drivers/clk/imx/clk-lpcg-scu.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2018 NXP
   4  *      Dong Aisheng <aisheng.dong@nxp.com>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/err.h>
   9 #include <linux/io.h>
  10 #include <linux/slab.h>
  11 #include <linux/spinlock.h>
  12
  13 #include "clk-scu.h"
  14
  15 static DEFINE_SPINLOCK(imx_lpcg_scu_lock);
  16
  17 #define CLK_GATE_SCU_LPCG_MASK          0x3
  18 #define CLK_GATE_SCU_LPCG_HW_SEL        BIT(0)
  19 #define CLK_GATE_SCU_LPCG_SW_SEL        BIT(1)
  20
  21 /*
  22  * struct clk_lpcg_scu - Description of LPCG clock
  23  *
  24  * @hw: clk_hw of this LPCG
  25  * @reg: register of this LPCG clock
  26  * @bit_idx: bit index of this LPCG clock
  27  * @hw_gate: HW auto gate enable
  28  *
  29  * This structure describes one LPCG clock
  30  */
  31 struct clk_lpcg_scu {
  32         struct clk_hw hw;
  33         void __iomem *reg;
  34         u8 bit_idx;
  35         bool hw_gate;
  36 };
  37
  38 #define to_clk_lpcg_scu(_hw) container_of(_hw, struct clk_lpcg_scu, hw)
  39
  40 static int clk_lpcg_scu_enable(struct clk_hw *hw)
  41 {
  42         struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw);
  43         unsigned long flags;
  44         u32 reg, val;
  45
  46         spin_lock_irqsave(&imx_lpcg_scu_lock, flags);
  47
  48         reg = readl_relaxed(clk->reg);
  49         reg &= ~(CLK_GATE_SCU_LPCG_MASK << clk->bit_idx);
  50
  51         val = CLK_GATE_SCU_LPCG_SW_SEL;
  52         if (clk->hw_gate)
  53                 val |= CLK_GATE_SCU_LPCG_HW_SEL;
  54
  55         reg |= val << clk->bit_idx;
  56         writel(reg, clk->reg);
  57
  58         spin_unlock_irqrestore(&imx_lpcg_scu_lock, flags);
  59
  60         return 0;
  61 }
  62
  63 static void clk_lpcg_scu_disable(struct clk_hw *hw)
  64 {
  65         struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw);
  66         unsigned long flags;
  67         u32 reg;
  68
  69         spin_lock_irqsave(&imx_lpcg_scu_lock, flags);
  70
  71         reg = readl_relaxed(clk->reg);
  72         reg &= ~(CLK_GATE_SCU_LPCG_MASK << clk->bit_idx);
  73         writel(reg, clk->reg);
  74
  75         spin_unlock_irqrestore(&imx_lpcg_scu_lock, flags);
  76 }
  77
  78 static const struct clk_ops clk_lpcg_scu_ops = {
  79         .enable = clk_lpcg_scu_enable,
  80         .disable = clk_lpcg_scu_disable,
  81 };
  82
  83 struct clk_hw *imx_clk_lpcg_scu(const char *name, const char *parent_name,
  84                                 unsigned long flags, void __iomem *reg,
  85                                 u8 bit_idx, bool hw_gate)
  86 {
  87         struct clk_lpcg_scu *clk;
  88         struct clk_init_data init;
  89         struct clk_hw *hw;
  90         int ret;
  91
  92         clk = kzalloc(sizeof(*clk), GFP_KERNEL);
  93         if (!clk)
  94                 return ERR_PTR(-ENOMEM);
  95
  96         clk->reg = reg;
  97         clk->bit_idx = bit_idx;
  98         clk->hw_gate = hw_gate;
  99
 100         init.name = name;
 101         init.ops = &clk_lpcg_scu_ops;
 102         init.flags = CLK_SET_RATE_PARENT | flags;
 103         init.parent_names = parent_name ? &parent_name : NULL;
 104         init.num_parents = parent_name ? 1 : 0;
 105
 106         clk->hw.init = &init;
 107
 108         hw = &clk->hw;
 109         ret = clk_hw_register(NULL, hw);
 110         if (ret) {
 111                 kfree(clk);
 112                 hw = ERR_PTR(ret);
 113         }
 114
 115         return hw;
 116 }