drivers/clk/mediatek/clk-apmixed.c

   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
  19 struct mtk_ref2usb_tx {
  20         struct clk_hw   hw;
  21         void __iomem    *base_addr;
  22 };
  23
  24 static 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
  29 static 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
  36 static 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
  56 static 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
  66 static 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
  72 struct 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 }