The debugfs_create_dir() function does not return NULL, it returns error
pointers. But in normal situations like this where the caller is not
dereferencing "emc->debugfs.root" then we are not supposed to check the
return. So instead of fixing these checks, we should delete them.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YMCQDTSyG8UuQoh0@mwanda
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Use common devm_tegra_core_dev_init_opp_table() helper for the OPP table
initialization.
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Fix compilation warning on 64bit platforms caused by implicit promotion
of 32bit signed integer to a 64bit unsigned value which happens after
enabling compile-testing of the EMC drivers.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Probing of EMC drivers may be deferred and in this case we get duplicated
info messages during kernel boot. Use dev_info_once() helper to silence
the duplicated messages.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210330230445.26619-7-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
There is no point calling dev_pm_opp_set_clkname() with the "name"
parameter set to NULL, this is already done by the OPP core at setup
time and should work as it is.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/0f22cc1791d8b88c50a9790c2dc19455b34ec7b0.1611742564.git.viresh.kumar@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Now Internal and External memory controllers are memory interconnection
providers. This allows us to use interconnect API for tuning of memory
configuration. EMC driver now supports OPPs and DVFS. MC driver now
supports tuning of memory arbitration latency, which needs to be done
for ISO memory clients, like a Display client for example.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Acked-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201203192439.16177-4-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Clang warns:
drivers/memory/tegra/tegra30-emc.c:1275:15: warning: variable 'np' is uninitialized when used here [-Wuninitialized]
of_node_put(np);
^~
drivers/memory/tegra/tegra30-emc.c:1269:24: note: initialize the variable 'np' to silence this warning
There does not need to be an of_node_put call in this error handling
block after the shuffling of the np assignment. Remove it so there is
no use of uninitialized memory.
Fixes: 5e00fd90183a ("memory: tegra30-emc: Continue probing if timings are missing in device-tree")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201119195244.1517236-1-natechancellor@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
EMC driver will become mandatory after turning it into interconnect
provider because interconnect users, like display controller driver, will
fail to probe using newer device-trees that have interconnect properties.
Thus make EMC driver to probe even if timings are missing in device-tree.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201111011456.7875-9-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Add modularization support to the Tegra30 EMC driver, which now can be
compiled as a loadable kernel module.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201111011456.7875-8-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
The platform_get_irq() prints error message telling that interrupt is
missing, hence there is no need to duplicated that message in the drivers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201104164923.21238-31-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Multiple Tegra drivers need to retrieve Memory Controller and there is
duplication of the retrieval code among the drivers.
Add new devm_tegra_memory_controller_get() helper to remove the code's
duplication and to fix put_device() which was missed in the duplicated
code. Make EMC drivers to use the new helper.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201104164923.21238-29-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
The memory clock-rate change could be running on a non-boot CPU, while the
boot CPU handles the EMC interrupt. This introduces an unnecessary latency
since boot CPU should handle the interrupt and then notify the sibling CPU
about clock-rate change completion. In some rare cases boot CPU could be
in uninterruptible state for a significant time (like in a case of KASAN +
NFS root), it could get to the point that completion timeouts before boot
CPU gets a chance to handle interrupt. The solution is to get rid of the
completion and replace it with interrupt-status polling.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Replace the symbolic permissions with octals in order to make them
readable.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Correctly set clk rate-range if number of available timings is zero.
This fixes noisy "invalid range [4294967295, 0]" error messages during
boot.
Fixes: 8cee32b400 ("memory: tegra: Implement EMC debugfs interface on Tegra30")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The code waits for auto calibration to be finished and not to be disabled.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Previously there was a problem where a late handshake handling caused
a memory corruption, this problem was resolved by issuing calibration
command right after changing the timing, but looks like the solution
wasn't entirely correct since calibration interval could be disabled as
well. Now programming sequence is completed immediately after receiving
handshake from CaR, without potentially long delays and in accordance to
the TRM's programming guide.
Secondly, the TRM's programming guide suggests to flush EMC writes by
reading any *MC* register before doing CaR changes. This is also addressed
now.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The current code doesn't prevent race conditions of suspend/resume vs CCF.
Let's take exclusive control over the EMC clock during suspend in a way
that is free from race conditions.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
A common debugfs interface is already available on Tegra20, Tegra124,
Tegra186 and Tegra194. Implement the same interface on Tegra30 to enable
testing of the EMC frequency scaling code using a unified interface.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Trying to suspend driver results in a crash if timings aren't available in
device-tree.
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Fixes: e34212c75a ("memory: tegra: Introduce Tegra30 EMC driver")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Introduce driver for the External Memory Controller (EMC) found on Tegra30
chips, it controls the external DRAM on the board. The purpose of this
driver is to program memory timing for external memory on the EMC clock
rate change.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
