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// SPDX-License-Identifier: GPL-2.0+
/*
* System clock support for AT91 architectures.
*
* Copyright (C) Microchip Technology Inc. and its subsidiaries
*
* Author: Claudiu Beznea <claudiu.beznea@microchip.com>
*
* Based on drivers/clk/at91/clk-system.c from Linux.
*/
#include <asm/processor.h>
#include <clk-uclass.h>
#include <dm.h>
#include <linux/io.h>
#include <linux/clk-provider.h>
#include <linux/clk/at91_pmc.h>
#include "pmc.h"
#define UBOOT_DM_CLK_AT91_SYSTEM "at91-system-clk"
#define SYSTEM_MAX_ID 31
struct clk_system {
void __iomem *base;
struct clk clk;
u8 id;
};
#define to_clk_system(_c) container_of(_c, struct clk_system, clk)
static inline int is_pck(int id)
{
return (id >= 8) && (id <= 15);
}
static inline bool clk_system_ready(void __iomem *base, int id)
{
unsigned int status;
pmc_read(base, AT91_PMC_SR, &status);
return !!(status & (1 << id));
}
static int clk_system_enable(struct clk *clk)
{
struct clk_system *sys = to_clk_system(clk);
pmc_write(sys->base, AT91_PMC_SCER, 1 << sys->id);
if (!is_pck(sys->id))
return 0;
while (!clk_system_ready(sys->base, sys->id)) {
debug("waiting for pck%u\n", sys->id);
cpu_relax();
}
return 0;
}
static int clk_system_disable(struct clk *clk)
{
struct clk_system *sys = to_clk_system(clk);
pmc_write(sys->base, AT91_PMC_SCDR, 1 << sys->id);
return 0;
}
static const struct clk_ops system_ops = {
.enable = clk_system_enable,
.disable = clk_system_disable,
.get_rate = clk_generic_get_rate,
};
struct clk *at91_clk_register_system(void __iomem *base, const char *name,
const char *parent_name, u8 id)
{
struct clk_system *sys;
struct clk *clk;
int ret;
if (!base || !name || !parent_name || id > SYSTEM_MAX_ID)
return ERR_PTR(-EINVAL);
sys = kzalloc(sizeof(*sys), GFP_KERNEL);
if (!sys)
return ERR_PTR(-ENOMEM);
sys->id = id;
sys->base = base;
clk = &sys->clk;
clk->flags = CLK_GET_RATE_NOCACHE;
ret = clk_register(clk, UBOOT_DM_CLK_AT91_SYSTEM, name, parent_name);
if (ret) {
kfree(sys);
clk = ERR_PTR(ret);
}
return clk;
}
U_BOOT_DRIVER(at91_system_clk) = {
.name = UBOOT_DM_CLK_AT91_SYSTEM,
.id = UCLASS_CLK,
.ops = &system_ops,
.flags = DM_FLAG_PRE_RELOC,
};
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