clk-pllv1.c
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#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include "clk.h"
#include "common.h"
#include "hardware.h"
/**
* pll v1
*
* @clk_hw clock source
* @parent the parent clock name
* @base base address of pll registers
*
* PLL clock version 1, found on i.MX1/21/25/27/31/35
*/
#define MFN_BITS (10)
#define MFN_SIGN (BIT(MFN_BITS - 1))
#define MFN_MASK (MFN_SIGN - 1)
struct clk_pllv1 {
struct clk_hw hw;
void __iomem *base;
};
#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk))
static inline bool mfn_is_negative(unsigned int mfn)
{
return !cpu_is_mx1() && !cpu_is_mx21() && (mfn & MFN_SIGN);
}
static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pllv1 *pll = to_clk_pllv1(hw);
long long ll;
int mfn_abs;
unsigned int mfi, mfn, mfd, pd;
u32 reg;
unsigned long rate;
reg = readl(pll->base);
/*
* Get the resulting clock rate from a PLL register value and the input
* frequency. PLLs with this register layout can be found on i.MX1,
* i.MX21, i.MX27 and i,MX31
*
* mfi + mfn / (mfd + 1)
* f = 2 * f_ref * --------------------
* pd + 1
*/
mfi = (reg >> 10) & 0xf;
mfn = reg & 0x3ff;
mfd = (reg >> 16) & 0x3ff;
pd = (reg >> 26) & 0xf;
mfi = mfi <= 5 ? 5 : mfi;
mfn_abs = mfn;
/*
* On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit
* 2's complements number.
* On i.MX27 the bit 9 is the sign bit.
*/
if (mfn_is_negative(mfn)) {
if (cpu_is_mx27())
mfn_abs = mfn & MFN_MASK;
else
mfn_abs = BIT(MFN_BITS) - mfn;
}
rate = parent_rate * 2;
rate /= pd + 1;
ll = (unsigned long long)rate * mfn_abs;
do_div(ll, mfd + 1);
if (mfn_is_negative(mfn))
ll = -ll;
ll = (rate * mfi) + ll;
return ll;
}
static struct clk_ops clk_pllv1_ops = {
.recalc_rate = clk_pllv1_recalc_rate,
};
struct clk *imx_clk_pllv1(const char *name, const char *parent,
void __iomem *base)
{
struct clk_pllv1 *pll;
struct clk *clk;
struct clk_init_data init;
pll = kmalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->base = base;
init.name = name;
init.ops = &clk_pllv1_ops;
init.flags = 0;
init.parent_names = &parent;
init.num_parents = 1;
pll->hw.init = &init;
clk = clk_register(NULL, &pll->hw);
if (IS_ERR(clk))
kfree(pll);
return clk;
}