This contains a patch that allows the DFLL to use clock rates higher
than 2^31-1 Hz by using the ->determine_rate() operation instead of the
->round_rate() operation. Other than that there's a couple of cleanups
in preparation for Tegra210 support.
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Merge tag 'tegra-for-4.4-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next
clk: tegra: Changes for v4.4-rc1
This contains a patch that allows the DFLL to use clock rates higher
than 2^31-1 Hz by using the ->determine_rate() operation instead of the
->round_rate() operation. Other than that there's a couple of cleanups
in preparation for Tegra210 support.
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: Thierry 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: Thierry Reding <treding@nvidia.com>
Fixes: c4fe70ada4 ("clk: tegra: Add closed loop support for the DFLL")
[vince.h@nvidia.com: Unlock rcu on error path]
Signed-off-by: Vince Hsu <vince.h@nvidia.com>
[sboyd@codeaurora.org: Dropped second hunk that nested the rcu
read lock unnecessarily]
Signed-off-by: Stephen 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: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Signed-off-by: Thierry 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: Stephen 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: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: Michael Turquette <mturquette@linaro.org>
[treding@nvidia.com: move setup code into ->probe()]
Signed-off-by: Thierry 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: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Thierry 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: Paul Walmsley <pwalmsley@nvidia.com>
Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Michael Turquette