This Kaffeine's BZ:
https://bugs.kde.org/show_bug.cgi?id=374693
affects SkyStar S2 PCI DVB-S/S2 rev 3.3 device. It could be due to
a Kernel bug.
While checking the Isil 6421, comparing with its manual, available at:
http://www.intersil.com/content/dam/Intersil/documents/isl6/isl6421a.pdf
It was noticed that, if the output load is highly capacitive, a different
approach
is recomended when energizing the LNBf.
Also, it is possible to detect if a current overload is happening, by checking
an
special flag.
Add support for it.
Tested on Skystar S2. Changes respect override_or option so should still work
fine
on cx88 based cards which disable dynamic current limit.
Changes since v1:
v2 - fixed incorrect checking of i2c return values
v3 - fix if logic to check if dcl needs re-enabling
- respect override_or values which aim to disable dcl
- only do long sleep on overload if dcl enabled
- add short sleep before re-enabling dcl
- only check overload and potentially return EINVAL if device is on
v4 - revert v3 sleep logic changes to remove tuning delays
Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
Signed-off-by: Jemma Denson <jden...@gmail.com>
---
drivers/media/dvb-frontends/isl6421.c | 76 +++++++++++++++++++++++++++++++++--
1 file changed, 72 insertions(+), 4 deletions(-)
diff --git a/drivers/media/dvb-frontends/isl6421.c
b/drivers/media/dvb-frontends/isl6421.c
index 838b42771a05..3f3487887672 100644
--- a/drivers/media/dvb-frontends/isl6421.c
+++ b/drivers/media/dvb-frontends/isl6421.c
@@ -38,35 +38,101 @@ struct isl6421 {
u8 override_and;
struct i2c_adapter *i2c;
u8 i2c_addr;
+ bool is_off;
};
static int isl6421_set_voltage(struct dvb_frontend *fe,
enum fe_sec_voltage voltage)
{
+ int ret;
+ u8 buf;
+ bool is_off;
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) };
+ struct i2c_msg msg[2] = {
+ {
+ .addr = isl6421->i2c_addr,
+ .flags = 0,
+ .buf = &isl6421->config,
+ .len = 1,
+ }, {
+ .addr = isl6421->i2c_addr,
+ .flags = I2C_M_RD,
+ .buf = &buf,
+ .len = 1,
+ }
+
+ };
isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
switch(voltage) {
case SEC_VOLTAGE_OFF:
+ is_off = true;
break;
case SEC_VOLTAGE_13:
+ is_off = false;
isl6421->config |= ISL6421_EN1;
break;
case SEC_VOLTAGE_18:
+ is_off = false;
isl6421->config |= (ISL6421_EN1 | ISL6421_VSEL1);
break;
default:
return -EINVAL;
}
+ /*
+ * If LNBf were not powered on, disable dynamic current limit, as,
+ * according with datasheet, highly capacitive load on the output may
+ * cause a difficult start-up.
+ */
+ if (isl6421->is_off && !is_off)
+ isl6421->config |= ISL6421_DCL;
+
isl6421->config |= isl6421->override_or;
isl6421->config &= isl6421->override_and;
- return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
+ ret = i2c_transfer(isl6421->i2c, msg, 2);
+ if (ret < 0)
+ return ret;
+ if (ret != 2)
+ return -EIO;
+
+ /* Store off status now incase future commands fail */
+ isl6421->is_off = is_off;
+
+ /* On overflow, the device will try again after 900 ms (typically) */
+ if (!is_off && (buf & ISL6421_OLF1))
+ msleep(1000);
+
+ /* Re-enable dynamic current limit */
+ if ((isl6421->config & ISL6421_DCL) &&
+ !(isl6421->override_or & ISL6421_DCL)) {
+ isl6421->config &= ~ISL6421_DCL;
+
+ ret = i2c_transfer(isl6421->i2c, msg, 2);
+ if (ret < 0)
+ return ret;
+ if (ret != 2)
+ return -EIO;
+ }
+
+ /* Check if overload flag is active. If so, disable power */
+ if (!is_off && (buf & ISL6421_OLF1)) {
+ isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
+ ret = i2c_transfer(isl6421->i2c, msg, 1);
+ if (ret < 0)
+ return ret;
+ if (ret != 1)
+ return -EIO;
+ isl6421->is_off = true;
+
+ dev_warn(&isl6421->i2c->dev,
+ "Overload current detected. disabling LNBf power\n");
+ return -EINVAL;
+ }
+
+ return 0;
}
static int isl6421_enable_high_lnb_voltage(struct dvb_frontend *fe, long arg)
@@ -148,6 +214,8 @@ struct dvb_frontend *isl6421_attach(struct dvb_frontend
*fe, struct i2c_adapter
return NULL;
}
+ isl6421->is_off = true;
+
/* install release callback */
fe->ops.release_sec = isl6421_release;
--
2.13.4
