Em Thu, 18 Nov 2021 21:09:05 -0500 Chuck Ritola <cjritola@xxxxxxxxx> escreveu: > Fixes a8293 failure to raise LNB voltage in PCTV 461e DVB-S2 Stick > affecting multiple users over several years as found here: > > http://www.linuxquestions.org/questions/linux-hardware-18/pctv-dvb-s2-stick-461e-not-feeding-lnb-4175529374/ > https://www.linuxtv.org/wiki/index.php/Pinnacle_PCTV_DVB-S2_Stick_(461e) > https://github.com/OpenELEC/OpenELEC.tv/issues/3731 > > Caused by vIN undervoltage lockout (status register bit 7) when raising LNB to 18V. > Addressed by using the higher-precision voltages available on the a8293 to gradually > increase (slew) the voltage when voltage increases are requested. > > Adds volt_slew_nanos_per_mv to a8293_platform_data struct for specifying slew rate. > If value is <1 or non-sane (>1600), the original no-slew version for a8293_set_voltage is used. > > Signed-off-by: Chuck Ritola <cjritola@xxxxxxxxx> > --- > drivers/media/dvb-frontends/a8293.c | 147 +++++++++++++++++++++++++- > drivers/media/dvb-frontends/a8293.h | 2 + > drivers/media/usb/em28xx/em28xx-dvb.c | 3 + > 3 files changed, 150 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/dvb-frontends/a8293.c b/drivers/media/dvb-frontends/a8293.c > index 57f52c004..f86af43ee 100644 > --- a/drivers/media/dvb-frontends/a8293.c > +++ b/drivers/media/dvb-frontends/a8293.c > @@ -3,16 +3,139 @@ > * Allegro A8293 SEC driver > * > * Copyright (C) 2011 Antti Palosaari <crope@xxxxxx> > + * Copyright (C) 2021 Chuck Ritola <cjritola@xxxxxxxxx> We don't usually add copyrights on files authored by others, except when the original author explicitly agree with that by sending his Signed-off-by or Acked-by. So, except if Antti agrees with that, please remove this change from the patch. Your credits will still be there stored at the git tree. > */ > > #include "a8293.h" > > +#define A8293_FLAG_ODT 0x10 > + > + > struct a8293_dev { > struct i2c_client *client; > u8 reg[2]; > + int volt_slew_nanos_per_mv; > }; > > -static int a8293_set_voltage(struct dvb_frontend *fe, > +/* > + * When increasing voltage, do so in minimal steps over time, minimizing risk of vIN undervoltage. > + */ > + > +static int a8293_set_voltage_slew(struct a8293_dev *dev, > + struct i2c_client *client, > + enum fe_sec_voltage fe_sec_voltage, > + int min_nanos_per_mv) > +{ > + int ret; > + u8 reg0, reg1; > + int new_volt_idx; > + const int idx_to_mv[] = {0, 12709, 13042, 13375, 14042, 15042, 18042, 18709, 19042}; > + const u8 idx_to_reg[] = {0x00, 0x20, 0x21, 0x22, 0x24, 0x27, 0x28, 0x2A, 0x2B }; > + int this_volt_idx; > + u8 status; > + int prev_volt_idx; > + > + dev_dbg(&client->dev, "set_voltage_slew fe_sec_voltage=%d\n", fe_sec_voltage); > + > + /* Read status register to clear any stale faults. */ > + ret = i2c_master_recv(client, &status, 1); > + if (ret < 0) > + goto err; > + > + /* Determine previous voltage */ > + switch (dev->reg[0] & 0x2F) { > + case 0x00: > + prev_volt_idx = 0; > + break; > + case 0x20: > + prev_volt_idx = 1; > + break; > + case 0x21: > + prev_volt_idx = 2; > + break; > + case 0x22: > + prev_volt_idx = 3; > + break; > + case 0x24: > + prev_volt_idx = 4; > + break; > + case 0x27: > + prev_volt_idx = 5; > + break; > + case 0x28: > + prev_volt_idx = 6; > + break; > + case 0x2A: > + prev_volt_idx = 7; > + break; > + case 0x2B: > + prev_volt_idx = 8; > + break; > + default: > + prev_volt_idx = 0; > + } > + > + /* Determine new voltage */ > + switch (fe_sec_voltage) { > + case SEC_VOLTAGE_OFF: > + new_volt_idx = 0; > + break; > + case SEC_VOLTAGE_13: > + new_volt_idx = 2; > + break; > + case SEC_VOLTAGE_18: > + new_volt_idx = 6; > + break; > + default: > + ret = -EINVAL; > + goto err; > + } > + > + /* Slew to new voltage if new voltage is greater than current voltage */ > + this_volt_idx = prev_volt_idx; > + if (this_volt_idx < new_volt_idx) { > + while (this_volt_idx < new_volt_idx) { > + int delta_mv = idx_to_mv[this_volt_idx+1] - idx_to_mv[this_volt_idx]; > + int min_wait_time = delta_mv * min_nanos_per_mv; > + > + reg0 = idx_to_reg[this_volt_idx+1]; > + reg0 |= A8293_FLAG_ODT; > + > + ret = i2c_master_send(client, ®0, 1); > + if (ret < 0) > + goto err; > + dev->reg[0] = reg0; > + this_volt_idx++; > + usleep_range(min_wait_time, min_wait_time * 2); > + } > + } else { /* Else just set the voltage */ > + reg0 = idx_to_reg[new_volt_idx]; > + reg0 |= A8293_FLAG_ODT; > + ret = i2c_master_send(client, ®0, 1); > + if (ret < 0) > + goto err; > + dev->reg[0] = reg0; > + } > + > + /* TMODE=0, TGATE=1 */ > + reg1 = 0x82; > + if (reg1 != dev->reg[1]) { > + ret = i2c_master_send(client, ®1, 1); > + if (ret < 0) > + goto err; > + dev->reg[1] = reg1; > + } > + > + usleep_range(1500, 5000); > + > + return 0; > +err: > + dev_dbg(&client->dev, "failed=%d\n", ret); > + return ret; > +} > + > + > +static int a8293_set_voltage_noslew(struct dvb_frontend *fe, > enum fe_sec_voltage fe_sec_voltage) > { > struct a8293_dev *dev = fe->sec_priv; > @@ -20,7 +143,7 @@ static int a8293_set_voltage(struct dvb_frontend *fe, > int ret; > u8 reg0, reg1; > > - dev_dbg(&client->dev, "fe_sec_voltage=%d\n", fe_sec_voltage); > + dev_dbg(&client->dev, "set_voltage_noslew fe_sec_voltage=%d\n", fe_sec_voltage); > > switch (fe_sec_voltage) { > case SEC_VOLTAGE_OFF: > @@ -62,6 +185,24 @@ static int a8293_set_voltage(struct dvb_frontend *fe, > return ret; > } > > +static int a8293_set_voltage(struct dvb_frontend *fe, > + enum fe_sec_voltage fe_sec_voltage) > +{ > + struct a8293_dev *dev = fe->sec_priv; > + struct i2c_client *client = dev->client; > + int volt_slew_nanos_per_mv = dev->volt_slew_nanos_per_mv; > + > + dev_dbg(&client->dev, "set_voltage volt_slew_nanos_per_mv=%d\n", volt_slew_nanos_per_mv); > + > + /* Use slew version if slew rate is set to a sane value */ > + if (volt_slew_nanos_per_mv > 0 && volt_slew_nanos_per_mv < 1600) > + a8293_set_voltage_slew(dev, client, fe_sec_voltage, volt_slew_nanos_per_mv); > + else > + a8293_set_voltage_noslew(fe, fe_sec_voltage); > + > + return 0; > +} > + > static int a8293_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -78,6 +219,7 @@ static int a8293_probe(struct i2c_client *client, > } > > dev->client = client; > + dev->volt_slew_nanos_per_mv = pdata->volt_slew_nanos_per_mv; > > /* check if the SEC is there */ > ret = i2c_master_recv(client, buf, 2); > @@ -127,5 +269,6 @@ static struct i2c_driver a8293_driver = { > module_i2c_driver(a8293_driver); > > MODULE_AUTHOR("Antti Palosaari <crope@xxxxxx>"); > +MODULE_AUTHOR("Chuck Ritola <cjritola@xxxxxxxxx>"); Same applies here. > MODULE_DESCRIPTION("Allegro A8293 SEC driver"); > MODULE_LICENSE("GPL"); > diff --git a/drivers/media/dvb-frontends/a8293.h b/drivers/media/dvb-frontends/a8293.h > index 8c09635ef..0a807c022 100644 > --- a/drivers/media/dvb-frontends/a8293.h > +++ b/drivers/media/dvb-frontends/a8293.h > @@ -18,9 +18,11 @@ > /** > * struct a8293_platform_data - Platform data for the a8293 driver > * @dvb_frontend: DVB frontend. > + * @volt_slew_nanos_per_mv: Slew rate when increasing LNB voltage, in nanoseconds per millivolt. > */ > struct a8293_platform_data { > struct dvb_frontend *dvb_frontend; > + int volt_slew_nanos_per_mv; > }; > > #endif /* A8293_H */ > diff --git a/drivers/media/usb/em28xx/em28xx-dvb.c b/drivers/media/usb/em28xx/em28xx-dvb.c > index 471bd7466..859f4a33e 100644 > --- a/drivers/media/usb/em28xx/em28xx-dvb.c > +++ b/drivers/media/usb/em28xx/em28xx-dvb.c > @@ -1208,6 +1208,9 @@ static int em28178_dvb_init_pctv_461e(struct em28xx *dev) > > /* attach SEC */ > a8293_pdata.dvb_frontend = dvb->fe[0]; > + /* 461e has a tendency to have vIN undervoltage troubles. Slew mitigates this. */ > + a8293_pdata.volt_slew_nanos_per_mv = 20; > + > dvb->i2c_client_sec = dvb_module_probe("a8293", NULL, > &dev->i2c_adap[dev->def_i2c_bus], > 0x08, &a8293_pdata); Thanks, Mauro
