1 files changed, 77 insertions, 4 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c b/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c
index 3b9012f8e380..f9bb41d8f4f3 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-i2c-core.c
@@ -185,6 +185,79 @@ static int pvr2_i2c_basic_op(struct pvr2_hdw *hdw,
 	}
 }
 
+
+/* This is a special entry point for cases of I2C transaction attempts to
+   the IR receiver.  The implementation here simulates the IR receiver by
+   issuing a command to the FX2 firmware and using that response to return
+   what the real I2C receiver would have returned.  We use this for 24xxx
+   devices, where the IR receiver chip has been removed and replaced with
+   FX2 related logic. */
+static int i2c_24xxx_ir(struct pvr2_hdw *hdw,
+			u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
+{
+	u8 dat[4];
+	unsigned int stat;
+
+	if (!(rlen || wlen)) {
+		/* This is a probe attempt.  Just let it succeed. */
+		return 0;
+	}
+
+	/* We don't understand this kind of transaction */
+	if ((wlen != 0) || (rlen == 0)) return -EIO;
+
+	if (rlen < 3) {
+		/* Mike Isely <isely@pobox.com> Appears to be a probe
+		   attempt from lirc.  Just fill in zeroes and return.  If
+		   we try instead to do the full transaction here, then bad
+		   things seem to happen within the lirc driver module
+		   (version 0.8.0-7 sources from Debian, when run under
+		   vanilla 2.6.17.6 kernel) - and I don't have the patience
+		   to chase it down. */
+		if (rlen > 0) rdata[0] = 0;
+		if (rlen > 1) rdata[1] = 0;
+		return 0;
+	}
+
+	/* Issue a command to the FX2 to read the IR receiver. */
+	LOCK_TAKE(hdw->ctl_lock); do {
+		hdw->cmd_buffer[0] = 0xec;
+		stat = pvr2_send_request(hdw,
+					 hdw->cmd_buffer,1,
+					 hdw->cmd_buffer,4);
+		dat[0] = hdw->cmd_buffer[0];
+		dat[1] = hdw->cmd_buffer[1];
+		dat[2] = hdw->cmd_buffer[2];
+		dat[3] = hdw->cmd_buffer[3];
+	} while (0); LOCK_GIVE(hdw->ctl_lock);
+
+	/* Give up if that operation failed. */
+	if (stat != 0) return stat;
+
+	/* Mangle the results into something that looks like the real IR
+	   receiver. */
+	rdata[2] = 0xc1;
+	if (dat[0] != 1) {
+		/* No code received. */
+		rdata[0] = 0;
+		rdata[1] = 0;
+	} else {
+		u16 val;
+		/* Mash the FX2 firmware-provided IR code into something
+		   that the normal i2c chip-level driver expects. */
+		val = dat[1];
+		val <<= 8;
+		val |= dat[2];
+		val >>= 1;
+		val &= ~0x0003;
+		val |= 0x8000;
+		rdata[0] = (val >> 8) & 0xffu;
+		rdata[1] = val & 0xffu;
+	}
+
+	return 0;
+}
+
 /* 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
@@ -887,17 +960,17 @@ 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.
+	/* 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;
 	}
 
-	// If however we're dealing with new hardware, insert some hacks in
-	// the I2C transfer stack to let things work better.
+	/* However, deal with various special cases for 24xxx hardware. */
 	if (hdw->hdw_type == PVR2_HDW_TYPE_24XXX) {
 		hdw->i2c_func[0x1b] = i2c_hack_wm8775;
 		hdw->i2c_func[0x44] = i2c_hack_cx25840;
+		hdw->i2c_func[0x18] = i2c_24xxx_ir;
 	}
 
 	// Configure the adapter and set up everything else related to it.