1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Qualcomm APCS clock controller driver
4 *
5 * Copyright (c) 2017, Linaro Limited
6 * Author: Georgi Djakov <georgi.djakov@linaro.org>
7 */
8
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16
17 #include "clk-regmap.h"
18 #include "clk-regmap-mux-div.h"
19
20 static const u32 gpll0_a53cc_map[] = { 4, 5 };
21
22 static const struct clk_parent_data pdata[] = {
23 { .fw_name = "aux", .name = "gpll0_vote", },
24 { .fw_name = "pll", .name = "a53pll", },
25 };
26
27 /*
28 * We use the notifier function for switching to a temporary safe configuration
29 * (mux and divider), while the A53 PLL is reconfigured.
30 */
a53cc_notifier_cb(struct notifier_block * nb,unsigned long event,void * data)31 static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event,
32 void *data)
33 {
34 int ret = 0;
35 struct clk_regmap_mux_div *md = container_of(nb,
36 struct clk_regmap_mux_div,
37 clk_nb);
38 if (event == PRE_RATE_CHANGE)
39 /* set the mux and divider to safe frequency (400mhz) */
40 ret = mux_div_set_src_div(md, 4, 3);
41
42 return notifier_from_errno(ret);
43 }
44
qcom_apcs_msm8916_clk_probe(struct platform_device * pdev)45 static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
46 {
47 struct device *dev = &pdev->dev;
48 struct device *parent = dev->parent;
49 struct device_node *np = parent->of_node;
50 struct clk_regmap_mux_div *a53cc;
51 struct regmap *regmap;
52 struct clk_init_data init = { };
53 int ret = -ENODEV;
54
55 regmap = dev_get_regmap(parent, NULL);
56 if (!regmap) {
57 dev_err(dev, "failed to get regmap: %d\n", ret);
58 return ret;
59 }
60
61 a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
62 if (!a53cc)
63 return -ENOMEM;
64
65 /* Use an unique name by appending parent's @unit-address */
66 init.name = devm_kasprintf(dev, GFP_KERNEL, "a53mux%s",
67 strchrnul(np->full_name, '@'));
68 if (!init.name)
69 return -ENOMEM;
70
71 init.parent_data = pdata;
72 init.num_parents = ARRAY_SIZE(pdata);
73 init.ops = &clk_regmap_mux_div_ops;
74 init.flags = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT;
75
76 a53cc->clkr.hw.init = &init;
77 a53cc->clkr.regmap = regmap;
78 a53cc->reg_offset = 0x50;
79 a53cc->hid_width = 5;
80 a53cc->hid_shift = 0;
81 a53cc->src_width = 3;
82 a53cc->src_shift = 8;
83 a53cc->parent_map = gpll0_a53cc_map;
84
85 a53cc->pclk = devm_clk_get(parent, NULL);
86 if (IS_ERR(a53cc->pclk)) {
87 ret = PTR_ERR(a53cc->pclk);
88 if (ret != -EPROBE_DEFER)
89 dev_err(dev, "failed to get clk: %d\n", ret);
90 return ret;
91 }
92
93 a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
94 ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
95 if (ret) {
96 dev_err(dev, "failed to register clock notifier: %d\n", ret);
97 return ret;
98 }
99
100 ret = devm_clk_register_regmap(dev, &a53cc->clkr);
101 if (ret) {
102 dev_err(dev, "failed to register regmap clock: %d\n", ret);
103 goto err;
104 }
105
106 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
107 &a53cc->clkr.hw);
108 if (ret) {
109 dev_err(dev, "failed to add clock provider: %d\n", ret);
110 goto err;
111 }
112
113 platform_set_drvdata(pdev, a53cc);
114
115 return 0;
116
117 err:
118 clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
119 return ret;
120 }
121
qcom_apcs_msm8916_clk_remove(struct platform_device * pdev)122 static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
123 {
124 struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
125
126 clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
127
128 return 0;
129 }
130
131 static struct platform_driver qcom_apcs_msm8916_clk_driver = {
132 .probe = qcom_apcs_msm8916_clk_probe,
133 .remove = qcom_apcs_msm8916_clk_remove,
134 .driver = {
135 .name = "qcom-apcs-msm8916-clk",
136 },
137 };
138 module_platform_driver(qcom_apcs_msm8916_clk_driver);
139
140 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
141 MODULE_LICENSE("GPL v2");
142 MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");
143