linux-sg2042/drivers/clk/at91/clk-sam9x60-pll.c

533 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Microchip Technology Inc.
*
*/
#include <linux/bitfield.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 PMC_PLL_CTRL0_DIV_MSK GENMASK(7, 0)
#define PMC_PLL_CTRL1_MUL_MSK GENMASK(31, 24)
#define PMC_PLL_CTRL1_FRACR_MSK GENMASK(21, 0)
#define PLL_DIV_MAX (FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, UINT_MAX) + 1)
#define UPLL_DIV 2
#define PLL_MUL_MAX (FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, UINT_MAX) + 1)
#define FCORE_MIN (600000000)
#define FCORE_MAX (1200000000)
#define PLL_MAX_ID 7
struct sam9x60_pll_core {
struct regmap *regmap;
spinlock_t *lock;
const struct clk_pll_characteristics *characteristics;
const struct clk_pll_layout *layout;
struct clk_hw hw;
u8 id;
};
struct sam9x60_frac {
struct sam9x60_pll_core core;
u32 frac;
u16 mul;
};
struct sam9x60_div {
struct sam9x60_pll_core core;
u8 div;
};
#define to_sam9x60_pll_core(hw) container_of(hw, struct sam9x60_pll_core, hw)
#define to_sam9x60_frac(core) container_of(core, struct sam9x60_frac, core)
#define to_sam9x60_div(core) container_of(core, struct sam9x60_div, core)
static inline bool sam9x60_pll_ready(struct regmap *regmap, int id)
{
unsigned int status;
regmap_read(regmap, AT91_PMC_PLL_ISR0, &status);
return !!(status & BIT(id));
}
static bool sam9x60_frac_pll_ready(struct regmap *regmap, u8 id)
{
return sam9x60_pll_ready(regmap, id);
}
static unsigned long sam9x60_frac_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct sam9x60_frac *frac = to_sam9x60_frac(core);
return (parent_rate * (frac->mul + 1) +
((u64)parent_rate * frac->frac >> 22));
}
static int sam9x60_frac_pll_prepare(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct sam9x60_frac *frac = to_sam9x60_frac(core);
struct regmap *regmap = core->regmap;
unsigned int val, cfrac, cmul;
unsigned long flags;
spin_lock_irqsave(core->lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_read(regmap, AT91_PMC_PLL_CTRL1, &val);
cmul = (val & core->layout->mul_mask) >> core->layout->mul_shift;
cfrac = (val & core->layout->frac_mask) >> core->layout->frac_shift;
if (sam9x60_frac_pll_ready(regmap, core->id) &&
(cmul == frac->mul && cfrac == frac->frac))
goto unlock;
/* Recommended value for PMC_PLL_ACR */
if (core->characteristics->upll)
val = AT91_PMC_PLL_ACR_DEFAULT_UPLL;
else
val = AT91_PMC_PLL_ACR_DEFAULT_PLLA;
regmap_write(regmap, AT91_PMC_PLL_ACR, val);
regmap_write(regmap, AT91_PMC_PLL_CTRL1,
(frac->mul << core->layout->mul_shift) |
(frac->frac << core->layout->frac_shift));
if (core->characteristics->upll) {
/* Enable the UTMI internal bandgap */
val |= AT91_PMC_PLL_ACR_UTMIBG;
regmap_write(regmap, AT91_PMC_PLL_ACR, val);
udelay(10);
/* Enable the UTMI internal regulator */
val |= AT91_PMC_PLL_ACR_UTMIVR;
regmap_write(regmap, AT91_PMC_PLL_ACR, val);
udelay(10);
}
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
AT91_PMC_PLL_CTRL0_ENLOCK | AT91_PMC_PLL_CTRL0_ENPLL,
AT91_PMC_PLL_CTRL0_ENLOCK | AT91_PMC_PLL_CTRL0_ENPLL);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
while (!sam9x60_pll_ready(regmap, core->id))
cpu_relax();
unlock:
spin_unlock_irqrestore(core->lock, flags);
return 0;
}
static void sam9x60_frac_pll_unprepare(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct regmap *regmap = core->regmap;
unsigned long flags;
spin_lock_irqsave(core->lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, AT91_PMC_PLL_CTRL0_ENPLL, 0);
if (core->characteristics->upll)
regmap_update_bits(regmap, AT91_PMC_PLL_ACR,
AT91_PMC_PLL_ACR_UTMIBG | AT91_PMC_PLL_ACR_UTMIVR, 0);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
spin_unlock_irqrestore(core->lock, flags);
}
static int sam9x60_frac_pll_is_prepared(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
return sam9x60_pll_ready(core->regmap, core->id);
}
static long sam9x60_frac_pll_compute_mul_frac(struct sam9x60_pll_core *core,
unsigned long rate,
unsigned long parent_rate,
bool update)
{
struct sam9x60_frac *frac = to_sam9x60_frac(core);
unsigned long tmprate, remainder;
unsigned long nmul = 0;
unsigned long nfrac = 0;
if (rate < FCORE_MIN || rate > FCORE_MAX)
return -ERANGE;
/*
* Calculate the multiplier associated with the current
* divider that provide the closest rate to the requested one.
*/
nmul = mult_frac(rate, 1, parent_rate);
tmprate = mult_frac(parent_rate, nmul, 1);
remainder = rate - tmprate;
if (remainder) {
nfrac = DIV_ROUND_CLOSEST_ULL((u64)remainder * (1 << 22),
parent_rate);
tmprate += DIV_ROUND_CLOSEST_ULL((u64)nfrac * parent_rate,
(1 << 22));
}
/* Check if resulted rate is a valid. */
if (tmprate < FCORE_MIN || tmprate > FCORE_MAX)
return -ERANGE;
if (update) {
frac->mul = nmul - 1;
frac->frac = nfrac;
}
return tmprate;
}
static long sam9x60_frac_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
return sam9x60_frac_pll_compute_mul_frac(core, rate, *parent_rate, false);
}
static int sam9x60_frac_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
return sam9x60_frac_pll_compute_mul_frac(core, rate, parent_rate, true);
}
static const struct clk_ops sam9x60_frac_pll_ops = {
.prepare = sam9x60_frac_pll_prepare,
.unprepare = sam9x60_frac_pll_unprepare,
.is_prepared = sam9x60_frac_pll_is_prepared,
.recalc_rate = sam9x60_frac_pll_recalc_rate,
.round_rate = sam9x60_frac_pll_round_rate,
.set_rate = sam9x60_frac_pll_set_rate,
};
static int sam9x60_div_pll_prepare(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct sam9x60_div *div = to_sam9x60_div(core);
struct regmap *regmap = core->regmap;
unsigned long flags;
unsigned int val, cdiv;
spin_lock_irqsave(core->lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val);
cdiv = (val & core->layout->div_mask) >> core->layout->div_shift;
/* Stop if enabled an nothing changed. */
if (!!(val & core->layout->endiv_mask) && cdiv == div->div)
goto unlock;
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
core->layout->div_mask | core->layout->endiv_mask,
(div->div << core->layout->div_shift) |
(1 << core->layout->endiv_shift));
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
while (!sam9x60_pll_ready(regmap, core->id))
cpu_relax();
unlock:
spin_unlock_irqrestore(core->lock, flags);
return 0;
}
static void sam9x60_div_pll_unprepare(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct regmap *regmap = core->regmap;
unsigned long flags;
spin_lock_irqsave(core->lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
core->layout->endiv_mask, 0);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
spin_unlock_irqrestore(core->lock, flags);
}
static int sam9x60_div_pll_is_prepared(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct regmap *regmap = core->regmap;
unsigned long flags;
unsigned int val;
spin_lock_irqsave(core->lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val);
spin_unlock_irqrestore(core->lock, flags);
return !!(val & core->layout->endiv_mask);
}
static unsigned long sam9x60_div_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct sam9x60_div *div = to_sam9x60_div(core);
return DIV_ROUND_CLOSEST_ULL(parent_rate, (div->div + 1));
}
static long sam9x60_div_pll_compute_div(struct sam9x60_pll_core *core,
unsigned long *parent_rate,
unsigned long rate)
{
const struct clk_pll_characteristics *characteristics =
core->characteristics;
struct clk_hw *parent = clk_hw_get_parent(&core->hw);
unsigned long tmp_rate, tmp_parent_rate, tmp_diff;
long best_diff = -1, best_rate = -EINVAL;
u32 divid, best_div;
if (!rate)
return 0;
if (rate < characteristics->output[0].min ||
rate > characteristics->output[0].max)
return -ERANGE;
for (divid = 1; divid < core->layout->div_mask; divid++) {
tmp_parent_rate = clk_hw_round_rate(parent, rate * divid);
if (!tmp_parent_rate)
continue;
tmp_rate = DIV_ROUND_CLOSEST_ULL(tmp_parent_rate, divid);
tmp_diff = abs(rate - tmp_rate);
if (best_diff < 0 || best_diff > tmp_diff) {
*parent_rate = tmp_parent_rate;
best_rate = tmp_rate;
best_diff = tmp_diff;
best_div = divid;
}
if (!best_diff)
break;
}
if (best_rate < characteristics->output[0].min ||
best_rate > characteristics->output[0].max)
return -ERANGE;
return best_rate;
}
static long sam9x60_div_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
return sam9x60_div_pll_compute_div(core, parent_rate, rate);
}
static int sam9x60_div_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
struct sam9x60_div *div = to_sam9x60_div(core);
div->div = DIV_ROUND_CLOSEST(parent_rate, rate) - 1;
return 0;
}
static const struct clk_ops sam9x60_div_pll_ops = {
.prepare = sam9x60_div_pll_prepare,
.unprepare = sam9x60_div_pll_unprepare,
.is_prepared = sam9x60_div_pll_is_prepared,
.recalc_rate = sam9x60_div_pll_recalc_rate,
.round_rate = sam9x60_div_pll_round_rate,
.set_rate = sam9x60_div_pll_set_rate,
};
struct clk_hw * __init
sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name,
struct clk_hw *parent_hw, u8 id,
const struct clk_pll_characteristics *characteristics,
const struct clk_pll_layout *layout, bool critical)
{
struct sam9x60_frac *frac;
struct clk_hw *hw;
struct clk_init_data init;
unsigned long parent_rate, flags;
unsigned int val;
int ret;
if (id > PLL_MAX_ID || !lock || !parent_hw)
return ERR_PTR(-EINVAL);
frac = kzalloc(sizeof(*frac), GFP_KERNEL);
if (!frac)
return ERR_PTR(-ENOMEM);
init.name = name;
init.parent_names = &parent_name;
init.num_parents = 1;
init.ops = &sam9x60_frac_pll_ops;
init.flags = CLK_SET_RATE_GATE;
if (critical)
init.flags |= CLK_IS_CRITICAL;
frac->core.id = id;
frac->core.hw.init = &init;
frac->core.characteristics = characteristics;
frac->core.layout = layout;
frac->core.regmap = regmap;
frac->core.lock = lock;
spin_lock_irqsave(frac->core.lock, flags);
if (sam9x60_pll_ready(regmap, id)) {
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, id);
regmap_read(regmap, AT91_PMC_PLL_CTRL1, &val);
frac->mul = FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, val);
frac->frac = FIELD_GET(PMC_PLL_CTRL1_FRACR_MSK, val);
} else {
/*
* This means the PLL is not setup by bootloaders. In this
* case we need to set the minimum rate for it. Otherwise
* a clock child of this PLL may be enabled before setting
* its rate leading to enabling this PLL with unsupported
* rate. This will lead to PLL not being locked at all.
*/
parent_rate = clk_hw_get_rate(parent_hw);
if (!parent_rate) {
hw = ERR_PTR(-EINVAL);
goto free;
}
ret = sam9x60_frac_pll_compute_mul_frac(&frac->core, FCORE_MIN,
parent_rate, true);
if (ret <= 0) {
hw = ERR_PTR(ret);
goto free;
}
}
spin_unlock_irqrestore(frac->core.lock, flags);
hw = &frac->core.hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(frac);
hw = ERR_PTR(ret);
}
return hw;
free:
spin_unlock_irqrestore(frac->core.lock, flags);
kfree(frac);
return hw;
}
struct clk_hw * __init
sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name, u8 id,
const struct clk_pll_characteristics *characteristics,
const struct clk_pll_layout *layout, bool critical)
{
struct sam9x60_div *div;
struct clk_hw *hw;
struct clk_init_data init;
unsigned long flags;
unsigned int val;
int ret;
if (id > PLL_MAX_ID || !lock)
return ERR_PTR(-EINVAL);
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
return ERR_PTR(-ENOMEM);
init.name = name;
init.parent_names = &parent_name;
init.num_parents = 1;
init.ops = &sam9x60_div_pll_ops;
init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
CLK_SET_RATE_PARENT;
if (critical)
init.flags |= CLK_IS_CRITICAL;
div->core.id = id;
div->core.hw.init = &init;
div->core.characteristics = characteristics;
div->core.layout = layout;
div->core.regmap = regmap;
div->core.lock = lock;
spin_lock_irqsave(div->core.lock, flags);
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, id);
regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val);
div->div = FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, val);
spin_unlock_irqrestore(div->core.lock, flags);
hw = &div->core.hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(div);
hw = ERR_PTR(ret);
}
return hw;
}