hwmon: (sch5627) Disallow write access if virtual registers are locked

[ Upstream commit 7da8a63543 ]

When the lock bit inside SCH5627_REG_CTRL is set, then the virtual
registers become read-only until the next power cycle.
Disallow write access to those registers in such a case.

Tested on a Fujitsu Esprimo P720.

Fixes: aa9f833dfc ("hwmon: (sch5627) Add pwmX_auto_channels_temp support")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230907052639.16491-3-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Armin Wolf 2023-09-07 07:26:36 +02:00 committed by Greg Kroah-Hartman
parent 0a31b778ee
commit 2c7c560262
1 changed files with 9 additions and 0 deletions

View File

@ -34,6 +34,7 @@
#define SCH5627_REG_CTRL 0x40
#define SCH5627_CTRL_START BIT(0)
#define SCH5627_CTRL_LOCK BIT(1)
#define SCH5627_CTRL_VBAT BIT(4)
#define SCH5627_NO_TEMPS 8
@ -231,6 +232,14 @@ static int reg_to_rpm(u16 reg)
static umode_t sch5627_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
int channel)
{
const struct sch5627_data *data = drvdata;
/* Once the lock bit is set, the virtual registers become read-only
* until the next power cycle.
*/
if (data->control & SCH5627_CTRL_LOCK)
return 0444;
if (type == hwmon_pwm && attr == hwmon_pwm_auto_channels_temp)
return 0644;