linuxdebug/drivers/clk/samsung/clk-exynos-arm64.c

95 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2021 Linaro Ltd.
* Copyright (C) 2021 Dávid Virág <virag.david003@gmail.com>
* Author: Sam Protsenko <semen.protsenko@linaro.org>
* Author: Dávid Virág <virag.david003@gmail.com>
*
* This file contains shared functions used by some arm64 Exynos SoCs,
* such as Exynos7885 or Exynos850 to register and init CMUs.
*/
#include <linux/clk.h>
#include <linux/of_address.h>
#include "clk-exynos-arm64.h"
/* Gate register bits */
#define GATE_MANUAL BIT(20)
#define GATE_ENABLE_HWACG BIT(28)
/* Gate register offsets range */
#define GATE_OFF_START 0x2000
#define GATE_OFF_END 0x2fff
/**
* exynos_arm64_init_clocks - Set clocks initial configuration
* @np: CMU device tree node with "reg" property (CMU addr)
* @reg_offs: Register offsets array for clocks to init
* @reg_offs_len: Number of register offsets in reg_offs array
*
* Set manual control mode for all gate clocks.
*/
static void __init exynos_arm64_init_clocks(struct device_node *np,
const unsigned long *reg_offs, size_t reg_offs_len)
{
void __iomem *reg_base;
size_t i;
reg_base = of_iomap(np, 0);
if (!reg_base)
panic("%s: failed to map registers\n", __func__);
for (i = 0; i < reg_offs_len; ++i) {
void __iomem *reg = reg_base + reg_offs[i];
u32 val;
/* Modify only gate clock registers */
if (reg_offs[i] < GATE_OFF_START || reg_offs[i] > GATE_OFF_END)
continue;
val = readl(reg);
val |= GATE_MANUAL;
val &= ~GATE_ENABLE_HWACG;
writel(val, reg);
}
iounmap(reg_base);
}
/**
* exynos_arm64_register_cmu - Register specified Exynos CMU domain
* @dev: Device object; may be NULL if this function is not being
* called from platform driver probe function
* @np: CMU device tree node
* @cmu: CMU data
*
* Register specified CMU domain, which includes next steps:
*
* 1. Enable parent clock of @cmu CMU
* 2. Set initial registers configuration for @cmu CMU clocks
* 3. Register @cmu CMU clocks using Samsung clock framework API
*/
void __init exynos_arm64_register_cmu(struct device *dev,
struct device_node *np, const struct samsung_cmu_info *cmu)
{
/* Keep CMU parent clock running (needed for CMU registers access) */
if (cmu->clk_name) {
struct clk *parent_clk;
if (dev)
parent_clk = clk_get(dev, cmu->clk_name);
else
parent_clk = of_clk_get_by_name(np, cmu->clk_name);
if (IS_ERR(parent_clk)) {
pr_err("%s: could not find bus clock %s; err = %ld\n",
__func__, cmu->clk_name, PTR_ERR(parent_clk));
} else {
clk_prepare_enable(parent_clk);
}
}
exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
samsung_cmu_register_one(np, cmu);
}