1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Marvell Armada 37xx SoC xtal clocks
4 *
5 * Copyright (C) 2016 Marvell
6 *
7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
8 *
9 */
10
11 #include <linux/clk-provider.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15
16 #define NB_GPIO1_LATCH 0x8
17 #define XTAL_MODE BIT(9)
18
armada_3700_xtal_clock_probe(struct platform_device * pdev)19 static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
20 {
21 struct device_node *np = pdev->dev.of_node;
22 const char *xtal_name = "xtal";
23 struct device_node *parent;
24 struct regmap *regmap;
25 struct clk_hw *xtal_hw;
26 unsigned int rate;
27 u32 reg;
28 int ret;
29
30 xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
31 if (!xtal_hw)
32 return -ENOMEM;
33
34 platform_set_drvdata(pdev, xtal_hw);
35
36 parent = np->parent;
37 if (!parent) {
38 dev_err(&pdev->dev, "no parent\n");
39 return -ENODEV;
40 }
41
42 regmap = syscon_node_to_regmap(parent);
43 if (IS_ERR(regmap)) {
44 dev_err(&pdev->dev, "cannot get regmap\n");
45 return PTR_ERR(regmap);
46 }
47
48 ret = regmap_read(regmap, NB_GPIO1_LATCH, ®);
49 if (ret) {
50 dev_err(&pdev->dev, "cannot read from regmap\n");
51 return ret;
52 }
53
54 if (reg & XTAL_MODE)
55 rate = 40000000;
56 else
57 rate = 25000000;
58
59 of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
60 xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
61 if (IS_ERR(xtal_hw))
62 return PTR_ERR(xtal_hw);
63 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
64
65 return ret;
66 }
67
armada_3700_xtal_clock_remove(struct platform_device * pdev)68 static void armada_3700_xtal_clock_remove(struct platform_device *pdev)
69 {
70 of_clk_del_provider(pdev->dev.of_node);
71 }
72
73 static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
74 { .compatible = "marvell,armada-3700-xtal-clock", },
75 { }
76 };
77
78 static struct platform_driver armada_3700_xtal_clock_driver = {
79 .probe = armada_3700_xtal_clock_probe,
80 .remove = armada_3700_xtal_clock_remove,
81 .driver = {
82 .name = "marvell-armada-3700-xtal-clock",
83 .of_match_table = armada_3700_xtal_clock_of_match,
84 },
85 };
86
87 builtin_platform_driver(armada_3700_xtal_clock_driver);
88