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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 <common.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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