Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros * AI Coding Assistant - LLMs and AI-powered development tools For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst AI Coding Assistant ------------------- CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and follow the AI coding assistants documentation before contributing to the Linux kernel: * Documentation/process/coding-assistants.rst This documentation contains essential requirements about licensing, attribution, and the Developer Certificate of Origin that all AI tools must comply with. Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
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The static 'struct qcom_cc_driver_data' contains probe match-like data
and is not modified: neither by the driver defining it nor by common.c
code using it.
Make it const for code safety and code readability.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260331091721.61613-3-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Static 'struct qcom_cc_desc' is not modified by drivers and can be made
const for code safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260331085521.37337-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Support the graphics clock controller for SM8750 for Graphics SW
driver to use the clocks. GXCLKCTL (Graphics GX Clock Controller) is a
block dedicated to managing clocks for the GPU subsystem on GX power
domain. The GX clock controller driver manages only the GX GDSC and the
rest of the resources of the controller are managed by the firmware.
Update the compatible for Graphics GX Clock Controller for SM8750 as the
GX clock controller is a reuse of the Kaanapali driver.
Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Co-developed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Signed-off-by: Taniya Das <taniya.das@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260305-gpucc_sm8750_v2-v5-2-78292b40b053@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The SM8750 features a "traditional" GPU_CC block, much of which is
controlled through the GMU microcontroller. GPU_CC block requires the MX
and CX rail control and thus add the corresponding power-domains and
require-opps. Additionally, there's an separate GX_CC block, where
the GX GDSC is moved.
Update the bindings to accommodate for SM8750 SoC.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Taniya Das <taniya.das@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260305-gpucc_sm8750_v2-v5-1-78292b40b053@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The CMN PLL in IPQ8074 SoC supplies fixed clocks to the networking
subsystem: bias_pll_cc_clk at 300 MHz and bias_pll_nss_noc_clk at
416.5 MHz.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20260311183942.10134-5-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The CMN PLL block in the IPQ8074 SoC takes 48 MHz as the reference
input clock. Its output clocks are the bias_pll_cc_clk (300 MHz) and
bias_pll_nss_noc_clk (416.5 MHz) clocks used by the networking
subsystem.
Add the related compatible for IPQ8074 to the ipq9574-cmn-pll
generic schema.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260311183942.10134-4-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The CMN PLL in IPQ6018 SoC supplies fixed clocks to the networking
subsystem: bias_pll_cc_clk at 300 MHz and bias_pll_nss_noc_clk at
416.5 MHz.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20260311183942.10134-3-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The CMN PLL block in the IPQ6018 SoC takes 48 MHz as the reference
input clock. Its output clocks are the bias_pll_cc_clk (300 MHz) and
bias_pll_nss_noc_clk (416.5 MHz) clocks used by the networking
subsystem.
Add the related compatible for IPQ6018 to the ipq9574-cmn-pll
generic schema.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260311183942.10134-2-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Some pm subdomains may be left in added to a parent domain state, if
gdsc_add_subdomain_list() function fails in the middle and bails from
a GDSC power domain controller registration out.
Fixes: b489235b4dc0 ("clk: qcom: Support attaching GDSCs to multiple parents")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Bryan O'Donoghue <bod@kernel.org>
Link: https://lore.kernel.org/r/20260328012619.832770-1-vladimir.zapolskiy@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
In order for the GCC votes on the GDSCs it provides to be propagated
to CX, CX needs to be declared as power domain of the GCC.
Document the missing power-domains property to that purpose.
Fixes: 95ba6820a665 ("dt-bindings: clock: qcom: document the Milos Global Clock Controller")
Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260327-dt-fix-milos-eliza-gcc-power-domains-v1-1-f14a22c73fe9@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
According to internal documentation, the UFS AXI PHY clock requires
FORCE_MEM_CORE_ON to be enabled for UFS MCQ mode to work. Without this,
the UFS controller fails when operating in MCQ mode, which is already
enabled in the device tree.
The UFS PHY ICE core clock already has this bit set, so apply the same
configuration to the UFS PHY AXI clock.
Fixes: 3d356ab4a1ec ("clk: qcom: Add support for Global clock controller on Eliza")
Reported-by: Nitin Rawat <nitin.rawat@oss.qualcomm.com>
Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260323-eliza-gcc-set-ufs-axi-phyforce-mem-core-on-v1-1-b6b7a6f3f8c5@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The MDSS resets have so far been left undescribed. Fix that.
Fixes: dd3d06622138 ("clk: qcom: Add display clock controller driver for SC7180")
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # sc7180-ecs-liva-qc710
Link: https://lore.kernel.org/r/20260120-topic-7180_dispcc_bcr-v1-2-0b1b442156c3@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Merge the addition of reset constants to the SC7180 display clock
controller through a topic branch, in order to make them available to
the DeviceTree branch as well.
Recently, when testing 10-bit dsi C-PHY panel, clks are different
from the usual. (dsi0_phy_pll_out_dsiclk's parent is dsi0_pll_bit_clk
now (dsiclk_sel = 0)) And we failed to set dsiclk's children.
dsi_link_clk_set_rate_6g: Set clk rates: pclk=172992000, byteclk=108120000
byteclk was set first to 108120000, so the vco rate was set to
108120000 * 7 * 1 * 1 = 756840000. When we was trying to set
172992000 on mdss_pixel_clk_src later.
Since there was no matched ratio, we failed to set it. And dsiclk
divider ratio was set to 15:1 (wrong cached register value 0xf and
didn't update), we finally got 50455997, apparently wrong.
dsi0vco_clk 1 1 0 756839941
dsi0_pll_out_div_clk 1 1 0 756839941
dsi0_pll_post_out_div_clk 0 0 0 216239983
dsi0_pll_bit_clk 2 2 0 756839941
dsi0_phy_pll_out_dsiclk 2 2 0 50455997
disp_cc_mdss_pclk1_clk_src 1 1 0 50455997
dsi0_pll_by_2_bit_clk 0 0 0 378419970
dsi0_phy_pll_out_byteclk 2 2 0 108119991
disp_cc_mdss_byte1_clk_src 2 2 0 108119991
Downstream clk_summary shows the mdss_pixel_clk_src support the
ratio(35:16)
dsi0_phy_pll_out_dsiclk 2 2 0 378420000
disp_cc_mdss_pclk1_clk_src 1 1 0 172992000
dsi0_phy_pll_out_byteclk 2 2 0 108120000
disp_cc_mdss_byte1_clk_src 2 2 0 108120000
After checking downstream source, 15:4 also seems to be supported,
add them two.
Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260321095029.2259489-1-mitltlatltl@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The MDSS resets have so far been left undescribed. Fix that.
Fixes: 75616da71291 ("dt-bindings: clock: Introduce QCOM sc7180 display clock bindings")
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # sc7180-ecs-liva-qc710
Link: https://lore.kernel.org/r/20260120-topic-7180_dispcc_bcr-v1-1-0b1b442156c3@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Add a driver for the display clock controller on Qualcomm Eliza SoC,
which is copied from SM8750 driver plus changes:
1. Additional DT_HDMI_PHY_PLL_CLK clock input,
2. Eight new HDMI clocks,
3. Different PLLs (lucid and pongo).
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260319-clk-qcom-dispcc-eliza-v3-2-d1f2b19a6e6b@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
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