forked from Minki/linux
bcd6f569e8
This patch adds a DT and non-DT based implementation of the common clock infrastructure for Versatile Express platform. It registers (statically or using DT) all required fixed clocks, initialises motherboard's SP810 cell (that provides clocks for SP804 timers) and explicitly registers VE "osc" driver, to make the clock generators available early. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
143 lines
3.9 KiB
C
143 lines
3.9 KiB
C
/*
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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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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Copyright (C) 2012 ARM Limited
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*/
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#include <linux/clkdev.h>
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#include <linux/clk-provider.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/vexpress.h>
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#include <asm/hardware/sp810.h>
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static struct clk *vexpress_sp810_timerclken[4];
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static DEFINE_SPINLOCK(vexpress_sp810_lock);
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static void __init vexpress_sp810_init(void __iomem *base)
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{
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int i;
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if (WARN_ON(!base))
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return;
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for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) {
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char name[12];
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const char *parents[] = {
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"v2m:refclk32khz", /* REFCLK */
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"v2m:refclk1mhz" /* TIMCLK */
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};
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snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
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vexpress_sp810_timerclken[i] = clk_register_mux(NULL, name,
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parents, 2, 0, base + SCCTRL,
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SCCTRL_TIMERENnSEL_SHIFT(i), 1,
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0, &vexpress_sp810_lock);
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if (WARN_ON(IS_ERR(vexpress_sp810_timerclken[i])))
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break;
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}
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}
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static const char * const vexpress_clk_24mhz_periphs[] __initconst = {
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"mb:uart0", "mb:uart1", "mb:uart2", "mb:uart3",
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"mb:mmci", "mb:kmi0", "mb:kmi1"
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};
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void __init vexpress_clk_init(void __iomem *sp810_base)
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{
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struct clk *clk;
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int i;
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clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
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CLK_IS_ROOT, 0);
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WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));
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clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
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CLK_IS_ROOT, 24000000);
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for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
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WARN_ON(clk_register_clkdev(clk, NULL,
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vexpress_clk_24mhz_periphs[i]));
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clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
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CLK_IS_ROOT, 32768);
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WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));
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clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
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CLK_IS_ROOT, 1000000);
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vexpress_sp810_init(sp810_base);
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for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
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WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));
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WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
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"v2m-timer0", "sp804"));
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WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
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"v2m-timer1", "sp804"));
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}
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#if defined(CONFIG_OF)
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struct clk *vexpress_sp810_of_get(struct of_phandle_args *clkspec, void *data)
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{
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if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] >
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ARRAY_SIZE(vexpress_sp810_timerclken)))
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return NULL;
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return vexpress_sp810_timerclken[clkspec->args[0]];
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}
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static const __initconst struct of_device_id vexpress_fixed_clk_match[] = {
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{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
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{ .compatible = "arm,vexpress-osc", .data = vexpress_osc_of_setup, },
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{}
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};
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void __init vexpress_clk_of_init(void)
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{
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struct device_node *node;
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struct clk *clk;
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struct clk *refclk, *timclk;
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of_clk_init(vexpress_fixed_clk_match);
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node = of_find_compatible_node(NULL, NULL, "arm,sp810");
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vexpress_sp810_init(of_iomap(node, 0));
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of_clk_add_provider(node, vexpress_sp810_of_get, NULL);
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/* Select "better" (faster) parent for SP804 timers */
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refclk = of_clk_get_by_name(node, "refclk");
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timclk = of_clk_get_by_name(node, "timclk");
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if (!WARN_ON(IS_ERR(refclk) || IS_ERR(timclk))) {
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int i = 0;
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if (clk_get_rate(refclk) > clk_get_rate(timclk))
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clk = refclk;
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else
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clk = timclk;
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for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
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WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i],
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clk));
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}
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WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
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"v2m-timer0", "sp804"));
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WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
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"v2m-timer1", "sp804"));
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}
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#endif
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