drivers/clk/qcom/apcs-sdx55.c

Source file repositories/reference/linux-study-clean/drivers/clk/qcom/apcs-sdx55.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/qcom/apcs-sdx55.c
Extension
.c
Size
3908 bytes
Lines
148
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
/*
 * Qualcomm SDX55 APCS clock controller driver
 *
 * Copyright (c) 2020, Linaro Limited
 * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "clk-regmap.h"
#include "clk-regmap-mux-div.h"

static const u32 apcs_mux_clk_parent_map[] = { 0, 1, 5 };

static const struct clk_parent_data pdata[] = {
	{ .fw_name = "ref" },
	{ .fw_name = "aux" },
	{ .fw_name = "pll" },
};

/*
 * We use the notifier function for switching to a temporary safe configuration
 * (mux and divider), while the A7 PLL is reconfigured.
 */
static int a7cc_notifier_cb(struct notifier_block *nb, unsigned long event,
			    void *data)
{
	int ret = 0;
	struct clk_regmap_mux_div *md = container_of(nb,
						     struct clk_regmap_mux_div,
						     clk_nb);
	if (event == PRE_RATE_CHANGE)
		/* set the mux and divider to safe frequency (400mhz) */
		ret = mux_div_set_src_div(md, 1, 2);

	return notifier_from_errno(ret);
}

static int qcom_apcs_sdx55_clk_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device *parent = dev->parent;
	struct device *cpu_dev;
	struct clk_regmap_mux_div *a7cc;
	struct regmap *regmap;
	struct clk_init_data init = { };
	int ret;

	regmap = dev_get_regmap(parent, NULL);
	if (!regmap) {
		dev_err(dev, "Failed to get parent regmap\n");
		return -ENODEV;
	}

	a7cc = devm_kzalloc(dev, sizeof(*a7cc), GFP_KERNEL);
	if (!a7cc)
		return -ENOMEM;

	init.name = "a7mux";
	init.parent_data = pdata;
	init.num_parents = ARRAY_SIZE(pdata);
	init.ops = &clk_regmap_mux_div_ops;

	a7cc->clkr.hw.init = &init;
	a7cc->clkr.regmap = regmap;
	a7cc->reg_offset = 0x8;
	a7cc->hid_width = 5;
	a7cc->hid_shift = 0;
	a7cc->src_width = 3;
	a7cc->src_shift = 8;
	a7cc->parent_map = apcs_mux_clk_parent_map;

	a7cc->pclk = devm_clk_get(parent, "pll");
	if (IS_ERR(a7cc->pclk))
		return dev_err_probe(dev, PTR_ERR(a7cc->pclk),
				     "Failed to get PLL clk\n");

	a7cc->clk_nb.notifier_call = a7cc_notifier_cb;
	ret = clk_notifier_register(a7cc->pclk, &a7cc->clk_nb);
	if (ret)
		return dev_err_probe(dev, ret,

Annotation

Implementation Notes