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linux-next/drivers/clk/mediatek/clk-pll.c

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/*
* Copyright (c) 2014 MediaTek Inc.
* Author: James Liao <jamesjj.liao@mediatek.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/clkdev.h>
#include <linux/delay.h>
#include "clk-mtk.h"
#define REG_CON0 0
#define REG_CON1 4
#define CON0_BASE_EN BIT(0)
#define CON0_PWR_ON BIT(0)
#define CON0_ISO_EN BIT(1)
#define CON0_PCW_CHG BIT(31)
#define AUDPLL_TUNER_EN BIT(31)
#define POSTDIV_MASK 0x7
#define INTEGER_BITS 7
/*
* MediaTek PLLs are configured through their pcw value. The pcw value describes
* a divider in the PLL feedback loop which consists of 7 bits for the integer
* part and the remaining bits (if present) for the fractional part. Also they
* have a 3 bit power-of-two post divider.
*/
struct mtk_clk_pll {
struct clk_hw hw;
void __iomem *base_addr;
void __iomem *pd_addr;
void __iomem *pwr_addr;
void __iomem *tuner_addr;
void __iomem *pcw_addr;
const struct mtk_pll_data *data;
};
static inline struct mtk_clk_pll *to_mtk_clk_pll(struct clk_hw *hw)
{
return container_of(hw, struct mtk_clk_pll, hw);
}
static int mtk_pll_is_prepared(struct clk_hw *hw)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
return (readl(pll->base_addr + REG_CON0) & CON0_BASE_EN) != 0;
}
static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
u32 pcw, int postdiv)
{
int pcwbits = pll->data->pcwbits;
int pcwfbits;
u64 vco;
u8 c = 0;
/* The fractional part of the PLL divider. */
pcwfbits = pcwbits > INTEGER_BITS ? pcwbits - INTEGER_BITS : 0;
vco = (u64)fin * pcw;
if (pcwfbits && (vco & GENMASK(pcwfbits - 1, 0)))
c = 1;
vco >>= pcwfbits;
if (c)
vco++;
return ((unsigned long)vco + postdiv - 1) / postdiv;
}
static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
int postdiv)
{
u32 con1, val;
int pll_en;
pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;
/* set postdiv */
val = readl(pll->pd_addr);
val &= ~(POSTDIV_MASK << pll->data->pd_shift);
val |= (ffs(postdiv) - 1) << pll->data->pd_shift;
/* postdiv and pcw need to set at the same time if on same register */
if (pll->pd_addr != pll->pcw_addr) {
writel(val, pll->pd_addr);
val = readl(pll->pcw_addr);
}
/* set pcw */
val &= ~GENMASK(pll->data->pcw_shift + pll->data->pcwbits - 1,
pll->data->pcw_shift);
val |= pcw << pll->data->pcw_shift;
writel(val, pll->pcw_addr);
con1 = readl(pll->base_addr + REG_CON1);
if (pll_en)
con1 |= CON0_PCW_CHG;
writel(con1, pll->base_addr + REG_CON1);
if (pll->tuner_addr)
writel(con1 + 1, pll->tuner_addr);
if (pll_en)
udelay(20);
}
/*
* mtk_pll_calc_values - calculate good values for a given input frequency.
* @pll: The pll
* @pcw: The pcw value (output)
* @postdiv: The post divider (output)
* @freq: The desired target frequency
* @fin: The input frequency
*
*/
static void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv,
u32 freq, u32 fin)
{
unsigned long fmin = 1000 * MHZ;
const struct mtk_pll_div_table *div_table = pll->data->div_table;
u64 _pcw;
u32 val;
if (freq > pll->data->fmax)
freq = pll->data->fmax;
if (div_table) {
if (freq > div_table[0].freq)
freq = div_table[0].freq;
for (val = 0; div_table[val + 1].freq != 0; val++) {
if (freq > div_table[val + 1].freq)
break;
}
*postdiv = 1 << val;
} else {
for (val = 0; val < 5; val++) {
*postdiv = 1 << val;
if ((u64)freq * *postdiv >= fmin)
break;
}
}
/* _pcw = freq * postdiv / fin * 2^pcwfbits */
_pcw = ((u64)freq << val) << (pll->data->pcwbits - INTEGER_BITS);
do_div(_pcw, fin);
*pcw = (u32)_pcw;
}
static int mtk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
u32 pcw = 0;
u32 postdiv;
mtk_pll_calc_values(pll, &pcw, &postdiv, rate, parent_rate);
mtk_pll_set_rate_regs(pll, pcw, postdiv);
return 0;
}
static unsigned long mtk_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
u32 postdiv;
u32 pcw;
postdiv = (readl(pll->pd_addr) >> pll->data->pd_shift) & POSTDIV_MASK;
postdiv = 1 << postdiv;
pcw = readl(pll->pcw_addr) >> pll->data->pcw_shift;
pcw &= GENMASK(pll->data->pcwbits - 1, 0);
return __mtk_pll_recalc_rate(pll, parent_rate, pcw, postdiv);
}
static long mtk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
u32 pcw = 0;
int postdiv;
mtk_pll_calc_values(pll, &pcw, &postdiv, rate, *prate);
return __mtk_pll_recalc_rate(pll, *prate, pcw, postdiv);
}
static int mtk_pll_prepare(struct clk_hw *hw)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
u32 r;
r = readl(pll->pwr_addr) | CON0_PWR_ON;
writel(r, pll->pwr_addr);
udelay(1);
r = readl(pll->pwr_addr) & ~CON0_ISO_EN;
writel(r, pll->pwr_addr);
udelay(1);
r = readl(pll->base_addr + REG_CON0);
r |= pll->data->en_mask;
writel(r, pll->base_addr + REG_CON0);
if (pll->tuner_addr) {
r = readl(pll->tuner_addr) | AUDPLL_TUNER_EN;
writel(r, pll->tuner_addr);
}
udelay(20);
if (pll->data->flags & HAVE_RST_BAR) {
r = readl(pll->base_addr + REG_CON0);
r |= pll->data->rst_bar_mask;
writel(r, pll->base_addr + REG_CON0);
}
return 0;
}
static void mtk_pll_unprepare(struct clk_hw *hw)
{
struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
u32 r;
if (pll->data->flags & HAVE_RST_BAR) {
r = readl(pll->base_addr + REG_CON0);
r &= ~pll->data->rst_bar_mask;
writel(r, pll->base_addr + REG_CON0);
}
if (pll->tuner_addr) {
r = readl(pll->tuner_addr) & ~AUDPLL_TUNER_EN;
writel(r, pll->tuner_addr);
}
r = readl(pll->base_addr + REG_CON0);
r &= ~CON0_BASE_EN;
writel(r, pll->base_addr + REG_CON0);
r = readl(pll->pwr_addr) | CON0_ISO_EN;
writel(r, pll->pwr_addr);
r = readl(pll->pwr_addr) & ~CON0_PWR_ON;
writel(r, pll->pwr_addr);
}
static const struct clk_ops mtk_pll_ops = {
.is_prepared = mtk_pll_is_prepared,
.prepare = mtk_pll_prepare,
.unprepare = mtk_pll_unprepare,
.recalc_rate = mtk_pll_recalc_rate,
.round_rate = mtk_pll_round_rate,
.set_rate = mtk_pll_set_rate,
};
static struct clk *mtk_clk_register_pll(const struct mtk_pll_data *data,
void __iomem *base)
{
struct mtk_clk_pll *pll;
struct clk_init_data init = {};
struct clk *clk;
const char *parent_name = "clk26m";
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->base_addr = base + data->reg;
pll->pwr_addr = base + data->pwr_reg;
pll->pd_addr = base + data->pd_reg;
pll->pcw_addr = base + data->pcw_reg;
if (data->tuner_reg)
pll->tuner_addr = base + data->tuner_reg;
pll->hw.init = &init;
pll->data = data;
init.name = data->name;
init.ops = &mtk_pll_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
clk = clk_register(NULL, &pll->hw);
if (IS_ERR(clk))
kfree(pll);
return clk;
}
void __init mtk_clk_register_plls(struct device_node *node,
const struct mtk_pll_data *plls, int num_plls, struct clk_onecell_data *clk_data)
{
void __iomem *base;
int r, i;
struct clk *clk;
base = of_iomap(node, 0);
if (!base) {
pr_err("%s(): ioremap failed\n", __func__);
return;
}
for (i = 0; i < num_plls; i++) {
const struct mtk_pll_data *pll = &plls[i];
clk = mtk_clk_register_pll(pll, base);
if (IS_ERR(clk)) {
pr_err("Failed to register clk %s: %ld\n",
pll->name, PTR_ERR(clk));
continue;
}
clk_data->clks[pll->id] = clk;
}
r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
if (r)
pr_err("%s(): could not register clock provider: %d\n",
__func__, r);
}