talos-op-linux/include/linux/clk-provider.h, branch v4.8.5

clk: core: support clocks which requires parents enable (part 1)

2016-07-02T00:40:23+00:00

On Freescale i.MX7D platform, all clocks operations, including enable/disable, rate change and re-parent, requires its parent clock enable. Current clock core can not support it well. This patch introduce a new flag CLK_OPS_PARENT_ENABLE to handle this special case in clock core that enable its parent clock firstly for each operation and disable it later after operation complete. The patch part 1 fixes the possible disabling clocks while its parent is off during kernel booting phase in clk_disable_unused_subtree(). Before the completion of kernel booting, clock tree is still not built completely, there may be a case that the child clock is on but its parent is off which could be caused by either HW initial reset state or bootloader initialization. Taking bootloader as an example, we may enable all clocks in HW by default. And during kernel booting time, the parent clock could be disabled in its driver probe due to calling clk_prepare_enable and clk_disable_unprepare. Because it's child clock is only enabled in HW while its SW usecount in clock tree is still 0, so clk_disable of parent clock will gate the parent clock in both HW and SW usecount ultimately. Then there will be a child clock is still on in HW but its parent is already off. Later in clk_disable_unused(), this clock disable accessing while its parent off will cause system hang due to the limitation of HW which must require its parent on. This patch simply enables the parent clock first before disabling if flag CLK_OPS_PARENT_ENABLE is set in clk_disable_unused_subtree(). This is a simple solution and only affects booting time. After kernel booting up the clock tree is already created, there will be no case that child is off but its parent is off. So no need do this checking for normal clk_disable() later. Cc: Michael Turquette Cc: Stephen Boyd Cc: Shawn Guo Signed-off-by: Dong Aisheng Signed-off-by: Stephen Boyd

Merge branch 'clk-hw-unregister-fixed-rate' into clk-next

2016-06-30T20:07:58+00:00

* clk-hw-unregister-fixed-rate: clk: fixed-rate: add clk_hw_unregister_fixed_rate()

clk: fixed-rate: add clk_hw_unregister_fixed_rate()

2016-06-30T20:07:10+00:00

This will be used to migrate to the clk_hw APIs. Signed-off-by: Masahiro Yamada Signed-off-by: Stephen Boyd

clk: Remove CLK_IS_ROOT flag

2016-06-01T21:56:57+00:00

Now that we've gotten rid of all the users of this flag we can retire the number, leaving a slot open for a future flag user. Signed-off-by: Stephen Boyd

Merge branch 'clk-hw-register' (early part) into clk-next

2016-04-21T21:47:18+00:00

* 'clk-hw-register' (early part): clk: fixed-rate: Add hw based registration APIs clk: gpio: Add hw based registration APIs clk: composite: Add hw based registration APIs clk: fractional-divider: Add hw based registration APIs clk: fixed-factor: Add hw based registration APIs clk: mux: Add hw based registration APIs clk: gate: Add hw based registration APIs clk: divider: Add hw based registration APIs clkdev: Add clk_hw based registration APIs clk: Add clk_hw OF clk providers clk: Add {devm_}clk_hw_{register,unregister}() APIs clkdev: Remove clk_register_clkdevs()

Merge branch 'clk-composite-unregister' into clk-next

2016-04-21T21:43:56+00:00

* clk-composite-unregister: clk: composite: Add unregister function

clk: composite: Add unregister function

2016-04-21T21:43:28+00:00

The composite clock didn't have any unregistration function, which forced us to use clk_unregister directly on it. While it was already not great from an API point of view, it also meant that we were leaking the clk_composite structure allocated in clk_register_composite. Add a clk_unregister_composite function to fix this. Signed-off-by: Maxime Ripard Signed-off-by: Stephen Boyd

clk: fixed-rate: Add hw based registration APIs

2016-04-19T23:57:12+00:00

Add registration APIs in the clk fixed-rate code to return struct clk_hw pointers instead of struct clk pointers. This way we hide the struct clk pointer from providers unless they need to use consumer facing APIs. Signed-off-by: Stephen Boyd

clk: gpio: Add hw based registration APIs

2016-04-19T23:56:28+00:00

Add registration APIs in the clk gpio code to return struct clk_hw pointers instead of struct clk pointers. This way we hide the struct clk pointer from providers unless they need to use consumer facing APIs. Signed-off-by: Stephen Boyd

clk: composite: Add hw based registration APIs

2016-04-19T23:56:28+00:00

Add registration APIs in the clk composite code to return struct clk_hw pointers instead of struct clk pointers. This way we hide the struct clk pointer from providers unless they need to use consumer facing APIs. Signed-off-by: Stephen Boyd