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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
* Copyright 2017~2018 NXP
*
* Author: Dong Aisheng <aisheng.dong@nxp.com>
*
*/
#include <linux/bits.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
#include "clk.h"
/* PLL Control Status Register (xPLLCSR) */
#define PLL_CSR_OFFSET 0x0
#define PLL_VLD BIT(24)
#define PLL_EN BIT(0)
/* PLL Configuration Register (xPLLCFG) */
#define PLL_CFG_OFFSET 0x08
#define BP_PLL_MULT 16
#define BM_PLL_MULT (0x7f << 16)
/* PLL Numerator Register (xPLLNUM) */
#define PLL_NUM_OFFSET 0x10
/* PLL Denominator Register (xPLLDENOM) */
#define PLL_DENOM_OFFSET 0x14
#define MAX_MFD 0x3fffffff
#define DEFAULT_MFD 1000000
struct clk_pllv4 {
struct clk_hw hw;
void __iomem *base;
};
/* Valid PLL MULT Table */
static const int pllv4_mult_table[] = {33, 27, 22, 20, 17, 16};
#define to_clk_pllv4(__hw) container_of(__hw, struct clk_pllv4, hw)
#define LOCK_TIMEOUT_US USEC_PER_MSEC
static inline int clk_pllv4_wait_lock(struct clk_pllv4 *pll)
{
u32 csr;
return readl_poll_timeout(pll->base + PLL_CSR_OFFSET,
csr, csr & PLL_VLD, 0, LOCK_TIMEOUT_US);
}
static int clk_pllv4_is_prepared(struct clk_hw *hw)
{
struct clk_pllv4 *pll = to_clk_pllv4(hw);
if (readl_relaxed(pll->base) & PLL_EN)
return 1;
return 0;
}
static unsigned long clk_pllv4_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pllv4 *pll = to_clk_pllv4(hw);
u32 mult, mfn, mfd;
u64 temp64;
mult = readl_relaxed(pll->base + PLL_CFG_OFFSET);
mult &= BM_PLL_MULT;
mult >>= BP_PLL_MULT;
mfn = readl_relaxed(pll->base + PLL_NUM_OFFSET);
mfd = readl_relaxed(pll->base + PLL_DENOM_OFFSET);
temp64 = parent_rate;
temp64 *= mfn;
do_div(temp64, mfd);
return (parent_rate * mult) + (u32)temp64;
}
static long clk_pllv4_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
unsigned long parent_rate = *prate;
unsigned long round_rate, i;
u32 mfn, mfd = DEFAULT_MFD;
bool found = false;
u64 temp64;
for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
round_rate = parent_rate * pllv4_mult_table[i];
if (rate >= round_rate) {
found = true;
break;
}
}
if (!found) {
pr_warn("%s: unable to round rate %lu, parent rate %lu\n",
clk_hw_get_name(hw), rate, parent_rate);
return 0;
}
if (parent_rate <= MAX_MFD)
mfd = parent_rate;
temp64 = (u64)(rate - round_rate);
temp64 *= mfd;
do_div(temp64, parent_rate);
mfn = temp64;
/*
* NOTE: The value of numerator must always be configured to be
* less than the value of the denominator. If we can't get a proper
* pair of mfn/mfd, we simply return the round_rate without using
* the frac part.
*/
if (mfn >= mfd)
return round_rate;
temp64 = (u64)parent_rate;
temp64 *= mfn;
do_div(temp64, mfd);
return round_rate + (u32)temp64;
}
static bool clk_pllv4_is_valid_mult(unsigned int mult)
{
int i;
/* check if mult is in valid MULT table */
for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
if (pllv4_mult_table[i] == mult)
return true;
}
return false;
}
static int clk_pllv4_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_pllv4 *pll = to_clk_pllv4(hw);
u32 val, mult, mfn, mfd = DEFAULT_MFD;
u64 temp64;
mult = rate / parent_rate;
if (!clk_pllv4_is_valid_mult(mult))
return -EINVAL;
if (parent_rate <= MAX_MFD)
mfd = parent_rate;
temp64 = (u64)(rate - mult * parent_rate);
temp64 *= mfd;
do_div(temp64, parent_rate);
mfn = temp64;
val = readl_relaxed(pll->base + PLL_CFG_OFFSET);
val &= ~BM_PLL_MULT;
val |= mult << BP_PLL_MULT;
writel_relaxed(val, pll->base + PLL_CFG_OFFSET);
writel_relaxed(mfn, pll->base + PLL_NUM_OFFSET);
writel_relaxed(mfd, pll->base + PLL_DENOM_OFFSET);
return 0;
}
static int clk_pllv4_prepare(struct clk_hw *hw)
{
u32 val;
struct clk_pllv4 *pll = to_clk_pllv4(hw);
val = readl_relaxed(pll->base);
val |= PLL_EN;
writel_relaxed(val, pll->base);
return clk_pllv4_wait_lock(pll);
}
static void clk_pllv4_unprepare(struct clk_hw *hw)
{
u32 val;
struct clk_pllv4 *pll = to_clk_pllv4(hw);
val = readl_relaxed(pll->base);
val &= ~PLL_EN;
writel_relaxed(val, pll->base);
}
static const struct clk_ops clk_pllv4_ops = {
.recalc_rate = clk_pllv4_recalc_rate,
.round_rate = clk_pllv4_round_rate,
.set_rate = clk_pllv4_set_rate,
.prepare = clk_pllv4_prepare,
.unprepare = clk_pllv4_unprepare,
.is_prepared = clk_pllv4_is_prepared,
};
struct clk_hw *imx_clk_hw_pllv4(const char *name, const char *parent_name,
void __iomem *base)
{
struct clk_pllv4 *pll;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->base = base;
init.name = name;
init.ops = &clk_pllv4_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_SET_RATE_GATE;
pll->hw.init = &init;
hw = &pll->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(pll);
hw = ERR_PTR(ret);
}
return hw;
}
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