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barebox/drivers/clk/clk-gate.c

79 lines
1.7 KiB
C

/*
* clk-gate.c - generic barebox clock support. Based on Linux clk support
*
* Copyright (c) 2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <common.h>
#include <io.h>
#include <malloc.h>
#include <linux/clk.h>
#include <linux/err.h>
struct clk_gate {
struct clk clk;
void __iomem *reg;
int shift;
const char *parent;
};
static int clk_gate_enable(struct clk *clk)
{
struct clk_gate *g = container_of(clk, struct clk_gate, clk);
u32 val;
val = readl(g->reg);
val |= 1 << g->shift;
writel(val, g->reg);
return 0;
}
static void clk_gate_disable(struct clk *clk)
{
struct clk_gate *g = container_of(clk, struct clk_gate, clk);
u32 val;
val = readl(g->reg);
val &= ~(1 << g->shift);
writel(val, g->reg);
}
struct clk_ops clk_gate_ops = {
.enable = clk_gate_enable,
.disable = clk_gate_disable,
};
struct clk *clk_gate(const char *name, const char *parent, void __iomem *reg,
u8 shift)
{
struct clk_gate *g = xzalloc(sizeof(*g));
int ret;
g->parent = parent;
g->reg = reg;
g->shift = shift;
g->clk.ops = &clk_gate_ops;
g->clk.name = name;
g->clk.parent_names = &g->parent;
g->clk.num_parents = 1;
ret = clk_register(&g->clk);
if (ret) {
free(g);
return ERR_PTR(ret);
}
return &g->clk;
}