Some drivers may need to acquire P-Unit managed resources from interrupt
context, where they cannot call iosf_mbi_punit_acquire().
This commit adds a notifier chain which allows a driver to get notified
(in a process context) before other drivers start accessing the PMIC bus,
so that the driver can acquire any resources, which it may need during
the window the other driver is accessing the PMIC, before hand.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
One some systems the P-Unit accesses the PMIC to change various voltages
through the same bus as other kernel drivers use for e.g. battery
monitoring.
If a driver sends requests to the P-Unit which require the P-Unit to access
the PMIC bus while another driver is also accessing the PMIC bus various
bad things happen.
This commit adds a mutex to protect the P-Unit against simultaneous
accesses and 2 functions to lock / unlock this mutex.
Note on these systems the i2c-bus driver will request a sempahore from the
P-Unit for exclusive access to the PMIC bus when i2c drivers are accessing
it, but this does not appear to be sufficient, we still need to avoid
making certain P-Unit requests during the access window to avoid problems.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-2-hdegoede@redhat.com
This is a third approach to workaround long standing issue with LPSS on
BayTrail. First one [1] was reverted since it didn't resolve the issue
comprehensively. Second one [2] was rejected by internal review.
The LPSS DMA controller does not have neither _PS0 nor _PS3 method. Moreover it
can be powered off automatically whenever the last LPSS device goes down. In
case of no power any access to the DMA controller will hang the system. The
behaviour is reproduced on some HP laptops based on Intel BayTrail [3,4] as
well as on ASuS T100TA transformer.
Power on the LPSS island through the registers accessible in a specific way.
[1] http://www.spinics.net/lists/linux-acpi/msg53963.html
[2] https://bugzilla.redhat.com/attachment.cgi?id=1066779&action=diff
[3] https://bugzilla.redhat.com/show_bug.cgi?id=1184273
[4] http://www.spinics.net/lists/dmaengine/msg01514.html
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The read and write opcodes are global for all units on SoC and even across
Intel SoCs. Remove duplication of corresponding constants. At the same time
convert all current users.
No functional change.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Boon Leong Ong <boon.leong.ong@intel.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Move the static variables to one place
- Fix indentations in the header
- Correct comments
No functional change.
[ tglx: Massaged changelog ]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David E . Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1436366709-17683-5-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Added all the MBI units below and their associated read/write
opcodes:
- Host Bridge Arbiter
- Host Bridge
- Remote Management Unit
- Memory Manager & eSRAM
- SoC Unit
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Link: http://lkml.kernel.org/r/1399668248-24199-3-git-send-email-david.e.box@linux.intel.com
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Currently drivers that run on non-IOSF systems (Core/Xeon) can't use the IOSF
driver on SOC's without selecting it which forces an unnecessary and limiting
dependency. Provides dummy functions to allow these modules to conditionally
use the driver on IOSF equipped platforms without impacting their ability to
compile and load on non-IOSF platforms. Build default m to ensure availability
on x86 SOC's.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1399668248-24199-2-git-send-email-david.e.box@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Current Intel SOC cores use a MailBox Interface (MBI) to provide access to
configuration registers on devices (called units) connected to the system
fabric. This is a support driver that implements access to this interface on
those platforms that can enumerate the device using PCI. Initial support is for
BayTrail, for which port definitons are provided. This is a requirement for
implementing platform specific features (e.g. RAPL driver requires this to
perform platform specific power management using the registers in PUNIT).
Dependant modules should select IOSF_MBI in their respective Kconfig
configuraiton. Serialized access is handled by all exported routines with
spinlocks.
The API includes 3 functions for access to unit registers:
int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
port: indicating the unit being accessed
opcode: the read or write port specific opcode
offset: the register offset within the port
mdr: the register data to be read, written, or modified
mask: bit locations in mdr to change
Returns nonzero on error
Note: GPU code handles access to the GFX unit. Therefore access to that unit
with this driver is disallowed to avoid conflicts.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1389216471-734-1-git-send-email-david.e.box@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Hans de Goede