aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clk/qcom/apcs-msm8916.c
blob: cf69a97d04396b7bb9975f958dabde949fb43a83 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
// SPDX-License-Identifier: GPL-2.0
/*
 * Qualcomm APCS clock controller driver
 *
 * Copyright (c) 2017, Linaro Limited
 * Author: Georgi Djakov <georgi.djakov@linaro.org>
 */

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

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

static const u32 gpll0_a53cc_map[] = { 4, 5 };

static const struct clk_parent_data pdata[] = {
	{ .fw_name = "aux", .name = "gpll0_vote", },
	{ .fw_name = "pll", .name = "a53pll", },
};

/*
 * We use the notifier function for switching to a temporary safe configuration
 * (mux and divider), while the A53 PLL is reconfigured.
 */
static int a53cc_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, 4, 3);

	return notifier_from_errno(ret);
}

static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device *parent = dev->parent;
	struct clk_regmap_mux_div *a53cc;
	struct regmap *regmap;
	struct clk_init_data init = { };
	int ret = -ENODEV;

	regmap = dev_get_regmap(parent, NULL);
	if (!regmap) {
		dev_err(dev, "failed to get regmap: %d\n", ret);
		return ret;
	}

	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
	if (!a53cc)
		return -ENOMEM;

	init.name = "a53mux";
	init.parent_data = pdata;
	init.num_parents = ARRAY_SIZE(pdata);
	init.ops = &clk_regmap_mux_div_ops;
	init.flags = CLK_SET_RATE_PARENT;

	a53cc->clkr.hw.init = &init;
	a53cc->clkr.regmap = regmap;
	a53cc->reg_offset = 0x50;
	a53cc->hid_width = 5;
	a53cc->hid_shift = 0;
	a53cc->src_width = 3;
	a53cc->src_shift = 8;
	a53cc->parent_map = gpll0_a53cc_map;

	a53cc->pclk = devm_clk_get(parent, NULL);
	if (IS_ERR(a53cc->pclk)) {
		ret = PTR_ERR(a53cc->pclk);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "failed to get clk: %d\n", ret);
		return ret;
	}

	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
	if (ret) {
		dev_err(dev, "failed to register clock notifier: %d\n", ret);
		return ret;
	}

	ret = devm_clk_register_regmap(dev, &a53cc->clkr);
	if (ret) {
		dev_err(dev, "failed to register regmap clock: %d\n", ret);
		goto err;
	}

	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
					  &a53cc->clkr.hw);
	if (ret) {
		dev_err(dev, "failed to add clock provider: %d\n", ret);
		goto err;
	}

	platform_set_drvdata(pdev, a53cc);

	return 0;

err:
	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
	return ret;
}

static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
{
	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);

	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);

	return 0;
}

static struct platform_driver qcom_apcs_msm8916_clk_driver = {
	.probe = qcom_apcs_msm8916_clk_probe,
	.remove = qcom_apcs_msm8916_clk_remove,
	.driver = {
		.name = "qcom-apcs-msm8916-clk",
	},
};
module_platform_driver(qcom_apcs_msm8916_clk_driver);

MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");