[PATCH 0/3] Power Management for Raspberry Pi V3D GPU

[Maíra Canal]

This series introduces Runtime PM for Raspberry Pi's GPU, V3D.
Currently, the GPU clock stays up during the whole operation, even if
the GPU is idle. By introducing Runtime PM, we can now turn off the
clock completely during idle. For example, with this series, when
checking `vcgencmd measure_clock v3d` in the Raspberry Pi 5, we get:

(idle)

$ vcgencmd measure_clock v3d
frequency(0)=0

(running glmark2)

$ vcgencmd measure_clock v3d
frequency(0)=960016128

To implement PM for V3D, it was needed to add a prepare and unprepare
hook to RPi's firmware clocks. Currently, they don't turn on and off,
nor lower the clock rate. Therefore, PATCH 1/3 addresses this issue in
clk/bcm/clk-raspberrypi.c.

The other two patches are related to PM enablement in the V3D driver.

To ease testing in Raspberry Pi 4 and 5, I prepared a downstream branch
backporting this series to rpi-6.12.y [1].

[1] https://github.com/mairacanal/linux-rpi/tree/v3d/downstream/power-management-v2

Best Regards,
- Maíra

---
Maíra Canal (3):
      clk: bcm: rpi: Turn firmware clock on/off when preparing/unpreparing
      drm/v3d: Allocate all resources before enabling the clock
      drm/v3d: Introduce Runtime Power Management

 drivers/clk/bcm/clk-raspberrypi.c |  41 ++++++++-
 drivers/gpu/drm/v3d/Makefile      |   3 +-
 drivers/gpu/drm/v3d/v3d_debugfs.c |  23 ++++-
 drivers/gpu/drm/v3d/v3d_drv.c     | 171 +++++++++++++++++++-------------------
 drivers/gpu/drm/v3d/v3d_drv.h     |  21 ++++-
 drivers/gpu/drm/v3d/v3d_gem.c     |  18 +++-
 drivers/gpu/drm/v3d/v3d_irq.c     |  15 ++--
 drivers/gpu/drm/v3d/v3d_mmu.c     |  12 ++-
 drivers/gpu/drm/v3d/v3d_power.c   |  79 ++++++++++++++++++
 drivers/gpu/drm/v3d/v3d_submit.c  |  19 ++++-
 10 files changed, 291 insertions(+), 111 deletions(-)
---
base-commit: a7352c849492a30b5d8491fcb9314ab376a3942f
change-id: 20250728-v3d-power-management-eebb2024dc96