Commit Graph

17 Commits

Author SHA1 Message Date
Viresh Kumar 4dab160eb1 PM / OPP: Allow platform specific custom set_opp() callbacks
The generic set_opp() handler isn't sufficient for platforms with
complex DVFS.  For example, some TI platforms have multiple regulators
for a CPU device. The order in which various supplies need to be
programmed is only known to the platform code and its best to leave it
to it.

This patch implements APIs to register platform specific set_opp()
callback.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-06 02:27:59 +01:00
Viresh Kumar 947355850f PM / OPP: Separate out _generic_set_opp()
Later patches would add support for custom set_opp() callbacks. This
patch separates out the code for _generic_set_opp() handler in order to
prepare for that.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-06 02:27:59 +01:00
Viresh Kumar dfbe4678d7 PM / OPP: Add infrastructure to manage multiple regulators
This patch adds infrastructure to manage multiple regulators and updates
the only user (cpufreq-dt) of dev_pm_opp_set{put}_regulator().

This is preparatory work for adding full support for devices with
multiple regulators.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-06 02:27:59 +01:00
Viresh Kumar 0f0fe7e013 PM / OPP: Manage supply's voltage/current in a separate structure
This is a preparatory step for multiple regulator per device support.
Move the voltage/current variables to a new structure.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-06 02:27:59 +01:00
Masahiro Yamada 4bee77dc73 PM / OPP: make _of_get_opp_desc_node() a static function
Since commit f47b72a15a ("PM / OPP: Move CONFIG_OF dependent code
in a separate file"), this function is defined and called only in
drivers/base/power/opp/of.c .

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 15:36:07 +02:00
Viresh Kumar 79ee2e8f73 PM / OPP: Add 'UNKNOWN' status for shared_opp in struct opp_table
dev_pm_opp_get_sharing_cpus() returns 0 even in the case when the OPP
core doesn't know whether or not the table is shared. It works on the
majority of platforms, where the OPP table is never created before
invoking the function and then -ENODEV is returned by it.

But in the case of one platform (Jetson TK1) at least, the situation
is a bit different. The OPP table has been created (somehow) before
dev_pm_opp_get_sharing_cpus() is called and it returns 0. Its caller
treats that as 'the CPUs don't share OPPs' and that leads to degraded
performance.

Fix this by converting 'shared_opp' in struct opp_table to an enum
and making dev_pm_opp_get_sharing_cpus() return -EINVAL in case when
the value of that field is "access unknown", so that the caller can
handle it accordingly (cpufreq-dt considers that as 'all CPUs share
the table', for example).

Fixes: 6f707daa38 "PM / OPP: Add dev_pm_opp_get_sharing_cpus()"
Reported-and-tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw : Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-16 15:50:36 +02:00
Viresh Kumar f47b72a15a PM / OPP: Move CONFIG_OF dependent code in a separate file
Recently, a few issues were noticed in the code where CONFIG_OF wasn't
consistently used for many routines. The core file is big enough now and
ifdef hackery makes it less readable.

Move OF-specific code to another file and compile that only if CONFIG_OF
is enabled.

Compile-tested:
- For ARM (exynos) with CONFIG_OF enabled
- For X86 with CONFIG_OF disabled (have to enable CONFIG_PM_OPP separately)

No functional changes.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-06 13:22:49 +02:00
Viresh Kumar 2c2709dc69 PM / OPP: Rename structures for clarity
Stephen pointed out recently, that few structures always confuse him as
they aren't named properly. And this patch tries to address that:

Names are updated as:
- device_opp or dev_opp -> opp_table
- dev_opp_list -> opp_tables
- dev_opp_list_lock -> opp_table_lock
- device_list_opp -> opp_device (it was never a list, but a structure)
- list_dev -> opp_dev
- And similar changes in comments and function names as well.

This also fixes checkpatch warnings that were generated with this patch.

No functional changes.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-21 14:24:35 +01:00
Viresh Kumar d54974c251 PM / OPP: Manage device clk
OPP core has got almost everything now to manage device's OPP
transitions, the only thing left is device's clk. Get that as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-10 01:11:54 +01:00
Viresh Kumar 50f8cfbd58 PM / OPP: Parse clock-latency and voltage-tolerance for v1 bindings
V2 bindings have better support for clock-latency and voltage-tolerance
and doesn't need special care. To use callbacks, like
dev_pm_opp_get_max_{transition|volt}_latency(), irrespective of the
bindings, the core needs to know clock-latency/voltage-tolerance for the
earlier bindings.

This patch reads clock-latency/voltage-tolerance from the device node,
irrespective of the bindings (to keep it simple) and use them only for
V1 bindings.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-10 01:11:54 +01:00
Viresh Kumar 9f8ea969d5 PM / OPP: get/put regulators from OPP core
This allows the OPP core to request/free the regulator resource,
attached to a device OPP. The regulator device is fetched using the name
provided by the driver, while calling: dev_pm_opp_set_regulator().

This will work for both OPP-v1 and v2 bindings.

This is a preliminary step for moving the OPP switching logic into the
OPP core.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-10 01:11:53 +01:00
Viresh Kumar 01fb4d3c39 PM / OPP: Parse 'opp-<prop>-<name>' bindings
OPP bindings (for few properties) allow a platform to choose a
value/range among a set of available options. The options are present as
opp-<prop>-<name>, where the platform needs to supply the <name> string.

The OPP properties which allow such an option are: opp-microvolt and
opp-microamp.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_prop_name() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10 23:08:51 +01:00
Viresh Kumar 7de36b0aa5 PM / OPP: Parse 'opp-supported-hw' binding
OPP bindings allow a platform to enable OPPs based on the version of the
hardware they are used for.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_supported_hw() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10 23:08:51 +01:00
Viresh Kumar dc4e7b1fa2 PM / OPP: Add missing doc comments
Few doc-style comments were missing, add them. Rearrange another one to
match the sequence within the structure.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-23 23:42:40 +01:00
Viresh Kumar deaa514651 PM / OPP: Add debugfs support
This patch adds debugfs support to OPP layer to export OPPs and their
properties for all the devices.

This creates a top level directory: /sys/kernel/debug/opp and then
device specific directories (based on device names) inside it. For
example: 'cpu0', 'cpu1', etc..

If multiple devices share the OPP table, then the real directory is
created only for the first device. For all others, links are created to
the real directory.

Inside the device specific directory, a separate directory is created
for each OPP. And within that files per opp property.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-23 23:38:23 +01:00
Viresh Kumar 87b4115db0 PM / OPP: Protect updates to list_dev with mutex
dev_opp_list_lock is used everywhere to protect device and OPP lists,
but dev_pm_opp_set_sharing_cpus() is missed somehow. And instead we used
rcu-lock, which wouldn't help here as we are adding a new list_dev.

This also fixes a problem where we have called kzalloc(..., GFP_KERNEL)
from within rcu-lock, which isn't allowed as kzalloc can sleep when
called with GFP_KERNEL.

With CONFIG_DEBUG_ATOMIC_SLEEP set, we get following lockdep-splat:

include/linux/rcupdate.h:578 Illegal context switch in RCU read-side critical section!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
5 locks held by swapper/0/1:
 #0:  (&dev->mutex){......}, at: [<c02f68f4>] __driver_attach+0x48/0x98
 #1:  (&dev->mutex){......}, at: [<c02f6904>] __driver_attach+0x58/0x98
 #2:  (cpu_hotplug.lock){++++++}, at: [<c00249d0>] get_online_cpus+0x40/0xb0
 #3:  (subsys mutex#5){+.+.+.}, at: [<c02f4f8c>] subsys_interface_register+0x44/0xdc
 #4:  (rcu_read_lock){......}, at: [<c0305c80>] dev_pm_opp_set_sharing_cpus+0x0/0x1e4

stack backtrace:
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G        W       4.3.0-rc7-00047-g81f5932958a8 #59
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c0016874>] (unwind_backtrace) from [<c001355c>] (show_stack+0x10/0x14)
[<c001355c>] (show_stack) from [<c022553c>] (dump_stack+0x94/0xbc)
[<c022553c>] (dump_stack) from [<c004904c>] (___might_sleep+0x24c/0x298)
[<c004904c>] (___might_sleep) from [<c00f07e4>] (kmem_cache_alloc+0xe8/0x164)
[<c00f07e4>] (kmem_cache_alloc) from [<c0305354>] (_add_list_dev+0x30/0x58)
[<c0305354>] (_add_list_dev) from [<c0305d50>] (dev_pm_opp_set_sharing_cpus+0xd0/0x1e4)
[<c0305d50>] (dev_pm_opp_set_sharing_cpus) from [<c040eda4>] (cpufreq_init+0x4cc/0x62c)
[<c040eda4>] (cpufreq_init) from [<c040a964>] (cpufreq_online+0xbc/0x73c)
[<c040a964>] (cpufreq_online) from [<c02f4fe0>] (subsys_interface_register+0x98/0xdc)
[<c02f4fe0>] (subsys_interface_register) from [<c040a640>] (cpufreq_register_driver+0x110/0x17c)
[<c040a640>] (cpufreq_register_driver) from [<c040ef64>] (dt_cpufreq_probe+0x60/0x8c)
[<c040ef64>] (dt_cpufreq_probe) from [<c02f8084>] (platform_drv_probe+0x44/0xa4)
[<c02f8084>] (platform_drv_probe) from [<c02f67c0>] (driver_probe_device+0x208/0x2f4)
[<c02f67c0>] (driver_probe_device) from [<c02f6940>] (__driver_attach+0x94/0x98)
[<c02f6940>] (__driver_attach) from [<c02f4c1c>] (bus_for_each_dev+0x68/0x9c)

Reported-by: Michael Turquette <mturquette@baylibre.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.3 <stable@vger.kernel.org> # 4.3
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-06 23:59:41 +01:00
Viresh Kumar f59d3ee848 PM / OPP: Move cpu specific code to opp/cpu.c
Move cpu device specific code out of generic opp library, and add it to
cpu.c.

Along with that, create a core-internal opp.h header, which will be used
to share structures and function prototypes within opp core.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-15 02:03:16 +02:00