143 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			143 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Qualcomm APCS clock controller driver
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 *
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 * Copyright (c) 2017, Linaro Limited
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 * Author: Georgi Djakov <georgi.djakov@linaro.org>
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 */
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include "clk-regmap.h"
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#include "clk-regmap-mux-div.h"
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static const u32 gpll0_a53cc_map[] = { 4, 5 };
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static const struct clk_parent_data pdata[] = {
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	{ .fw_name = "aux", .name = "gpll0_vote", },
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	{ .fw_name = "pll", .name = "a53pll", },
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};
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/*
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 * We use the notifier function for switching to a temporary safe configuration
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 * (mux and divider), while the A53 PLL is reconfigured.
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 */
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static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event,
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			     void *data)
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{
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	int ret = 0;
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	struct clk_regmap_mux_div *md = container_of(nb,
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						     struct clk_regmap_mux_div,
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						     clk_nb);
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	if (event == PRE_RATE_CHANGE)
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		/* set the mux and divider to safe frequency (400mhz) */
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		ret = mux_div_set_src_div(md, 4, 3);
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	return notifier_from_errno(ret);
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}
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static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
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{
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	struct device *dev = &pdev->dev;
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	struct device *parent = dev->parent;
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	struct device_node *np = parent->of_node;
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	struct clk_regmap_mux_div *a53cc;
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	struct regmap *regmap;
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	struct clk_init_data init = { };
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	int ret = -ENODEV;
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	regmap = dev_get_regmap(parent, NULL);
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	if (!regmap) {
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		dev_err(dev, "failed to get regmap: %d\n", ret);
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		return ret;
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	}
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	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
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	if (!a53cc)
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		return -ENOMEM;
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	/* Use an unique name by appending parent's @unit-address */
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	init.name = devm_kasprintf(dev, GFP_KERNEL, "a53mux%s",
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				   strchrnul(np->full_name, '@'));
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	if (!init.name)
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		return -ENOMEM;
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	init.parent_data = pdata;
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	init.num_parents = ARRAY_SIZE(pdata);
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	init.ops = &clk_regmap_mux_div_ops;
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	init.flags = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT;
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	a53cc->clkr.hw.init = &init;
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	a53cc->clkr.regmap = regmap;
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	a53cc->reg_offset = 0x50;
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	a53cc->hid_width = 5;
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	a53cc->hid_shift = 0;
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	a53cc->src_width = 3;
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	a53cc->src_shift = 8;
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	a53cc->parent_map = gpll0_a53cc_map;
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	a53cc->pclk = devm_clk_get(parent, NULL);
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	if (IS_ERR(a53cc->pclk)) {
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		ret = PTR_ERR(a53cc->pclk);
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		if (ret != -EPROBE_DEFER)
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			dev_err(dev, "failed to get clk: %d\n", ret);
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		return ret;
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	}
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	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
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	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
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	if (ret) {
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		dev_err(dev, "failed to register clock notifier: %d\n", ret);
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		return ret;
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	}
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	ret = devm_clk_register_regmap(dev, &a53cc->clkr);
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	if (ret) {
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		dev_err(dev, "failed to register regmap clock: %d\n", ret);
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		goto err;
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	}
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	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
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					  &a53cc->clkr.hw);
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	if (ret) {
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		dev_err(dev, "failed to add clock provider: %d\n", ret);
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		goto err;
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	}
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	platform_set_drvdata(pdev, a53cc);
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	return 0;
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err:
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	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
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	return ret;
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}
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static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
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{
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	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
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	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
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	return 0;
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}
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static struct platform_driver qcom_apcs_msm8916_clk_driver = {
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	.probe = qcom_apcs_msm8916_clk_probe,
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	.remove = qcom_apcs_msm8916_clk_remove,
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	.driver = {
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		.name = "qcom-apcs-msm8916-clk",
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	},
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};
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module_platform_driver(qcom_apcs_msm8916_clk_driver);
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MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");
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