cc2c05a90c
Update timer drivers to use DT_HAS_<compat>_ENABLED Kconfig symbol to expose the driver and enable it by default based on devicetree. We remove 'depend on' Kconfig for symbols that would be implied by the devicetree node existing. Signed-off-by: Kumar Gala <galak@kernel.org>
44 lines
1.6 KiB
Plaintext
44 lines
1.6 KiB
Plaintext
# Copyright (c) 2014-2015 Wind River Systems, Inc.
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# Copyright (c) 2016 Cadence Design Systems, Inc.
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# Copyright (c) 2019 Intel Corp.
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# SPDX-License-Identifier: Apache-2.0
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config RISCV_MACHINE_TIMER
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bool "RISCV Machine Timer"
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default y
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depends on DT_HAS_ANDESTECH_MACHINE_TIMER_ENABLED || \
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DT_HAS_NEORV32_MACHINE_TIMER_ENABLED || \
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DT_HAS_NUCLEI_SYSTIMER_ENABLED || \
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DT_HAS_SIFIVE_CLINT0_ENABLED || \
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DT_HAS_TELINK_MACHINE_TIMER_ENABLED
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select TICKLESS_CAPABLE
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select TIMER_HAS_64BIT_CYCLE_COUNTER
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help
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This module implements a kernel device driver for the generic RISCV machine
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timer driver. It provides the standard "system clock driver" interfaces.
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config RISCV_MACHINE_TIMER_SYSTEM_CLOCK_DIVIDER
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int
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default 0
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help
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Specifies the division ratio of the system clock supplied to the Machine Timer.
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A clock obtained by dividing the system clock by a value of [2^N] is
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supplied to the timer. Where N is this parameter's value.
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When N=2, it is divided by 4, and when N=5, it is divided by 32.
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Default case is N=0, this means use system clock as machine timer clock.
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It is normal configuration for RISC-V machine clock.
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This parameter usually depends on the hardware configuration.
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The division ratio should define in devicetree,
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and it is desirable usage that references it with using a function such as
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dt_node_int_prop_int from Kconfig. (Tune in the conf file is not preferable.)
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config RISCV_MACHINE_TIMER_MIN_DELAY
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int
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default 100
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help
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Specifies the minimum number of machine cycles before the RISC-V machine
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time compare register is allowed to be updated by the RISC-V machine timer
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driver.
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