_en50221* ca, int slot);
+
+	/* private data, used by caller */
+	void* data;
+
+	/* Opaque data used by the dvb_ca core. Do not modify! */
+	void* private;
+};
+
+
+
+
+/* ******************************************************************************** */
+/* Functions for reporting IRQ events */
+
+/**
+ * A CAMCHANGE IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ * @param change_type One of the DVB_CA_CAMCHANGE_* values
+ */
+void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221* pubca, int slot, int change_type);
+
+/**
+ * A CAMREADY IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221* pubca, int slot);
+
+/**
+ * An FR or a DA IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221* ca, int slot);
+
+
+
+/* ******************************************************************************** */
+/* Initialisation/shutdown functions */
+
+/**
+ * Initialise a new DVB CA device.
+ *
+ * @param dvb_adapter DVB adapter to attach the new CA device to.
+ * @param ca The dvb_ca instance.
+ * @param flags Flags describing the CA device (DVB_CA_EN50221_FLAG_*).
+ * @param slot_count Number of slots supported.
+ *
+ * @return 0 on success, nonzero on failure
+ */
+extern int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter, struct dvb_ca_en50221* ca, int flags, int slot_count);
+
+/**
+ * Release a DVB CA device.
+ *
+ * @param ca The associated dvb_ca instance.
+ */
+extern void dvb_ca_en50221_release(struct dvb_ca_en50221* ca);
+
+
+
+#endif
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ksyms.c linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ksyms.c
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ksyms.c	2004-01-16 18:25:17.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ksyms.c	2004-04-05 14:17:33.000000000 +0200
@@ -10,6 +10,7 @@
 #include "dvb_frontend.h"
 #include "dvb_net.h"
 #include "dvb_filter.h"
+#include "dvb_ca_en50221.h"
 
 EXPORT_SYMBOL(dvb_dmxdev_init);
 EXPORT_SYMBOL(dvb_dmxdev_release);
@@ -49,3 +50,8 @@
 EXPORT_SYMBOL(dvb_filter_pes2ts);
 EXPORT_SYMBOL(dvb_filter_get_ac3info);
 
+EXPORT_SYMBOL(dvb_ca_en50221_init);
+EXPORT_SYMBOL(dvb_ca_en50221_release);
+EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);
+EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);
+EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ringbuffer.c linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ringbuffer.c
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ringbuffer.c	2004-03-12 20:31:28.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ringbuffer.c	2004-04-14 12:31:21.000000000 +0200
@@ -3,9 +3,10 @@
  * dvb_ringbuffer.c: ring buffer implementation for the dvb driver
  *
  * Copyright (C) 2003 Oliver Endriss 
+ * Copyright (C) 2004 Andrew de Quincey
  * 
- * based on code originally found in av7110.c:
- * Copyright (C) 1999-2002 Ralph  Metzler 
+ * based on code originally found in av7110.c & dvb_ci.c:
+ * Copyright (C) 1999-2003 Ralph  Metzler
  *                       & Marcus Metzler for convergence integrated media GmbH
  *
  * This program is free software; you can redistribute it and/or
@@ -24,6 +25,8 @@
  */
 
 
+
+#define __KERNEL_SYSCALLS__
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -33,6 +36,8 @@
 
 #include "dvb_ringbuffer.h"
 
+#define PKT_READY 0
+#define PKT_DISPOSED 1
 
 
 void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len)
@@ -158,6 +163,109 @@
 	return len;
 }
 
+ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t len, int usermem)
+{
+        int status;
+        ssize_t oldpwrite = rbuf->pwrite;
+
+        DVB_RINGBUFFER_WRITE_BYTE(rbuf, len >> 8);
+        DVB_RINGBUFFER_WRITE_BYTE(rbuf, len & 0xff);
+        DVB_RINGBUFFER_WRITE_BYTE(rbuf, PKT_READY);
+        status = dvb_ringbuffer_write(rbuf, buf, len, usermem);
+
+        if (status < 0) rbuf->pwrite = oldpwrite;
+        return status;
+}
+
+ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
+                                int offset, u8* buf, size_t len, int usermem)
+{
+        size_t todo;
+        size_t split;
+        size_t pktlen;
+
+        pktlen = rbuf->data[idx] << 8;
+        pktlen |= rbuf->data[(idx + 1) % rbuf->size];
+        if (offset > pktlen) return -EINVAL;
+        if ((offset + len) > pktlen) len = pktlen - offset;
+
+        idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
+        todo = len;
+        split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
+        if (split > 0) {
+                if (!usermem)
+                        memcpy(buf, rbuf->data+idx, split);
+                else
+                        if (copy_to_user(buf, rbuf->data+idx, split))
+                                return -EFAULT;
+                buf += split;
+                todo -= split;
+                idx = 0;
+        }
+        if (!usermem)
+                memcpy(buf, rbuf->data+idx, todo);
+        else
+                if (copy_to_user(buf, rbuf->data+idx, todo))
+                        return -EFAULT;
+
+        return len;
+}
+
+void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx)
+{
+        size_t pktlen;
+
+        rbuf->data[(idx + 2) % rbuf->size] = PKT_DISPOSED;
+
+        // clean up disposed packets
+        while(dvb_ringbuffer_avail(rbuf) > DVB_RINGBUFFER_PKTHDRSIZE) {
+                if (DVB_RINGBUFFER_PEEK(rbuf, 2) == PKT_DISPOSED) {
+                        pktlen = DVB_RINGBUFFER_PEEK(rbuf, 0) << 8;
+                        pktlen |= DVB_RINGBUFFER_PEEK(rbuf, 1);
+                        DVB_RINGBUFFER_SKIP(rbuf, pktlen + DVB_RINGBUFFER_PKTHDRSIZE);
+                } else {
+                        // first packet is not disposed, so we stop cleaning now
+                        break;
+                }
+        }
+}
+
+ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen)
+{
+        int consumed;
+        int curpktlen;
+        int curpktstatus;
+
+        if (idx == -1) {
+	       idx = rbuf->pread;
+	} else {
+                curpktlen = rbuf->data[idx] << 8;
+                curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
+	        idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
+	}
+
+        consumed = (idx - rbuf->pread) % rbuf->size;
+
+        while((dvb_ringbuffer_avail(rbuf) - consumed) > DVB_RINGBUFFER_PKTHDRSIZE) {
+
+                curpktlen = rbuf->data[idx] << 8;
+                curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
+                curpktstatus = rbuf->data[(idx + 2) % rbuf->size];
+
+                if (curpktstatus == PKT_READY) {
+                        *pktlen = curpktlen;
+                        return idx;
+                }
+
+                consumed += curpktlen + DVB_RINGBUFFER_PKTHDRSIZE;
+                idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
+        }
+
+        // no packets available
+        return -1;
+}
+
+
 
 EXPORT_SYMBOL(dvb_ringbuffer_init);
 EXPORT_SYMBOL(dvb_ringbuffer_empty);
@@ -167,3 +275,7 @@
 EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup);
 EXPORT_SYMBOL(dvb_ringbuffer_read);
 EXPORT_SYMBOL(dvb_ringbuffer_write);
+EXPORT_SYMBOL(dvb_ringbuffer_pkt_write);
+EXPORT_SYMBOL(dvb_ringbuffer_pkt_read);
+EXPORT_SYMBOL(dvb_ringbuffer_pkt_dispose);
+EXPORT_SYMBOL(dvb_ringbuffer_pkt_next);
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ringbuffer.h linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ringbuffer.h
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/dvb_ringbuffer.h	2004-01-16 18:25:17.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/dvb_ringbuffer.h	2004-04-05 14:17:33.000000000 +0200
@@ -3,9 +3,10 @@
  * dvb_ringbuffer.h: ring buffer implementation for the dvb driver
  *
  * Copyright (C) 2003 Oliver Endriss 
+ * Copyright (C) 2004 Andrew de Quincey
  * 
- * based on code originally found in av7110.c:
- * Copyright (C) 1999-2002 Ralph Metzler & Marcus Metzler
+ * based on code originally found in av7110.c & dvb_ci.c:
+ * Copyright (C) 1999-2003 Ralph Metzler & Marcus Metzler
  *                         for convergence integrated media GmbH
  *
  * This program is free software; you can redistribute it and/or
@@ -39,6 +40,8 @@
         spinlock_t        lock;
 };
 
+#define DVB_RINGBUFFER_PKTHDRSIZE 3
+
 
 /*
 ** Notes:
@@ -120,4 +123,52 @@
 extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf,
                                     size_t len, int usermem);
 
+
+/**
+ * Write a packet into the ringbuffer.
+ *
+ * <rbuf> Ringbuffer to write to.
+ * <buf> Buffer to write.
+ * <len> Length of buffer (currently limited to 65535 bytes max).
+ * <usermem> Set to 1 if <buf> is in userspace.
+ * returns Number of bytes written, or -EFAULT, -ENOMEM, -EVINAL.
+ */
+extern ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf,
+                                        size_t len, int usermem);
+
+/**
+ * Read from a packet in the ringbuffer. Note: unlike dvb_ringbuffer_read(), this
+ * does NOT update the read pointer in the ringbuffer. You must use
+ * dvb_ringbuffer_pkt_dispose() to mark a packet as no longer required.
+ *
+ * <rbuf> Ringbuffer concerned.
+ * <idx> Packet index as returned by dvb_ringbuffer_pkt_next().
+ * <offset> Offset into packet to read from.
+ * <buf> Destination buffer for data.
+ * <len> Size of destination buffer.
+ * <usermem> Set to 1 if <buf> is in userspace.
+ * returns Number of bytes read, or -EFAULT.
+ */
+extern ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
+                                       int offset, u8* buf, size_t len, int usermem);
+
+/**
+ * Dispose of a packet in the ring buffer.
+ *
+ * <rbuf> Ring buffer concerned.
+ * <idx> Packet index as returned by dvb_ringbuffer_pkt_next().
+ */
+extern void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx);
+
+/**
+ * Get the index of the next packet in a ringbuffer.
+ *
+ * <rbuf> Ringbuffer concerned.
+ * <idx> Previous packet index, or -1 to return the first packet index.
+ * <pktlen> On success, will be updated to contain the length of the packet in bytes.
+ * returns Packet index (if >=0), or -1 if no packets available.
+ */
+extern ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen);
+
+
 #endif /* _DVB_RINGBUFFER_H_ */
diff -urawBN xx-linux-2.6.5/drivers/media/dvb/dvb-core/Makefile linux-2.6.5-patched/drivers/media/dvb/dvb-core/Makefile
--- xx-linux-2.6.5/drivers/media/dvb/dvb-core/Makefile	2003-12-18 03:59:56.000000000 +0100
+++ linux-2.6.5-patched/drivers/media/dvb/dvb-core/Makefile	2004-04-05 14:17:33.000000000 +0200
@@ -3,6 +3,7 @@
 #
 
 dvb-core-objs = dvbdev.o dmxdev.o dvb_demux.o dvb_filter.o \
-		dvb_functions.o dvb_frontend.o dvb_i2c.o dvb_net.o dvb_ksyms.o dvb_ringbuffer.o
+	        dvb_ca_en50221.o dvb_functions.o dvb_frontend.o \
+		dvb_i2c.o dvb_net.o dvb_ksyms.o dvb_ringbuffer.o
 
 obj-$(CONFIG_DVB_CORE) += dvb-core.o



  reply	other threads:[~2004-04-26 13:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-26 13:40 [PATCH 0/9] LinuxTV.org DVB update Michael Hunold
2004-04-26 13:40 ` [PATCH 1/9] V4L: Update the saa7146 driver Michael Hunold
2004-04-26 13:41   ` [PATCH 2/9] DVB: Documentation and Kconfig updazes Michael Hunold
2004-04-26 13:41     ` [PATCH 3/9] DVB: Update DVB budget drivers Michael Hunold
2004-04-26 13:42       ` Michael Hunold [this message]
2004-04-26 13:42         ` [PATCH 5/9] DVB: Other DVB core updates Michael Hunold
2004-04-26 13:42           ` [PATCH 6/9] DVB: AV7110 DVB driver updates Michael Hunold
2004-04-26 13:42             ` [PATCH 7/9] DVB: Misc. DVB frontend " Michael Hunold
2004-04-26 13:42               ` [PATCH 8/9] DVB: Misc. DVB USB " Michael Hunold
2004-04-26 13:42                 ` [PATCH 9/9] DVB: Follow saa7146 changes in affected V4L drivers Michael Hunold
2004-04-26 14:05     ` [PATCH 2/9] DVB: Documentation and Kconfig updazes Måns Rullgård

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