linux/drivers/clk/zte/clk.c

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/*
* Copyright 2014 Linaro Ltd.
* Copyright (C) 2014 ZTE Corporation.
*
* 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/iopoll.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/div64.h>
#include "clk.h"
#define to_clk_zx_pll(_hw) container_of(_hw, struct clk_zx_pll, hw)
#define to_clk_zx_audio(_hw) container_of(_hw, struct clk_zx_audio, hw)
#define CFG0_CFG1_OFFSET 4
#define LOCK_FLAG BIT(30)
#define POWER_DOWN BIT(31)
static int rate_to_idx(struct clk_zx_pll *zx_pll, unsigned long rate)
{
const struct zx_pll_config *config = zx_pll->lookup_table;
int i;
for (i = 0; i < zx_pll->count; i++) {
if (config[i].rate > rate)
return i > 0 ? i - 1 : 0;
if (config[i].rate == rate)
return i;
}
return i - 1;
}
static int hw_to_idx(struct clk_zx_pll *zx_pll)
{
const struct zx_pll_config *config = zx_pll->lookup_table;
u32 hw_cfg0, hw_cfg1;
int i;
hw_cfg0 = readl_relaxed(zx_pll->reg_base);
hw_cfg1 = readl_relaxed(zx_pll->reg_base + CFG0_CFG1_OFFSET);
/* For matching the value in lookup table */
hw_cfg0 &= ~LOCK_FLAG;
hw_cfg0 |= POWER_DOWN;
for (i = 0; i < zx_pll->count; i++) {
if (hw_cfg0 == config[i].cfg0 && hw_cfg1 == config[i].cfg1)
return i;
}
return -EINVAL;
}
static unsigned long zx_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
int idx;
idx = hw_to_idx(zx_pll);
if (unlikely(idx == -EINVAL))
return 0;
return zx_pll->lookup_table[idx].rate;
}
static long zx_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
int idx;
idx = rate_to_idx(zx_pll, rate);
return zx_pll->lookup_table[idx].rate;
}
static int zx_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
/* Assume current cpu is not running on current PLL */
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
const struct zx_pll_config *config;
int idx;
idx = rate_to_idx(zx_pll, rate);
config = &zx_pll->lookup_table[idx];
writel_relaxed(config->cfg0, zx_pll->reg_base);
writel_relaxed(config->cfg1, zx_pll->reg_base + CFG0_CFG1_OFFSET);
return 0;
}
static int zx_pll_enable(struct clk_hw *hw)
{
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
u32 reg;
reg = readl_relaxed(zx_pll->reg_base);
writel_relaxed(reg & ~POWER_DOWN, zx_pll->reg_base);
return readl_relaxed_poll_timeout(zx_pll->reg_base, reg,
reg & LOCK_FLAG, 0, 100);
}
static void zx_pll_disable(struct clk_hw *hw)
{
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
u32 reg;
reg = readl_relaxed(zx_pll->reg_base);
writel_relaxed(reg | POWER_DOWN, zx_pll->reg_base);
}
static int zx_pll_is_enabled(struct clk_hw *hw)
{
struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw);
u32 reg;
reg = readl_relaxed(zx_pll->reg_base);
return !(reg & POWER_DOWN);
}
static const struct clk_ops zx_pll_ops = {
.recalc_rate = zx_pll_recalc_rate,
.round_rate = zx_pll_round_rate,
.set_rate = zx_pll_set_rate,
.enable = zx_pll_enable,
.disable = zx_pll_disable,
.is_enabled = zx_pll_is_enabled,
};
struct clk *clk_register_zx_pll(const char *name, const char *parent_name,
unsigned long flags, void __iomem *reg_base,
const struct zx_pll_config *lookup_table,
int count, spinlock_t *lock)
{
struct clk_zx_pll *zx_pll;
struct clk *clk;
struct clk_init_data init;
zx_pll = kzalloc(sizeof(*zx_pll), GFP_KERNEL);
if (!zx_pll)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &zx_pll_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
zx_pll->reg_base = reg_base;
zx_pll->lookup_table = lookup_table;
zx_pll->count = count;
zx_pll->lock = lock;
zx_pll->hw.init = &init;
clk = clk_register(NULL, &zx_pll->hw);
if (IS_ERR(clk))
kfree(zx_pll);
return clk;
}
#define BPAR 1000000
static u32 calc_reg(u32 parent_rate, u32 rate)
{
u32 sel, integ, fra_div, tmp;
u64 tmp64 = (u64)parent_rate * BPAR;
do_div(tmp64, rate);
integ = (u32)tmp64 / BPAR;
integ = integ >> 1;
tmp = (u32)tmp64 % BPAR;
sel = tmp / BPAR;
tmp = tmp % BPAR;
fra_div = tmp * 0xff / BPAR;
tmp = (sel << 24) | (integ << 16) | (0xff << 8) | fra_div;
/* Set I2S integer divider as 1. This bit is reserved for SPDIF
* and do no harm.
*/
tmp |= BIT(28);
return tmp;
}
static u32 calc_rate(u32 reg, u32 parent_rate)
{
u32 sel, integ, fra_div, tmp;
u64 tmp64 = (u64)parent_rate * BPAR;
tmp = reg;
sel = (tmp >> 24) & BIT(0);
integ = (tmp >> 16) & 0xff;
fra_div = tmp & 0xff;
tmp = fra_div * BPAR;
tmp = tmp / 0xff;
tmp += sel * BPAR;
tmp += 2 * integ * BPAR;
do_div(tmp64, tmp);
return (u32)tmp64;
}
static unsigned long zx_audio_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_zx_audio *zx_audio = to_clk_zx_audio(hw);
u32 reg;
reg = readl_relaxed(zx_audio->reg_base);
return calc_rate(reg, parent_rate);
}
static long zx_audio_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
u32 reg;
if (rate * 2 > *prate)
return -EINVAL;
reg = calc_reg(*prate, rate);
return calc_rate(reg, *prate);
}
static int zx_audio_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_zx_audio *zx_audio = to_clk_zx_audio(hw);
u32 reg;
reg = calc_reg(parent_rate, rate);
writel_relaxed(reg, zx_audio->reg_base);
return 0;
}
#define ZX_AUDIO_EN BIT(25)
static int zx_audio_enable(struct clk_hw *hw)
{
struct clk_zx_audio *zx_audio = to_clk_zx_audio(hw);
u32 reg;
reg = readl_relaxed(zx_audio->reg_base);
writel_relaxed(reg & ~ZX_AUDIO_EN, zx_audio->reg_base);
return 0;
}
static void zx_audio_disable(struct clk_hw *hw)
{
struct clk_zx_audio *zx_audio = to_clk_zx_audio(hw);
u32 reg;
reg = readl_relaxed(zx_audio->reg_base);
writel_relaxed(reg | ZX_AUDIO_EN, zx_audio->reg_base);
}
static const struct clk_ops zx_audio_ops = {
.recalc_rate = zx_audio_recalc_rate,
.round_rate = zx_audio_round_rate,
.set_rate = zx_audio_set_rate,
.enable = zx_audio_enable,
.disable = zx_audio_disable,
};
struct clk *clk_register_zx_audio(const char *name,
const char * const parent_name,
unsigned long flags,
void __iomem *reg_base)
{
struct clk_zx_audio *zx_audio;
struct clk *clk;
struct clk_init_data init;
zx_audio = kzalloc(sizeof(*zx_audio), GFP_KERNEL);
if (!zx_audio)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &zx_audio_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
zx_audio->reg_base = reg_base;
zx_audio->hw.init = &init;
clk = clk_register(NULL, &zx_audio->hw);
if (IS_ERR(clk))
kfree(zx_audio);
return clk;
}