Hello,
Couple years ago the Tegra20 EMC driver was removed from the kernel
due to incompatible changes in the Tegra's clock driver. This patchset
introduces a modernized EMC driver. Currently the sole purpose of the
driver is to initialize DRAM frequency to maximum rate during of the
kernels boot-up. Later we may consider implementing dynamic memory
frequency scaling, utilizing functionality provided by this driver.
Changelog:
v4:
- Fixed "bad of_node_put()" error which was revealed by enabling
some extra kernel debug config options.
- The "emc-table" DT nodes are now parsed starting from the "emc"
node instead of the DT root.
- Adjusted code comment in the "Turn EMC clock gate into divider"
patch as was suggested by Stephen Boyd to the v3.
v3:
- Handle "nvidia,use-ram-code" DT property, its handling was missed
in the previous versions.
- Honor "emc-tables" DT node naming which is explicitly specified
in the DT binding, also was missed in the previous versions.
- Two new DT binding patches: one adds the EMC clock property,
other relocates the binding doc file to the appropriate directory.
One new patch that adds EMC clock property to the DTS file.
- Addressed v2 review comments from Thierry Reding. Driver does not
preserve backwards compatibility with older device tree binding.
- The PLL_M and PLL_P clocks are kept internal to the driver because
after some more considering I couldn't find a really good reason why
these clocks should be in the device tree.
- Some minor cleanups and fixes in the drivers code.
v2:
- Minor code cleanups like consistent use of writel_relaxed instead
of non-relaxed version, reworded error messages, etc.
- Factored out use_pllm_ud bit checking into a standalone patch for
consistency.
Dmitry Osipenko (8):
dt: bindings: tegra20-emc: Document interrupt property
dt: bindings: tegra20-emc: Document clock property
dt: bindings: Move tegra20-emc binding to memory-controllers directory
ARM: dts: tegra20: Add interrupt entry to External Memory Controller
ARM: dts: tegra20: Add clock entry to External Memory Controller
clk: tegra20: Turn EMC clock gate into divider
clk: tegra20: Check whether direct PLLM sourcing is turned off for EMC
memory: tegra: Introduce Tegra20 EMC driver
.../nvidia,tegra20-emc.txt | 4 +
arch/arm/boot/dts/tegra20.dtsi | 2 +
drivers/clk/tegra/clk-tegra20.c | 46 +-
drivers/memory/tegra/Kconfig | 10 +
drivers/memory/tegra/Makefile | 1 +
drivers/memory/tegra/tegra20-emc.c | 575 ++++++++++++++++++
6 files changed, 628 insertions(+), 10 deletions(-)
rename Documentation/devicetree/bindings/{arm/tegra =>
memory-controllers}/nvidia,tegra20-emc.txt (95%)
create mode 100644 drivers/memory/tegra/tegra20-emc.c
--
2.18.0
