blob: 759df93697d29d867fe7d5bd777e68d3598251cb [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Master clock support for AT91 architectures.
*
* Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
*
* Author: Claudiu Beznea <claudiu.beznea@microchip.com>
*
* Based on drivers/clk/at91/clk-master.c from Linux.
*/
#include <asm/processor.h>
#include <clk-uclass.h>
#include <common.h>
#include <dm.h>
#include <linux/clk-provider.h>
#include <linux/clk/at91_pmc.h>
#include "pmc.h"
#define UBOOT_DM_CLK_AT91_MASTER "at91-master-clk"
#define UBOOT_DM_CLK_AT91_SAMA7G5_MASTER "at91-sama7g5-master-clk"
#define MASTER_PRES_MASK 0x7
#define MASTER_PRES_MAX MASTER_PRES_MASK
#define MASTER_DIV_SHIFT 8
#define MASTER_DIV_MASK 0x3
#define PMC_MCR 0x30
#define PMC_MCR_ID_MSK GENMASK(3, 0)
#define PMC_MCR_CMD BIT(7)
#define PMC_MCR_DIV GENMASK(10, 8)
#define PMC_MCR_CSS GENMASK(20, 16)
#define PMC_MCR_CSS_SHIFT (16)
#define PMC_MCR_EN BIT(28)
#define PMC_MCR_ID(x) ((x) & PMC_MCR_ID_MSK)
#define MASTER_MAX_ID 4
struct clk_master {
void __iomem *base;
const struct clk_master_layout *layout;
const struct clk_master_characteristics *characteristics;
const u32 *mux_table;
const u32 *clk_mux_table;
u32 num_parents;
struct clk clk;
u8 id;
};
#define to_clk_master(_clk) container_of(_clk, struct clk_master, clk)
static inline bool clk_master_ready(struct clk_master *master)
{
unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY;
unsigned int status;
pmc_read(master->base, AT91_PMC_SR, &status);
return !!(status & bit);
}
static int clk_master_enable(struct clk *clk)
{
struct clk_master *master = to_clk_master(clk);
while (!clk_master_ready(master)) {
debug("waiting for mck %d\n", master->id);
cpu_relax();
}
return 0;
}
static ulong clk_master_get_rate(struct clk *clk)
{
struct clk_master *master = to_clk_master(clk);
const struct clk_master_layout *layout = master->layout;
const struct clk_master_characteristics *characteristics =
master->characteristics;
ulong rate = clk_get_parent_rate(clk);
unsigned int mckr;
u8 pres, div;
if (!rate)
return 0;
pmc_read(master->base, master->layout->offset, &mckr);
mckr &= layout->mask;
pres = (mckr >> layout->pres_shift) & MASTER_PRES_MASK;
div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
if (characteristics->have_div3_pres && pres == MASTER_PRES_MAX)
rate /= 3;
else
rate >>= pres;
rate /= characteristics->divisors[div];
if (rate < characteristics->output.min)
pr_warn("master clk is underclocked");
else if (rate > characteristics->output.max)
pr_warn("master clk is overclocked");
return rate;
}
static const struct clk_ops master_ops = {
.enable = clk_master_enable,
.get_rate = clk_master_get_rate,
};
struct clk *at91_clk_register_master(void __iomem *base,
const char *name, const char * const *parent_names,
int num_parents, const struct clk_master_layout *layout,
const struct clk_master_characteristics *characteristics,
const u32 *mux_table)
{
struct clk_master *master;
struct clk *clk;
unsigned int val;
int ret;
if (!base || !name || !num_parents || !parent_names ||
!layout || !characteristics || !mux_table)
return ERR_PTR(-EINVAL);
master = kzalloc(sizeof(*master), GFP_KERNEL);
if (!master)
return ERR_PTR(-ENOMEM);
master->layout = layout;
master->characteristics = characteristics;
master->base = base;
master->num_parents = num_parents;
master->mux_table = mux_table;
pmc_read(master->base, master->layout->offset, &val);
clk = &master->clk;
clk->flags = CLK_GET_RATE_NOCACHE | CLK_IS_CRITICAL;
ret = clk_register(clk, UBOOT_DM_CLK_AT91_MASTER, name,
parent_names[val & AT91_PMC_CSS]);
if (ret) {
kfree(master);
clk = ERR_PTR(ret);
}
return clk;
}
U_BOOT_DRIVER(at91_master_clk) = {
.name = UBOOT_DM_CLK_AT91_MASTER,
.id = UCLASS_CLK,
.ops = &master_ops,
.flags = DM_FLAG_PRE_RELOC,
};
static int clk_sama7g5_master_set_parent(struct clk *clk, struct clk *parent)
{
struct clk_master *master = to_clk_master(clk);
int index;
index = at91_clk_mux_val_to_index(master->clk_mux_table,
master->num_parents, parent->id);
if (index < 0)
return index;
index = at91_clk_mux_index_to_val(master->mux_table,
master->num_parents, index);
if (index < 0)
return index;
pmc_write(master->base, PMC_MCR, PMC_MCR_ID(master->id));
pmc_update_bits(master->base, PMC_MCR,
PMC_MCR_CSS | PMC_MCR_CMD | PMC_MCR_ID_MSK,
(index << PMC_MCR_CSS_SHIFT) | PMC_MCR_CMD |
PMC_MCR_ID(master->id));
return 0;
}
static int clk_sama7g5_master_enable(struct clk *clk)
{
struct clk_master *master = to_clk_master(clk);
pmc_write(master->base, PMC_MCR, PMC_MCR_ID(master->id));
pmc_update_bits(master->base, PMC_MCR,
PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK,
PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID(master->id));
return 0;
}
static int clk_sama7g5_master_disable(struct clk *clk)
{
struct clk_master *master = to_clk_master(clk);
pmc_write(master->base, PMC_MCR, master->id);
pmc_update_bits(master->base, PMC_MCR,
PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK,
PMC_MCR_CMD | PMC_MCR_ID(master->id));
return 0;
}
static ulong clk_sama7g5_master_set_rate(struct clk *clk, ulong rate)
{
struct clk_master *master = to_clk_master(clk);
ulong parent_rate = clk_get_parent_rate(clk);
ulong div, rrate;
if (!parent_rate)
return 0;
div = DIV_ROUND_CLOSEST(parent_rate, rate);
if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1))) {
return 0;
} else if (div == 3) {
rrate = DIV_ROUND_CLOSEST(parent_rate, MASTER_PRES_MAX);
div = MASTER_PRES_MAX;
} else {
rrate = DIV_ROUND_CLOSEST(parent_rate, div);
div = ffs(div) - 1;
}
pmc_write(master->base, PMC_MCR, master->id);
pmc_update_bits(master->base, PMC_MCR,
PMC_MCR_DIV | PMC_MCR_CMD | PMC_MCR_ID_MSK,
(div << MASTER_DIV_SHIFT) | PMC_MCR_CMD |
PMC_MCR_ID(master->id));
return rrate;
}
static ulong clk_sama7g5_master_get_rate(struct clk *clk)
{
struct clk_master *master = to_clk_master(clk);
ulong parent_rate = clk_get_parent_rate(clk);
unsigned int val;
ulong div;
if (!parent_rate)
return 0;
pmc_write(master->base, PMC_MCR, master->id);
pmc_read(master->base, PMC_MCR, &val);
div = (val >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
if (div == MASTER_PRES_MAX)
div = 3;
else
div = 1 << div;
return DIV_ROUND_CLOSEST(parent_rate, div);
}
static const struct clk_ops sama7g5_master_ops = {
.enable = clk_sama7g5_master_enable,
.disable = clk_sama7g5_master_disable,
.set_rate = clk_sama7g5_master_set_rate,
.get_rate = clk_sama7g5_master_get_rate,
.set_parent = clk_sama7g5_master_set_parent,
};
struct clk *at91_clk_sama7g5_register_master(void __iomem *base,
const char *name, const char * const *parent_names,
int num_parents, const u32 *mux_table, const u32 *clk_mux_table,
bool critical, u8 id)
{
struct clk_master *master;
struct clk *clk;
u32 val, index;
int ret;
if (!base || !name || !num_parents || !parent_names ||
!mux_table || !clk_mux_table || id > MASTER_MAX_ID)
return ERR_PTR(-EINVAL);
master = kzalloc(sizeof(*master), GFP_KERNEL);
if (!master)
return ERR_PTR(-ENOMEM);
master->base = base;
master->id = id;
master->mux_table = mux_table;
master->clk_mux_table = clk_mux_table;
master->num_parents = num_parents;
pmc_write(master->base, PMC_MCR, master->id);
pmc_read(master->base, PMC_MCR, &val);
index = at91_clk_mux_val_to_index(master->mux_table,
master->num_parents,
(val & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT);
if (index < 0) {
kfree(master);
return ERR_PTR(index);
}
clk = &master->clk;
clk->flags = CLK_GET_RATE_NOCACHE | (critical ? CLK_IS_CRITICAL : 0);
ret = clk_register(clk, UBOOT_DM_CLK_AT91_SAMA7G5_MASTER, name,
parent_names[index]);
if (ret) {
kfree(master);
clk = ERR_PTR(ret);
}
return clk;
}
U_BOOT_DRIVER(at91_sama7g5_master_clk) = {
.name = UBOOT_DM_CLK_AT91_SAMA7G5_MASTER,
.id = UCLASS_CLK,
.ops = &sama7g5_master_ops,
.flags = DM_FLAG_PRE_RELOC,
};
const struct clk_master_layout at91rm9200_master_layout = {
.mask = 0x31F,
.pres_shift = 2,
.offset = AT91_PMC_MCKR,
};
const struct clk_master_layout at91sam9x5_master_layout = {
.mask = 0x373,
.pres_shift = 4,
.offset = AT91_PMC_MCKR,
};