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barebox/arch/arm/mach-imx/clk-gate-exclusive.c

104 lines
2.4 KiB
C

/*
* Copyright 2014 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <common.h>
#include <io.h>
#include <malloc.h>
#include <linux/clk.h>
#include <linux/err.h>
#include "clk.h"
/**
* struct clk_gate_exclusive - i.MX specific gate clock which is mutually
* exclusive with other gate clocks
*
* @gate: the parent class
* @exclusive_mask: mask of gate bits which are mutually exclusive to this
* gate clock
*
* The imx exclusive gate clock is a subclass of basic clk_gate
* with an addtional mask to indicate which other gate bits in the same
* register is mutually exclusive to this gate clock.
*/
struct clk_gate_exclusive {
struct clk clk;
void __iomem *reg;
int shift;
const char *parent;
u32 exclusive_mask;
};
static int clk_gate_exclusive_enable(struct clk *clk)
{
struct clk_gate_exclusive *exgate = container_of(clk,
struct clk_gate_exclusive, clk);
u32 val = readl(exgate->reg);
if (val & exgate->exclusive_mask)
return -EBUSY;
val |= 1 << exgate->shift;
writel(val, exgate->reg);
return 0;
}
static void clk_gate_exclusive_disable(struct clk *clk)
{
struct clk_gate_exclusive *exgate = container_of(clk,
struct clk_gate_exclusive, clk);
u32 val = readl(exgate->reg);
val &= ~(1 << exgate->shift);
writel(val, exgate->reg);
}
static int clk_gate_exclusive_is_enabled(struct clk *clk)
{
struct clk_gate_exclusive *exgate = container_of(clk,
struct clk_gate_exclusive, clk);
return readl(exgate->reg) & (1 << exgate->shift);
}
static const struct clk_ops clk_gate_exclusive_ops = {
.enable = clk_gate_exclusive_enable,
.disable = clk_gate_exclusive_disable,
.is_enabled = clk_gate_exclusive_is_enabled,
};
struct clk *imx_clk_gate_exclusive(const char *name, const char *parent,
void __iomem *reg, u8 shift, u32 exclusive_mask)
{
struct clk_gate_exclusive *exgate;
int ret;
exgate = xzalloc(sizeof(*exgate));
exgate->parent = parent;
exgate->clk.name = name;
exgate->clk.ops = &clk_gate_exclusive_ops;
exgate->clk.flags = CLK_SET_RATE_PARENT;
exgate->clk.parent_names = &exgate->parent;
exgate->clk.num_parents = 1;
exgate->reg = reg;
exgate->shift = shift;
exgate->exclusive_mask = exclusive_mask;
ret = clk_register(&exgate->clk);
if (ret) {
free(exgate);
return ERR_PTR(ret);
}
return &exgate->clk;
}