summaryrefslogtreecommitdiff
path: root/drivers/clk/tegra/clk-periph-gate.c
AgeCommit message (Collapse)AuthorFilesLines
2021-05-31clk: tegra: Don't deassert reset on enabling clocksDmitry Osipenko1-8/+0
The Tegra clock driver contains legacy code which deasserts hardware reset when peripheral clocks are enabled. This behaviour comes from a pre-CCF era of the Tegra drivers. This is unacceptable for modern kernel drivers which use generic CCF and reset-control APIs because it breaks assumptions of the drivers about clk/reset sequences and about reset-propagation delays. Hence remove the awkward legacy behaviour from the clk driver. In particular PMC driver assumes that hardware blocks remains in reset while power domain is turning on, but the clk driver deasserts the reset before power clamp is removed, hence breaking the driver's assumption. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2021-05-31clk: tegra: Fix refcounting of gate clocksDmitry Osipenko1-25/+47
The refcounting of the gate clocks has a bug causing the enable_refcnt to underflow when unused clocks are disabled. This happens because clk provider erroneously bumps the refcount if clock is enabled at a boot time, which it shouldn't be doing, and it does this only for the gate clocks, while peripheral clocks are using the same gate ops and the peripheral clocks are missing the initial bump. Hence the refcount of the peripheral clocks is 0 when unused clocks are disabled and then the counter is decremented further by the gate ops, causing the integer underflow. Fix this problem by removing the erroneous bump and by implementing the disable_unused() callback, which disables the unused gates properly. The visible effect of the bug is such that the unused clocks are never gated if a loaded kernel module grabs the unused clocks and starts to use them. In practice this shouldn't cause any real problems for the drivers and boards supported by the kernel today. Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201Thomas Gleixner1-12/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 228 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-20clk: tegra: Fix disable unused for clocks sharing enable bitPeter De Schrijver1-0/+3
In case 2 clocks share an enable bit and one of them is enabled by a driver and the other one is not, CCF will think it's enabled because it will only look at the HW state. Therefore it will disable the clock and thus also disable the other clock which was enabled. Solve this by reading the initial state of the enable bit and incrementing the refcount if it's set. Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-04-28clk: tegra: Constify peripheral clock registersThierry Reding1-1/+1
The peripheral clock registers are defined in static tables. These tables never need to be modified at runtime, so they can reside in read-only memory. Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-07-20clk: tegra: Properly include clk.hStephen Boyd1-1/+0
Clock provider drivers generally shouldn't include clk.h because it's the consumer API. Only include clk.h in files that are using it. Also add in a clkdev.h include that was missing in a file using clkdev APIs. Cc: Peter De Schrijver <pdeschrijver@nvidia.com> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2014-07-17ARM: tegra: Move includes to include/soc/tegraThierry Reding1-1/+2
In order to not clutter the include/linux directory with SoC specific headers, move the Tegra-specific headers out into a separate directory. Signed-off-by: Thierry Reding <treding@nvidia.com>
2013-12-12clk: tegra: remove legacy reset APIsStephen Warren1-22/+0
Now that no code uses the custom Tegra module reset API, we can remove its implementation. Signed-off-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thierry Reding <treding@nvidia.com> Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
2013-11-26clk: tegra: simplify periph clock dataPeter De Schrijver1-2/+6
This patch determines the register bank for clock enable/disable and reset based on the clock ID instead of hardcoding it in the tables describing the clocks. This results in less data to be maintained in the tables, making the code easier to understand. The full benefit of the change will be realized once also other clocktypes will be table based. Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
2013-04-05clk: tegra: Workaround for Tegra114 MSENC problemPeter De Schrijver1-0/+9
Workaround a hardware bug in MSENC during clock enable. Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com> Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-04-05clk: tegra: Fix periph_clk_to_bit macroYen Lin1-1/+1
The parameter name should be "gate", not "periph". This worked, however, because it happens that everywhere periph_clk_to_bit is called, "gate" was in the local scope. Signed-off-by: Yen Lin <yelin@nvidia.com> Signed-off-by: Andrew Chew <achew@nvidia.com> Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com> Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com> Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-01-28clk: tegra: add Tegra specific clocksPrashant Gaikwad1-0/+179
Add Tegra specific clocks, pll, pll_out, peripheral, frac_divider, super. Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com> [swarren: alloc sizeof(*foo) not sizeof(struct foo), add comments re: storing pointers to stack variables, make a timeout loop more idiomatic, use _clk_pll_disable() not clk_disable_pll() from _program_pll() to avoid redundant lock operations, unified tegra_clk_periph() and tegra_clk_periph_nodiv(), unified tegra_clk_pll{,e}, rename all clock registration functions so they don't have the same name as the clock structs, return -EINVAL from clk_plle_enable when matching table rate not found, pass ops to _tegra_clk_register_pll rather than a bool.] Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Stephen Warren <swarren@nvidia.com>