blob: 1f3234f22667446557a2e8d36843378a2841ac73 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Toshiba Visconti PLL driver
*
* Copyright (c) 2021 TOSHIBA CORPORATION
* Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
*
* Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
*/
#include <linux/bitfield.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/io.h>
#include "pll.h"
struct visconti_pll {
struct clk_hw hw;
void __iomem *pll_base;
spinlock_t *lock;
unsigned long flags;
const struct visconti_pll_rate_table *rate_table;
size_t rate_count;
struct visconti_pll_provider *ctx;
};
#define PLL_CONF_REG 0x0000
#define PLL_CTRL_REG 0x0004
#define PLL_FRACMODE_REG 0x0010
#define PLL_INTIN_REG 0x0014
#define PLL_FRACIN_REG 0x0018
#define PLL_REFDIV_REG 0x001c
#define PLL_POSTDIV_REG 0x0020
#define PLL_CONFIG_SEL BIT(0)
#define PLL_PLLEN BIT(4)
#define PLL_BYPASS BIT(16)
#define PLL_INTIN_MASK GENMASK(11, 0)
#define PLL_FRACIN_MASK GENMASK(23, 0)
#define PLL_REFDIV_MASK GENMASK(5, 0)
#define PLL_POSTDIV_MASK GENMASK(2, 0)
#define PLL0_FRACMODE_DACEN BIT(4)
#define PLL0_FRACMODE_DSMEN BIT(0)
#define PLL_CREATE_FRACMODE(table) (table->dacen << 4 | table->dsmen)
#define PLL_CREATE_OSTDIV(table) (table->postdiv2 << 4 | table->postdiv1)
static inline struct visconti_pll *to_visconti_pll(struct clk_hw *hw)
{
return container_of(hw, struct visconti_pll, hw);
}
static void visconti_pll_get_params(struct visconti_pll *pll,
struct visconti_pll_rate_table *rate_table)
{
u32 postdiv, val;
val = readl(pll->pll_base + PLL_FRACMODE_REG);
rate_table->dacen = FIELD_GET(PLL0_FRACMODE_DACEN, val);
rate_table->dsmen = FIELD_GET(PLL0_FRACMODE_DSMEN, val);
rate_table->fracin = readl(pll->pll_base + PLL_FRACIN_REG) & PLL_FRACIN_MASK;
rate_table->intin = readl(pll->pll_base + PLL_INTIN_REG) & PLL_INTIN_MASK;
rate_table->refdiv = readl(pll->pll_base + PLL_REFDIV_REG) & PLL_REFDIV_MASK;
postdiv = readl(pll->pll_base + PLL_POSTDIV_REG);
rate_table->postdiv1 = postdiv & PLL_POSTDIV_MASK;
rate_table->postdiv2 = (postdiv >> 4) & PLL_POSTDIV_MASK;
}
static const struct visconti_pll_rate_table *visconti_get_pll_settings(struct visconti_pll *pll,
unsigned long rate)
{
const struct visconti_pll_rate_table *rate_table = pll->rate_table;
int i;
for (i = 0; i < pll->rate_count; i++)
if (rate == rate_table[i].rate)
return &rate_table[i];
return NULL;
}
static unsigned long visconti_get_pll_rate_from_data(struct visconti_pll *pll,
const struct visconti_pll_rate_table *rate)
{
const struct visconti_pll_rate_table *rate_table = pll->rate_table;
int i;
for (i = 0; i < pll->rate_count; i++)
if (memcmp(&rate_table[i].dacen, &rate->dacen,
sizeof(*rate) - sizeof(unsigned long)) == 0)
return rate_table[i].rate;
/* set default */
return rate_table[0].rate;
}
static long visconti_pll_round_rate(struct clk_hw *hw,
unsigned long rate, unsigned long *prate)
{
struct visconti_pll *pll = to_visconti_pll(hw);
const struct visconti_pll_rate_table *rate_table = pll->rate_table;
int i;
/* Assumming rate_table is in descending order */
for (i = 0; i < pll->rate_count; i++)
if (rate >= rate_table[i].rate)
return rate_table[i].rate;
/* return minimum supported value */
return rate_table[i - 1].rate;
}
static unsigned long visconti_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct visconti_pll *pll = to_visconti_pll(hw);
struct visconti_pll_rate_table rate_table;
memset(&rate_table, 0, sizeof(rate_table));
visconti_pll_get_params(pll, &rate_table);
return visconti_get_pll_rate_from_data(pll, &rate_table);
}
static int visconti_pll_set_params(struct visconti_pll *pll,
const struct visconti_pll_rate_table *rate_table)
{
writel(PLL_CREATE_FRACMODE(rate_table), pll->pll_base + PLL_FRACMODE_REG);
writel(PLL_CREATE_OSTDIV(rate_table), pll->pll_base + PLL_POSTDIV_REG);
writel(rate_table->intin, pll->pll_base + PLL_INTIN_REG);
writel(rate_table->fracin, pll->pll_base + PLL_FRACIN_REG);
writel(rate_table->refdiv, pll->pll_base + PLL_REFDIV_REG);
return 0;
}
static int visconti_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct visconti_pll *pll = to_visconti_pll(hw);
const struct visconti_pll_rate_table *rate_table;
rate_table = visconti_get_pll_settings(pll, rate);
if (!rate_table)
return -EINVAL;
return visconti_pll_set_params(pll, rate_table);
}
static int visconti_pll_is_enabled(struct clk_hw *hw)
{
struct visconti_pll *pll = to_visconti_pll(hw);
u32 reg;
reg = readl(pll->pll_base + PLL_CTRL_REG);
return (reg & PLL_PLLEN);
}
static int visconti_pll_enable(struct clk_hw *hw)
{
struct visconti_pll *pll = to_visconti_pll(hw);
const struct visconti_pll_rate_table *rate_table = pll->rate_table;
unsigned long flags;
u32 reg;
if (visconti_pll_is_enabled(hw))
return 0;
spin_lock_irqsave(pll->lock, flags);
writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg |= PLL_BYPASS;
writel(reg, pll->pll_base + PLL_CTRL_REG);
visconti_pll_set_params(pll, &rate_table[0]);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg &= ~PLL_PLLEN;
writel(reg, pll->pll_base + PLL_CTRL_REG);
udelay(1);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg |= PLL_PLLEN;
writel(reg, pll->pll_base + PLL_CTRL_REG);
udelay(40);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg &= ~PLL_BYPASS;
writel(reg, pll->pll_base + PLL_CTRL_REG);
spin_unlock_irqrestore(pll->lock, flags);
return 0;
}
static void visconti_pll_disable(struct clk_hw *hw)
{
struct visconti_pll *pll = to_visconti_pll(hw);
unsigned long flags;
u32 reg;
if (!visconti_pll_is_enabled(hw))
return;
spin_lock_irqsave(pll->lock, flags);
writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg |= PLL_BYPASS;
writel(reg, pll->pll_base + PLL_CTRL_REG);
reg = readl(pll->pll_base + PLL_CTRL_REG);
reg &= ~PLL_PLLEN;
writel(reg, pll->pll_base + PLL_CTRL_REG);
spin_unlock_irqrestore(pll->lock, flags);
}
static const struct clk_ops visconti_pll_ops = {
.enable = visconti_pll_enable,
.disable = visconti_pll_disable,
.is_enabled = visconti_pll_is_enabled,
.round_rate = visconti_pll_round_rate,
.recalc_rate = visconti_pll_recalc_rate,
.set_rate = visconti_pll_set_rate,
};
static struct clk_hw *visconti_register_pll(struct visconti_pll_provider *ctx,
const char *name,
const char *parent_name,
int offset,
const struct visconti_pll_rate_table *rate_table,
spinlock_t *lock)
{
struct clk_init_data init;
struct visconti_pll *pll;
struct clk_hw *pll_hw_clk;
size_t len;
int ret;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
init.name = name;
init.flags = CLK_IGNORE_UNUSED;
init.parent_names = &parent_name;
init.num_parents = 1;
for (len = 0; rate_table[len].rate != 0; )
len++;
pll->rate_count = len;
pll->rate_table = kmemdup(rate_table,
pll->rate_count * sizeof(struct visconti_pll_rate_table),
GFP_KERNEL);
WARN(!pll->rate_table, "%s: could not allocate rate table for %s\n", __func__, name);
init.ops = &visconti_pll_ops;
pll->hw.init = &init;
pll->pll_base = ctx->reg_base + offset;
pll->lock = lock;
pll->ctx = ctx;
pll_hw_clk = &pll->hw;
ret = clk_hw_register(NULL, &pll->hw);
if (ret) {
pr_err("failed to register pll clock %s : %d\n", name, ret);
kfree(pll->rate_table);
kfree(pll);
pll_hw_clk = ERR_PTR(ret);
}
return pll_hw_clk;
}
static void visconti_pll_add_lookup(struct visconti_pll_provider *ctx,
struct clk_hw *hw_clk,
unsigned int id)
{
if (id)
ctx->clk_data.hws[id] = hw_clk;
}
void __init visconti_register_plls(struct visconti_pll_provider *ctx,
const struct visconti_pll_info *list,
unsigned int nr_plls,
spinlock_t *lock)
{
int idx;
for (idx = 0; idx < nr_plls; idx++, list++) {
struct clk_hw *clk;
clk = visconti_register_pll(ctx,
list->name,
list->parent,
list->base_reg,
list->rate_table,
lock);
if (IS_ERR(clk)) {
pr_err("failed to register clock %s\n", list->name);
continue;
}
visconti_pll_add_lookup(ctx, clk, list->id);
}
}
struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np,
void __iomem *base,
unsigned long nr_plls)
{
struct visconti_pll_provider *ctx;
int i;
ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_plls), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
for (i = 0; i < nr_plls; ++i)
ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
ctx->node = np;
ctx->reg_base = base;
ctx->clk_data.num = nr_plls;
return ctx;
}