linux/drivers/clk/mxs/clk-ref.c
Stephen Boyd bb0bf35452 clk: mxs: Include clk.h in C files that use it
Clock provider drivers generally shouldn't include clk.h because
it's the consumer API. The clk.h include is being included in all
mxs files because it's part of mxs/clk.h even though nothing
actually requires it in that file. Move the clk.h include to the
C files that are actually using it and remove the clk.h include
from the header file. The clkdev.h include isn't used either, so
drop it too.

Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-20 11:11:07 -07:00

154 lines
3.3 KiB
C

/*
* Copyright 2012 Freescale Semiconductor, Inc.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"
/**
* struct clk_ref - mxs reference clock
* @hw: clk_hw for the reference clock
* @reg: register address
* @idx: the index of the reference clock within the same register
*
* The mxs reference clock sources from pll. Every 4 reference clocks share
* one register space, and @idx is used to identify them. Each reference
* clock has a gate control and a fractional * divider. The rate is calculated
* as pll rate * (18 / FRAC), where FRAC = 18 ~ 35.
*/
struct clk_ref {
struct clk_hw hw;
void __iomem *reg;
u8 idx;
};
#define to_clk_ref(_hw) container_of(_hw, struct clk_ref, hw)
static int clk_ref_enable(struct clk_hw *hw)
{
struct clk_ref *ref = to_clk_ref(hw);
writel_relaxed(1 << ((ref->idx + 1) * 8 - 1), ref->reg + CLR);
return 0;
}
static void clk_ref_disable(struct clk_hw *hw)
{
struct clk_ref *ref = to_clk_ref(hw);
writel_relaxed(1 << ((ref->idx + 1) * 8 - 1), ref->reg + SET);
}
static unsigned long clk_ref_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_ref *ref = to_clk_ref(hw);
u64 tmp = parent_rate;
u8 frac = (readl_relaxed(ref->reg) >> (ref->idx * 8)) & 0x3f;
tmp *= 18;
do_div(tmp, frac);
return tmp;
}
static long clk_ref_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
unsigned long parent_rate = *prate;
u64 tmp = parent_rate;
u8 frac;
tmp = tmp * 18 + rate / 2;
do_div(tmp, rate);
frac = tmp;
if (frac < 18)
frac = 18;
else if (frac > 35)
frac = 35;
tmp = parent_rate;
tmp *= 18;
do_div(tmp, frac);
return tmp;
}
static int clk_ref_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_ref *ref = to_clk_ref(hw);
unsigned long flags;
u64 tmp = parent_rate;
u32 val;
u8 frac, shift = ref->idx * 8;
tmp = tmp * 18 + rate / 2;
do_div(tmp, rate);
frac = tmp;
if (frac < 18)
frac = 18;
else if (frac > 35)
frac = 35;
spin_lock_irqsave(&mxs_lock, flags);
val = readl_relaxed(ref->reg);
val &= ~(0x3f << shift);
val |= frac << shift;
writel_relaxed(val, ref->reg);
spin_unlock_irqrestore(&mxs_lock, flags);
return 0;
}
static const struct clk_ops clk_ref_ops = {
.enable = clk_ref_enable,
.disable = clk_ref_disable,
.recalc_rate = clk_ref_recalc_rate,
.round_rate = clk_ref_round_rate,
.set_rate = clk_ref_set_rate,
};
struct clk *mxs_clk_ref(const char *name, const char *parent_name,
void __iomem *reg, u8 idx)
{
struct clk_ref *ref;
struct clk *clk;
struct clk_init_data init;
ref = kzalloc(sizeof(*ref), GFP_KERNEL);
if (!ref)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_ref_ops;
init.flags = 0;
init.parent_names = (parent_name ? &parent_name: NULL);
init.num_parents = (parent_name ? 1 : 0);
ref->reg = reg;
ref->idx = idx;
ref->hw.init = &init;
clk = clk_register(NULL, &ref->hw);
if (IS_ERR(clk))
kfree(ref);
return clk;
}