UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

media: isl6421: add checks for current overflow 

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 <mchehab@s-opensource.com>
Signed-off-by: Jemma Denson <jdenson@gmail.com>
This commit is contained in:
Jemma Denson 2017-08-19 07:38:26 -04:00 committed by Mauro Carvalho Chehab
parent 7112b490af
commit 214824156c
1 changed files with 72 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
drivers/media/dvb-frontends/isl6421.c
View File

@ -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;