131 lines
3.5 KiB
C
131 lines
3.5 KiB
C
/*
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* clk-fixed-factor.c - generic barebox clock support. Based on Linux clk support
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*
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* Copyright (c) 2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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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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*/
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#include <common.h>
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#include <io.h>
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#include <malloc.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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struct clk_fixed_factor {
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struct clk clk;
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int mult;
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int div;
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const char *parent;
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};
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static unsigned long clk_fixed_factor_recalc_rate(struct clk *clk,
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unsigned long parent_rate)
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{
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struct clk_fixed_factor *f = container_of(clk, struct clk_fixed_factor, clk);
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return (parent_rate / f->div) * f->mult;
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}
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static long clk_factor_round_rate(struct clk *clk, unsigned long rate,
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unsigned long *prate)
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{
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struct clk_fixed_factor *fix = container_of(clk, struct clk_fixed_factor, clk);
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if (clk->flags & CLK_SET_RATE_PARENT) {
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unsigned long best_parent;
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best_parent = (rate / fix->mult) * fix->div;
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*prate = clk_round_rate(clk_get_parent(clk), best_parent);
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}
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return (*prate / fix->div) * fix->mult;
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}
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static int clk_factor_set_rate(struct clk *clk, unsigned long rate,
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unsigned long parent_rate)
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{
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struct clk_fixed_factor *fix = container_of(clk, struct clk_fixed_factor, clk);
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if (clk->flags & CLK_SET_RATE_PARENT) {
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printk("%s: %ld -> parent %ld\n", __func__, rate, rate * fix->div / fix->mult);
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return clk_set_rate(clk_get_parent(clk), rate * fix->div / fix->mult);
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}
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return 0;
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}
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static struct clk_ops clk_fixed_factor_ops = {
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.set_rate = clk_factor_set_rate,
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.round_rate = clk_factor_round_rate,
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.recalc_rate = clk_fixed_factor_recalc_rate,
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};
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struct clk *clk_fixed_factor(const char *name,
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const char *parent, unsigned int mult, unsigned int div, unsigned flags)
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{
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struct clk_fixed_factor *f = xzalloc(sizeof(*f));
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int ret;
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f->mult = mult;
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f->div = div;
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f->parent = parent;
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f->clk.ops = &clk_fixed_factor_ops;
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f->clk.name = name;
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f->clk.flags = flags;
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f->clk.parent_names = &f->parent;
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f->clk.num_parents = 1;
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ret = clk_register(&f->clk);
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if (ret) {
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free(f);
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return ERR_PTR(ret);
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}
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return &f->clk;
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}
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#if defined(CONFIG_OFTREE) && defined(CONFIG_COMMON_CLK_OF_PROVIDER)
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/**
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* of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
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*/
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static int of_fixed_factor_clk_setup(struct device_node *node)
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{
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struct clk *clk;
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const char *clk_name = node->name;
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const char *parent_name;
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u32 div, mult;
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if (of_property_read_u32(node, "clock-div", &div)) {
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pr_err("%s Fixed factor clock <%s> must have a clock-div property\n",
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__func__, node->name);
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return -EINVAL;
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}
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if (of_property_read_u32(node, "clock-mult", &mult)) {
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pr_err("%s Fixed factor clock <%s> must have a clock-mult property\n",
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__func__, node->name);
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return -EINVAL;
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}
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of_property_read_string(node, "clock-output-names", &clk_name);
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parent_name = of_clk_get_parent_name(node, 0);
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clk = clk_fixed_factor(clk_name, parent_name, mult, div, 0);
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if (IS_ERR(clk))
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return IS_ERR(clk);
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return of_clk_add_provider(node, of_clk_src_simple_get, clk);
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}
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CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
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of_fixed_factor_clk_setup);
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#endif
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