V4L/DVB (4228a): pvrusb2 to kernel 2.6.18

Implement V4L2 driver for the Hauppauge PVR USB2 TV tuner.

The Hauppauge PVR USB2 is a USB connected TV tuner with an embedded
cx23416 hardware MPEG2 encoder.  There are two major variants of this
device; this driver handles both.  Any V4L2 application which
understands MPEG2 video stream data should be able to work with this
device.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 937 insertions, 0 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c b/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c
new file mode 100644
index 000000000000..c8d0bdee3ff1
--- /dev/null
+++ b/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c
@@ -0,0 +1,937 @@
+/*
+ *
+ *  $Id$
+ *
+ *  Copyright (C) 2005 Mike Isely <isely@pobox.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
+ *
+ *  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
+ *
+ */
+
+#include "pvrusb2-i2c-core.h"
+#include "pvrusb2-hdw-internal.h"
+#include "pvrusb2-debug.h"
+
+#define trace_i2c(...) pvr2_trace(PVR2_TRACE_I2C,__VA_ARGS__)
+
+/*
+
+  This module attempts to implement a compliant I2C adapter for the pvrusb2
+  device.  By doing this we can then make use of existing functionality in
+  V4L (e.g. tuner.c) rather than rolling our own.
+
+*/
+
+static unsigned int i2c_scan = 0;
+module_param(i2c_scan, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
+
+static int pvr2_i2c_write(struct pvr2_hdw *hdw, /* Context */
+			  u8 i2c_addr,      /* I2C address we're talking to */
+			  u8 *data,         /* Data to write */
+			  u16 length)       /* Size of data to write */
+{
+	/* Return value - default 0 means success */
+	int ret;
+
+
+	if (!data) length = 0;
+	if (length > (sizeof(hdw->cmd_buffer) - 3)) {
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "Killing an I2C write to %u that is too large"
+			   " (desired=%u limit=%u)",
+			   i2c_addr,
+			   length,(unsigned int)(sizeof(hdw->cmd_buffer) - 3));
+		return -ENOTSUPP;
+	}
+
+	LOCK_TAKE(hdw->ctl_lock);
+
+	/* Clear the command buffer (likely to be paranoia) */
+	memset(hdw->cmd_buffer, 0, sizeof(hdw->cmd_buffer));
+
+	/* Set up command buffer for an I2C write */
+	hdw->cmd_buffer[0] = 0x08;      /* write prefix */
+	hdw->cmd_buffer[1] = i2c_addr;  /* i2c addr of chip */
+	hdw->cmd_buffer[2] = length;    /* length of what follows */
+	if (length) memcpy(hdw->cmd_buffer + 3, data, length);
+
+	/* Do the operation */
+	ret = pvr2_send_request(hdw,
+				hdw->cmd_buffer,
+				length + 3,
+				hdw->cmd_buffer,
+				1);
+	if (!ret) {
+		if (hdw->cmd_buffer[0] != 8) {
+			ret = -EIO;
+			if (hdw->cmd_buffer[0] != 7) {
+				trace_i2c("unexpected status"
+					  " from i2_write[%d]: %d",
+					  i2c_addr,hdw->cmd_buffer[0]);
+			}
+		}
+	}
+
+	LOCK_GIVE(hdw->ctl_lock);
+
+	return ret;
+}
+
+static int pvr2_i2c_read(struct pvr2_hdw *hdw, /* Context */
+			 u8 i2c_addr,       /* I2C address we're talking to */
+			 u8 *data,          /* Data to write */
+			 u16 dlen,          /* Size of data to write */
+			 u8 *res,           /* Where to put data we read */
+			 u16 rlen)          /* Amount of data to read */
+{
+	/* Return value - default 0 means success */
+	int ret;
+
+
+	if (!data) dlen = 0;
+	if (dlen > (sizeof(hdw->cmd_buffer) - 4)) {
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "Killing an I2C read to %u that has wlen too large"
+			   " (desired=%u limit=%u)",
+			   i2c_addr,
+			   dlen,(unsigned int)(sizeof(hdw->cmd_buffer) - 4));
+		return -ENOTSUPP;
+	}
+	if (res && (rlen > (sizeof(hdw->cmd_buffer) - 1))) {
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "Killing an I2C read to %u that has rlen too large"
+			   " (desired=%u limit=%u)",
+			   i2c_addr,
+			   rlen,(unsigned int)(sizeof(hdw->cmd_buffer) - 1));
+		return -ENOTSUPP;
+	}
+
+	LOCK_TAKE(hdw->ctl_lock);
+
+	/* Clear the command buffer (likely to be paranoia) */
+	memset(hdw->cmd_buffer, 0, sizeof(hdw->cmd_buffer));
+
+	/* Set up command buffer for an I2C write followed by a read */
+	hdw->cmd_buffer[0] = 0x09;  /* read prefix */
+	hdw->cmd_buffer[1] = dlen;  /* arg length */
+	hdw->cmd_buffer[2] = rlen;  /* answer length. Device will send one
+				       more byte (status). */
+	hdw->cmd_buffer[3] = i2c_addr;  /* i2c addr of chip */
+	if (dlen) memcpy(hdw->cmd_buffer + 4, data, dlen);
+
+	/* Do the operation */
+	ret = pvr2_send_request(hdw,
+				hdw->cmd_buffer,
+				4 + dlen,
+				hdw->cmd_buffer,
+				rlen + 1);
+	if (!ret) {
+		if (hdw->cmd_buffer[0] != 8) {
+			ret = -EIO;
+			if (hdw->cmd_buffer[0] != 7) {
+				trace_i2c("unexpected status"
+					  " from i2_read[%d]: %d",
+					  i2c_addr,hdw->cmd_buffer[0]);
+			}
+		}
+	}
+
+	/* Copy back the result */
+	if (res && rlen) {
+		if (ret) {
+			/* Error, just blank out the return buffer */
+			memset(res, 0, rlen);
+		} else {
+			memcpy(res, hdw->cmd_buffer + 1, rlen);
+		}
+	}
+
+	LOCK_GIVE(hdw->ctl_lock);
+
+	return ret;
+}
+
+/* This is the common low level entry point for doing I2C operations to the
+   hardware. */
+int pvr2_i2c_basic_op(struct pvr2_hdw *hdw,
+		      u8 i2c_addr,
+		      u8 *wdata,
+		      u16 wlen,
+		      u8 *rdata,
+		      u16 rlen)
+{
+	if (!rdata) rlen = 0;
+	if (!wdata) wlen = 0;
+	if (rlen || !wlen) {
+		return pvr2_i2c_read(hdw,i2c_addr,wdata,wlen,rdata,rlen);
+	} else {
+		return pvr2_i2c_write(hdw,i2c_addr,wdata,wlen);
+	}
+}
+
+#ifdef CONFIG_VIDEO_PVRUSB2_24XXX
+
+/* This is a special entry point that is entered if an I2C operation is
+   attempted to a wm8775 chip on model 24xxx hardware.  Autodetect of this
+   part doesn't work, but we know it is really there.  So let's look for
+   the autodetect attempt and just return success if we see that. */
+static int i2c_hack_wm8775(struct pvr2_hdw *hdw,
+			   u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
+{
+	if (!(rlen || wlen)) {
+		// This is a probe attempt.  Just let it succeed.
+		return 0;
+	}
+	return pvr2_i2c_basic_op(hdw,i2c_addr,wdata,wlen,rdata,rlen);
+}
+
+/* This is a special entry point that is entered if an I2C operation is
+   attempted to a cx25840 chip on model 24xxx hardware.  This chip can
+   sometimes wedge itself.  Worse still, when this happens msp3400 can
+   falsely detect this part and then the system gets hosed up after msp3400
+   gets confused and dies.  What we want to do here is try to keep msp3400
+   away and also try to notice if the chip is wedged and send a warning to
+   the system log. */
+static int i2c_hack_cx25840(struct pvr2_hdw *hdw,
+			    u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
+{
+	int ret;
+	unsigned int subaddr;
+	u8 wbuf[2];
+	int state = hdw->i2c_cx25840_hack_state;
+
+	if (!(rlen || wlen)) {
+		// Probe attempt - always just succeed and don't bother the
+		// hardware (this helps to make the state machine further
+		// down somewhat easier).
+		return 0;
+	}
+
+	if (state == 3) {
+		return pvr2_i2c_basic_op(hdw,i2c_addr,wdata,wlen,rdata,rlen);
+	}
+
+	/* We're looking for the exact pattern where the revision register
+	   is being read.  The cx25840 module will always look at the
+	   revision register first.  Any other pattern of access therefore
+	   has to be a probe attempt from somebody else so we'll reject it.
+	   Normally we could just let each client just probe the part
+	   anyway, but when the cx25840 is wedged, msp3400 will get a false
+	   positive and that just screws things up... */
+
+	if (wlen == 0) {
+		switch (state) {
+		case 1: subaddr = 0x0100; break;
+		case 2: subaddr = 0x0101; break;
+		default: goto fail;
+		}
+	} else if (wlen == 2) {
+		subaddr = (wdata[0] << 8) | wdata[1];
+		switch (subaddr) {
+		case 0x0100: state = 1; break;
+		case 0x0101: state = 2; break;
+		default: goto fail;
+		}
+	} else {
+		goto fail;
+	}
+	if (!rlen) goto success;
+	state = 0;
+	if (rlen != 1) goto fail;
+
+	/* If we get to here then we have a legitimate read for one of the
+	   two revision bytes, so pass it through. */
+	wbuf[0] = subaddr >> 8;
+	wbuf[1] = subaddr;
+	ret = pvr2_i2c_basic_op(hdw,i2c_addr,wbuf,2,rdata,rlen);
+
+	if ((ret != 0) || (*rdata == 0x04) || (*rdata == 0x0a)) {
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "WARNING: Detected a wedged cx25840 chip;"
+			   " the device will not work.");
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "WARNING: Try power cycling the pvrusb2 device.");
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
+			   "WARNING: Disabling further access to the device"
+			   " to prevent other foul-ups.");
+		// This blocks all further communication with the part.
+		hdw->i2c_func[0x44] = 0;
+		pvr2_hdw_render_useless(hdw);
+		goto fail;
+	}
+
+	/* Success! */
+	pvr2_trace(PVR2_TRACE_CHIPS,"cx25840 appears to be OK.");
+	state = 3;
+
+ success:
+	hdw->i2c_cx25840_hack_state = state;
+	return 0;
+
+ fail:
+	hdw->i2c_cx25840_hack_state = state;
+	return -EIO;
+}
+
+#endif /* CONFIG_VIDEO_PVRUSB2_24XXX */
+
+/* This is a very, very limited I2C adapter implementation.  We can only
+   support what we actually know will work on the device... */
+static int pvr2_i2c_xfer(struct i2c_adapter *i2c_adap,
+			 struct i2c_msg msgs[],
+			 int num)
+{
+	int ret = -ENOTSUPP;
+	pvr2_i2c_func funcp = 0;
+	struct pvr2_hdw *hdw = (struct pvr2_hdw *)(i2c_adap->algo_data);
+
+	if (!num) {
+		ret = -EINVAL;
+		goto done;
+	}
+	if ((msgs[0].flags & I2C_M_NOSTART)) {
+		trace_i2c("i2c refusing I2C_M_NOSTART");
+		goto done;
+	}
+	if (msgs[0].addr < PVR2_I2C_FUNC_CNT) {
+		funcp = hdw->i2c_func[msgs[0].addr];
+	}
+	if (!funcp) {
+		ret = -EIO;
+		goto done;
+	}
+
+	if (num == 1) {
+		if (msgs[0].flags & I2C_M_RD) {
+			/* Simple read */
+			u16 tcnt,bcnt,offs;
+			if (!msgs[0].len) {
+				/* Length == 0 read.  This is a probe. */
+				if (funcp(hdw,msgs[0].addr,0,0,0,0)) {
+					ret = -EIO;
+					goto done;
+				}
+				ret = 1;
+				goto done;
+			}
+			/* If the read is short enough we'll do the whole
+			   thing atomically.  Otherwise we have no choice
+			   but to break apart the reads. */
+			tcnt = msgs[0].len;
+			offs = 0;
+			while (tcnt) {
+				bcnt = tcnt;
+				if (bcnt > sizeof(hdw->cmd_buffer)-1) {
+					bcnt = sizeof(hdw->cmd_buffer)-1;
+				}
+				if (funcp(hdw,msgs[0].addr,0,0,
+					  msgs[0].buf+offs,bcnt)) {
+					ret = -EIO;
+					goto done;
+				}
+				offs += bcnt;
+				tcnt -= bcnt;
+			}
+			ret = 1;
+			goto done;
+		} else {
+			/* Simple write */
+			ret = 1;
+			if (funcp(hdw,msgs[0].addr,
+				  msgs[0].buf,msgs[0].len,0,0)) {
+				ret = -EIO;
+			}
+			goto done;
+		}
+	} else if (num == 2) {
+		if (msgs[0].addr != msgs[1].addr) {
+			trace_i2c("i2c refusing 2 phase transfer with"
+				  " conflicting target addresses");
+			ret = -ENOTSUPP;
+			goto done;
+		}
+		if ((!((msgs[0].flags & I2C_M_RD))) &&
+		    (msgs[1].flags & I2C_M_RD)) {
+			u16 tcnt,bcnt,wcnt,offs;
+			/* Write followed by atomic read.  If the read
+			   portion is short enough we'll do the whole thing
+			   atomically.  Otherwise we have no choice but to
+			   break apart the reads. */
+			tcnt = msgs[1].len;
+			wcnt = msgs[0].len;
+			offs = 0;
+			while (tcnt || wcnt) {
+				bcnt = tcnt;
+				if (bcnt > sizeof(hdw->cmd_buffer)-1) {
+					bcnt = sizeof(hdw->cmd_buffer)-1;
+				}
+				if (funcp(hdw,msgs[0].addr,
+					  msgs[0].buf,wcnt,
+					  msgs[1].buf+offs,bcnt)) {
+					ret = -EIO;
+					goto done;
+				}
+				offs += bcnt;
+				tcnt -= bcnt;
+				wcnt = 0;
+			}
+			ret = 2;
+			goto done;
+		} else {
+			trace_i2c("i2c refusing complex transfer"
+				  " read0=%d read1=%d",
+				  (msgs[0].flags & I2C_M_RD),
+				  (msgs[1].flags & I2C_M_RD));
+		}
+	} else {
+		trace_i2c("i2c refusing %d phase transfer",num);
+	}
+
+ done:
+	if (pvrusb2_debug & PVR2_TRACE_I2C_TRAF) {
+		unsigned int idx,offs,cnt;
+		for (idx = 0; idx < num; idx++) {
+			cnt = msgs[idx].len;
+			printk(KERN_INFO
+			       "pvrusb2 i2c xfer %u/%u:"
+			       " addr=0x%x len=%d %s%s",
+			       idx+1,num,
+			       msgs[idx].addr,
+			       cnt,
+			       (msgs[idx].flags & I2C_M_RD ?
+				"read" : "write"),
+			       (msgs[idx].flags & I2C_M_NOSTART ?
+				" nostart" : ""));
+			if ((ret > 0) || !(msgs[idx].flags & I2C_M_RD)) {
+				if (cnt > 8) cnt = 8;
+				printk(" [");
+				for (offs = 0; offs < (cnt>8?8:cnt); offs++) {
+					if (offs) printk(" ");
+					printk("%02x",msgs[idx].buf[offs]);
+				}
+				if (offs < cnt) printk(" ...");
+				printk("]");
+			}
+			if (idx+1 == num) {
+				printk(" result=%d",ret);
+			}
+			printk("\n");
+		}
+		if (!num) {
+			printk(KERN_INFO
+			       "pvrusb2 i2c xfer null transfer result=%d\n",
+			       ret);
+		}
+	}
+	return ret;
+}
+
+static int pvr2_i2c_control(struct i2c_adapter *adapter,
+			    unsigned int cmd, unsigned long arg)
+{
+	return 0;
+}
+
+static u32 pvr2_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA;
+}
+
+static int pvr2_i2c_core_singleton(struct i2c_client *cp,
+				   unsigned int cmd,void *arg)
+{
+	int stat;
+	if (!cp) return -EINVAL;
+	if (!(cp->driver)) return -EINVAL;
+	if (!(cp->driver->command)) return -EINVAL;
+	if (!try_module_get(cp->driver->driver.owner)) return -EAGAIN;
+	stat = cp->driver->command(cp,cmd,arg);
+	module_put(cp->driver->driver.owner);
+	return stat;
+}
+
+int pvr2_i2c_client_cmd(struct pvr2_i2c_client *cp,unsigned int cmd,void *arg)
+{
+	int stat;
+	if (pvrusb2_debug & PVR2_TRACE_I2C_CMD) {
+		char buf[100];
+		unsigned int cnt;
+		cnt = pvr2_i2c_client_describe(cp,PVR2_I2C_DETAIL_DEBUG,
+					       buf,sizeof(buf));
+		pvr2_trace(PVR2_TRACE_I2C_CMD,
+			   "i2c COMMAND (code=%u 0x%x) to %.*s",
+			   cmd,cmd,cnt,buf);
+	}
+	stat = pvr2_i2c_core_singleton(cp->client,cmd,arg);
+	if (pvrusb2_debug & PVR2_TRACE_I2C_CMD) {
+		char buf[100];
+		unsigned int cnt;
+		cnt = pvr2_i2c_client_describe(cp,PVR2_I2C_DETAIL_DEBUG,
+					       buf,sizeof(buf));
+		pvr2_trace(PVR2_TRACE_I2C_CMD,
+			   "i2c COMMAND to %.*s (ret=%d)",cnt,buf,stat);
+	}
+	return stat;
+}
+
+int pvr2_i2c_core_cmd(struct pvr2_hdw *hdw,unsigned int cmd,void *arg)
+{
+	struct list_head *item,*nc;
+	struct pvr2_i2c_client *cp;
+	int stat = -EINVAL;
+
+	if (!hdw) return stat;
+
+	mutex_lock(&hdw->i2c_list_lock);
+	list_for_each_safe(item,nc,&hdw->i2c_clients) {
+		cp = list_entry(item,struct pvr2_i2c_client,list);
+		if (!cp->recv_enable) continue;
+		mutex_unlock(&hdw->i2c_list_lock);
+		stat = pvr2_i2c_client_cmd(cp,cmd,arg);
+		mutex_lock(&hdw->i2c_list_lock);
+	}
+	mutex_unlock(&hdw->i2c_list_lock);
+	return stat;
+}
+
+
+static int handler_check(struct pvr2_i2c_client *cp)
+{
+	struct pvr2_i2c_handler *hp = cp->handler;
+	if (!hp) return 0;
+	if (!hp->func_table->check) return 0;
+	return hp->func_table->check(hp->func_data) != 0;
+}
+
+#define BUFSIZE 500
+
+void pvr2_i2c_core_sync(struct pvr2_hdw *hdw)
+{
+	unsigned long msk;
+	unsigned int idx;
+	struct list_head *item,*nc;
+	struct pvr2_i2c_client *cp;
+
+	if (!hdw->i2c_linked) return;
+	if (!(hdw->i2c_pend_types & PVR2_I2C_PEND_ALL)) {
+		return;
+	}
+	mutex_lock(&hdw->i2c_list_lock); do {
+		pvr2_trace(PVR2_TRACE_I2C_CORE,"i2c: core_sync BEGIN");
+		if (hdw->i2c_pend_types & PVR2_I2C_PEND_DETECT) {
+			/* One or more I2C clients have attached since we
+			   last synced.  So scan the list and identify the
+			   new clients. */
+			char *buf;
+			unsigned int cnt;
+			unsigned long amask = 0;
+			buf = kmalloc(BUFSIZE,GFP_KERNEL);
+			pvr2_trace(PVR2_TRACE_I2C_CORE,"i2c: PEND_DETECT");
+			hdw->i2c_pend_types &= ~PVR2_I2C_PEND_DETECT;
+			list_for_each(item,&hdw->i2c_clients) {
+				cp = list_entry(item,struct pvr2_i2c_client,
+						list);
+				if (!cp->detected_flag) {
+					cp->ctl_mask = 0;
+					pvr2_i2c_probe(hdw,cp);
+					cp->detected_flag = !0;
+					msk = cp->ctl_mask;
+					cnt = 0;
+					if (buf) {
+						cnt = pvr2_i2c_client_describe(
+							cp,
+							PVR2_I2C_DETAIL_ALL,
+							buf,BUFSIZE);
+					}
+					trace_i2c("Probed: %.*s",cnt,buf);
+					if (handler_check(cp)) {
+						hdw->i2c_pend_types |=
+							PVR2_I2C_PEND_CLIENT;
+					}
+					cp->pend_mask = msk;
+					hdw->i2c_pend_mask |= msk;
+					hdw->i2c_pend_types |=
+						PVR2_I2C_PEND_REFRESH;
+				}
+				amask |= cp->ctl_mask;
+			}
+			hdw->i2c_active_mask = amask;
+			if (buf) kfree(buf);
+		}
+		if (hdw->i2c_pend_types & PVR2_I2C_PEND_STALE) {
+			/* Need to do one or more global updates.  Arrange
+			   for this to happen. */
+			unsigned long m2;
+			pvr2_trace(PVR2_TRACE_I2C_CORE,
+				   "i2c: PEND_STALE (0x%lx)",
+				   hdw->i2c_stale_mask);
+			hdw->i2c_pend_types &= ~PVR2_I2C_PEND_STALE;
+			list_for_each(item,&hdw->i2c_clients) {
+				cp = list_entry(item,struct pvr2_i2c_client,
+						list);
+				m2 = hdw->i2c_stale_mask;
+				m2 &= cp->ctl_mask;
+				m2 &= ~cp->pend_mask;
+				if (m2) {
+					pvr2_trace(PVR2_TRACE_I2C_CORE,
+						   "i2c: cp=%p setting 0x%lx",
+						   cp,m2);
+					cp->pend_mask |= m2;
+				}
+			}
+			hdw->i2c_pend_mask |= hdw->i2c_stale_mask;
+			hdw->i2c_stale_mask = 0;
+			hdw->i2c_pend_types |= PVR2_I2C_PEND_REFRESH;
+		}
+		if (hdw->i2c_pend_types & PVR2_I2C_PEND_CLIENT) {
+			/* One or more client handlers are asking for an
+			   update.  Run through the list of known clients
+			   and update each one. */
+			pvr2_trace(PVR2_TRACE_I2C_CORE,"i2c: PEND_CLIENT");
+			hdw->i2c_pend_types &= ~PVR2_I2C_PEND_CLIENT;
+			list_for_each_safe(item,nc,&hdw->i2c_clients) {
+				cp = list_entry(item,struct pvr2_i2c_client,
+						list);
+				if (!cp->handler) continue;
+				if (!cp->handler->func_table->update) continue;
+				pvr2_trace(PVR2_TRACE_I2C_CORE,
+					   "i2c: cp=%p update",cp);
+				mutex_unlock(&hdw->i2c_list_lock);
+				cp->handler->func_table->update(
+					cp->handler->func_data);
+				mutex_lock(&hdw->i2c_list_lock);
+				/* If client's update function set some
+				   additional pending bits, account for that
+				   here. */
+				if (cp->pend_mask & ~hdw->i2c_pend_mask) {
+					hdw->i2c_pend_mask |= cp->pend_mask;
+					hdw->i2c_pend_types |=
+						PVR2_I2C_PEND_REFRESH;
+				}
+			}
+		}
+		if (hdw->i2c_pend_types & PVR2_I2C_PEND_REFRESH) {
+			const struct pvr2_i2c_op *opf;
+			unsigned long pm;
+			/* Some actual updates are pending.  Walk through
+			   each update type and perform it. */
+			pvr2_trace(PVR2_TRACE_I2C_CORE,"i2c: PEND_REFRESH"
+				   " (0x%lx)",hdw->i2c_pend_mask);
+			hdw->i2c_pend_types &= ~PVR2_I2C_PEND_REFRESH;
+			pm = hdw->i2c_pend_mask;
+			hdw->i2c_pend_mask = 0;
+			for (idx = 0, msk = 1; pm; idx++, msk <<= 1) {
+				if (!(pm & msk)) continue;
+				pm &= ~msk;
+				list_for_each(item,&hdw->i2c_clients) {
+					cp = list_entry(item,
+							struct pvr2_i2c_client,
+							list);
+					if (cp->pend_mask & msk) {
+						cp->pend_mask &= ~msk;
+						cp->recv_enable = !0;
+					} else {
+						cp->recv_enable = 0;
+					}
+				}
+				opf = pvr2_i2c_get_op(idx);
+				if (!opf) continue;
+				mutex_unlock(&hdw->i2c_list_lock);
+				opf->update(hdw);
+				mutex_lock(&hdw->i2c_list_lock);
+			}
+		}
+		pvr2_trace(PVR2_TRACE_I2C_CORE,"i2c: core_sync END");
+	} while (0); mutex_unlock(&hdw->i2c_list_lock);
+}
+
+int pvr2_i2c_core_check_stale(struct pvr2_hdw *hdw)
+{
+	unsigned long msk,sm,pm;
+	unsigned int idx;
+	const struct pvr2_i2c_op *opf;
+	struct list_head *item;
+	struct pvr2_i2c_client *cp;
+	unsigned int pt = 0;
+
+	pvr2_trace(PVR2_TRACE_I2C_CORE,"pvr2_i2c_core_check_stale BEGIN");
+
+	pm = hdw->i2c_active_mask;
+	sm = 0;
+	for (idx = 0, msk = 1; pm; idx++, msk <<= 1) {
+		if (!(msk & pm)) continue;
+		pm &= ~msk;
+		opf = pvr2_i2c_get_op(idx);
+		if (!opf) continue;
+		if (opf->check(hdw)) {
+			sm |= msk;
+		}
+	}
+	if (sm) pt |= PVR2_I2C_PEND_STALE;
+
+	list_for_each(item,&hdw->i2c_clients) {
+		cp = list_entry(item,struct pvr2_i2c_client,list);
+		if (!handler_check(cp)) continue;
+		pt |= PVR2_I2C_PEND_CLIENT;
+	}
+
+	if (pt) {
+		mutex_lock(&hdw->i2c_list_lock); do {
+			hdw->i2c_pend_types |= pt;
+			hdw->i2c_stale_mask |= sm;
+			hdw->i2c_pend_mask |= hdw->i2c_stale_mask;
+		} while (0); mutex_unlock(&hdw->i2c_list_lock);
+	}
+
+	pvr2_trace(PVR2_TRACE_I2C_CORE,
+		   "i2c: types=0x%x stale=0x%lx pend=0x%lx",
+		   hdw->i2c_pend_types,
+		   hdw->i2c_stale_mask,
+		   hdw->i2c_pend_mask);
+	pvr2_trace(PVR2_TRACE_I2C_CORE,"pvr2_i2c_core_check_stale END");
+
+	return (hdw->i2c_pend_types & PVR2_I2C_PEND_ALL) != 0;
+}
+
+unsigned int pvr2_i2c_client_describe(struct pvr2_i2c_client *cp,
+				      unsigned int detail,
+				      char *buf,unsigned int maxlen)
+{
+	unsigned int ccnt,bcnt;
+	int spcfl = 0;
+	const struct pvr2_i2c_op *opf;
+
+	ccnt = 0;
+	if (detail & PVR2_I2C_DETAIL_DEBUG) {
+		bcnt = scnprintf(buf,maxlen,
+				 "ctxt=%p ctl_mask=0x%lx",
+				 cp,cp->ctl_mask);
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		spcfl = !0;
+	}
+	bcnt = scnprintf(buf,maxlen,
+			 "%s%s @ 0x%x",
+			 (spcfl ? " " : ""),
+			 cp->client->name,
+			 cp->client->addr);
+	ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+	if ((detail & PVR2_I2C_DETAIL_HANDLER) &&
+	    cp->handler && cp->handler->func_table->describe) {
+		bcnt = scnprintf(buf,maxlen," (");
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		bcnt = cp->handler->func_table->describe(
+			cp->handler->func_data,buf,maxlen);
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		bcnt = scnprintf(buf,maxlen,")");
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+	}
+	if ((detail & PVR2_I2C_DETAIL_CTLMASK) && cp->ctl_mask) {
+		unsigned int idx;
+		unsigned long msk,sm;
+		int spcfl;
+		bcnt = scnprintf(buf,maxlen," [");
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		sm = 0;
+		spcfl = 0;
+		for (idx = 0, msk = 1; msk; idx++, msk <<= 1) {
+			if (!(cp->ctl_mask & msk)) continue;
+			opf = pvr2_i2c_get_op(idx);
+			if (opf) {
+				bcnt = scnprintf(buf,maxlen,"%s%s",
+						 spcfl ? " " : "",
+						 opf->name);
+				ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+				spcfl = !0;
+			} else {
+				sm |= msk;
+			}
+		}
+		if (sm) {
+			bcnt = scnprintf(buf,maxlen,"%s%lx",
+					 idx != 0 ? " " : "",sm);
+			ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		}
+		bcnt = scnprintf(buf,maxlen,"]");
+		ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+	}
+	return ccnt;
+}
+
+unsigned int pvr2_i2c_report(struct pvr2_hdw *hdw,
+			     char *buf,unsigned int maxlen)
+{
+	unsigned int ccnt,bcnt;
+	struct list_head *item;
+	struct pvr2_i2c_client *cp;
+	ccnt = 0;
+	mutex_lock(&hdw->i2c_list_lock); do {
+		list_for_each(item,&hdw->i2c_clients) {
+			cp = list_entry(item,struct pvr2_i2c_client,list);
+			bcnt = pvr2_i2c_client_describe(
+				cp,
+				(PVR2_I2C_DETAIL_HANDLER|
+				 PVR2_I2C_DETAIL_CTLMASK),
+				buf,maxlen);
+			ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+			bcnt = scnprintf(buf,maxlen,"\n");
+			ccnt += bcnt; buf += bcnt; maxlen -= bcnt;
+		}
+	} while (0); mutex_unlock(&hdw->i2c_list_lock);
+	return ccnt;
+}
+
+static int pvr2_i2c_attach_inform(struct i2c_client *client)
+{
+	struct pvr2_hdw *hdw = (struct pvr2_hdw *)(client->adapter->algo_data);
+	struct pvr2_i2c_client *cp;
+	int fl = !(hdw->i2c_pend_types & PVR2_I2C_PEND_ALL);
+	cp = kmalloc(sizeof(*cp),GFP_KERNEL);
+	trace_i2c("i2c_attach [client=%s @ 0x%x ctxt=%p]",
+		  client->name,
+		  client->addr,cp);
+	if (!cp) return -ENOMEM;
+	memset(cp,0,sizeof(*cp));
+	INIT_LIST_HEAD(&cp->list);
+	cp->client = client;
+	mutex_lock(&hdw->i2c_list_lock); do {
+		list_add_tail(&cp->list,&hdw->i2c_clients);
+		hdw->i2c_pend_types |= PVR2_I2C_PEND_DETECT;
+	} while (0); mutex_unlock(&hdw->i2c_list_lock);
+	if (fl) pvr2_hdw_poll_trigger_unlocked(hdw);
+	return 0;
+}
+
+static int pvr2_i2c_detach_inform(struct i2c_client *client)
+{
+	struct pvr2_hdw *hdw = (struct pvr2_hdw *)(client->adapter->algo_data);
+	struct pvr2_i2c_client *cp;
+	struct list_head *item,*nc;
+	unsigned long amask = 0;
+	int foundfl = 0;
+	mutex_lock(&hdw->i2c_list_lock); do {
+		list_for_each_safe(item,nc,&hdw->i2c_clients) {
+			cp = list_entry(item,struct pvr2_i2c_client,list);
+			if (cp->client == client) {
+				trace_i2c("pvr2_i2c_detach"
+					  " [client=%s @ 0x%x ctxt=%p]",
+					  client->name,
+					  client->addr,cp);
+				if (cp->handler &&
+				    cp->handler->func_table->detach) {
+					cp->handler->func_table->detach(
+						cp->handler->func_data);
+				}
+				list_del(&cp->list);
+				kfree(cp);
+				foundfl = !0;
+				continue;
+			}
+			amask |= cp->ctl_mask;
+		}
+		hdw->i2c_active_mask = amask;
+	} while (0); mutex_unlock(&hdw->i2c_list_lock);
+	if (!foundfl) {
+		trace_i2c("pvr2_i2c_detach [client=%s @ 0x%x ctxt=<unknown>]",
+			  client->name,
+			  client->addr);
+	}
+	return 0;
+}
+
+static struct i2c_algorithm pvr2_i2c_algo_template = {
+	.master_xfer   = pvr2_i2c_xfer,
+	.algo_control  = pvr2_i2c_control,
+	.functionality = pvr2_i2c_functionality,
+};
+
+static struct i2c_adapter pvr2_i2c_adap_template = {
+	.owner         = THIS_MODULE,
+	.class	   = I2C_CLASS_TV_ANALOG,
+	.id            = I2C_HW_B_BT848,
+	.client_register = pvr2_i2c_attach_inform,
+	.client_unregister = pvr2_i2c_detach_inform,
+};
+
+static void do_i2c_scan(struct pvr2_hdw *hdw)
+{
+	struct i2c_msg msg[1];
+	int i,rc;
+	msg[0].addr = 0;
+	msg[0].flags = I2C_M_RD;
+	msg[0].len = 0;
+	msg[0].buf = 0;
+	printk("%s: i2c scan beginning\n",hdw->name);
+	for (i = 0; i < 128; i++) {
+		msg[0].addr = i;
+		rc = i2c_transfer(&hdw->i2c_adap,msg,
+				  sizeof(msg)/sizeof(msg[0]));
+		if (rc != 1) continue;
+		printk("%s: i2c scan: found device @ 0x%x\n",hdw->name,i);
+	}
+	printk("%s: i2c scan done.\n",hdw->name);
+}
+
+void pvr2_i2c_core_init(struct pvr2_hdw *hdw)
+{
+	unsigned int idx;
+
+	// The default action for all possible I2C addresses is just to do
+	// the transfer normally.
+	for (idx = 0; idx < PVR2_I2C_FUNC_CNT; idx++) {
+		hdw->i2c_func[idx] = pvr2_i2c_basic_op;
+	}
+
+#ifdef CONFIG_VIDEO_PVRUSB2_24XXX
+	// If however we're dealing with new hardware, insert some hacks in
+	// the I2C transfer stack to let things work better.
+	if (hdw->hdw_type == PVR2_HDW_TYPE_24XXX) {
+		hdw->i2c_func[0x1b] = i2c_hack_wm8775;
+		hdw->i2c_func[0x44] = i2c_hack_cx25840;
+	}
+#endif
+
+	// Configure the adapter and set up everything else related to it.
+	memcpy(&hdw->i2c_adap,&pvr2_i2c_adap_template,sizeof(hdw->i2c_adap));
+	memcpy(&hdw->i2c_algo,&pvr2_i2c_algo_template,sizeof(hdw->i2c_algo));
+	strlcpy(hdw->i2c_adap.name,hdw->name,sizeof(hdw->i2c_adap.name));
+	hdw->i2c_adap.algo = &hdw->i2c_algo;
+	hdw->i2c_adap.algo_data = hdw;
+	hdw->i2c_pend_mask = 0;
+	hdw->i2c_stale_mask = 0;
+	hdw->i2c_active_mask = 0;
+	INIT_LIST_HEAD(&hdw->i2c_clients);
+	mutex_init(&hdw->i2c_list_lock);
+	hdw->i2c_linked = !0;
+	i2c_add_adapter(&hdw->i2c_adap);
+	if (i2c_scan) do_i2c_scan(hdw);
+}
+
+void pvr2_i2c_core_done(struct pvr2_hdw *hdw)
+{
+	if (hdw->i2c_linked) {
+		i2c_del_adapter(&hdw->i2c_adap);
+		hdw->i2c_linked = 0;
+	}
+}
+
+/*
+  Stuff for Emacs to see, in order to encourage consistent editing style:
+  *** Local Variables: ***
+  *** mode: c ***
+  *** fill-column: 75 ***
+  *** tab-width: 8 ***
+  *** c-basic-offset: 8 ***
+  *** End: ***
+  */