1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2019 DENX Software Engineering
4 * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
5 *
6 * Copyright 2012 Freescale Semiconductor, Inc.
7 * Copyright 2012 Linaro Ltd.
8 *
9 * The code contained herein is licensed under the GNU General Public
10 * License. You may obtain a copy of the GNU General Public License
11 * Version 2 or later at the following locations:
12 *
13 * http://www.opensource.org/licenses/gpl-license.html
14 * http://www.gnu.org/copyleft/gpl.html
15 */
16
17#include <common.h>
18#include <asm/io.h>
19#include <malloc.h>
20#include <clk-uclass.h>
21#include <dm/device.h>
22#include <dm/devres.h>
23#include <linux/clk-provider.h>
24#include <div64.h>
25#include <clk.h>
26#include "clk.h"
27#include <linux/err.h>
28
29#define UBOOT_DM_CLK_IMX_PFD "imx_clk_pfd"
30
31struct clk_pfd {
32	struct clk	clk;
33	void __iomem	*reg;
34	u8		idx;
35};
36
37#define to_clk_pfd(_clk) container_of(_clk, struct clk_pfd, clk)
38
39#define SET	0x4
40#define CLR	0x8
41#define OTG	0xc
42
43static unsigned long clk_pfd_recalc_rate(struct clk *clk)
44{
45	struct clk_pfd *pfd =
46		to_clk_pfd(dev_get_clk_ptr(clk->dev));
47	unsigned long parent_rate = clk_get_parent_rate(clk);
48	u64 tmp = parent_rate;
49	u8 frac = (readl(pfd->reg) >> (pfd->idx * 8)) & 0x3f;
50
51	tmp *= 18;
52	do_div(tmp, frac);
53
54	return tmp;
55}
56
57static unsigned long clk_pfd_set_rate(struct clk *clk, unsigned long rate)
58{
59	struct clk_pfd *pfd = to_clk_pfd(clk);
60	unsigned long parent_rate = clk_get_parent_rate(clk);
61	u64 tmp = parent_rate;
62	u8 frac;
63
64	tmp = tmp * 18 + rate / 2;
65	do_div(tmp, rate);
66	frac = tmp;
67	if (frac < 12)
68		frac = 12;
69	else if (frac > 35)
70		frac = 35;
71
72	writel(0x3f << (pfd->idx * 8), pfd->reg + CLR);
73	writel(frac << (pfd->idx * 8), pfd->reg + SET);
74
75	return 0;
76}
77
78static const struct clk_ops clk_pfd_ops = {
79	.get_rate	= clk_pfd_recalc_rate,
80	.set_rate	= clk_pfd_set_rate,
81};
82
83struct clk *imx_clk_pfd(const char *name, const char *parent_name,
84			void __iomem *reg, u8 idx)
85{
86	struct clk_pfd *pfd;
87	struct clk *clk;
88	int ret;
89
90	pfd = kzalloc(sizeof(*pfd), GFP_KERNEL);
91	if (!pfd)
92		return ERR_PTR(-ENOMEM);
93
94	pfd->reg = reg;
95	pfd->idx = idx;
96
97	/* register the clock */
98	clk = &pfd->clk;
99
100	ret = clk_register(clk, UBOOT_DM_CLK_IMX_PFD, name, parent_name);
101	if (ret) {
102		kfree(pfd);
103		return ERR_PTR(ret);
104	}
105
106	return clk;
107}
108
109U_BOOT_DRIVER(clk_pfd) = {
110	.name	= UBOOT_DM_CLK_IMX_PFD,
111	.id	= UCLASS_CLK,
112	.ops	= &clk_pfd_ops,
113	.flags = DM_FLAG_PRE_RELOC,
114};
115