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// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Copyright 2018 NXP.
*
* This driver supports the SCCG plls found in the imx8m SOCs
*
* Documentation for this SCCG pll can be found at:
* https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
#include <linux/bitfield.h>
#include "clk.h"
/* PLL CFGs */
#define PLL_CFG0 0x0
#define PLL_CFG1 0x4
#define PLL_CFG2 0x8
#define PLL_DIVF1_MASK GENMASK(18, 13)
#define PLL_DIVF2_MASK GENMASK(12, 7)
#define PLL_DIVR1_MASK GENMASK(27, 25)
#define PLL_DIVR2_MASK GENMASK(24, 19)
#define PLL_DIVQ_MASK GENMASK(6, 1)
#define PLL_REF_MASK GENMASK(2, 0)
#define PLL_LOCK_MASK BIT(31)
#define PLL_PD_MASK BIT(7)
/* These are the specification limits for the SSCG PLL */
#define PLL_REF_MIN_FREQ 25000000UL
#define PLL_REF_MAX_FREQ 235000000UL
#define PLL_STAGE1_MIN_FREQ 1600000000UL
#define PLL_STAGE1_MAX_FREQ 2400000000UL
#define PLL_STAGE1_REF_MIN_FREQ 25000000UL
#define PLL_STAGE1_REF_MAX_FREQ 54000000UL
#define PLL_STAGE2_MIN_FREQ 1200000000UL
#define PLL_STAGE2_MAX_FREQ 2400000000UL
#define PLL_STAGE2_REF_MIN_FREQ 54000000UL
#define PLL_STAGE2_REF_MAX_FREQ 75000000UL
#define PLL_OUT_MIN_FREQ 20000000UL
#define PLL_OUT_MAX_FREQ 1200000000UL
#define PLL_DIVR1_MAX 7
#define PLL_DIVR2_MAX 63
#define PLL_DIVF1_MAX 63
#define PLL_DIVF2_MAX 63
#define PLL_DIVQ_MAX 63
#define PLL_BYPASS_NONE 0x0
#define PLL_BYPASS1 0x2
#define PLL_BYPASS2 0x1
#define SSCG_PLL_BYPASS1_MASK BIT(5)
#define SSCG_PLL_BYPASS2_MASK BIT(4)
#define SSCG_PLL_BYPASS_MASK GENMASK(5, 4)
#define PLL_SCCG_LOCK_TIMEOUT 70
struct clk_sccg_pll_setup {
int divr1, divf1;
int divr2, divf2;
int divq;
int bypass;
uint64_t vco1;
uint64_t vco2;
uint64_t fout;
uint64_t ref;
uint64_t ref_div1;
uint64_t ref_div2;
uint64_t fout_request;
int fout_error;
};
struct clk_sccg_pll {
struct clk_hw hw;
const struct clk_ops ops;
void __iomem *base;
struct clk_sccg_pll_setup setup;
u8 parent;
u8 bypass1;
u8 bypass2;
};
#define to_clk_sccg_pll(_hw) container_of(_hw, struct clk_sccg_pll, hw)
static int clk_sccg_pll_wait_lock(struct clk_sccg_pll *pll)
{
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
/* don't wait for lock if all plls are bypassed */
if (!(val & SSCG_PLL_BYPASS2_MASK))
return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK,
0, PLL_SCCG_LOCK_TIMEOUT);
return 0;
}
static int clk_sccg_pll2_check_match(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int new_diff = temp_setup->fout - temp_setup->fout_request;
int diff = temp_setup->fout_error;
if (abs(diff) > abs(new_diff)) {
temp_setup->fout_error = new_diff;
memcpy(setup, temp_setup, sizeof(struct clk_sccg_pll_setup));
if (temp_setup->fout_request == temp_setup->fout)
return 0;
}
return -1;
}
static int clk_sccg_divq_lookup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int ret = -EINVAL;
for (temp_setup->divq = 0; temp_setup->divq <= PLL_DIVQ_MAX;
temp_setup->divq++) {
temp_setup->vco2 = temp_setup->vco1;
do_div(temp_setup->vco2, temp_setup->divr2 + 1);
temp_setup->vco2 *= 2;
temp_setup->vco2 *= temp_setup->divf2 + 1;
if (temp_setup->vco2 >= PLL_STAGE2_MIN_FREQ &&
temp_setup->vco2 <= PLL_STAGE2_MAX_FREQ) {
temp_setup->fout = temp_setup->vco2;
do_div(temp_setup->fout, 2 * (temp_setup->divq + 1));
ret = clk_sccg_pll2_check_match(setup, temp_setup);
if (!ret) {
temp_setup->bypass = PLL_BYPASS1;
return ret;
}
}
}
return ret;
}
static int clk_sccg_divf2_lookup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int ret = -EINVAL;
for (temp_setup->divf2 = 0; temp_setup->divf2 <= PLL_DIVF2_MAX;
temp_setup->divf2++) {
ret = clk_sccg_divq_lookup(setup, temp_setup);
if (!ret)
return ret;
}
return ret;
}
static int clk_sccg_divr2_lookup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int ret = -EINVAL;
for (temp_setup->divr2 = 0; temp_setup->divr2 <= PLL_DIVR2_MAX;
temp_setup->divr2++) {
temp_setup->ref_div2 = temp_setup->vco1;
do_div(temp_setup->ref_div2, temp_setup->divr2 + 1);
if (temp_setup->ref_div2 >= PLL_STAGE2_REF_MIN_FREQ &&
temp_setup->ref_div2 <= PLL_STAGE2_REF_MAX_FREQ) {
ret = clk_sccg_divf2_lookup(setup, temp_setup);
if (!ret)
return ret;
}
}
return ret;
}
static int clk_sccg_pll2_find_setup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup,
uint64_t ref)
{
int ret = -EINVAL;
if (ref < PLL_STAGE1_MIN_FREQ || ref > PLL_STAGE1_MAX_FREQ)
return ret;
temp_setup->vco1 = ref;
ret = clk_sccg_divr2_lookup(setup, temp_setup);
return ret;
}
static int clk_sccg_divf1_lookup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int ret = -EINVAL;
for (temp_setup->divf1 = 0; temp_setup->divf1 <= PLL_DIVF1_MAX;
temp_setup->divf1++) {
uint64_t vco1 = temp_setup->ref;
do_div(vco1, temp_setup->divr1 + 1);
vco1 *= 2;
vco1 *= temp_setup->divf1 + 1;
ret = clk_sccg_pll2_find_setup(setup, temp_setup, vco1);
if (!ret) {
temp_setup->bypass = PLL_BYPASS_NONE;
return ret;
}
}
return ret;
}
static int clk_sccg_divr1_lookup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup)
{
int ret = -EINVAL;
for (temp_setup->divr1 = 0; temp_setup->divr1 <= PLL_DIVR1_MAX;
temp_setup->divr1++) {
temp_setup->ref_div1 = temp_setup->ref;
do_div(temp_setup->ref_div1, temp_setup->divr1 + 1);
if (temp_setup->ref_div1 >= PLL_STAGE1_REF_MIN_FREQ &&
temp_setup->ref_div1 <= PLL_STAGE1_REF_MAX_FREQ) {
ret = clk_sccg_divf1_lookup(setup, temp_setup);
if (!ret)
return ret;
}
}
return ret;
}
static int clk_sccg_pll1_find_setup(struct clk_sccg_pll_setup *setup,
struct clk_sccg_pll_setup *temp_setup,
uint64_t ref)
{
int ret = -EINVAL;
if (ref < PLL_REF_MIN_FREQ || ref > PLL_REF_MAX_FREQ)
return ret;
temp_setup->ref = ref;
ret = clk_sccg_divr1_lookup(setup, temp_setup);
return ret;
}
static int clk_sccg_pll_find_setup(struct clk_sccg_pll_setup *setup,
uint64_t prate,
uint64_t rate, int try_bypass)
{
struct clk_sccg_pll_setup temp_setup;
int ret = -EINVAL;
memset(&temp_setup, 0, sizeof(struct clk_sccg_pll_setup));
memset(setup, 0, sizeof(struct clk_sccg_pll_setup));
temp_setup.fout_error = PLL_OUT_MAX_FREQ;
temp_setup.fout_request = rate;
switch (try_bypass) {
case PLL_BYPASS2:
if (prate == rate) {
setup->bypass = PLL_BYPASS2;
setup->fout = rate;
ret = 0;
}
break;
case PLL_BYPASS1:
ret = clk_sccg_pll2_find_setup(setup, &temp_setup, prate);
break;
case PLL_BYPASS_NONE:
ret = clk_sccg_pll1_find_setup(setup, &temp_setup, prate);
break;
}
return ret;
}
static int clk_sccg_pll_is_prepared(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val = readl_relaxed(pll->base + PLL_CFG0);
return (val & PLL_PD_MASK) ? 0 : 1;
}
static int clk_sccg_pll_prepare(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
val &= ~PLL_PD_MASK;
writel_relaxed(val, pll->base + PLL_CFG0);
return clk_sccg_pll_wait_lock(pll);
}
static void clk_sccg_pll_unprepare(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
val |= PLL_PD_MASK;
writel_relaxed(val, pll->base + PLL_CFG0);
}
static unsigned long clk_sccg_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val, divr1, divf1, divr2, divf2, divq;
u64 temp64;
val = readl_relaxed(pll->base + PLL_CFG2);
divr1 = FIELD_GET(PLL_DIVR1_MASK, val);
divr2 = FIELD_GET(PLL_DIVR2_MASK, val);
divf1 = FIELD_GET(PLL_DIVF1_MASK, val);
divf2 = FIELD_GET(PLL_DIVF2_MASK, val);
divq = FIELD_GET(PLL_DIVQ_MASK, val);
temp64 = parent_rate;
val = readl(pll->base + PLL_CFG0);
if (val & SSCG_PLL_BYPASS2_MASK) {
temp64 = parent_rate;
} else if (val & SSCG_PLL_BYPASS1_MASK) {
temp64 *= divf2;
do_div(temp64, (divr2 + 1) * (divq + 1));
} else {
temp64 *= 2;
temp64 *= (divf1 + 1) * (divf2 + 1);
do_div(temp64, (divr1 + 1) * (divr2 + 1) * (divq + 1));
}
return temp64;
}
static int clk_sccg_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
struct clk_sccg_pll_setup *setup = &pll->setup;
u32 val;
/* set bypass here too since the parent might be the same */
val = readl(pll->base + PLL_CFG0);
val &= ~SSCG_PLL_BYPASS_MASK;
val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, setup->bypass);
writel(val, pll->base + PLL_CFG0);
val = readl_relaxed(pll->base + PLL_CFG2);
val &= ~(PLL_DIVF1_MASK | PLL_DIVF2_MASK);
val &= ~(PLL_DIVR1_MASK | PLL_DIVR2_MASK | PLL_DIVQ_MASK);
val |= FIELD_PREP(PLL_DIVF1_MASK, setup->divf1);
val |= FIELD_PREP(PLL_DIVF2_MASK, setup->divf2);
val |= FIELD_PREP(PLL_DIVR1_MASK, setup->divr1);
val |= FIELD_PREP(PLL_DIVR2_MASK, setup->divr2);
val |= FIELD_PREP(PLL_DIVQ_MASK, setup->divq);
writel_relaxed(val, pll->base + PLL_CFG2);
return clk_sccg_pll_wait_lock(pll);
}
static u8 clk_sccg_pll_get_parent(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
u8 ret = pll->parent;
val = readl(pll->base + PLL_CFG0);
if (val & SSCG_PLL_BYPASS2_MASK)
ret = pll->bypass2;
else if (val & SSCG_PLL_BYPASS1_MASK)
ret = pll->bypass1;
return ret;
}
static int clk_sccg_pll_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl(pll->base + PLL_CFG0);
val &= ~SSCG_PLL_BYPASS_MASK;
val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, pll->setup.bypass);
writel(val, pll->base + PLL_CFG0);
return clk_sccg_pll_wait_lock(pll);
}
static int __clk_sccg_pll_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req,
uint64_t min,
uint64_t max,
uint64_t rate,
int bypass)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
struct clk_sccg_pll_setup *setup = &pll->setup;
struct clk_hw *parent_hw = NULL;
int bypass_parent_index;
int ret = -EINVAL;
req->max_rate = max;
req->min_rate = min;
switch (bypass) {
case PLL_BYPASS2:
bypass_parent_index = pll->bypass2;
break;
case PLL_BYPASS1:
bypass_parent_index = pll->bypass1;
break;
default:
bypass_parent_index = pll->parent;
break;
}
parent_hw = clk_hw_get_parent_by_index(hw, bypass_parent_index);
ret = __clk_determine_rate(parent_hw, req);
if (!ret) {
ret = clk_sccg_pll_find_setup(setup, req->rate,
rate, bypass);
}
req->best_parent_hw = parent_hw;
req->best_parent_rate = req->rate;
req->rate = setup->fout;
return ret;
}
static int clk_sccg_pll_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
struct clk_sccg_pll_setup *setup = &pll->setup;
uint64_t rate = req->rate;
uint64_t min = req->min_rate;
uint64_t max = req->max_rate;
int ret = -EINVAL;
if (rate < PLL_OUT_MIN_FREQ || rate > PLL_OUT_MAX_FREQ)
return ret;
ret = __clk_sccg_pll_determine_rate(hw, req, req->rate, req->rate,
rate, PLL_BYPASS2);
if (!ret)
return ret;
ret = __clk_sccg_pll_determine_rate(hw, req, PLL_STAGE1_REF_MIN_FREQ,
PLL_STAGE1_REF_MAX_FREQ, rate,
PLL_BYPASS1);
if (!ret)
return ret;
ret = __clk_sccg_pll_determine_rate(hw, req, PLL_REF_MIN_FREQ,
PLL_REF_MAX_FREQ, rate,
PLL_BYPASS_NONE);
if (!ret)
return ret;
if (setup->fout >= min && setup->fout <= max)
ret = 0;
return ret;
}
static const struct clk_ops clk_sccg_pll_ops = {
.prepare = clk_sccg_pll_prepare,
.unprepare = clk_sccg_pll_unprepare,
.is_prepared = clk_sccg_pll_is_prepared,
.recalc_rate = clk_sccg_pll_recalc_rate,
.set_rate = clk_sccg_pll_set_rate,
.set_parent = clk_sccg_pll_set_parent,
.get_parent = clk_sccg_pll_get_parent,
.determine_rate = clk_sccg_pll_determine_rate,
};
struct clk *imx_clk_sccg_pll(const char *name,
const char * const *parent_names,
u8 num_parents,
u8 parent, u8 bypass1, u8 bypass2,
void __iomem *base,
unsigned long flags)
{
struct clk_sccg_pll *pll;
struct clk_init_data init;
struct clk_hw *hw;
int ret;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->parent = parent;
pll->bypass1 = bypass1;
pll->bypass2 = bypass2;
pll->base = base;
init.name = name;
init.ops = &clk_sccg_pll_ops;
init.flags = flags;
init.parent_names = parent_names;
init.num_parents = num_parents;
pll->base = base;
pll->hw.init = &init;
hw = &pll->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(pll);
return ERR_PTR(ret);
}
return hw->clk;
}