1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (c) 2015 MediaTek Inc.
 4 * Author: James Liao <jamesjj.liao@mediatek.com>
 5 */
 6
 7#include <linux/delay.h>
 8#include <linux/of_address.h>
 9#include <linux/slab.h>
10
11#include "clk-mtk.h"
12
13#define REF2USB_TX_EN		BIT(0)
14#define REF2USB_TX_LPF_EN	BIT(1)
15#define REF2USB_TX_OUT_EN	BIT(2)
16#define REF2USB_EN_MASK		(REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
17				 REF2USB_TX_OUT_EN)
18
19struct mtk_ref2usb_tx {
20	struct clk_hw	hw;
21	void __iomem	*base_addr;
22};
23
24static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
25{
26	return container_of(hw, struct mtk_ref2usb_tx, hw);
27}
28
29static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
30{
31	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
32
33	return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
34}
35
36static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
37{
38	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
39	u32 val;
40
41	val = readl(tx->base_addr);
42
43	val |= REF2USB_TX_EN;
44	writel(val, tx->base_addr);
45	udelay(100);
46
47	val |= REF2USB_TX_LPF_EN;
48	writel(val, tx->base_addr);
49
50	val |= REF2USB_TX_OUT_EN;
51	writel(val, tx->base_addr);
52
53	return 0;
54}
55
56static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
57{
58	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
59	u32 val;
60
61	val = readl(tx->base_addr);
62	val &= ~REF2USB_EN_MASK;
63	writel(val, tx->base_addr);
64}
65
66static const struct clk_ops mtk_ref2usb_tx_ops = {
67	.is_prepared	= mtk_ref2usb_tx_is_prepared,
68	.prepare	= mtk_ref2usb_tx_prepare,
69	.unprepare	= mtk_ref2usb_tx_unprepare,
70};
71
72struct clk * __init mtk_clk_register_ref2usb_tx(const char *name,
73			const char *parent_name, void __iomem *reg)
74{
75	struct mtk_ref2usb_tx *tx;
76	struct clk_init_data init = {};
77	struct clk *clk;
78
79	tx = kzalloc(sizeof(*tx), GFP_KERNEL);
80	if (!tx)
81		return ERR_PTR(-ENOMEM);
82
83	tx->base_addr = reg;
84	tx->hw.init = &init;
85
86	init.name = name;
87	init.ops = &mtk_ref2usb_tx_ops;
88	init.parent_names = &parent_name;
89	init.num_parents = 1;
90
91	clk = clk_register(NULL, &tx->hw);
92
93	if (IS_ERR(clk)) {
94		pr_err("Failed to register clk %s: %ld\n", name, PTR_ERR(clk));
95		kfree(tx);
96	}
97
98	return clk;
99}