On Thu, Oct 24, 2024 at 08:10:37PM +0200, Jerome Brunet wrote: > Add a module parameter to force the write protection mode of pmbus chips. > > 2 protections modes are provided to start with: > * 0: Remove the write protection if possible > * 1: Enable full write protection if possible > > Of course, if the parameter is not provided, the default write protection > status of the pmbus chips is left untouched. > > Suggested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx> > --- > Documentation/admin-guide/kernel-parameters.txt | 4 ++ > drivers/hwmon/pmbus/pmbus_core.c | 74 ++++++++++++++++++------- > 2 files changed, 59 insertions(+), 19 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 1518343bbe2237f1d577df5656339d6224b769be..aa79242fe0a9238f618182289f18563ed63cba1c 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4733,6 +4733,10 @@ > Format: { parport<nr> | timid | 0 } > See also Documentation/admin-guide/parport.rst. > > + pmbus.wp= [HW] PMBus Chips write protection forced mode > + Format: { 0 | 1 } > + See drivers/hwmon/pmbus/pmbus_core.c > + I have always seen that file as applicable for core kernel parameters, not for driver kernel parameters. I can not accept a global change like this without guidance. Please explain why it is desirable to have this parameter documented here and not in driver documentation. > pmtmr= [X86] Manual setup of pmtmr I/O Port. > Override pmtimer IOPort with a hex value. > e.g. pmtmr=0x508 > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index 7bdd8f2ffcabc51500437182f411e9826cd7a55d..ce697ca03de01c0e5a352f8f6b72671137721868 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -31,6 +31,20 @@ > #define PMBUS_ATTR_ALLOC_SIZE 32 > #define PMBUS_NAME_SIZE 24 > > +/* > + * PMBus write protect forced mode: > + * PMBus may come up with a variety of write protection configuration. > + * 'pmbus_wp' may be used if a particular write protection is necessary. > + * The ability to actually alter the protection may also depend on the chip > + * so the actual runtime write protection configuration may differ from > + * the requested one. pmbus_core currently support the following value: > + * - 0: write protection removed > + * - 1: write protection fully enabled, including OPERATION and VOUT_COMMAND > + * registers. Chips essentially become read-only with this. Would it be desirable to also suppport the ability to set the output voltage but not limits (PB_WP_VOUT) ? Guenter