swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 52721d9d3334c1cb1f76219a161084094ec634dc authored by Linus Torvalds on 19 July 2015, 21:45:02 UTC
Linux 4.2-rc3
Linux 4.2-rc3
Tip revision: 52721d9
clk-pll.c
/*
* 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 "clk.h"
#define to_clk_zx_pll(_hw) container_of(_hw, struct clk_zx_pll, 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;
}