linux-stable/drivers/clk/ingenic
Maxime Ripard 65c1f037b4 clk: ingenic: tcu: Switch to determine_rate
The Ingenic TCU 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: Paul Cercueil <paul@crapouillou.net>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-60-971d5077e7d2@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2023-06-08 18:39:34 -07:00
..
cgu.c clk: ingenic: cgu: Switch to determine_rate 2023-06-08 18:39:34 -07:00
cgu.h clk: ingenic: Add .set_rate_hook() for PLL clocks 2022-10-27 11:59:05 -07:00
jz4725b-cgu.c clk: ingenic: Mark critical clocks in Ingenic SoCs 2022-05-18 13:56:22 -07:00
jz4740-cgu.c clk: ingenic: Mark critical clocks in Ingenic SoCs 2022-05-18 13:56:22 -07:00
jz4755-cgu.c clk: Add Ingenic JZ4755 CGU driver 2022-11-01 12:36:22 -07:00
jz4760-cgu.c clk: ingenic: jz4760: Update M/N/OD calculation algorithm 2023-01-25 16:08:27 -08:00
jz4770-cgu.c clk: ingenic: Mark critical clocks in Ingenic SoCs 2022-05-18 13:56:22 -07:00
jz4780-cgu.c clk: ingenic: Mark critical clocks in Ingenic SoCs 2022-05-18 13:56:22 -07:00
Kconfig clk: Add Ingenic JZ4755 CGU driver 2022-11-01 12:36:22 -07:00
Makefile clk: Add Ingenic JZ4755 CGU driver 2022-11-01 12:36:22 -07:00
pm.c clk: ingenic: Handle setting the Low-Power Mode bit 2019-06-25 15:43:15 -07:00
pm.h clk: ingenic: Handle setting the Low-Power Mode bit 2019-06-25 15:43:15 -07:00
tcu.c clk: ingenic: tcu: Switch to determine_rate 2023-06-08 18:39:34 -07:00
x1000-cgu.c clk: ingenic: Minor cosmetic fixups for X1000 2022-10-27 11:59:05 -07:00
x1830-cgu.c clk: ingenic: Mark critical clocks in Ingenic SoCs 2022-05-18 13:56:22 -07:00