This patch updates dev_pm_opp_find_freq_*() routines to get a reference
to the OPPs returned by them.

Also updates the users of dev_pm_opp_find_freq_*() routines to call
dev_pm_opp_put() after they are done using the OPPs.

As it is guaranteed the that OPPs wouldn't get freed while being used,
the RCU read side locking present with the users isn't required anymore.
Drop it as well.

This patch also updates all users of devfreq_recommended_opp() which was
returning an OPP received from the OPP core.

Note that some of the OPP core routines have gained
rcu_read_{lock|unlock}() calls, as those still use RCU specific APIs
within them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> [Devfreq]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of copying parts of the CVB table into a separate structure,
keep track of the selected CVB table and directly reference data from
it.
Signed-off-by: NThierry Reding <treding@nvidia.com>

This flag is a no-op now. Remove usage of the flag.
Acked-by: NRhyland Klein <rklein@nvidia.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

The monitor code is used with DEBUG_FS only, so move it into the
corresponding #ifdef block to avoid potential compiler warnings.
Signed-off-by: NThierry Reding <treding@nvidia.com>

The OPP list needs to be protected against concurrent accesses. Using
simple RCU read locks does the trick and gets rid of the following
lockdep warning:

	===============================
	[ INFO: suspicious RCU usage. ]
	4.2.0-next-20150908 #1 Not tainted
	-------------------------------
	drivers/base/power/opp.c:460 Missing rcu_read_lock() or dev_opp_list_lock protection!

	other info that might help us debug this:

	rcu_scheduler_active = 1, debug_locks = 0
	4 locks held by kworker/u8:0/6:
	 #0:  ("%s""deferwq"){++++.+}, at: [<c0040d8c>] process_one_work+0x118/0x4bc
	 #1:  (deferred_probe_work){+.+.+.}, at: [<c0040d8c>] process_one_work+0x118/0x4bc
	 #2:  (&dev->mutex){......}, at: [<c03b8194>] __device_attach+0x20/0x118
	 #3:  (prepare_lock){+.+...}, at: [<c054bc08>] clk_prepare_lock+0x10/0xf8

	stack backtrace:
	CPU: 2 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.0-next-20150908 #1
	Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
	Workqueue: deferwq deferred_probe_work_func
	[<c001802c>] (unwind_backtrace) from [<c00135a4>] (show_stack+0x10/0x14)
	[<c00135a4>] (show_stack) from [<c02a8418>] (dump_stack+0x94/0xd4)
	[<c02a8418>] (dump_stack) from [<c03c6f6c>] (dev_pm_opp_find_freq_ceil+0x108/0x114)
	[<c03c6f6c>] (dev_pm_opp_find_freq_ceil) from [<c0551a3c>] (dfll_calculate_rate_request+0xb8/0x170)
	[<c0551a3c>] (dfll_calculate_rate_request) from [<c0551b10>] (dfll_clk_round_rate+0x1c/0x2c)
	[<c0551b10>] (dfll_clk_round_rate) from [<c054de2c>] (clk_calc_new_rates+0x1b8/0x228)
	[<c054de2c>] (clk_calc_new_rates) from [<c054e44c>] (clk_core_set_rate_nolock+0x44/0xac)
	[<c054e44c>] (clk_core_set_rate_nolock) from [<c054e4d8>] (clk_set_rate+0x24/0x34)
	[<c054e4d8>] (clk_set_rate) from [<c0512460>] (tegra124_cpufreq_probe+0x120/0x230)
	[<c0512460>] (tegra124_cpufreq_probe) from [<c03b9cbc>] (platform_drv_probe+0x44/0xac)
	[<c03b9cbc>] (platform_drv_probe) from [<c03b84c8>] (driver_probe_device+0x218/0x304)
	[<c03b84c8>] (driver_probe_device) from [<c03b69b0>] (bus_for_each_drv+0x60/0x94)
	[<c03b69b0>] (bus_for_each_drv) from [<c03b8228>] (__device_attach+0xb4/0x118)
	ata1: SATA link down (SStatus 0 SControl 300)
	[<c03b8228>] (__device_attach) from [<c03b77c8>] (bus_probe_device+0x88/0x90)
	[<c03b77c8>] (bus_probe_device) from [<c03b7be8>] (deferred_probe_work_func+0x58/0x8c)
	[<c03b7be8>] (deferred_probe_work_func) from [<c0040dfc>] (process_one_work+0x188/0x4bc)
	[<c0040dfc>] (process_one_work) from [<c004117c>] (worker_thread+0x4c/0x4f4)
	[<c004117c>] (worker_thread) from [<c0047230>] (kthread+0xe4/0xf8)
	[<c0047230>] (kthread) from [<c000f7d0>] (ret_from_fork+0x14/0x24)
Signed-off-by: NThierry Reding <treding@nvidia.com>
Fixes: c4fe70ad ("clk: tegra: Add closed loop support for the DFLL")
[vince.h@nvidia.com: Unlock rcu on error path]
Signed-off-by: NVince Hsu <vince.h@nvidia.com>
[sboyd@codeaurora.org: Dropped second hunk that nested the rcu
read lock unnecessarily]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

The new determine_rate prototype allows for clock rates exceeding
2^31-1 Hz to be used. Switch the DFLL clock to use determine_rate
instead of round_rate and unlock the top rates supported by the
Tegra124.
Signed-off-by: NMikko Perttunen <mikko.perttunen@kapsi.fi>
Signed-off-by: NThierry Reding <treding@nvidia.com>

The latest Tegra clk pull had some problems. Fix them.

drivers/clk/tegra/clk-tegra124.c:1450:6: warning: symbol 'tegra124_clock_assert_dfll_dvco_reset' was not declared. Should it be static?
drivers/clk/tegra/clk-tegra124.c:1466:6: warning: symbol 'tegra124_clock_deassert_dfll_dvco_reset' was not declared. Should it be static?
drivers/clk/tegra/clk-tegra124.c:1476:5: warning: symbol 'tegra124_reset_assert' was not declared. Should it be static?
drivers/clk/tegra/clk-tegra124.c:1486:5: warning: symbol 'tegra124_reset_deassert' was not declared. Should it be static?
drivers/clk/tegra/clk-dfll.c:590 dfll_load_i2c_lut() warn: inconsistent indenting
drivers/clk/tegra/clk-dfll.c:1448 dfll_build_i2c_lut() warn: unsigned 'td->i2c_lut[0]' is never less than zero.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

Add basic platform driver support for the fast CPU cluster DFLL
clocksource found on Tegra124 SoCs. This small driver selects the
appropriate Tegra124-specific characterization data and integration
code. It relies on the DFLL common code to do most of the work.
Signed-off-by: NTuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: NMikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: NMichael Turquette <mturquette@linaro.org>
[treding@nvidia.com: move setup code into ->probe()]
Signed-off-by: NThierry Reding <treding@nvidia.com>

With closed loop support, the clock rate of the DFLL can be adjusted.

The oscillator itself in the DFLL is a free-running oscillator whose
rate is directly determined the supply voltage. However, the DFLL
module contains logic to compare the DFLL output rate to a fixed
reference clock (51 MHz) and make a decision to either lower or raise
the DFLL supply voltage. The DFLL module can then autonomously change
the supply voltage by communicating with an off-chip PMIC via either I2C
or PWM signals. This driver currently supports only I2C.
Signed-off-by: NTuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: NMikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: NPeter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: NMichael Turquette <mturquette@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>

Add shared code to support the Tegra DFLL clocksource in open-loop
mode. This root clocksource is present on the Tegra124 SoCs. The
DFLL is the intended primary clock source for the fast CPU cluster.

This code is very closely based on a patch by Paul Walmsley from
December (http://comments.gmane.org/gmane.linux.ports.tegra/15273),
which in turn comes from the internal driver by originally created
by Aleksandr Frid <afrid@nvidia.com>.

Subsequent patches will add support for closed loop mode and drivers
for the Tegra124 fast CPU cluster DFLL devices, which rely on this
code.
Signed-off-by: NPaul Walmsley <pwalmsley@nvidia.com>
Signed-off-by: NTuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: NMikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: NPeter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: NMichael Turquette <mturquette@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>