V4L/DVB (9811): Add support for the CX24113 DVB-S tuner driver

This commit adds support for the CX24113 DVB-S tuner driver and thus support for the Technisat Skystar2 revision 2.8.
The driver was created with the help of Technisat. Thank you very much.
Signed-off-by: NPatrick Boettcher <pb@linuxtv.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/b2c2/Kconfig

@@ -14,6 +14,7 @@ config DVB_B2C2_FLEXCOP
 	select DVB_ISL6421 if !DVB_FE_CUSTOMISE
 	select DVB_CX24123 if !DVB_FE_CUSTOMISE
 	select MEDIA_TUNER_SIMPLE if !MEDIA_TUNER_CUSTOMIZE
+	select DVB_TUNER_CX24113 if !DVB_FE_CUSTOMISE
 	help
 	  Support for the digital TV receiver chip made by B2C2 Inc. included in
 	  Technisats PCI cards and USB boxes.

drivers/media/dvb/frontends/Kconfig

@@ -118,6 +118,14 @@ config DVB_TUNER_ITD1000
 	help
 	  A DVB-S tuner module. Say Y when you want to support this frontend.
 
+config DVB_TUNER_CX24113
+	tristate "Conexant CX24113/CX24128 tuner for DVB-S/DSS"
+	depends on DVB_CORE && I2C
+	default m if DVB_FE_CUSTOMISE
+	help
+	  A DVB-S tuner module. Say Y when you want to support this frontend.
+
+
 config DVB_TDA826X
 	tristate "Philips TDA826X silicon tuner"
 	depends on DVB_CORE && I2C

drivers/media/dvb/frontends/Makefile

@@ -54,6 +54,7 @@ obj-$(CONFIG_DVB_S5H1409) += s5h1409.o
 obj-$(CONFIG_DVB_TUNER_ITD1000) += itd1000.o
 obj-$(CONFIG_DVB_AU8522) += au8522.o
 obj-$(CONFIG_DVB_TDA10048) += tda10048.o
+obj-$(CONFIG_DVB_TUNER_CX24113) += cx24113.o
 obj-$(CONFIG_DVB_S5H1411) += s5h1411.o
 obj-$(CONFIG_DVB_LGS8GL5) += lgs8gl5.o
 obj-$(CONFIG_DVB_DUMMY_FE) += dvb_dummy_fe.o

drivers/media/dvb/frontends/cx24113.c

+/*
+ *  Driver for Conexant CX24113/CX24128 Tuner (Satelite)
+ *
+ *  Copyright (C) 2007-8 Patrick Boettcher <pb@linuxtv.org>
+ *
+ *  Developed for BBTI / Technisat
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include "dvb_frontend.h"
+#include "cx24113.h"
+
+static int debug;
+
+#define info(args...) do { printk(KERN_INFO "CX24113: " args); } while (0)
+#define err(args...)  do { printk(KERN_ERR  "CX24113: " args); } while (0)
+
+#define dprintk(args...) \
+	do { \
+		if (debug) { \
+			printk(KERN_DEBUG "CX24113: %s: ", __func__); \
+			printk(args); \
+		} \
+	} while (0)
+
+struct cx24113_state {
+	struct i2c_adapter *i2c;
+	const struct cx24113_config *config;
+
+#define REV_CX24113 0x23
+	u8 rev;
+	u8 ver;
+
+    u8 icp_mode:1;
+
+#define ICP_LEVEL1 0
+#define ICP_LEVEL2 1
+#define ICP_LEVEL3 2
+#define ICP_LEVEL4 3
+    u8 icp_man:2;
+    u8 icp_auto_low:2;
+    u8 icp_auto_mlow:2;
+    u8 icp_auto_mhi:2;
+    u8 icp_auto_hi:2;
+    u8 icp_dig;
+
+#define LNA_MIN_GAIN 0
+#define LNA_MID_GAIN 1
+#define LNA_MAX_GAIN 2
+    u8 lna_gain:2;
+
+    u8 acp_on:1;
+
+    u8 vco_mode:2;
+    u8 vco_shift:1;
+#define VCOBANDSEL_6 0x80
+#define VCOBANDSEL_5 0x01
+#define VCOBANDSEL_4 0x02
+#define VCOBANDSEL_3 0x04
+#define VCOBANDSEL_2 0x08
+#define VCOBANDSEL_1 0x10
+    u8 vco_band;
+
+#define VCODIV4 4
+#define VCODIV2 2
+	u8 vcodiv;
+
+    u8 bs_delay:4;
+    u16 bs_freqcnt:13;
+    u16 bs_rdiv;
+    u8 prescaler_mode:1;
+
+    u8 rfvga_bias_ctrl;
+
+	s16 tuner_gain_thres;
+	u8  gain_level;
+
+	u32 frequency;
+
+	u8 refdiv;
+
+	u8 Fwindow_enabled;
+};
+
+static int cx24113_writereg(struct cx24113_state *state, int reg, int data)
+{
+	u8 buf[] = { reg, data };
+	struct i2c_msg msg = { .addr = state->config->i2c_addr,
+		.flags = 0, .buf = buf, .len = 2 };
+	int err = i2c_transfer(state->i2c, &msg, 1);
+	if (err != 1) {
+		printk(KERN_DEBUG "%s: writereg error(err == %i, reg == 0x%02x,"
+			 " data == 0x%02x)\n", __func__, err, reg, data);
+		return err;
+	}
+
+	return 0;
+}
+
+static int cx24113_readreg(struct cx24113_state *state, u8 reg)
+{
+	int ret;
+	u8 b;
+	struct i2c_msg msg[] = {
+		{ .addr = state->config->i2c_addr,
+			.flags = 0, .buf = &reg, .len = 1 },
+		{ .addr = state->config->i2c_addr,
+			.flags = I2C_M_RD, .buf = &b, .len = 1 }
+	};
+
+	ret = i2c_transfer(state->i2c, msg, 2);
+
+	if (ret != 2) {
+		printk(KERN_DEBUG "%s: reg=0x%x (error=%d)\n",
+			__func__, reg, ret);
+		return ret;
+	}
+
+	return b;
+}
+
+static void cx24113_set_parameters(struct cx24113_state *state)
+{
+	u8 r;
+
+	r = cx24113_readreg(state, 0x10) & 0x82;
+	r |= state->icp_mode;
+	r |= state->icp_man << 4;
+	r |= state->icp_dig << 2;
+	r |= state->prescaler_mode << 5;
+	cx24113_writereg(state, 0x10, r);
+
+	r = (state->icp_auto_low  << 0) | (state->icp_auto_mlow << 2)
+		| (state->icp_auto_mhi << 4) | (state->icp_auto_hi << 6);
+	cx24113_writereg(state, 0x11, r);
+
+	if (state->rev == REV_CX24113) {
+		r = cx24113_readreg(state, 0x20) & 0xec;
+		r |= state->lna_gain;
+		r |= state->rfvga_bias_ctrl << 4;
+		cx24113_writereg(state, 0x20, r);
+	}
+
+	r = cx24113_readreg(state, 0x12) & 0x03;
+	r |= state->acp_on << 2;
+	r |= state->bs_delay << 4;
+	cx24113_writereg(state, 0x12, r);
+
+	r = cx24113_readreg(state, 0x18) & 0x40;
+	r |= state->vco_shift;
+	if (state->vco_band == VCOBANDSEL_6)
+		r |= (1 << 7);
+	else
+		r |= (state->vco_band << 1);
+	cx24113_writereg(state, 0x18, r);
+
+	r  = cx24113_readreg(state, 0x14) & 0x20;
+	r |= (state->vco_mode << 6) | ((state->bs_freqcnt >> 8) & 0x1f);
+	cx24113_writereg(state, 0x14, r);
+	cx24113_writereg(state, 0x15, (state->bs_freqcnt        & 0xff));
+
+	cx24113_writereg(state, 0x16, (state->bs_rdiv >> 4) & 0xff);
+	r = (cx24113_readreg(state, 0x17) & 0x0f) |
+		((state->bs_rdiv & 0x0f) << 4);
+	cx24113_writereg(state, 0x17, r);
+}
+
+#define VGA_0 0x00
+#define VGA_1 0x04
+#define VGA_2 0x02
+#define VGA_3 0x06
+#define VGA_4 0x01
+#define VGA_5 0x05
+#define VGA_6 0x03
+#define VGA_7 0x07
+
+#define RFVGA_0 0x00
+#define RFVGA_1 0x01
+#define RFVGA_2 0x02
+#define RFVGA_3 0x03
+
+static int cx24113_set_gain_settings(struct cx24113_state *state,
+		s16 power_estimation)
+{
+	u8 ampout = cx24113_readreg(state, 0x1d) & 0xf0,
+	   vga    = cx24113_readreg(state, 0x1f) & 0x3f,
+	   rfvga  = cx24113_readreg(state, 0x20) & 0xf3;
+	u8 gain_level = power_estimation >= state->tuner_gain_thres;
+
+	dprintk("power estimation: %d, thres: %d, gain_level: %d/%d\n",
+			power_estimation, state->tuner_gain_thres,
+			state->gain_level, gain_level);
+
+	if (gain_level == state->gain_level)
+		return 0; /* nothing to be done */
+
+	ampout |= 0xf;
+
+	if (gain_level) {
+		rfvga |= RFVGA_0 << 2;
+		vga   |= (VGA_7 << 3) | VGA_7;
+	} else {
+		rfvga |= RFVGA_2 << 2;
+		vga  |= (VGA_6 << 3) | VGA_2;
+	}
+	state->gain_level = gain_level;
+
+	cx24113_writereg(state, 0x1d, ampout);
+	cx24113_writereg(state, 0x1f, vga);
+	cx24113_writereg(state, 0x20, rfvga);
+
+	return 1; /* did something */
+}
+
+static int cx24113_set_Fref(struct cx24113_state *state, u8 high)
+{
+	u8 xtal = cx24113_readreg(state, 0x02);
+	if (state->rev == 0x43 && state->vcodiv == VCODIV4)
+		high = 1;
+
+	xtal &= ~0x2;
+	if (high)
+		xtal |= high << 1;
+	return cx24113_writereg(state, 0x02, xtal);
+}
+
+static int cx24113_enable(struct cx24113_state *state, u8 enable)
+{
+	u8 r21 = (cx24113_readreg(state, 0x21) & 0xc0) | enable;
+	if (state->rev == REV_CX24113)
+		r21 |= (1 << 1);
+	return cx24113_writereg(state, 0x21, r21);
+}
+
+static int cx24113_set_bandwidth(struct cx24113_state *state, u32 bandwidth_khz)
+{
+	u8 r;
+
+	if (bandwidth_khz <= 19000)
+		r = 0x03 << 6;
+	else if (bandwidth_khz <= 25000)
+		r = 0x02 << 6;
+	else
+		r = 0x01 << 6;
+
+	dprintk("bandwidth to be set: %d\n", bandwidth_khz);
+	bandwidth_khz *= 10;
+	bandwidth_khz -= 10000;
+	bandwidth_khz /= 1000;
+	bandwidth_khz += 5;
+	bandwidth_khz /= 10;
+
+	dprintk("bandwidth: %d %d\n", r >> 6, bandwidth_khz);
+
+	r |= bandwidth_khz & 0x3f;
+
+	return cx24113_writereg(state, 0x1e, r);
+}
+
+static int cx24113_set_clk_inversion(struct cx24113_state *state, u8 on)
+{
+	u8 r = (cx24113_readreg(state, 0x10) & 0x7f) | ((on & 0x1) << 7);
+	return cx24113_writereg(state, 0x10, r);
+}
+
+static int cx24113_get_status(struct dvb_frontend *fe, u32 *status)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	u8 r = (cx24113_readreg(state, 0x10) & 0x02) >> 1;
+	if (r)
+		*status |= TUNER_STATUS_LOCKED;
+	dprintk("PLL locked: %d\n", r);
+	return 0;
+}
+
+static u8 cx24113_set_ref_div(struct cx24113_state *state, u8 refdiv)
+{
+	if (state->rev == 0x43 && state->vcodiv == VCODIV4)
+		refdiv = 2;
+	return state->refdiv = refdiv;
+}
+
+static void cx24113_calc_pll_nf(struct cx24113_state *state, u16 *n, s32 *f)
+{
+	s32 N;
+	s64 F;
+	u8 R, r;
+	u8 vcodiv;
+	u8 factor;
+	s32 freq_hz = state->frequency * 1000;
+
+	if (state->config->xtal_khz < 20000)
+		factor = 1;
+	else
+		factor = 2;
+
+	if (state->rev == REV_CX24113) {
+		if (state->frequency >= 1100000)
+			vcodiv = VCODIV2;
+		else
+			vcodiv = VCODIV4;
+	} else {
+		if (state->frequency >= 1165000)
+			vcodiv = VCODIV2;
+		else
+			vcodiv = VCODIV4;
+	}
+	state->vcodiv = vcodiv;
+
+	dprintk("calculating N/F for %dHz with vcodiv %d\n", freq_hz, vcodiv);
+	R = 0;
+	do {
+		R = cx24113_set_ref_div(state, R + 1);
+
+		/* calculate tuner PLL settings: */
+		N =  (freq_hz / 100 * vcodiv) * R;
+		N /= (state->config->xtal_khz) * factor * 2;
+		N += 5;     /* For round up. */
+		N /= 10;
+		N -= 32;
+	} while (N < 6 && R < 3);
+
+	if (N < 6) {
+		err("strange frequency: N < 6\n");
+		return;
+	}
+	F = freq_hz;
+	F *= (u64) (R * vcodiv * 262144);
+    dprintk("1 N: %d, F: %lld, R: %d\n", N, F, R);
+	do_div(F, state->config->xtal_khz*1000 * factor * 2);
+    dprintk("2 N: %d, F: %lld, R: %d\n", N, F, R);
+	F -= (N + 32) * 262144;
+
+    dprintk("3 N: %d, F: %lld, R: %d\n", N, F, R);
+
+	if (state->Fwindow_enabled) {
+		if (F > (262144 / 2 - 1638))
+			F = 262144 / 2 - 1638;
+		if (F < (-262144 / 2 + 1638))
+			F = -262144 / 2 + 1638;
+		if ((F < 3277 && F > 0) || (F > -3277 && F < 0)) {
+			F = 0;
+			r = cx24113_readreg(state, 0x10);
+			cx24113_writereg(state, 0x10, r | (1 << 6));
+		}
+	}
+	dprintk("4 N: %d, F: %lld, R: %d\n", N, F, R);
+
+	*n = (u16) N;
+	*f = (s32) F;
+}
+
+
+static void cx24113_set_nfr(struct cx24113_state *state, u16 n, s32 f, u8 r)
+{
+	u8 reg;
+	cx24113_writereg(state, 0x19, (n >> 1) & 0xff);
+
+	reg = ((n & 0x1) << 7) | ((f >> 11) & 0x7f);
+	cx24113_writereg(state, 0x1a, reg);
+
+	cx24113_writereg(state, 0x1b, (f >> 3) & 0xff);
+
+	reg = cx24113_readreg(state, 0x1c) & 0x1f;
+	cx24113_writereg(state, 0x1c, reg | ((f & 0x7) << 5));
+
+	cx24113_set_Fref(state, r - 1);
+}
+
+static int cx24113_set_frequency(struct cx24113_state *state, u32 frequency)
+{
+	u8 r = 1; /* or 2 */
+	u16 n = 6;
+	s32 f = 0;
+
+    r = cx24113_readreg(state, 0x14);
+	cx24113_writereg(state, 0x14, r & 0x3f);
+
+    r = cx24113_readreg(state, 0x10);
+    cx24113_writereg(state, 0x10, r & 0xbf);
+
+	state->frequency = frequency;
+
+	dprintk("tuning to frequency: %d\n", frequency);
+
+    cx24113_calc_pll_nf(state, &n, &f);
+    cx24113_set_nfr(state, n, f, state->refdiv);
+
+	r = cx24113_readreg(state, 0x18) & 0xbf;
+    if (state->vcodiv != VCODIV2)
+		r |= 1 << 6;
+	cx24113_writereg(state, 0x18, r);
+
+	/* The need for this sleep is not clear. But helps in some cases */
+	msleep(5);
+
+	r = cx24113_readreg(state, 0x1c) & 0xef;
+	cx24113_writereg(state, 0x1c, r | (1 << 4));
+	return 0;
+}
+
+static int cx24113_init(struct dvb_frontend *fe)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	int ret;
+
+	state->tuner_gain_thres = -50;
+	state->gain_level = 255; /* to force a gain-setting initialization */
+	state->icp_mode = 0;
+
+	if (state->config->xtal_khz < 11000) {
+		state->icp_auto_hi  = ICP_LEVEL4;
+		state->icp_auto_mhi  = ICP_LEVEL4;
+		state->icp_auto_mlow = ICP_LEVEL3;
+		state->icp_auto_low = ICP_LEVEL3;
+	} else {
+		state->icp_auto_hi  = ICP_LEVEL4;
+		state->icp_auto_mhi  = ICP_LEVEL4;
+		state->icp_auto_mlow = ICP_LEVEL3;
+		state->icp_auto_low = ICP_LEVEL2;
+	}
+
+	state->icp_dig = ICP_LEVEL3;
+	state->icp_man = ICP_LEVEL1;
+	state->acp_on  = 1;
+	state->vco_mode = 0;
+	state->vco_shift = 0;
+	state->vco_band = VCOBANDSEL_1;
+	state->bs_delay = 8;
+	state->bs_freqcnt = 0x0fff;
+	state->bs_rdiv = 0x0fff;
+	state->prescaler_mode = 0;
+	state->lna_gain = LNA_MAX_GAIN;
+	state->rfvga_bias_ctrl = 1;
+	state->Fwindow_enabled = 1;
+
+	cx24113_set_Fref(state, 0);
+	cx24113_enable(state, 0x3d);
+	cx24113_set_parameters(state);
+
+	cx24113_set_gain_settings(state, -30);
+
+	cx24113_set_bandwidth(state, 18025);
+	cx24113_set_clk_inversion(state, 1);
+
+	if (state->config->xtal_khz >= 40000)
+		ret = cx24113_writereg(state, 0x02,
+			(cx24113_readreg(state, 0x02) & 0xfb) | (1 << 2));
+	else
+		ret = cx24113_writereg(state, 0x02,
+			(cx24113_readreg(state, 0x02) & 0xfb) | (0 << 2));
+
+	return ret;
+}
+
+static int cx24113_set_params(struct dvb_frontend *fe,
+		struct dvb_frontend_parameters *p)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	/* for a ROLL-OFF factor of 0.35, 0.2: 600, 0.25: 625 */
+	u32 roll_off = 675;
+	u32 bw;
+
+	bw  = ((p->u.qpsk.symbol_rate/100) * roll_off) / 1000;
+	bw += (10000000/100) + 5;
+	bw /= 10;
+	bw += 1000;
+	cx24113_set_bandwidth(state, bw);
+
+	cx24113_set_frequency(state, p->frequency);
+	msleep(5);
+	return cx24113_get_status(fe, &bw);
+}
+
+static s8 cx24113_agc_table[2][10] = {
+	{-54, -41, -35, -30, -25, -21, -16, -10,  -6,  -2},
+	{-39, -35, -30, -25, -19, -15, -11,  -5,   1,   9},
+};
+
+void cx24113_agc_callback(struct dvb_frontend *fe)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	s16 s, i;
+	if (!fe->ops.read_signal_strength)
+		return;
+
+	do {
+		/* this only works with the current CX24123 implementation */
+		fe->ops.read_signal_strength(fe, (u16 *) &s);
+		s >>= 8;
+		dprintk("signal strength: %d\n", s);
+		for (i = 0; i < sizeof(cx24113_agc_table[0]); i++)
+			if (cx24113_agc_table[state->gain_level][i] > s)
+				break;
+		s = -25 - i*5;
+	} while (cx24113_set_gain_settings(state, s));
+}
+EXPORT_SYMBOL(cx24113_agc_callback);
+
+static int cx24113_get_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	*frequency = state->frequency;
+	return 0;
+}
+
+static int cx24113_release(struct dvb_frontend *fe)
+{
+	struct cx24113_state *state = fe->tuner_priv;
+	dprintk("\n");
+    fe->tuner_priv = NULL;
+	kfree(state);
+	return 0;
+}
+
+static const struct dvb_tuner_ops cx24113_tuner_ops = {
+	.info = {
+		.name           = "Conexant CX24113",
+		.frequency_min  = 950000,
+		.frequency_max  = 2150000,
+		.frequency_step = 125,
+	},
+
+	.release       = cx24113_release,
+
+	.init          = cx24113_init,
+	.sleep         = NULL,
+
+	.set_params    = cx24113_set_params,
+	.get_frequency = cx24113_get_frequency,
+	.get_bandwidth = NULL,
+	.get_status    = cx24113_get_status,
+};
+
+struct dvb_frontend *cx24113_attach(struct dvb_frontend *fe,
+		const struct cx24113_config *config, struct i2c_adapter *i2c)
+{
+	/* allocate memory for the internal state */
+	struct cx24113_state *state =
+		kzalloc(sizeof(struct cx24113_state), GFP_KERNEL);
+	if (state == NULL) {
+		err("Unable to kmalloc\n");
+		goto error;
+	}
+
+	/* setup the state */
+	state->config = config;
+	state->i2c = i2c;
+
+	info("trying to detect myself\n");
+
+	/* making a dummy read, because of some expected troubles
+	 * after power on */
+	cx24113_readreg(state, 0x00);
+
+	switch (state->rev = cx24113_readreg(state, 0x00)) {
+	case 0x43:
+		info("unknown device\n");
+		break;
+	case REV_CX24113:
+		info("CX24113\n");
+		break;
+	default:
+		err("unsupported revision: %x\n", state->rev);
+		goto error;
+	}
+	state->ver = cx24113_readreg(state, 0x01);
+	info("version: %x\n", state->ver);
+
+	/* create dvb_frontend */
+	memcpy(&fe->ops.tuner_ops, &cx24113_tuner_ops,
+			sizeof(struct dvb_tuner_ops));
+	fe->tuner_priv = state;
+	return fe;
+
+error:
+	kfree(state);
+
+	return NULL;
+}
+EXPORT_SYMBOL(cx24113_attach);
+
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Activates frontend debugging (default:0)");
+
+MODULE_AUTHOR("Patrick Boettcher <pb@linuxtv.org>");
+MODULE_DESCRIPTION("DVB Frontend module for Conexant CX24113/CX24128hardware");
+MODULE_LICENSE("GPL");
+

drivers/media/dvb/frontends/cx24113.h

@@ -16,7 +16,7 @@
  *
  *  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., 675 Mass Ave, Cambridge, MA 02139, USA.=
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #ifndef CX24113_H
@@ -30,9 +30,13 @@ struct cx24113_config {
 	u32 xtal_khz;
 };
 
-/* TODO: #if defined(CONFIG_DVB_TUNER_CX24113) || \
- * (defined(CONFIG_DVB_TUNER_CX24113_MODULE) && defined(MODULE)) */
+#if defined(CONFIG_DVB_TUNER_CX24113) || \
+	(defined(CONFIG_DVB_TUNER_CX24113_MODULE) && defined(MODULE))
+extern struct dvb_frontend *cx24113_attach(struct dvb_frontend *,
+	const struct cx24113_config *config, struct i2c_adapter *i2c);
 
+extern void cx24113_agc_callback(struct dvb_frontend *fe);
+#else
 static inline struct dvb_frontend *cx24113_attach(struct dvb_frontend *fe,
 	const struct cx24113_config *config, struct i2c_adapter *i2c)
 {
@@ -44,5 +48,6 @@ static inline void cx24113_agc_callback(struct dvb_frontend *fe)
 {
 	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
 }
+#endif
 
 #endif /* CX24113_H */