linux/drivers/clk
Maxime Ripard 93d2725aff clk: bcm: rpi: Discover the firmware clocks
The RaspberryPi4 firmware actually exposes more clocks than are currently
handled by the driver and we will need to change some of them directly
based on the pixel rate for the display related clocks, or the load for the
GPU.

Since the firmware implements DVFS, this rate change can have a number of
side-effects, including adjusting the various PLL voltages or the PLL
parents. The firmware also implements thermal throttling, so even some
thermal pressure can change those parameters behind Linux back.

DVFS is currently implemented on the arm, core, h264, v3d, isp and hevc
clocks, so updating any of them using the MMIO driver (and thus behind the
firmware's back) can lead to troubles, the arm clock obviously being the
most problematic.

In order to make Linux play as nice as possible with those constraints, it
makes sense to rely on the firmware clocks as much as possible. However,
the firmware doesn't seem to provide some equivalents to their MMIO
counterparts, so we can't really replace that driver entirely.

Fortunately, the firmware has an interface to discover the clocks it
exposes.

Let's use it to discover, register the clocks in the clocks framework and
then expose them through the device tree for consumers to use them.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/438d73962741a8c5f7c689319b7443b930a87fde.1592210452.git-series.maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-06-19 17:21:17 -07:00
..
actions Merge branches 'clk-cdce-regulator', 'clk-bcm', 'clk-evict-parent-cache' and 'clk-actions' into clk-next 2019-09-19 15:31:46 -07:00
analogbits treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
at91 clk: at91: allow setting all PMC clock parents via DT 2020-05-26 20:22:50 -07:00
axis treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
axs10x clk: axs10x: use devm_platform_ioremap_resource() to simplify code 2019-10-16 16:17:50 -07:00
baikal-t1 clk: baikal-t1: remove redundant assignment to variable 'divider' 2020-06-09 13:45:37 -07:00
bcm clk: bcm: rpi: Discover the firmware clocks 2020-06-19 17:21:17 -07:00
berlin treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
davinci clk: davinci: use devm_platform_ioremap_resource() to simplify code 2019-10-16 16:17:14 -07:00
h8300 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hisilicon Merge branches 'clk-hisi', 'clk-amlogic', 'clk-samsung', 'clk-renesas' and 'clk-imx' into clk-next 2019-11-27 08:14:17 -08:00
imgtec treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
imx clk: imx: use imx8m_clk_hw_composite_bus for i.MX8M bus clk slice 2020-05-21 22:37:48 +08:00
ingenic clk: ingenic: Mark ingenic_tcu_of_match as __maybe_unused 2020-05-28 16:47:02 -07:00
keystone treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
loongson1 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
mediatek treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
meson clk: meson: meson8b: Don't rely on u-boot to init all GP_PLL registers 2020-05-02 01:53:32 +02:00
microchip clk: let init callback return an error code 2019-12-23 18:53:13 -08:00
mmp This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
mvebu clk: Fix Kconfig indentation 2020-01-04 23:34:39 -08:00
mxs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 159 2019-05-30 11:26:37 -07:00
nxp treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 159 2019-05-30 11:26:37 -07:00
pistachio treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422 2019-06-05 17:37:15 +02:00
pxa clk: pxa: fix one of the pxa RTC clocks 2019-11-13 15:01:17 -08:00
qcom This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
renesas clk: renesas: cpg-mssr: Fix STBCR suspend/resume handling 2020-05-18 11:06:33 +02:00
rockchip clk: rockchip: fix incorrect configuration of rk3228 aclk_gpu* clocks 2020-04-13 09:35:24 +02:00
samsung clk: samsung: exynos5433: Add IGNORE_UNUSED flag to sclk_i2s1 2020-05-19 16:58:42 +02:00
sifive A few clk driver fixes 2019-05-30 16:33:37 -07:00
sirf clk: sirf: Don't reference clk_init_data after registration 2019-08-16 10:20:07 -07:00
socfpga clk: socfpga: agilex: add clock driver for the Agilex platform 2020-05-26 19:13:05 -07:00
spear clk: spear: Make structure i2s_sclk_masks constant 2019-09-06 10:27:40 -07:00
sprd This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
st clk: clk-flexgen: fix clock-critical handling 2020-05-27 01:14:06 -07:00
sunxi clk: sunxi: Fix incorrect usage of round_down() 2020-04-14 09:21:05 +02:00
sunxi-ng clk: sunxi-ng: sun8i-de2: Sort structures 2020-02-12 19:01:16 +01:00
tegra This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
ti treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
uniphier clk: uniphier: Add SCSSI clock gate for each channel 2020-01-04 23:14:22 -08:00
ux500 clk: ux500: Fix up the SGA clock for some variants 2020-01-04 23:27:15 -08:00
versatile treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
x86 clk: intel: remove redundant initialization of variable rate64 2020-05-28 16:00:33 -07:00
zte clk: zx296718: Don't reference clk_init_data after registration 2019-08-16 10:20:15 -07:00
zynq treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 401 2019-06-05 17:37:13 +02:00
zynqmp This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
clk-asm9260.c clk: asm9260: fix __clk_hw_register_fixed_rate_with_accuracy typo 2020-04-13 12:20:06 -07:00
clk-aspeed.c clk: aspeed: Add RMII RCLK gates for both AST2500 MACs 2019-11-26 10:02:48 -08:00
clk-aspeed.h clk: aspeed: Move structures to header 2019-09-06 15:17:02 -07:00
clk-ast2600.c clk: ast2600: Fix AHB clock divider for A1 2020-05-27 01:36:22 -07:00
clk-axi-clkgen.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 177 2019-05-30 11:29:19 -07:00
clk-axm5516.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
clk-bd718x7.c clk: bd718x7: Support ROHM BD71828 clk block 2020-01-24 07:22:47 +00:00
clk-bm1880.c clk: bm1800: Remove set but not used variable 'fref' 2019-12-24 00:10:33 -08:00
clk-bulk.c clk: Make clk_bulk_get_all() return a valid "id" 2019-09-17 13:26:31 -07:00
clk-cdce706.c This round of clk driver and framework updates is heavy on the driver update 2019-07-17 10:07:48 -07:00
clk-cdce925.c clk: clk-cdce925: Add regulator support 2019-09-06 10:31:16 -07:00
clk-clps711x.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
clk-composite.c clk: composite: add _register_composite_pdata() variants 2020-01-28 13:26:48 -08:00
clk-conf.c clk: Tag clk core files with SPDX 2018-12-11 09:57:47 -08:00
clk-cs2000-cp.c clk: cs2000-cp: convert to SPDX identifiers 2018-08-02 13:55:00 -07:00
clk-devres.c clk: Add devm_clk_bulk_get_optional() function 2019-06-25 14:28:01 -07:00
clk-divider.c clk: divider: Add support for specifying parents via DT/pointers 2020-01-07 23:08:02 -08:00
clk-efm32gg.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
clk-fixed-factor.c Merge branch 'clk-parent-rewrite-1' into clk-next 2019-05-07 11:46:13 -07:00
clk-fixed-mmio.c clk: Remove io.h from clk-provider.h 2019-05-15 13:21:37 -07:00
clk-fixed-rate.c clk: fixed-rate: Add clk flags for parent accuracy 2020-01-06 23:07:34 -08:00
clk-fractional-divider.c clk: Remove io.h from clk-provider.h 2019-05-15 13:21:37 -07:00
clk-fsl-sai.c clk: fsl-sai: new driver 2020-01-28 13:26:48 -08:00
clk-gate.c clk: gate: Add support for specifying parents via DT/pointers 2020-01-06 23:10:12 -08:00
clk-gemini.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00
clk-gpio.c clk: gpio: Use DT way of specifying parents 2020-01-05 13:34:36 -08:00
clk-hi655x.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
clk-highbank.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
clk-hsdk-pll.c CLK: HSDK: CGU: add support for 148.5MHz clock 2020-05-28 21:06:39 -07:00
clk-lochnagar.c clk: lochnagar: Don't reference clk_init_data after registration 2019-08-16 10:20:07 -07:00
clk-max9485.c clk: Add driver for MAX9485 2018-07-06 13:44:06 -07:00
clk-max77686.c clk: clk-max77686: Clean clkdev lookup leak and use devm 2019-02-06 10:35:03 -08:00
clk-milbeaut.c clk: milbeaut: Don't reference clk_init_data after registration 2019-08-16 10:20:15 -07:00
clk-moxart.c
clk-multiplier.c clk: Remove io.h from clk-provider.h 2019-05-15 13:21:37 -07:00
clk-mux.c clk: mux: Add support for specifying parents via DT/pointers 2020-01-06 23:10:05 -08:00
clk-nomadik.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -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 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
clk-oxnas.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
clk-palmas.c clk: palmas: constify clk_ops structure 2018-11-06 09:41:44 -08:00
clk-plldig.c clk: ls1028a: fix a dereference of pointer 'parent' before a null check 2020-02-03 23:03:49 -08:00
clk-pwm.c This round of clk driver and framework updates is heavy on the driver update 2019-07-17 10:07:48 -07:00
clk-qoriq.c clk: qoriq: add cpufreq platform device 2020-05-07 10:47:27 +05:30
clk-rk808.c - Core Frameworks 2019-07-15 20:18:40 -07:00
clk-s2mps11.c clk: s2mps11: constify clk_ops structure 2018-11-06 09:42:12 -08:00
clk-scmi.c clk: scmi: Match scmi device by both name and protocol id 2019-12-24 11:36:46 +00:00
clk-scpi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
clk-si514.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
clk-si544.c clk: clk-si544: Implement small frequency change support 2019-06-27 13:45:38 -07:00
clk-si570.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
clk-si5341.c clk: clk-si5341: Add support for the Si5345 series 2020-05-28 21:00:51 -07:00
clk-si5351.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
clk-si5351.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
clk-stm32f4.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -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: stm32mp1: Add ddrperfm clock 2019-04-29 11:13:23 -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 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336 2019-06-05 17:37:07 +02:00
clk-u300.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
clk-versaclock5.c clk: vc5: Add support for IDT VersaClock 5P49V6965 2020-05-30 12:28:51 -07:00
clk-vt8500.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
clk-wm831x.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
clk-xgene.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
clk.c This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
clk.h clk: consoldiate the __clk_get_hw() declarations 2019-07-12 11:00:14 -07:00
clkdev.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00