Commit Graph

4 Commits

Author SHA1 Message Date
Animesh Manna aa9145c4fa drm/i915/skl: Documentation for CSR firmware
Added docbook info regarding context save and restore (CSR)
firmware support added from gen9 onwards to drive newly added
DMC (Display microcontroller) in display engine.

v1: Initial version as RFC.

v2: Used "DOC:" tag for csr description based on review comment from Daniel.

Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-20 11:25:57 +02:00
Suketu Shah 5aefb2398a drm/i915/skl: Assert the requirements to enter or exit DC5.
Warn if the conditions to enter or exit DC5 are not satisfied such
as support for runtime PM, state of power well, CSR loading etc.

v2: Removed camelcase in functions and variables.

v3: Do some minimal check to assert if CSR program is not loaded.

v4:
1] Used an appropriate function lookup_power_well() to identify power well,
instead of using a magic number which can change in future.
2] Split the conditions further in assert_can_enable_DC5() and added more checks.
3] Removed all WARNs from assert_can_disable_DC5 as they were unnecessary and added two
   new ones.
4] Changed variable names as updated in earlier patches.

v5:
1] Change lookup_power_well function to take an int power well id.
2] Define a new intel_display_power_well_is_enabled helper function to check whether a
   particular power well is enabled.
3] Use CSR-related mutex in assert_csr_loaded function.

v6: Remove use of dc5_enabled variable as it's no longer needed.

v7:
1] Rebase to latest.
2] Move all DC5-related functions from intel_display.c to intel_runtime_pm.c.

v8: After adding dmc ver 1.0 support rebased on top of nightly. (Animesh)

v9: Modified below changes based on review comments from Imre.
- Moved intel_display_power_well_is_enabled() to intel_runtime_pm.c.
- Removed mutex lock from assert_csr_loaded(). (Animesh)

Issue: VIZ-2819
Signed-off-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Suketu Shah <suketu.j.shah@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-08 13:03:13 +02:00
Suketu Shah dc17430054 drm/i915/skl: Add DC5 Trigger Sequence
Add triggers as per expectations mentioned in gen9_enable_dc5
and gen9_disable_dc5 patch.

Also call POSTING_READ for every write to a register to ensure that
its written immediately.

v1: Remove POSTING_READ calls as they've already been added in previous patches.

v2: Rebase to move all runtime pm specific changes to intel_runtime_pm.c file.

Modified as per review comments from Imre:
1] Change variable name 'dc5_allowed' to 'dc5_enabled' to correspond to relevant
   functions.
2] Move the check dc5_enabled in skl_set_power_well() to disable DC5 into
   gen9_disable_DC5 which is a more appropriate place.
3] Convert checks for 'pm.dc5_enabled' and 'pm.suspended' in skl_set_power_well()
   to warnings. However, removing them for now as they'll be included in a future patch
   asserting DC-state entry/exit criteria.
4] Enable DC5, only when CSR firmware is verified to be loaded. Create new structure
   to track 'enabled' and 'deferred' status of DC5.
5] Ensure runtime PM reference is obtained, if CSR is not loaded, to avoid entering
   runtime-suspend and release it when it's loaded.
6] Protect necessary CSR-related code with locks.
7] Move CSR-loading call to runtime PM initialization, as power domains needed to be
   accessed during deferred DC5-enabling, are not initialized earlier.

v3: Rebase to latest.

Modified as per review comments from Imre:
1] Use blocking wait for CSR-loading to finish to enable DC5  for simplicity, instead of
   deferring enabling DC5 until CSR is loaded.
2] Obtain runtime PM reference during CSR-loading initialization itself as deferred DC5-
   enabling is removed and release it at the end of CSR-loading functionality.
3] Revert calling CSR-loading functionality to the beginning of i915 driver-load
   functionality to avoid any delay in loading.
4] Define another variable to track whether CSR-loading failed and use it to avoid enabling
   DC5 if it's true.
5] Define CSR-load-status accessor functions for use later.

v4:
1] Disable DC5 before enabling PG2 instead of after it.
2] DC5 was being mistaken enabled even when CSR-loading timed-out. Fix that.
3] Enable DC5-related functionality using a macro.
4] Remove dc5_enabled tracking variable and its use as it's not needed now.

v5:
1] Mark CSR failed to load where necessary in finish_csr_load function.
2] Use mutex-protected accessor function to check if CSR loaded instead of directly
   accessing the variable.
3] Prefix csr_load_status_get/set function names with intel_.

v6: rebase to latest.
v7: Rebase on top of nightly (Damien)
v8: Squashed the patch from Imre - added csr helper pointers to simplify the code. (Imre)
v9: After adding dmc ver 1.0 support rebased on top of nightly. (Animesh)
v10: Added a enum for different csr states, suggested by Imre. (Animesh)

v11: Based on review comments from Imre, Damien and Daniel following changes done
- enum name chnaged to csr_state (singular form).
- FW_UNINITIALIZED used as zeroth element in enum csr_state.
- Prototype changed for helper function(set/get csr status), using enum csr_state instead of bool.

v12: Based on review comment from Imre, introduced bool fw_loaded local to finish_csr_load() which helps
calling once to set the csr status. The same flag used to fail RPM if find any issue during
firmware loading.

Issue: VIZ-2819
Signed-off-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Suketu Shah <suketu.j.shah@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-08 13:03:11 +02:00
Daniel Vetter eb805623d8 drm/i915/skl: Add support to load SKL CSR firmware.
Display Context Save and Restore support is needed for
various SKL Display C states like DC5, DC6.

This implementation is added based on first version of DMC CSR program
that we received from h/w team.

Here we are using request_firmware based design.
Finally this firmware should end up in linux-firmware tree.

For SKL platform its mandatory to ensure that we load this
csr program before enabling DC states like DC5/DC6.

As CSR program gets reset on various conditions, we should ensure
to load it during boot and in future change to be added to load
this system resume sequence too.

v1: Initial relese as RFC patch

v2: Design change as per Daniel, Damien and Shobit's review comments
request firmware method followed.

v3: Some optimization and functional changes.
Pulled register defines into drivers/gpu/drm/i915/i915_reg.h
Used kmemdup to allocate and duplicate firmware content.
Ensured to free allocated buffer.

v4: Modified as per review comments from Satheesh and Daniel
Removed temporary buffer.
Optimized number of writes by replacing I915_WRITE with I915_WRITE64.

v5:
Modified as per review comemnts from Damien.
- Changed name for functions and firmware.
- Introduced HAS_CSR.
- Reverted back previous change and used csr_buf with u8 size.
- Using cpu_to_be64 for endianness change.

Modified as per review comments from Imre.
- Modified registers and macro names to be a bit closer to bspec terminology
and the existing register naming in the driver.
- Early return for non SKL platforms in intel_load_csr_program function.
- Added locking around CSR program load function as it may be called
concurrently during system/runtime resume.
- Releasing the fw before loading the program for consistency
- Handled error path during f/w load.

v6: Modified as per review comments from Imre.
- Corrected out_freecsr sequence.

v7: Modified as per review comments from Imre.
Fail loading fw if fw->size%8!=0.

v8: Rebase to latest.

v9: Rebase on top of -nightly (Damien)

v10: Enabled support for dmc firmware ver 1.0.
According to ver 1.0 in a single binary package all the firmware's that are
required for different stepping's of the product will be stored. The package
contains the css header, followed by the package header and the actual dmc
firmwares. Package header contains the firmware/stepping mapping table and
the corresponding firmware offsets to the individual binaries, within the
package. Each individual program binary contains the header and the payload
sections whose size is specified in the header section. This changes are done
to extract the specific firmaware from the package. (Animesh)

v11: Modified as per review comemnts from Imre.
- Added code comment from bpec for header structure elements.
- Added __packed to avoid structure padding.
- Added helper functions for stepping and substepping info.
- Added code comment for CSR_MAX_FW_SIZE.
- Disabled BXT firmware loading, will be enabled with dmc 1.0 support.
- Changed skl_stepping_info based on bspec, earlier used from config DB.
- Removed duplicate call of cpu_to_be* from intel_csr_load_program function.
- Used cpu_to_be32 instead of cpu_to_be64 as firmware binary in dword aligned.
- Added sanity check for header length.
- Added sanity check for mmio address got from firmware binary.
- kmalloc done separately for dmc header and dmc firmware. (Animesh)

v12: Modified as per review comemnts from Imre.
- Corrected the typo error in skl stepping info structure.
- Added out-of-bound access for skl_stepping_info.
- Sanity check for mmio address modified.
- Sanity check added for stepping and substeppig.
- Modified the intel_dmc_info structure, cache only the required header info. (Animesh)

v13: clarify firmware load error message.
The reason for a firmware loading failure can be obscure if the driver
is built-in. Provide an explanation to the user about the likely reason for
the failure and how to resolve it. (Imre)

v14: Suggested by Jani.
- fix s/I915/CONFIG_DRM_I915/ typo
- add fw_path to the firmware object instead of using a static ptr (Jani)

v15:
1) Changed the firmware name as dmc_gen9.bin, everytime for a new firmware version a symbolic link
with same name will help not to build kernel again.
2) Changes done as per review comments from Imre.
- Error check removed for intel_csr_ucode_init.
- Moved csr-specific data structure to intel_csr.h and optimization done on structure definition.
- fw->data used directly for parsing the header info & memory allocation
only done separately for payload. (Animesh)

v16:
- No need for out_regs label in i915_driver_load(), so removed it.
- Changed the firmware name as skl_dmc_ver1.bin, followed naming convention <platform>_dmc_<api-version>.bin (Animesh)

Issue: VIZ-2569
Signed-off-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-08 13:03:10 +02:00