forked from Minki/linux
5af744ebae
Add driver for dynamic scaling the DDR Controller on imx8m chips. Actual
frequency switching is implemented inside TF-A, this driver wraps the
SMC calls and synchronizes the clk tree.
The DRAM clocks on imx8m have the following structure (abridged):
+----------+ |\ +------+
| dram_pll |-------|M| dram_core | |
+----------+ |U|---------->| D |
/--|X| | D |
dram_alt_root | |/ | R |
| | C |
+---------+ | |
|FIX DIV/4| | |
+---------+ | |
composite: | | |
+----------+ | | |
| dram_alt |----/ | |
+----------+ | |
| dram_apb |-------------------->| |
+----------+ +------+
The dram_pll is used for higher rates and dram_alt is used for lower
rates. The dram_alt and dram_apb clocks are "imx composite" and their
parent can also be modified.
This driver will prepare/enable the new parents ahead of switching (so
that the expected roots are enabled) and afterwards it will call
clk_set_parent to ensure the parents in clock framework are up-to-date.
The driver relies on dram_pll dram_alt and dram_apb being marked with
CLK_GET_RATE_NOCACHE for rate updates.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
[cw00.choi: Edit the COMPILE_TEST module dependency in Kconfig]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
19 lines
788 B
Makefile
19 lines
788 B
Makefile
# SPDX-License-Identifier: GPL-2.0
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obj-$(CONFIG_PM_DEVFREQ) += devfreq.o
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obj-$(CONFIG_PM_DEVFREQ_EVENT) += devfreq-event.o
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obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) += governor_simpleondemand.o
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obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE) += governor_performance.o
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obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o
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obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o
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obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
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# DEVFREQ Drivers
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obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
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obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o
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obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
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obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o
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obj-$(CONFIG_ARM_TEGRA20_DEVFREQ) += tegra20-devfreq.o
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# DEVFREQ Event Drivers
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obj-$(CONFIG_PM_DEVFREQ_EVENT) += event/
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