James Liao | cdb2bab | 2015-05-20 15:59:21 +0800 | [diff] [blame] | 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 | |
| 27 | struct mtk_ref2usb_tx { |
| 28 | struct clk_hw hw; |
| 29 | void __iomem *base_addr; |
| 30 | }; |
| 31 | |
| 32 | static 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 | |
| 37 | static 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 | |
| 44 | static 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 | |
| 64 | static 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 | |
| 74 | static 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 | |
| 80 | struct 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 | } |