146 lines
3.2 KiB
C
146 lines
3.2 KiB
C
/*
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* clk-gate.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_gate {
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struct clk clk;
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void __iomem *reg;
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int shift;
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const char *parent;
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unsigned flags;
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};
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#define to_clk_gate(_clk) container_of(_clk, struct clk_gate, clk)
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static void clk_gate_endisable(struct clk *clk, int enable)
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{
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struct clk_gate *gate = container_of(clk, struct clk_gate, clk);
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int set = gate->flags & CLK_GATE_INVERTED ? 1 : 0;
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u32 val;
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set ^= enable;
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if (gate->flags & CLK_GATE_HIWORD_MASK) {
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val = BIT(gate->shift + 16);
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if (set)
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val |= BIT(gate->shift);
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} else {
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val = readl(gate->reg);
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if (set)
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val |= BIT(gate->shift);
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else
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val &= ~BIT(gate->shift);
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}
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writel(val, gate->reg);
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}
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static int clk_gate_enable(struct clk *clk)
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{
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clk_gate_endisable(clk, 1);
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return 0;
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}
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static void clk_gate_disable(struct clk *clk)
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{
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clk_gate_endisable(clk, 0);
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}
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static int clk_gate_is_enabled(struct clk *clk)
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{
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struct clk_gate *g = container_of(clk, struct clk_gate, clk);
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u32 val;
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val = readl(g->reg);
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if (val & (1 << g->shift))
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return g->flags & CLK_GATE_INVERTED ? 0 : 1;
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else
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return g->flags & CLK_GATE_INVERTED ? 1 : 0;
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}
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static struct clk_ops clk_gate_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_enable,
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.disable = clk_gate_disable,
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.is_enabled = clk_gate_is_enabled,
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};
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struct clk *clk_gate_alloc(const char *name, const char *parent,
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void __iomem *reg, u8 shift, unsigned flags, u8 clk_gate_flags)
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{
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struct clk_gate *g = xzalloc(sizeof(*g));
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g->parent = parent;
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g->reg = reg;
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g->shift = shift;
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g->clk.ops = &clk_gate_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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g->flags = clk_gate_flags;
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return &g->clk;
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}
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void clk_gate_free(struct clk *clk_gate)
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{
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struct clk_gate *g = to_clk_gate(clk_gate);
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free(g);
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}
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struct clk *clk_gate(const char *name, const char *parent, void __iomem *reg,
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u8 shift, unsigned flags, u8 clk_gate_flags)
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{
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struct clk *g;
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int ret;
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g = clk_gate_alloc(name , parent, reg, shift, flags, clk_gate_flags);
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ret = clk_register(g);
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if (ret) {
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free(to_clk_gate(g));
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return ERR_PTR(ret);
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}
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return g;
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}
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struct clk *clk_gate_inverted(const char *name, const char *parent,
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void __iomem *reg, u8 shift, unsigned flags)
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{
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struct clk *clk;
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struct clk_gate *g;
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clk = clk_gate(name, parent, reg, shift, flags, CLK_GATE_INVERTED);
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if (IS_ERR(clk))
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return clk;
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g = container_of(clk, struct clk_gate, clk);
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return clk;
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}
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