Hi,
This is a follow-up of the discussion here: https://lore.kernel.org/linux-clk/20210319150355.xzw7ikwdaga2dwhv@gilmour/
This implements a mechanism to raise and lower clock rates based on consumer workloads, with an example of such an implementation for the RaspberryPi4 HDMI controller.
There's a couple of things worth discussing:
- The name is in conflict with clk_request_rate, and even though it feels like the right name to me, we should probably avoid any confusion
- The code so far implements a policy of always going for the lowest rate possible. While we don't have an use-case for something else, this should maybe be made more flexible?
Let me know what you think Maxime
Changes from v1: - Return NULL in clk_request_start if clk pointer is NULL - Test for clk_req pointer in clk_request_done - Add another user in vc4 - Rebased on top of v5.15-rc1
Dom Cobley (1): drm/vc4: hvs: Convert to the new clock request API
Maxime Ripard (2): clk: Introduce a clock request API drm/vc4: hdmi: Convert to the new clock request API
drivers/clk/clk.c | 126 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/vc4/vc4_hdmi.c | 15 ++-- drivers/gpu/drm/vc4/vc4_hdmi.h | 3 + drivers/gpu/drm/vc4/vc4_kms.c | 5 +- include/linux/clk.h | 4 ++ 5 files changed, 146 insertions(+), 7 deletions(-)