drivers/clk/tegra/clk-tegra-fixed.c

Source file repositories/reference/linux-study-clean/drivers/clk/tegra/clk-tegra-fixed.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/tegra/clk-tegra-fixed.c
Extension
.c
Size
2674 bytes
Lines
119
Domain
Driver Families
Bucket
drivers/clk
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012, 2013, NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/io.h>
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clk/tegra.h>

#include "clk.h"
#include "clk-id.h"

#define OSC_CTRL			0x50
#define OSC_CTRL_OSC_FREQ_SHIFT		28
#define OSC_CTRL_PLL_REF_DIV_SHIFT	26
#define OSC_CTRL_MASK			(0x3f2 |	\
					(0xf << OSC_CTRL_OSC_FREQ_SHIFT))

static u32 osc_ctrl_ctx;

int __init tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
			      unsigned long *input_freqs, unsigned int num,
			      unsigned int clk_m_div, unsigned long *osc_freq,
			      unsigned long *pll_ref_freq)
{
	struct clk *clk, *osc;
	struct clk **dt_clk;
	u32 val, pll_ref_div;
	unsigned osc_idx;

	val = readl_relaxed(clk_base + OSC_CTRL);
	osc_ctrl_ctx = val & OSC_CTRL_MASK;
	osc_idx = val >> OSC_CTRL_OSC_FREQ_SHIFT;

	if (osc_idx < num)
		*osc_freq = input_freqs[osc_idx];
	else
		*osc_freq = 0;

	if (!*osc_freq) {
		WARN_ON(1);
		return -EINVAL;
	}

	dt_clk = tegra_lookup_dt_id(tegra_clk_osc, clks);
	if (!dt_clk)
		return 0;

	osc = clk_register_fixed_rate(NULL, "osc", NULL, 0, *osc_freq);
	*dt_clk = osc;

	/* osc_div2 */
	dt_clk = tegra_lookup_dt_id(tegra_clk_osc_div2, clks);
	if (dt_clk) {
		clk = clk_register_fixed_factor(NULL, "osc_div2", "osc",
						0, 1, 2);
		*dt_clk = clk;
	}

	/* osc_div4 */
	dt_clk = tegra_lookup_dt_id(tegra_clk_osc_div4, clks);
	if (dt_clk) {
		clk = clk_register_fixed_factor(NULL, "osc_div4", "osc",
						0, 1, 4);
		*dt_clk = clk;
	}

	dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m, clks);
	if (!dt_clk)
		return 0;

	clk = clk_register_fixed_factor(NULL, "clk_m", "osc",
					0, 1, clk_m_div);
	*dt_clk = clk;

	/* pll_ref */
	val = (val >> OSC_CTRL_PLL_REF_DIV_SHIFT) & 3;
	pll_ref_div = 1 << val;
	dt_clk = tegra_lookup_dt_id(tegra_clk_pll_ref, clks);
	if (!dt_clk)
		return 0;

	clk = clk_register_fixed_factor(NULL, "pll_ref", "osc",
					0, 1, pll_ref_div);
	*dt_clk = clk;

Annotation

Implementation Notes