diff -r 9d9bc92d7c33 drivers/media/dvb/frontends/isl6421.c
--- a/drivers/media/dvb/frontends/isl6421.c	Sat Sep 19 12:48:44 2009 +0200
+++ b/drivers/media/dvb/frontends/isl6421.c	Tue Nov 03 23:23:05 2009 +0100
@@ -3,6 +3,9 @@
  *
  * Copyright (C) 2006 Andrew de Quincey
  * Copyright (C) 2006 Oliver Endriss
+ * Copyright (C) 2009 Ales Jurik and Jan Petrous (added optional 22k tone
+ *                    support and temporary diseqc overcurrent enable until
+ *                    next command - set voltage or tone)
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -35,12 +38,23 @@
 #include "dvb_frontend.h"
 #include "isl6421.h"
 
+static int tone_control;
+module_param(tone_control, int, S_IRUGO);
+MODULE_PARM_DESC(tone_control, "Set ISL6421 to control 22kHz tone");
+
+static int overcurrent_enable;
+module_param(overcurrent_enable, int, S_IRUGO);
+MODULE_PARM_DESC(overcurrent_enable, "Set ISL6421 to temporary enable "
+		"overcurrent when diseqc command is active");
+
 struct isl6421 {
 	u8			config;
 	u8			override_or;
 	u8			override_and;
 	struct i2c_adapter	*i2c;
 	u8			i2c_addr;
+	int (*diseqc_send_master_cmd_orig)(struct dvb_frontend *fe,
+			struct dvb_diseqc_master_cmd *cmd);
 };
 
 static int isl6421_set_voltage(struct dvb_frontend *fe, fe_sec_voltage_t voltage)
@@ -60,6 +74,55 @@ static int isl6421_set_voltage(struct dv
 		break;
 	case SEC_VOLTAGE_18:
 		isl6421->config |= (ISL6421_EN1 | ISL6421_VSEL1);
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	isl6421->config |= isl6421->override_or;
+	isl6421->config &= isl6421->override_and;
+
+	return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
+}
+
+static int isl6421_send_diseqc(struct dvb_frontend *fe,
+				struct dvb_diseqc_master_cmd *cmd)
+{
+	struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
+	struct i2c_msg msg = {	.addr = isl6421->i2c_addr, .flags = 0,
+				.buf = &isl6421->config,
+				.len = sizeof(isl6421->config) };
+
+	isl6421->config |= ISL6421_DCL;
+
+	isl6421->config |= isl6421->override_or;
+	isl6421->config &= isl6421->override_and;
+
+	if (i2c_transfer(isl6421->i2c, &msg, 1) != 1)
+		return -EIO;
+
+	isl6421->config &= ~ISL6421_DCL;
+
+	return isl6421->diseqc_send_master_cmd_orig(fe, cmd);
+}
+
+static int isl6421_set_tone(struct dvb_frontend *fe, fe_sec_tone_mode_t tone)
+{
+	struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
+	struct i2c_msg msg = {	.addr = isl6421->i2c_addr, .flags = 0,
+				.buf = &isl6421->config,
+				.len = sizeof(isl6421->config) };
+
+	isl6421->config &= ~(ISL6421_ENT1);
+
+	printk(KERN_INFO "%s: %s\n", __func__, ((tone == SEC_TONE_OFF) ?
+				"Off" : "On"));
+
+	switch (tone) {
+	case SEC_TONE_ON:
+		isl6421->config |= ISL6421_ENT1;
+		break;
+	case SEC_TONE_OFF:
 		break;
 	default:
 		return -EINVAL;
@@ -91,18 +154,26 @@ static int isl6421_enable_high_lnb_volta
 
 static void isl6421_release(struct dvb_frontend *fe)
 {
+	struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
+
 	/* power off */
 	isl6421_set_voltage(fe, SEC_VOLTAGE_OFF);
+
+	if (overcurrent_enable)
+		fe->ops.diseqc_send_master_cmd =
+			isl6421->diseqc_send_master_cmd_orig;
 
 	/* free */
 	kfree(fe->sec_priv);
 	fe->sec_priv = NULL;
 }
 
-struct dvb_frontend *isl6421_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, u8 i2c_addr,
-		   u8 override_set, u8 override_clear)
+struct dvb_frontend *isl6421_attach(struct dvb_frontend *fe,
+		struct i2c_adapter *i2c, u8 i2c_addr, u8 override_set,
+		u8 override_clear)
 {
 	struct isl6421 *isl6421 = kmalloc(sizeof(struct isl6421), GFP_KERNEL);
+
 	if (!isl6421)
 		return NULL;
 
@@ -131,6 +202,33 @@ struct dvb_frontend *isl6421_attach(stru
 	/* override frontend ops */
 	fe->ops.set_voltage = isl6421_set_voltage;
 	fe->ops.enable_high_lnb_voltage = isl6421_enable_high_lnb_voltage;
+	if (tone_control)
+		fe->ops.set_tone = isl6421_set_tone;
+
+	printk(KERN_INFO "ISL6421 attached on addr=%x\n", i2c_addr);
+
+	if (overcurrent_enable) {
+		if ((override_set & ISL6421_DCL) ||
+				(override_clear & ISL6421_DCL)) {
+			/* there is no sense to use overcurrent_enable
+			 * with DCL bit set in any override byte */
+			if (override_set & ISL6421_DCL)
+				printk(KERN_WARNING "ISL6421 overcurrent_enable"
+						" with DCL bit in override_set,"
+						" overcurrent_enable ignored\n");
+			if (override_clear & ISL6421_DCL)
+				printk(KERN_WARNING "ISL6421 overcurrent_enable"
+						" with DCL bit in override_clear,"
+						" overcurrent_enable ignored\n");
+		} else {
+			printk(KERN_WARNING "ISL6421 overcurrent_enable "
+					" activated. WARNING: it can be "
+					" dangerous for your hardware!");
+			isl6421->diseqc_send_master_cmd_orig =
+				fe->ops.diseqc_send_master_cmd;
+			fe->ops.diseqc_send_master_cmd = isl6421_send_diseqc;
+		}
+	}
 
 	return fe;
 }