drivers/clk/mediatek/clk-apmixed.c

   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 }