clk-gate-exclusive.c
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/*
* 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 <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.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_gate gate;
u32 exclusive_mask;
};
static int clk_gate_exclusive_enable(struct clk_hw *hw)
{
struct clk_gate *gate = container_of(hw, struct clk_gate, hw);
struct clk_gate_exclusive *exgate = container_of(gate,
struct clk_gate_exclusive, gate);
u32 val = readl(gate->reg);
if (val & exgate->exclusive_mask)
return -EBUSY;
return clk_gate_ops.enable(hw);
}
static void clk_gate_exclusive_disable(struct clk_hw *hw)
{
clk_gate_ops.disable(hw);
}
static int clk_gate_exclusive_is_enabled(struct clk_hw *hw)
{
return clk_gate_ops.is_enabled(hw);
}
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;
struct clk_gate *gate;
struct clk *clk;
struct clk_init_data init;
if (exclusive_mask == 0)
return ERR_PTR(-EINVAL);
exgate = kzalloc(sizeof(*exgate), GFP_KERNEL);
if (!exgate)
return ERR_PTR(-ENOMEM);
gate = &exgate->gate;
init.name = name;
init.ops = &clk_gate_exclusive_ops;
init.flags = CLK_SET_RATE_PARENT;
init.parent_names = parent ? &parent : NULL;
init.num_parents = parent ? 1 : 0;
gate->reg = reg;
gate->bit_idx = shift;
gate->lock = &imx_ccm_lock;
gate->hw.init = &init;
exgate->exclusive_mask = exclusive_mask;
clk = clk_register(NULL, &gate->hw);
if (IS_ERR(clk))
kfree(exgate);
return clk;
}