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 | */ |
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, src: 4, div: 3); |
41 | |
42 | return notifier_from_errno(err: ret); |
43 | } |
44 | |
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(dev: 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, size: 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, fmt: "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(dev: parent, NULL); |
86 | if (IS_ERR(ptr: a53cc->pclk)) { |
87 | ret = PTR_ERR(ptr: 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(clk: a53cc->pclk, nb: &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, rclk: &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, get: of_clk_hw_simple_get, |
107 | data: &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, data: a53cc); |
114 | |
115 | return 0; |
116 | |
117 | err: |
118 | clk_notifier_unregister(clk: a53cc->pclk, nb: &a53cc->clk_nb); |
119 | return ret; |
120 | } |
121 | |
122 | static void 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(clk: a53cc->pclk, nb: &a53cc->clk_nb); |
127 | } |
128 | |
129 | static struct platform_driver qcom_apcs_msm8916_clk_driver = { |
130 | .probe = qcom_apcs_msm8916_clk_probe, |
131 | .remove_new = qcom_apcs_msm8916_clk_remove, |
132 | .driver = { |
133 | .name = "qcom-apcs-msm8916-clk" , |
134 | }, |
135 | }; |
136 | module_platform_driver(qcom_apcs_msm8916_clk_driver); |
137 | |
138 | MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>" ); |
139 | MODULE_LICENSE("GPL v2" ); |
140 | MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver" ); |
141 | |