linux/drivers/clk/at91/clk-peripheral.c

369 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*/
#include <linux/bitops.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pmc.h"
DEFINE_SPINLOCK(pmc_pcr_lock);
#define PERIPHERAL_ID_MIN 2
#define PERIPHERAL_ID_MAX 31
#define PERIPHERAL_MASK(id) (1 << ((id) & PERIPHERAL_ID_MAX))
#define PERIPHERAL_MAX_SHIFT 3
struct clk_peripheral {
struct clk_hw hw;
struct regmap *regmap;
u32 id;
};
#define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw)
struct clk_sam9x5_peripheral {
struct clk_hw hw;
struct regmap *regmap;
struct clk_range range;
spinlock_t *lock;
u32 id;
u32 div;
const struct clk_pcr_layout *layout;
bool auto_div;
};
#define to_clk_sam9x5_peripheral(hw) \
container_of(hw, struct clk_sam9x5_peripheral, hw)
static int clk_peripheral_enable(struct clk_hw *hw)
{
struct clk_peripheral *periph = to_clk_peripheral(hw);
int offset = AT91_PMC_PCER;
u32 id = periph->id;
if (id < PERIPHERAL_ID_MIN)
return 0;
if (id > PERIPHERAL_ID_MAX)
offset = AT91_PMC_PCER1;
regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id));
return 0;
}
static void clk_peripheral_disable(struct clk_hw *hw)
{
struct clk_peripheral *periph = to_clk_peripheral(hw);
int offset = AT91_PMC_PCDR;
u32 id = periph->id;
if (id < PERIPHERAL_ID_MIN)
return;
if (id > PERIPHERAL_ID_MAX)
offset = AT91_PMC_PCDR1;
regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id));
}
static int clk_peripheral_is_enabled(struct clk_hw *hw)
{
struct clk_peripheral *periph = to_clk_peripheral(hw);
int offset = AT91_PMC_PCSR;
unsigned int status;
u32 id = periph->id;
if (id < PERIPHERAL_ID_MIN)
return 1;
if (id > PERIPHERAL_ID_MAX)
offset = AT91_PMC_PCSR1;
regmap_read(periph->regmap, offset, &status);
return status & PERIPHERAL_MASK(id) ? 1 : 0;
}
static const struct clk_ops peripheral_ops = {
.enable = clk_peripheral_enable,
.disable = clk_peripheral_disable,
.is_enabled = clk_peripheral_is_enabled,
};
struct clk_hw * __init
at91_clk_register_peripheral(struct regmap *regmap, const char *name,
const char *parent_name, u32 id)
{
struct clk_peripheral *periph;
struct clk_init_data init;
struct clk_hw *hw;
int ret;
if (!name || !parent_name || id > PERIPHERAL_ID_MAX)
return ERR_PTR(-EINVAL);
periph = kzalloc(sizeof(*periph), GFP_KERNEL);
if (!periph)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &peripheral_ops;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
init.flags = 0;
periph->id = id;
periph->hw.init = &init;
periph->regmap = regmap;
hw = &periph->hw;
ret = clk_hw_register(NULL, &periph->hw);
if (ret) {
kfree(periph);
hw = ERR_PTR(ret);
}
return hw;
}
static void clk_sam9x5_peripheral_autodiv(struct clk_sam9x5_peripheral *periph)
{
struct clk_hw *parent;
unsigned long parent_rate;
int shift = 0;
if (!periph->auto_div)
return;
if (periph->range.max) {
parent = clk_hw_get_parent_by_index(&periph->hw, 0);
parent_rate = clk_hw_get_rate(parent);
if (!parent_rate)
return;
for (; shift < PERIPHERAL_MAX_SHIFT; shift++) {
if (parent_rate >> shift <= periph->range.max)
break;
}
}
periph->auto_div = false;
periph->div = shift;
}
static int clk_sam9x5_peripheral_enable(struct clk_hw *hw)
{
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
unsigned long flags;
if (periph->id < PERIPHERAL_ID_MIN)
return 0;
spin_lock_irqsave(periph->lock, flags);
regmap_write(periph->regmap, periph->layout->offset,
(periph->id & periph->layout->pid_mask));
regmap_update_bits(periph->regmap, periph->layout->offset,
periph->layout->div_mask | periph->layout->cmd |
AT91_PMC_PCR_EN,
field_prep(periph->layout->div_mask, periph->div) |
periph->layout->cmd |
AT91_PMC_PCR_EN);
spin_unlock_irqrestore(periph->lock, flags);
return 0;
}
static void clk_sam9x5_peripheral_disable(struct clk_hw *hw)
{
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
unsigned long flags;
if (periph->id < PERIPHERAL_ID_MIN)
return;
spin_lock_irqsave(periph->lock, flags);
regmap_write(periph->regmap, periph->layout->offset,
(periph->id & periph->layout->pid_mask));
regmap_update_bits(periph->regmap, periph->layout->offset,
AT91_PMC_PCR_EN | periph->layout->cmd,
periph->layout->cmd);
spin_unlock_irqrestore(periph->lock, flags);
}
static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw)
{
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
unsigned long flags;
unsigned int status;
if (periph->id < PERIPHERAL_ID_MIN)
return 1;
spin_lock_irqsave(periph->lock, flags);
regmap_write(periph->regmap, periph->layout->offset,
(periph->id & periph->layout->pid_mask));
regmap_read(periph->regmap, periph->layout->offset, &status);
spin_unlock_irqrestore(periph->lock, flags);
return status & AT91_PMC_PCR_EN ? 1 : 0;
}
static unsigned long
clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
unsigned long flags;
unsigned int status;
if (periph->id < PERIPHERAL_ID_MIN)
return parent_rate;
spin_lock_irqsave(periph->lock, flags);
regmap_write(periph->regmap, periph->layout->offset,
(periph->id & periph->layout->pid_mask));
regmap_read(periph->regmap, periph->layout->offset, &status);
spin_unlock_irqrestore(periph->lock, flags);
if (status & AT91_PMC_PCR_EN) {
periph->div = field_get(periph->layout->div_mask, status);
periph->auto_div = false;
} else {
clk_sam9x5_peripheral_autodiv(periph);
}
return parent_rate >> periph->div;
}
static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long *parent_rate)
{
int shift = 0;
unsigned long best_rate;
unsigned long best_diff;
unsigned long cur_rate = *parent_rate;
unsigned long cur_diff;
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max)
return *parent_rate;
if (periph->range.max) {
for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
cur_rate = *parent_rate >> shift;
if (cur_rate <= periph->range.max)
break;
}
}
if (rate >= cur_rate)
return cur_rate;
best_diff = cur_rate - rate;
best_rate = cur_rate;
for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
cur_rate = *parent_rate >> shift;
if (cur_rate < rate)
cur_diff = rate - cur_rate;
else
cur_diff = cur_rate - rate;
if (cur_diff < best_diff) {
best_diff = cur_diff;
best_rate = cur_rate;
}
if (!best_diff || cur_rate < rate)
break;
}
return best_rate;
}
static int clk_sam9x5_peripheral_set_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long parent_rate)
{
int shift;
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) {
if (parent_rate == rate)
return 0;
else
return -EINVAL;
}
if (periph->range.max && rate > periph->range.max)
return -EINVAL;
for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
if (parent_rate >> shift == rate) {
periph->auto_div = false;
periph->div = shift;
return 0;
}
}
return -EINVAL;
}
static const struct clk_ops sam9x5_peripheral_ops = {
.enable = clk_sam9x5_peripheral_enable,
.disable = clk_sam9x5_peripheral_disable,
.is_enabled = clk_sam9x5_peripheral_is_enabled,
.recalc_rate = clk_sam9x5_peripheral_recalc_rate,
.round_rate = clk_sam9x5_peripheral_round_rate,
.set_rate = clk_sam9x5_peripheral_set_rate,
};
struct clk_hw * __init
at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
const struct clk_pcr_layout *layout,
const char *name, const char *parent_name,
u32 id, const struct clk_range *range)
{
struct clk_sam9x5_peripheral *periph;
struct clk_init_data init;
struct clk_hw *hw;
int ret;
if (!name || !parent_name)
return ERR_PTR(-EINVAL);
periph = kzalloc(sizeof(*periph), GFP_KERNEL);
if (!periph)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &sam9x5_peripheral_ops;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
init.flags = 0;
periph->id = id;
periph->hw.init = &init;
periph->div = 0;
periph->regmap = regmap;
periph->lock = lock;
if (layout->div_mask)
periph->auto_div = true;
periph->layout = layout;
periph->range = *range;
hw = &periph->hw;
ret = clk_hw_register(NULL, &periph->hw);
if (ret) {
kfree(periph);
hw = ERR_PTR(ret);
} else {
clk_sam9x5_peripheral_autodiv(periph);
pmc_register_id(id);
}
return hw;
}