/*
* Support for Legend Silicon DMB-TH demodulator
* LGS8913, LGS8GL5
* experimental support LGS8G42, LGS8G52
*
* Copyright (C) 2007,2008 David T.L. Wong <davidtlwong@gmail.com>
* Copyright (C) 2008 Sirius International (Hong Kong) Limited
* Timothy Lee <timothy.lee@siriushk.com> (for initial work on LGS8GL5)
*
* 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 <asm/div64.h>
#include "dvb_frontend.h"
#include "lgs8gxx.h"
#include "lgs8gxx_priv.h"
#define dprintk(args...) \
do { \
if (debug) \
printk(KERN_DEBUG "lgs8gxx: " args); \
} while (0)
static int debug;
static int fake_signal_str;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
module_param(fake_signal_str, int, 0644);
MODULE_PARM_DESC(fake_signal_str, "fake signal strength for LGS8913."
"Signal strength calculation is slow.(default:off).");
/* LGS8GXX internal helper functions */
static int lgs8gxx_write_reg(struct lgs8gxx_state *priv, u8 reg, u8 data)
{
int ret;
u8 buf[] = { reg, data };
struct i2c_msg msg = { .flags = 0, .buf = buf, .len = 2 };
msg.addr = priv->config->demod_address;
if (reg >= 0xC0)
msg.addr += 0x02;
if (debug >= 2)
printk(KERN_DEBUG "%s: reg=0x%02X, data=0x%02X\n",
__func__, reg, data);
ret = i2c_transfer(priv->i2c, &msg, 1);
if (ret != 1)
dprintk(KERN_DEBUG "%s: error reg=0x%x, data=0x%x, ret=%i\n",
__func__, reg, data, ret);
return (ret != 1) ? -1 : 0;
}
static int lgs8gxx_read_reg(struct lgs8gxx_state *priv, u8 reg, u8 *p_data)
{
int ret;
u8 dev_addr;
u8 b0[] = { reg };
u8 b1[] = { 0 };
struct i2c_msg msg[] = {
{ .flags = 0, .buf = b0, .len = 1 },
{ .flags = I2C_M_RD, .buf = b1, .len = 1 },
};
dev_addr = priv->config->demod_address;
if (reg >= 0xC0)
dev_addr += 0x02;
msg[1].addr = msg[0].addr = dev_addr;
ret = i2c_transfer(priv->i2c, msg, 2);
if (ret != 2) {
dprintk(KERN_DEBUG "%s: error reg=0x%x, ret=%i\n",
__func__, reg, ret);
return -1;
}
*p_data = b1[0];
if (debug >= 2)
printk(KERN_DEBUG "%s: reg=0x%02X, data=0x%02X\n",
__func__, reg, b1[0]);
return 0;
}
static int lgs8gxx_soft_reset(struct lgs8gxx_state *priv)
{
lgs8gxx_write_reg(priv, 0x02, 0x00);
msleep(1);
lgs8gxx_write_reg(priv, 0x02, 0x01);
msleep(100);
return 0;
}
static int lgs8gxx_set_ad_mode(struct lgs8gxx_state *priv)
{
const struct lgs8gxx_config *config = priv->config;
u8 if_conf;
if_conf = 0x10; /* AGC output on; */
if_conf |=
((config->ext_adc) ? 0x80 : 0x00) |
((config->if_neg_center) ? 0x04 : 0x00) |
((config->if_freq == 0) ? 0x08 : 0x00) | /* Baseband */
((config->ext_adc && config->adc_signed) ? 0x02 : 0x00) |
((config->ext_adc && config->if_neg_edge) ? 0x01 : 0x00);
if (config->ext_adc &&
(config->prod == LGS8GXX_PROD_LGS8G52)) {
lgs8gxx_write_reg(priv, 0xBA, 0x40);
}
lgs8gxx_write_reg(priv, 0x07, if_conf);
return 0;
}
static int lgs8gxx_set_if_freq(struct lgs8gxx_state *priv, u32 freq /*in kHz*/)
{
u64 val;
u32 v32;
u32 if_clk;
if_clk = priv->config->if_clk_freq;
val = freq;
if (freq != 0) {
val *= (u64)1 << 32;
if (if_clk != 0)
do_div(val, if_clk);
v32 = val & 0xFFFFFFFF;
dprintk("Set IF Freq to %dkHz\n", freq);
} else {
v32 = 0;
dprintk("Set IF Freq to baseband\n");
}
dprintk("AFC_INIT_FREQ = 0x%08X\n", v32);
lgs8gxx_write_reg(priv, 0x09, 0xFF & (v32));
lgs8gxx_write_reg(priv, 0x0A, 0xFF & (v32 >> 8));
lgs8gxx_write_reg(priv, 0x0B, 0xFF & (v32 >> 16));
lgs8gxx_write_reg(priv, 0x0C, 0xFF & (v32 >> 24));
return 0;
}
static int lgs8gxx_set_mode_auto(struct lgs8gxx_state *priv)
{
u8 t;
if (priv->config->prod == LGS8GXX_PROD_LGS8913)
lgs8gxx_write_reg(priv, 0xC6, 0x01);
lgs8gxx_read_reg(priv, 0x7E, &t);
lgs8gxx_write_reg(priv, 0x7E, t | 0x01);
/* clear FEC self reset */
lgs8gxx_read_reg(priv, 0xC5, &t);
lgs8gxx_write_reg(priv, 0xC5, t & 0xE0);
if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
/* FEC auto detect */
lgs8gxx_write_reg(priv, 0xC1, 0x03);
lgs8gxx_read_reg(priv, 0x7C, &t);
t = (t & 0x8C) | 0x03;
lgs8gxx_write_reg(priv, 0x7C, t);
}
if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
/* BER test mode */
lgs8gxx_read_reg(priv, 0xC3, &t);
t = (t & 0xEF) | 0x10;
lgs8gxx_write_reg(priv, 0xC3, t);
}
if (priv->config->prod == LGS8GXX_PROD_LGS8G52)
lgs8gxx_write_reg(priv, 0xD9, 0x40);
return 0;
}
static int lgs8gxx_set_mode_manual(struct lgs8gxx_state *priv)
{
int ret = 0;
u8 t;
/* turn off auto-detect; manual settings */
lgs8gxx_write_reg(priv, 0x7E, 0);
if (priv->config->prod == LGS8GXX_PROD_LGS8913)
lgs8gxx_write_reg(priv, 0xC1, 0);
ret = lgs8gxx_read_reg(priv, 0xC5, &t);
t = (t & 0xE0) | 0x06;
lgs8gxx_write_reg(priv, 0xC5, t);
lgs8gxx_soft_reset(priv);
return 0;
}
static int lgs8gxx_is_locked(struct lgs8gxx_state *priv, u8 *locked)
{
int ret = 0;
u8 t;
ret = lgs8gxx_read_reg(priv, 0x4B, &t);
if (ret != 0)
return ret;
*locked = ((t & 0xC0) == 0xC0) ? 1 : 0;
return 0;
}
static int lgs8gxx_is_autodetect_finished(struct lgs8gxx_state *priv,
u8 *finished)
{
int ret = 0;
u8 t;
ret = lgs8gxx_read_reg(priv, 0xA4, &t);
if (ret != 0)
return ret;
*finished = ((t & 0x3) == 0x1) ? 1 : 0;
return 0;
}
static int lgs8gxx_autolock_gi(struct lgs8gxx_state *priv, u8 gi, u8 *locked)
{
int err;
u8 ad_fini = 0;
if (gi == GI_945)
dprintk("try GI 945\n");
else if (gi == GI_595)
dprintk("try GI 595\n");
else if (gi == GI_420)
dprintk("try GI 420\n");
lgs8gxx_write_reg(priv, 0x04, gi);
lgs8gxx_soft_reset(priv);
msleep(50);
err = lgs8gxx_is_autodetect_finished(priv, &ad_fini);
if (err != 0)
return err;
if (ad_fini) {
err = lgs8gxx_is_locked(priv, locked);
if (err != 0)
return err;
}
return 0;
}
static int lgs8gxx_auto_detect(struct lgs8gxx_state *priv,
u8 *detected_param, u8 *gi)
{
int i, j;
int err = 0;
u8 locked = 0, tmp_gi;
dprintk("%s\n", __func__);
lgs8gxx_set_mode_auto(priv);
/* Guard Interval */
lgs8gxx_write_reg(priv, 0x03, 00);
for (i = 0; i < 2; i++) {
for (j = 0; j < 2; j++) {
tmp_gi = GI_945;
err = lgs8gxx_autolock_gi(priv, GI_945, &locked);
if (err)
goto out;
if (locked)
goto locked;
}
for (j = 0; j < 2; j++) {
tmp_gi = GI_420;
err = lgs8gxx_autolock_gi(priv, GI_420, &locked);
if (err)
goto out;
if (locked)
goto locked;
}
tmp_gi = GI_595;
err = lgs8gxx_autolock_gi(priv, GI_595, &locked);
if (err)
goto out;
if (locked)
goto locked;
}
locked:
if ((err == 0) && (locked == 1)) {
u8 t;
lgs8gxx_read_reg(priv, 0xA2, &t);
*detected_param = t;
if (tmp_gi == GI_945)
dprintk("GI 945 locked\n");
else if (tmp_gi == GI_595)
dprintk("GI 595 locked\n");
else if (tmp_gi == GI_420)
dprintk("GI 420 locked\n");
*gi = tmp_gi;
}
if (!locked)
err = -1;
out:
return err;
}
static void lgs8gxx_auto_lock(struct lgs8gxx_state *priv)
{
s8 err;
u8 gi = 0x2;
u8 detected_param = 0;
err = lgs8gxx_auto_detect(priv, &detected_param, &gi);
if (err != 0) {
dprintk("lgs8gxx_auto_detect failed\n");
}
/* Apply detected parameters */
if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
u8 inter_leave_len = detected_param & TIM_MASK ;
inter_leave_len = (inter_leave_len == TIM_LONG) ? 0x60 : 0x40;
detected_param &= CF_MASK | SC_MASK | LGS_FEC_MASK;
detected_param |= inter_leave_len;
}
lgs8gxx_write_reg(priv, 0x7D, detected_param);
if (priv->config->prod == LGS8GXX_PROD_LGS8913)
lgs8gxx_write_reg(priv, 0xC0, detected_param);
/* lgs8gxx_soft_reset(priv); */
/* Enter manual mode */
lgs8gxx_set_mode_manual(priv);
switch (gi) {
case GI_945:
priv->curr_gi = 945; break;
case GI_595:
priv->curr_gi = 595; break;
case GI_420:
priv->curr_gi = 420; break;
default:
priv->curr_gi = 945; break;
}
}
static int lgs8gxx_set_mpeg_mode(struct lgs8gxx_state *priv,
u8 serial, u8 clk_pol, u8 clk_gated)
{
int ret = 0;
u8 t;
ret = lgs8gxx_read_reg(priv, 0xC2, &t);
if (ret != 0)
return ret;
t &= 0xF8;
t |= serial ? TS_SERIAL : TS_PARALLEL;
t |= clk_pol ? TS_CLK_INVERTED : TS_CLK_NORMAL;
t |= clk_gated ? TS_CLK_GATED : TS_CLK_FREERUN;
ret = lgs8gxx_write_reg(priv, 0xC2, t);
if (ret != 0)
return ret;
return 0;
}
/* LGS8913 demod frontend functions */
static int lgs8913_init(struct lgs8gxx_state *priv)
{
u8 t;
/* LGS8913 specific */
lgs8gxx_write_reg(priv, 0xc1, 0x3);
lgs8gxx_read_reg(priv, 0x7c, &t);
lgs8gxx_write_reg(priv, 0x7c, (t&0x8c) | 0x3);
/* LGS8913 specific */
lgs8gxx_read_reg(priv, 0xc3, &t);
lgs8gxx_write_reg(priv, 0xc3, t&0x10);
return 0;
}
static int lgs8gxx_init(struct dvb_frontend *fe)
{
struct lgs8gxx_state *priv =
(struct lgs8gxx_state *)fe->demodulator_priv;
const struct lgs8gxx_config *config = priv->config;
u8 data = 0;
s8 err;
dprintk("%s\n", __func__);
lgs8gxx_read_reg(priv, 0, &data);
dprintk("reg 0 = 0x%02X\n", data);
/* Setup MPEG output format */
err = lgs8gxx_set_mpeg_mode(priv, config->serial_ts,
config->ts_clk_pol,
config->ts_clk_gated);
if (err != 0)
return -EIO;
if (config->prod == LGS8GXX_PROD_LGS8913)
lgs8913_init(priv);
lgs8gxx_set_if_freq(priv, priv->config->if_freq);
if (config->prod != LGS8GXX_PROD_LGS8913)
lgs8gxx_set_ad_mode(priv);
return 0;
}
static void lgs8gxx_release(struct dvb_frontend *fe)
{
struct lgs8gxx_state *state = fe->demodulator_priv;
dprintk("%s\n", __func__);
kfree(state);
}
static int lgs8gxx_write(struct dvb_frontend *fe, u8 *buf, int len)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
if (len != 2)
return -EINVAL;
return lgs8gxx_write_reg(priv, buf[0], buf[1]);
}
static int lgs8gxx_set_fe(struct dvb_frontend *fe,
struct dvb_frontend_parameters *fe_params)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
dprintk("%s\n", __func__);
/* set frequency */
if (fe->ops.tuner_ops.set_params) {
fe->ops.tuner_ops.set_params(fe, fe_params);
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
}
/* start auto lock */
lgs8gxx_auto_lock(priv);
msleep(10);
return 0;
}
static int lgs8gxx_get_fe(struct dvb_frontend *fe,
struct dvb_frontend_parameters *fe_params)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
u8 t;
dprintk("%s\n", __func__);
/* TODO: get real readings from device */
/* inversion status */
fe_params->inversion = INVERSION_OFF;
/* bandwidth */
fe_params->u.ofdm.bandwidth = BANDWIDTH_8_MHZ;
lgs8gxx_read_reg(priv, 0x7D, &t);
fe_params->u.ofdm.code_rate_HP = FEC_AUTO;
fe_params->u.ofdm.code_rate_LP = FEC_AUTO;
/* constellation */
switch (t & SC_MASK) {
case SC_QAM64:
fe_params->u.ofdm.constellation = QAM_64;
break;
case SC_QAM32:
fe_params->u.ofdm.constellation = QAM_32;
break;
case SC_QAM16:
fe_params->u.ofdm.constellation = QAM_16;
break;
case SC_QAM4:
case SC_QAM4NR:
fe_params->u.ofdm.constellation = QPSK;
break;
default:
fe_params->u.ofdm.constellation = QAM_64;
}
/* transmission mode */
fe_params->u.ofdm.transmission_mode = TRANSMISSION_MODE_AUTO;
/* guard interval */
fe_params->u.ofdm.guard_interval = GUARD_INTERVAL_AUTO;
/* hierarchy */
fe_params->u.ofdm.hierarchy_information = HIERARCHY_NONE;
return 0;
}
static
int lgs8gxx_get_tune_settings(struct dvb_frontend *fe,
struct dvb_frontend_tune_settings *fesettings)
{
/* FIXME: copy from tda1004x.c */
fesettings->min_delay_ms = 800;
fesettings->step_size = 0;
fesettings->max_drift = 0;
return 0;
}
static int lgs8gxx_read_status(struct dvb_frontend *fe, fe_status_t *fe_status)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
s8 ret;
u8 t;
dprintk("%s\n", __func__);
ret = lgs8gxx_read_reg(priv, 0x4B, &t);
if (ret != 0)
return -EIO;
dprintk("Reg 0x4B: 0x%02X\n", t);
*fe_status = 0;
if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
if ((t & 0x40) == 0x40)
*fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER;
if ((t & 0x80) == 0x80)
*fe_status |= FE_HAS_VITERBI | FE_HAS_SYNC |
FE_HAS_LOCK;
} else {
if ((t & 0x80) == 0x80)
*fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
}
/* success */
dprintk("%s: fe_status=0x%x\n", __func__, *fe_status);
return 0;
}
static int lgs8gxx_read_signal_agc(struct lgs8gxx_state *priv, u16 *signal)
{
u16 v;
u8 agc_lvl[2], cat;
dprintk("%s()\n", __func__);
lgs8gxx_read_reg(priv, 0x3F, &agc_lvl[0]);
lgs8gxx_read_reg(priv, 0x3E, &agc_lvl[1]);
v = agc_lvl[0];
v <<= 8;
v |= agc_lvl[1];
dprintk("agc_lvl: 0x%04X\n", v);
if (v < 0x100)
cat = 0;
else if (v < 0x190)
cat = 5;
else if (v < 0x2A8)
cat = 4;
else if (v < 0x381)
cat = 3;
else if (v < 0x400)
cat = 2;
else if (v == 0x400)
cat = 1;
else
cat = 0;
*signal = cat;
return 0;
}
static int lgs8913_read_signal_strength(struct lgs8gxx_state *priv, u16 *signal)
{
u8 t; s8 ret;
s16 max_strength = 0;
u8 str;
u16 i, gi = priv->curr_gi;
dprintk("%s\n", __func__);
ret = lgs8gxx_read_reg(priv, 0x4B, &t);
if (ret != 0)
return -EIO;
if (fake_signal_str) {
if ((t & 0xC0) == 0xC0) {
dprintk("Fake signal strength as 50\n");
*signal = 0x32;
} else
*signal = 0;
return 0;
}
dprintk("gi = %d\n", gi);
for (i = 0; i < gi; i++) {
if ((i & 0xFF) == 0)
lgs8gxx_write_reg(priv, 0x84, 0x03 & (i >> 8));
lgs8gxx_write_reg(priv, 0x83, i & 0xFF);
lgs8gxx_read_reg(priv, 0x94, &str);
if (max_strength < str)
max_strength = str;
}
*signal = max_strength;
dprintk("%s: signal=0x%02X\n", __func__, *signal);
lgs8gxx_read_reg(priv, 0x95, &t);
dprintk("%s: AVG Noise=0x%02X\n", __func__, t);
return 0;
}
static int lgs8gxx_read_signal_strength(struct dvb_frontend *fe, u16 *signal)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
if (priv->config->prod == LGS8GXX_PROD_LGS8913)
return lgs8913_read_signal_strength(priv, signal);
else
return lgs8gxx_read_signal_agc(priv, signal);
}
static int lgs8gxx_read_snr(struct dvb_frontend *fe, u16 *snr)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
u8 t;
*snr = 0;
lgs8gxx_read_reg(priv, 0x95, &t);
dprintk("AVG Noise=0x%02X\n", t);
*snr = 256 - t;
*snr <<= 8;
dprintk("snr=0x%x\n", *snr);
return 0;
}
static int lgs8gxx_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
*ucblocks = 0;
dprintk("%s: ucblocks=0x%x\n", __func__, *ucblocks);
return 0;
}
static int lgs8gxx_read_ber(struct dvb_frontend *fe, u32 *ber)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
u8 r0, r1, r2, r3;
u32 total_cnt, err_cnt;
dprintk("%s\n", __func__);
lgs8gxx_write_reg(priv, 0xc6, 0x01);
lgs8gxx_write_reg(priv, 0xc6, 0x41);
lgs8gxx_write_reg(priv, 0xc6, 0x01);
msleep(200);
lgs8gxx_write_reg(priv, 0xc6, 0x81);
lgs8gxx_read_reg(priv, 0xd0, &r0);
lgs8gxx_read_reg(priv, 0xd1, &r1);
lgs8gxx_read_reg(priv, 0xd2, &r2);
lgs8gxx_read_reg(priv, 0xd3, &r3);
total_cnt = (r3 << 24) | (r2 << 16) | (r1 << 8) | (r0);
lgs8gxx_read_reg(priv, 0xd4, &r0);
lgs8gxx_read_reg(priv, 0xd5, &r1);
lgs8gxx_read_reg(priv, 0xd6, &r2);
lgs8gxx_read_reg(priv, 0xd7, &r3);
err_cnt = (r3 << 24) | (r2 << 16) | (r1 << 8) | (r0);
dprintk("error=%d total=%d\n", err_cnt, total_cnt);
if (total_cnt == 0)
*ber = 0;
else
*ber = err_cnt * 100 / total_cnt;
dprintk("%s: ber=0x%x\n", __func__, *ber);
return 0;
}
static int lgs8gxx_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
{
struct lgs8gxx_state *priv = fe->demodulator_priv;
if (priv->config->tuner_address == 0)
return 0;
if (enable) {
u8 v = 0x80 | priv->config->tuner_address;
return lgs8gxx_write_reg(priv, 0x01, v);
}
return lgs8gxx_write_reg(priv, 0x01, 0);
}
static struct dvb_frontend_ops lgs8gxx_ops = {
.info = {
.name = "Legend Silicon LGS8913/LGS8GXX DMB-TH",
.type = FE_OFDM,
.frequency_min = 474000000,
.frequency_max = 858000000,
.frequency_stepsize = 10000,
.caps =
FE_CAN_FEC_AUTO |
FE_CAN_QAM_AUTO |
FE_CAN_TRANSMISSION_MODE_AUTO |
FE_CAN_GUARD_INTERVAL_AUTO
},
.release = lgs8gxx_release,
.init = lgs8gxx_init,
.write = lgs8gxx_write,
.i2c_gate_ctrl = lgs8gxx_i2c_gate_ctrl,
.set_frontend = lgs8gxx_set_fe,
.get_frontend = lgs8gxx_get_fe,
.get_tune_settings = lgs8gxx_get_tune_settings,
.read_status = lgs8gxx_read_status,
.read_ber = lgs8gxx_read_ber,
.read_signal_strength = lgs8gxx_read_signal_strength,
.read_snr = lgs8gxx_read_snr,
.read_ucblocks = lgs8gxx_read_ucblocks,
};
struct dvb_frontend *lgs8gxx_attach(const struct lgs8gxx_config *config,
struct i2c_adapter *i2c)
{
struct lgs8gxx_state *priv = NULL;
u8 data = 0;
dprintk("%s()\n", __func__);
if (config == NULL || i2c == NULL)
return NULL;
priv = kzalloc(sizeof(struct lgs8gxx_state), GFP_KERNEL);
if (priv == NULL)
goto error_out;
priv->config = config;
priv->i2c = i2c;
/* check if the demod is there */
if (lgs8gxx_read_reg(priv, 0, &data) != 0) {
dprintk("%s lgs8gxx not found at i2c addr 0x%02X\n",
__func__, priv->config->demod_address);
goto error_out;
}
lgs8gxx_read_reg(priv, 1, &data);
memcpy(&priv->frontend.ops, &lgs8gxx_ops,
sizeof(struct dvb_frontend_ops));
priv->frontend.demodulator_priv = priv;
return &priv->frontend;
error_out:
dprintk("%s() error_out\n", __func__);
kfree(priv);
return NULL;
}
EXPORT_SYMBOL(lgs8gxx_attach);
MODULE_DESCRIPTION("Legend Silicon LGS8913/LGS8GXX DMB-TH demodulator driver");
MODULE_AUTHOR("David T. L. Wong <davidtlwong@gmail.com>");
MODULE_LICENSE("GPL");
