V4L/DVB(7767): Move tuners to common/tuners

There were several issues in the past, caused by the hybrid tuner design, since
now, the same tuner can be used by drivers/media/dvb and drivers/media/video.

Kconfig items were rearranged, to split V4L/DVB core from their drivers.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 670 insertions, 0 deletions

diff --git a/drivers/media/common/tuners/mt20xx.c b/drivers/media/common/tuners/mt20xx.c
new file mode 100644
index 00000000000..fbcb2823373
--- /dev/null
+++ b/drivers/media/common/tuners/mt20xx.c
@@ -0,0 +1,670 @@
+/*
+ * i2c tv tuner chip device driver
+ * controls microtune tuners, mt2032 + mt2050 at the moment.
+ *
+ * This "mt20xx" module was split apart from the original "tuner" module.
+ */
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/videodev.h>
+#include "tuner-i2c.h"
+#include "mt20xx.h"
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "enable verbose debug messages");
+
+/* ---------------------------------------------------------------------- */
+
+static unsigned int optimize_vco  = 1;
+module_param(optimize_vco,      int, 0644);
+
+static unsigned int tv_antenna    = 1;
+module_param(tv_antenna,        int, 0644);
+
+static unsigned int radio_antenna;
+module_param(radio_antenna,     int, 0644);
+
+/* ---------------------------------------------------------------------- */
+
+#define MT2032 0x04
+#define MT2030 0x06
+#define MT2040 0x07
+#define MT2050 0x42
+
+static char *microtune_part[] = {
+	[ MT2030 ] = "MT2030",
+	[ MT2032 ] = "MT2032",
+	[ MT2040 ] = "MT2040",
+	[ MT2050 ] = "MT2050",
+};
+
+struct microtune_priv {
+	struct tuner_i2c_props i2c_props;
+
+	unsigned int xogc;
+	//unsigned int radio_if2;
+
+	u32 frequency;
+};
+
+static int microtune_release(struct dvb_frontend *fe)
+{
+	kfree(fe->tuner_priv);
+	fe->tuner_priv = NULL;
+
+	return 0;
+}
+
+static int microtune_get_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	*frequency = priv->frequency;
+	return 0;
+}
+
+// IsSpurInBand()?
+static int mt2032_spurcheck(struct dvb_frontend *fe,
+			    int f1, int f2, int spectrum_from,int spectrum_to)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int n1=1,n2,f;
+
+	f1=f1/1000; //scale to kHz to avoid 32bit overflows
+	f2=f2/1000;
+	spectrum_from/=1000;
+	spectrum_to/=1000;
+
+	tuner_dbg("spurcheck f1=%d f2=%d  from=%d to=%d\n",
+		  f1,f2,spectrum_from,spectrum_to);
+
+	do {
+	    n2=-n1;
+	    f=n1*(f1-f2);
+	    do {
+		n2--;
+		f=f-f2;
+		tuner_dbg("spurtest n1=%d n2=%d ftest=%d\n",n1,n2,f);
+
+		if( (f>spectrum_from) && (f<spectrum_to))
+			tuner_dbg("mt2032 spurcheck triggered: %d\n",n1);
+	    } while ( (f>(f2-spectrum_to)) || (n2>-5));
+	    n1++;
+	} while (n1<5);
+
+	return 1;
+}
+
+static int mt2032_compute_freq(struct dvb_frontend *fe,
+			       unsigned int rfin,
+			       unsigned int if1, unsigned int if2,
+			       unsigned int spectrum_from,
+			       unsigned int spectrum_to,
+			       unsigned char *buf,
+			       int *ret_sel,
+			       unsigned int xogc) //all in Hz
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned int fref,lo1,lo1n,lo1a,s,sel,lo1freq, desired_lo1,
+		desired_lo2,lo2,lo2n,lo2a,lo2num,lo2freq;
+
+	fref= 5250 *1000; //5.25MHz
+	desired_lo1=rfin+if1;
+
+	lo1=(2*(desired_lo1/1000)+(fref/1000)) / (2*fref/1000);
+	lo1n=lo1/8;
+	lo1a=lo1-(lo1n*8);
+
+	s=rfin/1000/1000+1090;
+
+	if(optimize_vco) {
+		if(s>1890) sel=0;
+		else if(s>1720) sel=1;
+		else if(s>1530) sel=2;
+		else if(s>1370) sel=3;
+		else sel=4; // >1090
+	}
+	else {
+		if(s>1790) sel=0; // <1958
+		else if(s>1617) sel=1;
+		else if(s>1449) sel=2;
+		else if(s>1291) sel=3;
+		else sel=4; // >1090
+	}
+	*ret_sel=sel;
+
+	lo1freq=(lo1a+8*lo1n)*fref;
+
+	tuner_dbg("mt2032: rfin=%d lo1=%d lo1n=%d lo1a=%d sel=%d, lo1freq=%d\n",
+		  rfin,lo1,lo1n,lo1a,sel,lo1freq);
+
+	desired_lo2=lo1freq-rfin-if2;
+	lo2=(desired_lo2)/fref;
+	lo2n=lo2/8;
+	lo2a=lo2-(lo2n*8);
+	lo2num=((desired_lo2/1000)%(fref/1000))* 3780/(fref/1000); //scale to fit in 32bit arith
+	lo2freq=(lo2a+8*lo2n)*fref + lo2num*(fref/1000)/3780*1000;
+
+	tuner_dbg("mt2032: rfin=%d lo2=%d lo2n=%d lo2a=%d num=%d lo2freq=%d\n",
+		  rfin,lo2,lo2n,lo2a,lo2num,lo2freq);
+
+	if(lo1a<0 || lo1a>7 || lo1n<17 ||lo1n>48 || lo2a<0 ||lo2a >7 ||lo2n<17 || lo2n>30) {
+		tuner_info("mt2032: frequency parameters out of range: %d %d %d %d\n",
+			   lo1a, lo1n, lo2a,lo2n);
+		return(-1);
+	}
+
+	mt2032_spurcheck(fe, lo1freq, desired_lo2,  spectrum_from, spectrum_to);
+	// should recalculate lo1 (one step up/down)
+
+	// set up MT2032 register map for transfer over i2c
+	buf[0]=lo1n-1;
+	buf[1]=lo1a | (sel<<4);
+	buf[2]=0x86; // LOGC
+	buf[3]=0x0f; //reserved
+	buf[4]=0x1f;
+	buf[5]=(lo2n-1) | (lo2a<<5);
+	if(rfin >400*1000*1000)
+		buf[6]=0xe4;
+	else
+		buf[6]=0xf4; // set PKEN per rev 1.2
+	buf[7]=8+xogc;
+	buf[8]=0xc3; //reserved
+	buf[9]=0x4e; //reserved
+	buf[10]=0xec; //reserved
+	buf[11]=(lo2num&0xff);
+	buf[12]=(lo2num>>8) |0x80; // Lo2RST
+
+	return 0;
+}
+
+static int mt2032_check_lo_lock(struct dvb_frontend *fe)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int try,lock=0;
+	unsigned char buf[2];
+
+	for(try=0;try<10;try++) {
+		buf[0]=0x0e;
+		tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+		tuner_i2c_xfer_recv(&priv->i2c_props,buf,1);
+		tuner_dbg("mt2032 Reg.E=0x%02x\n",buf[0]);
+		lock=buf[0] &0x06;
+
+		if (lock==6)
+			break;
+
+		tuner_dbg("mt2032: pll wait 1ms for lock (0x%2x)\n",buf[0]);
+		udelay(1000);
+	}
+	return lock;
+}
+
+static int mt2032_optimize_vco(struct dvb_frontend *fe,int sel,int lock)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned char buf[2];
+	int tad1;
+
+	buf[0]=0x0f;
+	tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+	tuner_i2c_xfer_recv(&priv->i2c_props,buf,1);
+	tuner_dbg("mt2032 Reg.F=0x%02x\n",buf[0]);
+	tad1=buf[0]&0x07;
+
+	if(tad1 ==0) return lock;
+	if(tad1 ==1) return lock;
+
+	if(tad1==2) {
+		if(sel==0)
+			return lock;
+		else sel--;
+	}
+	else {
+		if(sel<4)
+			sel++;
+		else
+			return lock;
+	}
+
+	tuner_dbg("mt2032 optimize_vco: sel=%d\n",sel);
+
+	buf[0]=0x0f;
+	buf[1]=sel;
+	tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+	lock=mt2032_check_lo_lock(fe);
+	return lock;
+}
+
+
+static void mt2032_set_if_freq(struct dvb_frontend *fe, unsigned int rfin,
+			       unsigned int if1, unsigned int if2,
+			       unsigned int from, unsigned int to)
+{
+	unsigned char buf[21];
+	int lint_try,ret,sel,lock=0;
+	struct microtune_priv *priv = fe->tuner_priv;
+
+	tuner_dbg("mt2032_set_if_freq rfin=%d if1=%d if2=%d from=%d to=%d\n",
+		  rfin,if1,if2,from,to);
+
+	buf[0]=0;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+	tuner_i2c_xfer_recv(&priv->i2c_props,buf,21);
+
+	buf[0]=0;
+	ret=mt2032_compute_freq(fe,rfin,if1,if2,from,to,&buf[1],&sel,priv->xogc);
+	if (ret<0)
+		return;
+
+	// send only the relevant registers per Rev. 1.2
+	buf[0]=0;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,4);
+	buf[5]=5;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf+5,4);
+	buf[11]=11;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf+11,3);
+	if(ret!=3)
+		tuner_warn("i2c i/o error: rc == %d (should be 3)\n",ret);
+
+	// wait for PLLs to lock (per manual), retry LINT if not.
+	for(lint_try=0; lint_try<2; lint_try++) {
+		lock=mt2032_check_lo_lock(fe);
+
+		if(optimize_vco)
+			lock=mt2032_optimize_vco(fe,sel,lock);
+		if(lock==6) break;
+
+		tuner_dbg("mt2032: re-init PLLs by LINT\n");
+		buf[0]=7;
+		buf[1]=0x80 +8+priv->xogc; // set LINT to re-init PLLs
+		tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+		mdelay(10);
+		buf[1]=8+priv->xogc;
+		tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+	}
+
+	if (lock!=6)
+		tuner_warn("MT2032 Fatal Error: PLLs didn't lock.\n");
+
+	buf[0]=2;
+	buf[1]=0x20; // LOGC for optimal phase noise
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+	if (ret!=2)
+		tuner_warn("i2c i/o error: rc == %d (should be 2)\n",ret);
+}
+
+
+static int mt2032_set_tv_freq(struct dvb_frontend *fe,
+			      struct analog_parameters *params)
+{
+	int if2,from,to;
+
+	// signal bandwidth and picture carrier
+	if (params->std & V4L2_STD_525_60) {
+		// NTSC
+		from = 40750*1000;
+		to   = 46750*1000;
+		if2  = 45750*1000;
+	} else {
+		// PAL
+		from = 32900*1000;
+		to   = 39900*1000;
+		if2  = 38900*1000;
+	}
+
+	mt2032_set_if_freq(fe, params->frequency*62500,
+			   1090*1000*1000, if2, from, to);
+
+	return 0;
+}
+
+static int mt2032_set_radio_freq(struct dvb_frontend *fe,
+				 struct analog_parameters *params)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int if2;
+
+	if (params->std & V4L2_STD_525_60) {
+		tuner_dbg("pinnacle ntsc\n");
+		if2 = 41300 * 1000;
+	} else {
+		tuner_dbg("pinnacle pal\n");
+		if2 = 33300 * 1000;
+	}
+
+	// per Manual for FM tuning: first if center freq. 1085 MHz
+	mt2032_set_if_freq(fe, params->frequency * 125 / 2,
+			   1085*1000*1000,if2,if2,if2);
+
+	return 0;
+}
+
+static int mt2032_set_params(struct dvb_frontend *fe,
+			     struct analog_parameters *params)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int ret = -EINVAL;
+
+	switch (params->mode) {
+	case V4L2_TUNER_RADIO:
+		ret = mt2032_set_radio_freq(fe, params);
+		priv->frequency = params->frequency * 125 / 2;
+		break;
+	case V4L2_TUNER_ANALOG_TV:
+	case V4L2_TUNER_DIGITAL_TV:
+		ret = mt2032_set_tv_freq(fe, params);
+		priv->frequency = params->frequency * 62500;
+		break;
+	}
+
+	return ret;
+}
+
+static struct dvb_tuner_ops mt2032_tuner_ops = {
+	.set_analog_params = mt2032_set_params,
+	.release           = microtune_release,
+	.get_frequency     = microtune_get_frequency,
+};
+
+// Initialization as described in "MT203x Programming Procedures", Rev 1.2, Feb.2001
+static int mt2032_init(struct dvb_frontend *fe)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned char buf[21];
+	int ret,xogc,xok=0;
+
+	// Initialize Registers per spec.
+	buf[1]=2; // Index to register 2
+	buf[2]=0xff;
+	buf[3]=0x0f;
+	buf[4]=0x1f;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf+1,4);
+
+	buf[5]=6; // Index register 6
+	buf[6]=0xe4;
+	buf[7]=0x8f;
+	buf[8]=0xc3;
+	buf[9]=0x4e;
+	buf[10]=0xec;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf+5,6);
+
+	buf[12]=13;  // Index register 13
+	buf[13]=0x32;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf+12,2);
+
+	// Adjust XOGC (register 7), wait for XOK
+	xogc=7;
+	do {
+		tuner_dbg("mt2032: xogc = 0x%02x\n",xogc&0x07);
+		mdelay(10);
+		buf[0]=0x0e;
+		tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+		tuner_i2c_xfer_recv(&priv->i2c_props,buf,1);
+		xok=buf[0]&0x01;
+		tuner_dbg("mt2032: xok = 0x%02x\n",xok);
+		if (xok == 1) break;
+
+		xogc--;
+		tuner_dbg("mt2032: xogc = 0x%02x\n",xogc&0x07);
+		if (xogc == 3) {
+			xogc=4; // min. 4 per spec
+			break;
+		}
+		buf[0]=0x07;
+		buf[1]=0x88 + xogc;
+		ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+		if (ret!=2)
+			tuner_warn("i2c i/o error: rc == %d (should be 2)\n",ret);
+	} while (xok != 1 );
+	priv->xogc=xogc;
+
+	memcpy(&fe->ops.tuner_ops, &mt2032_tuner_ops, sizeof(struct dvb_tuner_ops));
+
+	return(1);
+}
+
+static void mt2050_set_antenna(struct dvb_frontend *fe, unsigned char antenna)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned char buf[2];
+	int ret;
+
+	buf[0] = 6;
+	buf[1] = antenna ? 0x11 : 0x10;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,2);
+	tuner_dbg("mt2050: enabled antenna connector %d\n", antenna);
+}
+
+static void mt2050_set_if_freq(struct dvb_frontend *fe,unsigned int freq, unsigned int if2)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned int if1=1218*1000*1000;
+	unsigned int f_lo1,f_lo2,lo1,lo2,f_lo1_modulo,f_lo2_modulo,num1,num2,div1a,div1b,div2a,div2b;
+	int ret;
+	unsigned char buf[6];
+
+	tuner_dbg("mt2050_set_if_freq freq=%d if1=%d if2=%d\n",
+		  freq,if1,if2);
+
+	f_lo1=freq+if1;
+	f_lo1=(f_lo1/1000000)*1000000;
+
+	f_lo2=f_lo1-freq-if2;
+	f_lo2=(f_lo2/50000)*50000;
+
+	lo1=f_lo1/4000000;
+	lo2=f_lo2/4000000;
+
+	f_lo1_modulo= f_lo1-(lo1*4000000);
+	f_lo2_modulo= f_lo2-(lo2*4000000);
+
+	num1=4*f_lo1_modulo/4000000;
+	num2=4096*(f_lo2_modulo/1000)/4000;
+
+	// todo spurchecks
+
+	div1a=(lo1/12)-1;
+	div1b=lo1-(div1a+1)*12;
+
+	div2a=(lo2/8)-1;
+	div2b=lo2-(div2a+1)*8;
+
+	if (debug > 1) {
+		tuner_dbg("lo1 lo2 = %d %d\n", lo1, lo2);
+		tuner_dbg("num1 num2 div1a div1b div2a div2b= %x %x %x %x %x %x\n",
+			  num1,num2,div1a,div1b,div2a,div2b);
+	}
+
+	buf[0]=1;
+	buf[1]= 4*div1b + num1;
+	if(freq<275*1000*1000) buf[1] = buf[1]|0x80;
+
+	buf[2]=div1a;
+	buf[3]=32*div2b + num2/256;
+	buf[4]=num2-(num2/256)*256;
+	buf[5]=div2a;
+	if(num2!=0) buf[5]=buf[5]|0x40;
+
+	if (debug > 1) {
+		int i;
+		tuner_dbg("bufs is: ");
+		for(i=0;i<6;i++)
+			printk("%x ",buf[i]);
+		printk("\n");
+	}
+
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,6);
+	if (ret!=6)
+		tuner_warn("i2c i/o error: rc == %d (should be 6)\n",ret);
+}
+
+static int mt2050_set_tv_freq(struct dvb_frontend *fe,
+			      struct analog_parameters *params)
+{
+	unsigned int if2;
+
+	if (params->std & V4L2_STD_525_60) {
+		// NTSC
+		if2 = 45750*1000;
+	} else {
+		// PAL
+		if2 = 38900*1000;
+	}
+	if (V4L2_TUNER_DIGITAL_TV == params->mode) {
+		// DVB (pinnacle 300i)
+		if2 = 36150*1000;
+	}
+	mt2050_set_if_freq(fe, params->frequency*62500, if2);
+	mt2050_set_antenna(fe, tv_antenna);
+
+	return 0;
+}
+
+static int mt2050_set_radio_freq(struct dvb_frontend *fe,
+				 struct analog_parameters *params)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int if2;
+
+	if (params->std & V4L2_STD_525_60) {
+		tuner_dbg("pinnacle ntsc\n");
+		if2 = 41300 * 1000;
+	} else {
+		tuner_dbg("pinnacle pal\n");
+		if2 = 33300 * 1000;
+	}
+
+	mt2050_set_if_freq(fe, params->frequency * 125 / 2, if2);
+	mt2050_set_antenna(fe, radio_antenna);
+
+	return 0;
+}
+
+static int mt2050_set_params(struct dvb_frontend *fe,
+			     struct analog_parameters *params)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	int ret = -EINVAL;
+
+	switch (params->mode) {
+	case V4L2_TUNER_RADIO:
+		ret = mt2050_set_radio_freq(fe, params);
+		priv->frequency = params->frequency * 125 / 2;
+		break;
+	case V4L2_TUNER_ANALOG_TV:
+	case V4L2_TUNER_DIGITAL_TV:
+		ret = mt2050_set_tv_freq(fe, params);
+		priv->frequency = params->frequency * 62500;
+		break;
+	}
+
+	return ret;
+}
+
+static struct dvb_tuner_ops mt2050_tuner_ops = {
+	.set_analog_params = mt2050_set_params,
+	.release           = microtune_release,
+	.get_frequency     = microtune_get_frequency,
+};
+
+static int mt2050_init(struct dvb_frontend *fe)
+{
+	struct microtune_priv *priv = fe->tuner_priv;
+	unsigned char buf[2];
+	int ret;
+
+	buf[0]=6;
+	buf[1]=0x10;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,2); //  power
+
+	buf[0]=0x0f;
+	buf[1]=0x0f;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,2); // m1lo
+
+	buf[0]=0x0d;
+	ret=tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+	tuner_i2c_xfer_recv(&priv->i2c_props,buf,1);
+
+	tuner_dbg("mt2050: sro is %x\n",buf[0]);
+
+	memcpy(&fe->ops.tuner_ops, &mt2050_tuner_ops, sizeof(struct dvb_tuner_ops));
+
+	return 0;
+}
+
+struct dvb_frontend *microtune_attach(struct dvb_frontend *fe,
+				      struct i2c_adapter* i2c_adap,
+				      u8 i2c_addr)
+{
+	struct microtune_priv *priv = NULL;
+	char *name;
+	unsigned char buf[21];
+	int company_code;
+
+	priv = kzalloc(sizeof(struct microtune_priv), GFP_KERNEL);
+	if (priv == NULL)
+		return NULL;
+	fe->tuner_priv = priv;
+
+	priv->i2c_props.addr = i2c_addr;
+	priv->i2c_props.adap = i2c_adap;
+	priv->i2c_props.name = "mt20xx";
+
+	//priv->radio_if2 = 10700 * 1000;	/* 10.7MHz - FM radio */
+
+	memset(buf,0,sizeof(buf));
+
+	name = "unknown";
+
+	tuner_i2c_xfer_send(&priv->i2c_props,buf,1);
+	tuner_i2c_xfer_recv(&priv->i2c_props,buf,21);
+	if (debug) {
+		int i;
+		tuner_dbg("MT20xx hexdump:");
+		for(i=0;i<21;i++) {
+			printk(" %02x",buf[i]);
+			if(((i+1)%8)==0) printk(" ");
+		}
+		printk("\n");
+	}
+	company_code = buf[0x11] << 8 | buf[0x12];
+	tuner_info("microtune: companycode=%04x part=%02x rev=%02x\n",
+		   company_code,buf[0x13],buf[0x14]);
+
+
+	if (buf[0x13] < ARRAY_SIZE(microtune_part) &&
+	    NULL != microtune_part[buf[0x13]])
+		name = microtune_part[buf[0x13]];
+	switch (buf[0x13]) {
+	case MT2032:
+		mt2032_init(fe);
+		break;
+	case MT2050:
+		mt2050_init(fe);
+		break;
+	default:
+		tuner_info("microtune %s found, not (yet?) supported, sorry :-/\n",
+			   name);
+		return NULL;
+	}
+
+	strlcpy(fe->ops.tuner_ops.info.name, name,
+		sizeof(fe->ops.tuner_ops.info.name));
+	tuner_info("microtune %s found, OK\n",name);
+	return fe;
+}
+
+EXPORT_SYMBOL_GPL(microtune_attach);
+
+MODULE_DESCRIPTION("Microtune tuner driver");
+MODULE_AUTHOR("Ralph Metzler, Gerd Knorr, Gunther Mayer");
+MODULE_LICENSE("GPL");
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */