1/*
2 * Copyright (c) 2015 MediaTek Inc.
3 * Author: James Liao <jamesjj.liao@mediatek.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 */
14
15#include <linux/delay.h>
16#include <linux/of_address.h>
17#include <linux/slab.h>
18
19#include "clk-mtk.h"
20
21#define REF2USB_TX_EN		BIT(0)
22#define REF2USB_TX_LPF_EN	BIT(1)
23#define REF2USB_TX_OUT_EN	BIT(2)
24#define REF2USB_EN_MASK		(REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
25				 REF2USB_TX_OUT_EN)
26
27struct mtk_ref2usb_tx {
28	struct clk_hw	hw;
29	void __iomem	*base_addr;
30};
31
32static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
33{
34	return container_of(hw, struct mtk_ref2usb_tx, hw);
35}
36
37static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
38{
39	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
40
41	return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
42}
43
44static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
45{
46	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
47	u32 val;
48
49	val = readl(tx->base_addr);
50
51	val |= REF2USB_TX_EN;
52	writel(val, tx->base_addr);
53	udelay(100);
54
55	val |= REF2USB_TX_LPF_EN;
56	writel(val, tx->base_addr);
57
58	val |= REF2USB_TX_OUT_EN;
59	writel(val, tx->base_addr);
60
61	return 0;
62}
63
64static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
65{
66	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
67	u32 val;
68
69	val = readl(tx->base_addr);
70	val &= ~REF2USB_EN_MASK;
71	writel(val, tx->base_addr);
72}
73
74static const struct clk_ops mtk_ref2usb_tx_ops = {
75	.is_prepared	= mtk_ref2usb_tx_is_prepared,
76	.prepare	= mtk_ref2usb_tx_prepare,
77	.unprepare	= mtk_ref2usb_tx_unprepare,
78};
79
80struct clk * __init mtk_clk_register_ref2usb_tx(const char *name,
81			const char *parent_name, void __iomem *reg)
82{
83	struct mtk_ref2usb_tx *tx;
84	struct clk_init_data init = {};
85	struct clk *clk;
86
87	tx = kzalloc(sizeof(*tx), GFP_KERNEL);
88	if (!tx)
89		return ERR_PTR(-ENOMEM);
90
91	tx->base_addr = reg;
92	tx->hw.init = &init;
93
94	init.name = name;
95	init.ops = &mtk_ref2usb_tx_ops;
96	init.parent_names = &parent_name;
97	init.num_parents = 1;
98
99	clk = clk_register(NULL, &tx->hw);
100
101	if (IS_ERR(clk)) {
102		pr_err("Failed to register clk %s: %ld\n", name, PTR_ERR(clk));
103		kfree(tx);
104	}
105
106	return clk;
107}
108