xref: /openbmc/u-boot/drivers/clk/at91/clk-plladiv.c (revision 8a23fc9c)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Microhip / Atmel Corporation
4  *               Wenyou.Yang <wenyou.yang@microchip.com>
5  */
6 
7 #include <common.h>
8 #include <clk-uclass.h>
9 #include <dm/device.h>
10 #include <linux/io.h>
11 #include <mach/at91_pmc.h>
12 #include "pmc.h"
13 
14 static int at91_plladiv_clk_enable(struct clk *clk)
15 {
16 	return 0;
17 }
18 
19 static ulong at91_plladiv_clk_get_rate(struct clk *clk)
20 {
21 	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
22 	struct at91_pmc *pmc = plat->reg_base;
23 	struct clk source;
24 	ulong clk_rate;
25 	int ret;
26 
27 	ret = clk_get_by_index(clk->dev, 0, &source);
28 	if (ret)
29 		return -EINVAL;
30 
31 	clk_rate = clk_get_rate(&source);
32 	if (readl(&pmc->mckr) & AT91_PMC_MCKR_PLLADIV_2)
33 		clk_rate /= 2;
34 
35 	return clk_rate;
36 }
37 
38 static ulong at91_plladiv_clk_set_rate(struct clk *clk, ulong rate)
39 {
40 	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
41 	struct at91_pmc *pmc = plat->reg_base;
42 	struct clk source;
43 	ulong parent_rate;
44 	int ret;
45 
46 	ret = clk_get_by_index(clk->dev, 0, &source);
47 	if (ret)
48 		return -EINVAL;
49 
50 	parent_rate = clk_get_rate(&source);
51 	if ((parent_rate != rate) && ((parent_rate) / 2 != rate))
52 		return -EINVAL;
53 
54 	if (parent_rate != rate) {
55 		writel((readl(&pmc->mckr) | AT91_PMC_MCKR_PLLADIV_2),
56 		       &pmc->mckr);
57 	}
58 
59 	return 0;
60 }
61 
62 static struct clk_ops at91_plladiv_clk_ops = {
63 	.enable = at91_plladiv_clk_enable,
64 	.get_rate = at91_plladiv_clk_get_rate,
65 	.set_rate = at91_plladiv_clk_set_rate,
66 };
67 
68 static int at91_plladiv_clk_probe(struct udevice *dev)
69 {
70 	return at91_pmc_core_probe(dev);
71 }
72 
73 static const struct udevice_id at91_plladiv_clk_match[] = {
74 	{ .compatible = "atmel,at91sam9x5-clk-plldiv" },
75 	{}
76 };
77 
78 U_BOOT_DRIVER(at91_plladiv_clk) = {
79 	.name = "at91-plladiv-clk",
80 	.id = UCLASS_CLK,
81 	.of_match = at91_plladiv_clk_match,
82 	.probe = at91_plladiv_clk_probe,
83 	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
84 	.ops = &at91_plladiv_clk_ops,
85 };
86