On Fri, 17 Oct 2025 at 17:32, Nicolas Frattaroli <[email protected]> wrote: > > This series introduces two new drivers to accomplish controlling the > frequency and power of the Mali GPU on MediaTek MT8196 SoCs. > > The reason why it's not as straightforward as with other SoCs is that > the MT8196 has quite complex glue logic in order to squeeze the maximum > amount of performance possible out of the silicon. There's an additional > MCU running a specialised firmware, which communicates with the > application processor through a mailbox and some reserved memory, and is > in charge of controlling the regulators, the PLL clocks, and the power > gating of the GPU, all while also being in charge of any DVFS control. > > This set of drivers is enough to communicate desired OPP index limits to > the aforementioned MCU, referred to as "GPUEB" from here on out. The > GPUEB is still free to lower the effective frequency if the GPU has no > jobs going on at all, even when a higher OPP is set. > > The power- and frequency control driver, mtk-mfg-pmdomain, is now > implemented as a power domain driver, with a set_performance_state > operation. It also exposes itself as a clock provider, so that panthor > can read the actual achieved DVFS clock rate as per the GPUEB firmware. > > This power domain approach means that panthor does not need to know > about how the frequency control works on this SoC, as the OPP core > framework already takes care of it. The only exception is that panthor > needs to not register OPPs from DT itself if there already is an OPP > table present. > > The mailbox driver is a fairly bog-standard common mailbox framework > driver, just specific to the firmware that runs on the GPUEB. It was > merged in v6.18 already. > > Signed-off-by: Nicolas Frattaroli <[email protected]>
This looks good to me! I can certainly pick up patch2 and patch5, but before I go ahead I just wanted to check what is the preferred merging strategy? The drm/gpu patches can go independently from the pmdomain patches others, right? In either case, I can pick this complete series too via my pmdomain tree, if that makes sense for everyone. Please let me know. Kind regards Uffe > --- > Changes in v8: > - mtk-mfg-pmdomain: remove unused shmem variable that caused a warning > on GCC, but not clang > - Link to v7: > https://lore.kernel.org/r/[email protected] > > Changes in v7: > - panthor: rename "t" to "table" > - panthor: add code comment explaining why an existing OPP table is > being checked for > - mtk-mfg-pmdomain: use GF_REG_MAGIC offset for sake of consistency > - mtk-mfg-pmdomain: remove redundant semicolon after mtk_mfg_mt8196_init > - mtk-mfg-pmdomain: fix resource leaks on probe failure > - mtk-mfg-pmdomain: enable/disable EB clock during MT8196 init, which is > needed for the register read > - Rebase onto next-20251014, which drops already merged patches, namely > mailbox driver+bindings, and drops the ASN_HASH patch series > dependency, which was also merged > - Link to v6: > https://lore.kernel.org/r/[email protected] > > Changes in v6: > - mailbox: move buf definition into if condition, as per Chia-I Wu > - panthor: remove the redundant NULL checks in panthor_devfreq_get_freq > - mtk-mfg-pmdomain: adjust return style consistency > - mtk-mfg-pmdomain: add docstring for mtk_mfg_send_ipi to explain it's > blocking > - mtk-mfg-pmdomain: use CMD_FIX_DUAL_TARGET_OPPIDX instead of > CMD_FIX_TARGET_OPPIDX. > - mtk-mfg-pmdomain: reword code comments to not be in the "we" style > - mtk-mfg-pmdomain: shuffle around mbox allocations as per Angelo > - mtk-mfg-pmdomain: don't pointlessly turn on EB clock in probe, > reducing the need for a comment explaining the bookkeeping > - mtk-mfg-pmdomain: consistently use dev_err_probe and Capitalise first > letter of error string > - mtk-mfg-pmdomain: get rid of redundant ret = dev_err_probe assignment > - mtk-mfg-pmdomain: reintroduce stack OPP table, choose min(gpu, stack) > when adding frequencies. Fixes gaps in OPP levels where only stack > changed, but gpu had duplicates, which resulted in choosing a too slow > OPP > - mtk-mfg-pmdomain: stub round_rate clk op to opt out of CCF always > "rounding" a devfreq rate request to the current rate > - Link to v5: > https://lore.kernel.org/r/[email protected] > > Changes in v5: > - mtk-mfg-pmdomain binding: add memory-regions property, remove shmem > property, as we now correctly describe the shared memory as a regular > memory region > - mtk-mfg-pmdomain binding: get rid of redundant | > - drop "dt-bindings: sram: Add compatible for > mediatek,mt8196-gpufreq-sram" as part of the move to reserved memory > - mtk-mfg-pmdomain: move to using reserved-memory for GPUEB shared > memory > - mtk-mfg-pmdomain: demote some types to smaller sizes in struct > mtk_mfg, as per Angelo's suggestions > - mtk-mfg-pmdomain: use units.h for Hz-to-KHz > - mtk-mfg-pmdomain: change for loop in attach_dev to reduce indentation > - mtk-mfg-pmdomain: simplify return in mtk_mfg_power_off > - mtk-mfg-pmdomain: move of_device_id after probe > - mtk_mfg_pmdomain: map mmio by index > - mtk_mfg_pmdomain: add error checking to pm_genpd_init() > - mtk_mfg_pmdomain: add remove function > - mtk_mfg_pmdomain: remove last_opp member and logic, since OPP core > already does that for us > - mtk_mfg_pmdomain: adjust comment in mtk_mfg_set_performance to explain > why we're doing what we're doing > - mtk_mfg_pmdomain: call mtk_mfg_set_oppidx in mtk_mfg_power_on with > the performance_state we deferred setting while it was powered off > - mtk_mfg_pmdomain: add inline function for PWR_ACK checking, as it's > now used twice with the added remove function > - mtk-mfg-pmdomain: add suppress_bind_attrs so people don't play with > that > - mtk-mfg-pmdomain: change KConfig from tristate to bool, as module > unloading results in strange likely firmware-induced hardware state > woes in the mali GPU > - mtk-mfg-pmdomain: read IPI magic in power_on, don't zero it after > confirming that seemingly had no purpose > - mtk-mfg-pmdomain: misc style changes > - Link to v4: > https://lore.kernel.org/r/[email protected] > > Changes in v4: > - rebase onto next-20250922, which includes Laura Nao's clock patches > - refactor mediatek_mfg into a pmdomain driver called "mtk-mfg-pmdomain" > - move mt8196-gpufreq binding to the power subdirectory > - mali-valhall-csf binding: adjust for power-domains usage > - mali-valhall-csf binding: use clocks on mt8196 > - mailbox: prefix defines with "GPUEB_" > - mailbox: get rid of custom of_xlate > - mailbox: rename "CLOGGED" to "BLOCKED" > - mailbox: adjust send_data comment to include more technical info > - mailbox: misc style improvements > - panthor: drop "drm/panthor: devfreq: make get_dev_status use > get_cur_freq", as it is now not necessary and makes the code worse > - panthor: drop "drm/panthor: devfreq: add pluggable devfreq providers" > - panthor: drop "drm/panthor: add no_clocks soc_data member for MT8196", > as we now have clocks courtesy of gpufreq > - panthor: check for existing opp table before registering a new one > - mtk-mfg-pmdomain: add turbo_below variant data, which marks OPPs below > a certain index as turbo for the OPP subsystem > - mtk-mfg-pmdomain: no longer read stack OPPs, as they weren't used > - mtk-mfg-pmdomain: get rid of num gpu opp != num stack opp check. > That's the firmware's problem should it ever happen, not ours > - mtk-mfg-pmdomain: some small name and whitespace changes on the defines > - Link to v3: > https://lore.kernel.org/r/[email protected] > > Changes in v3: > - mali-valhall-csf binding: get rid of clocks for MT8196, rebase onto > Chia-I Wu's patch > - mt8196-gpufreq binding: rename hw_revision to hw-revision > - mt8196-gpufreq binding: rename clocks > - mt8196-gpufreq binding: drop pointless label in example > - mailbox binding: drop pointless label in example > - mailbox: whitespace changes on defines > - mailbox: remove rx_buf member from channel struct, use stack buffer > - mailbox: check in probe that no rx_len exceeds MBOX_MAX_RX_SIZE > - panthor: add no_clocks SoC data patch, also rebase onto Chia-I Wu's > series > - panthor: refactor devfreq provider functionality to do allocation and > initialisation of panthor_devfreq struct in panthor in all cases > - panthor: drop the patch that moves struct panthor_devfreq to a header > file, as it no longer needs to be exposed to devfreq providers > - mediatek_mfg: refactor devfreq provider functionality to decouple it > more from panthor itself > - mediatek_mfg: move SRAM magic to a #define > - mediatek_mfg: begrudgingly rename member "padding_lol" to "reserved" > - mediatek_mfg: use local struct device pointer var in more places > - mediatek_mfg: change wording of sleep command failure error message, > but keep the format specifier because I don't want to throw bare > errnos at users > - mediatek_mfg: remove unnecessary braces around dev_err EB power off > timeout message > - mediatek_mfg: allocate rx_data for channels that expect a response > - mediatek_mfg: memcpy the rx buffer from the common mailbox framework > in the rx callback to rx_data, as mssg now points to stack memory > - mediatek_mfg: make SRAM clearing message dev_dbg > - mediatek_mfg: no longer print physical address of SRAM > - mediatek_mfg: expand on the GF_REG_OPP_TABLE_STK comment, toning down > its defeatist attitude in the process > - mediatek_mfg: style fixes in mtk_mfg_get_closest_opp_idx > - mediatek_mfg: rename clocks and hw-revision reg as per binding > - Link to v2: > https://lore.kernel.org/r/[email protected] > > Changes in v2: > - mali-valhall-csf binding: move from performance-controller to > performance-domains property > - mali-valhall-csf binding: fix vendor name oopsie in compatible of if > condition > - mt8196-gpufreq binding: move from performance-controller to > performance-domains by adding the cells property > - mt8196-gpufreq binding: rename e2_id to hw_revision > - mt8196-gpufreq binding: add description that mentions "MediaTek > Flexible Graphics" > - mt8196-gpufreq binding: get rid of mailbox channels we're unlikely to > use any time soon, if ever > - mt8196-gpufreq binding: change name of mailbox channels to use - > instead of _ > - mailbox binding: change reg-names to "data" and "ctl" > - drm/panthor: mediatek_mfg: rename e2_id to hw_revision > - drm/panthor: devfreq: switch from performance-controller to > performance-domains > - drm/panthor: devfreq: get rid of the accidental get_cur_freq function > move > - mailbox: rename mtk_gpueb_mbox_ch to mtk_gpueb_mbox_chan_desc > - mailbox: use smaller types in mtk_gpueb_mbox_chan_desc where possible > - mailbox: add per-channel runtime data struct > - mailbox: request one threaded IRQ per channel, pass channel struct as > data > - mailbox: make num_channels in variant struct u8 > - mailbox: get rid of no_response, as it was redundant > - mailbox: enable and disable clock in mailbox startup/shutdown > - mailbox: point con_priv of mailbox framework channel struct to this > driver's channel struct > - mailbox: request and free the threaded IRQ in startup/shutdown > - mailbox: only clear IRQ bit flag once RX data has been read from MMIO > - mailbox: reduce needlessly large receive buffer size > - mailbox: handle allocation errors wherever they could pop up > - mailbox: style cleanups in mtk_gpueb_mbox_read_rx > - mailbox: call platform_get_irq earlier on in probe > - mailbox: set drvdata later on in probe > - mailbox: ioremap resources by index, not name > - mailbox: handle devm_mbox_controller_register errors > - mailbox: rename channels to correspond to bindings > - mailbox: document a few of the private driver structs to be kind to > the next person who will look at this code > - Link to v1: > https://lore.kernel.org/r/[email protected] > > --- > Nicolas Frattaroli (5): > dt-bindings: gpu: mali-valhall-csf: add mediatek,mt8196-mali variant > dt-bindings: power: Add MT8196 GPU frequency control binding > drm/panthor: call into devfreq for current frequency > drm/panthor: Use existing OPP table if present > pmdomain: mediatek: Add support for MFlexGraphics > > .../bindings/gpu/arm,mali-valhall-csf.yaml | 37 +- > .../bindings/power/mediatek,mt8196-gpufreq.yaml | 117 +++ > drivers/gpu/drm/panthor/panthor_devfreq.c | 62 +- > drivers/gpu/drm/panthor/panthor_devfreq.h | 2 + > drivers/gpu/drm/panthor/panthor_device.h | 3 - > drivers/gpu/drm/panthor/panthor_drv.c | 4 +- > drivers/pmdomain/mediatek/Kconfig | 16 + > drivers/pmdomain/mediatek/Makefile | 1 + > drivers/pmdomain/mediatek/mtk-mfg-pmdomain.c | 1044 > ++++++++++++++++++++ > 9 files changed, 1268 insertions(+), 18 deletions(-) > --- > base-commit: 3477f49ff0433a241da12ec9cecf6c9b2bd1c6f8 > change-id: 20250829-mt8196-gpufreq-a7645670d182 > > Best regards, > -- > Nicolas Frattaroli <[email protected]> >
