124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
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* clk-gate-shared.c - generic barebox clock support. Based on Linux clk support
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*
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* Copyright (c) 2017 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_gate_shared {
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struct clk clk;
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const char *parent;
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const char *companion_gate;
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struct clk *companion_clk;
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};
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#define to_clk_gate_shared(_clk) container_of(_clk, struct clk_gate_shared, clk)
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static struct clk *lookup_companion(struct clk_gate_shared *g)
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{
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if (IS_ERR(g->companion_clk))
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g->companion_clk = clk_lookup(g->companion_gate);
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if (IS_ERR(g->companion_clk))
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return NULL;
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return g->companion_clk;
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}
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static int clk_gate_shared_enable(struct clk *clk)
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{
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struct clk_gate_shared *g = to_clk_gate_shared(clk);
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return clk_enable(lookup_companion(g));
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}
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static void clk_gate_shared_disable(struct clk *clk)
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{
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struct clk_gate_shared *g = to_clk_gate_shared(clk);
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clk_disable(lookup_companion(g));
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}
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static int clk_gate_shared_is_enabled(struct clk *clk)
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{
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struct clk_gate_shared *g = to_clk_gate_shared(clk);
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return clk_is_enabled(lookup_companion(g));
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}
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static struct clk_ops clk_gate_shared_ops = {
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.set_rate = clk_parent_set_rate,
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.round_rate = clk_parent_round_rate,
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.enable = clk_gate_shared_enable,
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.disable = clk_gate_shared_disable,
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.is_enabled = clk_gate_shared_is_enabled,
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};
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struct clk *clk_gate_shared_alloc(const char *name, const char *parent, const char *companion,
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unsigned flags)
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{
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struct clk_gate_shared *g = xzalloc(sizeof(*g));
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g->parent = parent;
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g->companion_gate = companion;
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g->companion_clk = ERR_PTR(-EINVAL);
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g->clk.ops = &clk_gate_shared_ops;
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g->clk.name = name;
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g->clk.flags = flags;
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g->clk.parent_names = &g->parent;
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g->clk.num_parents = 1;
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return &g->clk;
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}
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void clk_gate_shared_free(struct clk *clk)
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{
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struct clk_gate_shared *g = to_clk_gate_shared(clk);
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free(g);
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}
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/*
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* clk_gate_shared - register a gate controlled by another gate
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* @name: The name of the new clock gate
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* @parent: The parent name of the new clock
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* companion: The hardware gate this clock is controlled by
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* @flags: common CLK_* flags
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*
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* This gate clock is used when a single software control knob controls multiple
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* gates in hardware. The first gate is then registered as the real hardware gate,
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* the others are registered with this function. This gate has no hardware control
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* itself, but only enables/disabled its companion hardware gate.
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*/
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struct clk *clk_gate_shared(const char *name, const char *parent, const char *companion,
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unsigned flags)
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{
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struct clk *clk;
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int ret;
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clk = clk_gate_shared_alloc(name , parent, companion, flags);
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ret = clk_register(clk);
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if (ret) {
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clk_gate_shared_free(clk);
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return ERR_PTR(ret);
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}
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return clk;
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}
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