linux/drivers/clk/actions
Maxime Ripard 939b61f67e clk: actions: composite: fact: Switch to determine_rate
The Actions composite factor clocks implements a mux with a set_parent
hook, but doesn't provide a determine_rate implementation.

This is a bit odd, since set_parent() is there to, as its name implies,
change the parent of a clock. However, the most likely candidate to
trigger that parent change is a call to clk_set_rate(), with
determine_rate() figuring out which parent is the best suited for a
given rate.

The other trigger would be a call to clk_set_parent(), but it's far less
used, and it doesn't look like there's any obvious user for that clock.

So, the set_parent hook is effectively unused, possibly because of an
oversight. However, it could also be an explicit decision by the
original author to avoid any reparenting but through an explicit call to
clk_set_parent().

The driver does implement round_rate() though, which means that we can
change the rate of the clock, but we will never get to change the
parent.

However, It's hard to tell whether it's been done on purpose or not.

Since we'll start mandating a determine_rate() implementation, let's
convert the round_rate() implementation to a determine_rate(), which
will also make the current behavior explicit. And if it was an
oversight, the clock behaviour can be adjusted later on.

Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: linux-actions@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-48-971d5077e7d2@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2023-06-08 18:39:32 -07:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
owl-common.c clk: actions: Don't reference clk_init_data after registration 2019-08-16 10:19:49 -07:00
owl-common.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-composite.c clk: actions: composite: fact: Switch to determine_rate 2023-06-08 18:39:32 -07:00
owl-composite.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-divider.c clk: actions: Add divider clock support 2018-04-06 14:18:17 -07:00
owl-divider.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-factor.c clk/actions/owl-factor.c: remove superfluous headers 2021-11-02 14:28:29 -07:00
owl-factor.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-fixed-factor.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-gate.c
owl-gate.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-mux.c clk: actions: Add mux clock support 2018-04-06 14:17:46 -07:00
owl-mux.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-pll.c clk: actions: remove redundant assignment after a mask operation 2022-04-22 19:01:20 -07:00
owl-pll.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-reset.c clk: actions: Add Actions Semi Owl SoCs Reset Management Unit support 2018-10-16 14:41:39 -07:00
owl-reset.h clk: actions: Use the correct style for SPDX License Identifier 2019-05-01 13:01:07 -07:00
owl-s500.c clk: actions: Make sentinel elements more obvious 2022-03-11 18:13:24 -08:00
owl-s700.c clk: actions: Make sentinel elements more obvious 2022-03-11 18:13:24 -08:00
owl-s900.c clk: actions: Make sentinel elements more obvious 2022-03-11 18:13:24 -08:00