cf07053214
Log core clock and Meta timer frequencies during init in architecture generic code, removing the need for equivalent log messages in SoC specific code. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de>
111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
/*
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* arch/metag/kernel/clock.c
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*
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* Copyright (C) 2012 Imagination Technologies Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <asm/param.h>
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#include <asm/clock.h>
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struct meta_clock_desc _meta_clock;
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/* Default machine get_core_freq callback. */
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static unsigned long get_core_freq_default(void)
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{
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#ifdef CONFIG_METAG_META21
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/*
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* Meta 2 cores divide down the core clock for the Meta timers, so we
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* can estimate the core clock from the divider.
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*/
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return (metag_in32(EXPAND_TIMER_DIV) + 1) * 1000000;
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#else
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/*
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* On Meta 1 we don't know the core clock, but assuming the Meta timer
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* is correct it can be estimated based on loops_per_jiffy.
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*/
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return (loops_per_jiffy * HZ * 5) >> 1;
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#endif
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}
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static struct clk *clk_core;
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/* Clk based get_core_freq callback. */
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static unsigned long get_core_freq_clk(void)
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{
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return clk_get_rate(clk_core);
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}
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/**
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* init_metag_core_clock() - Set up core clock from devicetree.
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*
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* Checks to see if a "core" clock is provided in the device tree, and overrides
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* the get_core_freq callback to use it.
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*/
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static void __init init_metag_core_clock(void)
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{
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/*
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* See if a core clock is provided by the devicetree (and
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* registered by the init callback above).
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*/
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struct device_node *node;
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node = of_find_compatible_node(NULL, NULL, "img,meta");
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if (!node) {
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pr_warn("%s: no compatible img,meta DT node found\n",
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__func__);
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return;
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}
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clk_core = of_clk_get_by_name(node, "core");
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if (IS_ERR(clk_core)) {
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pr_warn("%s: no core clock found in DT\n",
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__func__);
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return;
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}
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/*
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* Override the core frequency callback to use
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* this clk.
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*/
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_meta_clock.get_core_freq = get_core_freq_clk;
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}
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/**
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* init_metag_clocks() - Set up clocks from devicetree.
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*
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* Set up important clocks from device tree. In particular any needed for clock
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* sources.
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*/
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void __init init_metag_clocks(void)
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{
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init_metag_core_clock();
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pr_info("Core clock frequency: %lu Hz\n", get_coreclock());
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}
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/**
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* setup_meta_clocks() - Early set up of the Meta clock.
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* @desc: Clock descriptor usually provided by machine description
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*
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* Ensures all callbacks are valid.
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*/
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void __init setup_meta_clocks(struct meta_clock_desc *desc)
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{
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/* copy callbacks */
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if (desc)
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_meta_clock = *desc;
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/* set fallback functions */
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if (!_meta_clock.get_core_freq)
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_meta_clock.get_core_freq = get_core_freq_default;
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}
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