linux/drivers/clk
Martin Blumenstingl d6e81845b7 clk: meson: clk-pll: check if the clock is already enabled
Since commit 6f888e7bc7bd58 ("clk: meson: clk-pll: add enable bit") our
PLLs also support the "enable" bit. Currently meson_clk_pll_enable
unconditionally resets the PLL, enables it, takes it out of reset and
waits until it is locked.

This works fine for our current clock trees. However, there will be a
problem once we allow modifications to sys_pll on Meson8, Meson8b and
Meson8m2 (which will be required for CPU frequency scaling):
the CPU clock is derived from the sys_pll clock. Once clk_enable is
called on the CPU clock this will be propagated by the common clock
framework up until the sys_pll clock. If we reset the PLL
unconditionally in meson_clk_pll_enable the CPU will be stopped (on
Meson8, Meson8b and Meson8m2).
To prevent this we simply check if the PLL is already enabled and do
reset the PLL if it's already enabled and locked.

Now that we have a utility function to check whether the PLL is enabled
we can also pass that to our clk_ops to let the common clock framework
know about the status of the hardware clock.
For now this is of limited use since the only common clock framework's
internal "disabled unused clocks" mechanism checks for this. Everything
else still uses the ref-counting (internal to the common clock
framework) when clk_enable is called.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181115224048.13511-2-martin.blumenstingl@googlemail.com
2018-11-23 15:11:57 +01:00
..
actions clk: actions: Add Actions Semi S900 SoC Reset Management Unit support 2018-10-16 14:41:53 -07:00
at91 Merge branches 'clk-actions-reset', 'clk-imx7-init-critical', 'clk-mmp2-ids' and 'clk-at91-pmc-rework' into clk-next 2018-10-18 15:43:48 -07:00
axis
axs10x clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
bcm clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
berlin This time we have a good set of changes to the core framework that do some 2018-06-09 12:06:24 -07:00
davinci clk: davinci: kill davinci_clk_reset_assert/deassert() 2018-10-02 08:54:14 -07:00
h8300 clk: h8300: pr_err() strings should end with newlines 2017-12-06 22:40:02 -08:00
hisilicon Merge branches 'clk-samsung', 'clk-hisi3670' and 'clk-at91-div-0' into clk-next 2018-10-18 15:41:36 -07:00
imgtec Update MIPS email addresses 2017-11-03 09:02:30 -07:00
imx Merge branches 'clk-imx6-mmdc', 'clk-qcom-krait', 'clk-rockchip' and 'clk-smp2s11-match' into clk-next 2018-10-18 15:44:01 -07:00
ingenic clk: Add Ingenic jz4725b CGU driver 2018-10-16 15:19:48 -07:00
keystone Merge branch 'clk-k3-tisci' into clk-next 2018-10-18 15:40:10 -07:00
loongson1
mediatek clk: mediatek: remove unused array audio_parents 2018-08-30 18:29:36 -07:00
meson clk: meson: clk-pll: check if the clock is already enabled 2018-11-23 15:11:57 +01:00
microchip
mmp clk: mmp2: fix the clock id for sdh2_clk and sdh3_clk 2018-10-17 09:02:31 -07:00
mvebu This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
mxs clk: mxs: make clk_ops const 2017-11-01 23:25:43 -07:00
nxp clk: lpc32xx: Set name of regmap_config 2018-03-19 14:35:16 -07:00
pistachio
pxa clk: pxa: export 32kHz PLL 2018-07-06 13:52:57 -07:00
qcom Merge branches 'clk-fixed-rate-remove' and 'clk-qcom-cleanup' into clk-next 2018-10-18 15:44:13 -07:00
renesas Merge branch 'clk-renesas' into clk-next 2018-10-18 15:38:51 -07:00
rockchip clk: rockchip: Fix static checker warning in rockchip_ddrclk_get_parent call 2018-10-17 15:12:51 +02:00
samsung clk: samsung: Use clk_hw API for calling clk framework from clk notifiers 2018-10-05 13:36:39 +02:00
sirf We have two changes to the core framework this time around. The first being a 2017-11-17 20:04:24 -08:00
socfpga clk: socfpga: stratix10: fix the sdmmc_free_clk mux 2018-07-06 11:08:02 -07:00
spear clk: spear: fix WDT clock definition on SPEAr600 2018-04-06 13:45:34 -07:00
sprd clk: sprd: add RTC gate for SC9860 2018-03-16 15:53:30 -07:00
st clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
sunxi clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
sunxi-ng This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
tegra clk: tegra210: Include size.h for compilation ease 2018-10-16 15:33:01 -07:00
ti This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
uniphier clk: uniphier: add clock frequency support for SPI 2018-07-25 16:26:18 -07:00
ux500 clk: ux500: Drop AB8540/9540 support 2018-03-23 09:36:11 -07:00
versatile clk: versatile: Remove WARNs in ->round_rate() 2018-03-16 15:31:16 -07:00
x86 clk: x86: Stop marking clocks as CLK_IS_CRITICAL 2018-09-17 18:47:58 -07:00
zte clk: move clock common macros out from vendor directories 2017-12-21 15:00:38 -08:00
zynq clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
zynqmp drivers: clk: Add ZynqMP clock driver 2018-10-09 13:29:19 +02:00
clk-asm9260.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-aspeed.c The new and exciting feature this time around is in the clk core. 2018-08-15 21:41:21 -07:00
clk-axi-clkgen.c clk: axi-clkgen: Round closest in round_rate() and recalc_rate() 2017-12-21 18:07:53 -08:00
clk-axm5516.c
clk-bulk.c clk: add new APIs to operate on all available clocks 2018-10-16 15:42:48 -07:00
clk-cdce706.c
clk-cdce925.c Merge branches 'clk-dt-name', 'clk-ti-of-node' and 'clk-sa' into clk-next 2018-10-18 15:33:52 -07:00
clk-clps711x.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00
clk-composite.c
clk-conf.c clk: Convert to using %pOF instead of full_name 2017-07-21 15:49:54 -07:00
clk-cs2000-cp.c clk: cs2000-cp: convert to SPDX identifiers 2018-08-02 13:55:00 -07:00
clk-devres.c clk: add managed version of clk_bulk_get_all 2018-10-16 15:42:49 -07:00
clk-divider.c clk: divider: read-only divider can propagate rate change 2018-03-12 15:10:26 -07:00
clk-efm32gg.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00
clk-fixed-factor.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-fixed-rate.c clk: fixed-rate: fix of_node_get-put imbalance 2018-10-18 13:40:15 -07:00
clk-fractional-divider.c clk: fractional-divider: allow overriding of approximation 2017-08-08 17:39:48 +02:00
clk-gate.c clk: gate: expose clk_gate_ops::is_enabled 2017-08-31 18:35:45 -07:00
clk-gemini.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00
clk-gpio.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-hi655x.c clk: hi6220: Add the hi655x's pmic clock 2017-04-21 19:18:53 -07:00
clk-highbank.c
clk-hsdk-pll.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-max9485.c clk: Add driver for MAX9485 2018-07-06 13:44:06 -07:00
clk-max77686.c clk: max77686: Add SPDX license identifiers 2018-08-27 14:16:51 -07:00
clk-moxart.c clk: Convert to using %pOF instead of full_name 2017-07-21 15:49:54 -07:00
clk-multiplier.c
clk-mux.c clk: honor CLK_MUX_ROUND_CLOSEST in generic clk mux 2018-04-16 09:25:07 -07:00
clk-nomadik.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-npcm7xx.c This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
clk-nspire.c
clk-oxnas.c
clk-palmas.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-pwm.c
clk-qoriq.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-rk808.c
clk-s2mps11.c Merge branches 'clk-imx6-mmdc', 'clk-qcom-krait', 'clk-rockchip' and 'clk-smp2s11-match' into clk-next 2018-10-18 15:44:01 -07:00
clk-scmi.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-scpi.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-si514.c clk-si514, clk-si544: Implement prepare/unprepare/is_prepared operations 2018-06-29 10:59:40 -07:00
clk-si544.c clk-si514, clk-si544: Implement prepare/unprepare/is_prepared operations 2018-06-29 10:59:40 -07:00
clk-si570.c
clk-si5351.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-si5351.h
clk-stm32f4.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-stm32h7.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-stm32mp1.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-tango4.c clk: Convert to using %pOFn instead of device_node.name 2018-08-30 09:50:20 -07:00
clk-twl6040.c clk: make clk_init_data const 2017-11-01 23:25:51 -07:00
clk-u300.c clk: clk-u300: Fix a typo in two comment lines 2017-11-13 17:39:43 -08:00
clk-versaclock5.c clk: vc5: Add support for IDT VersaClock 5P49V5925 2017-07-17 11:51:00 -07:00
clk-vt8500.c
clk-wm831x.c clk: make clk_init_data const 2017-11-01 23:25:51 -07:00
clk-xgene.c clk: clk-xgene: Adjust six checks for null pointers 2017-11-13 17:40:03 -08:00
clk.c clk: Clean up suspend/resume coding style 2018-10-11 09:28:13 -07:00
clk.h clk: Move __clk_{get,put}() into private clk.h API 2018-01-04 15:13:29 -08:00
clkdev.c ARM: 8778/1: clkdev: don't call __of_clk_get_by_name() unnecessarily from clk_get() 2018-08-13 16:27:52 +01:00
Kconfig This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00
Makefile This time it looks like a quieter release cycle in the clk tree. I guess that's 2018-10-31 11:08:30 -07:00