drivers/clk/imx/clk-gate-93.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2022 NXP
   4  *
   5  * Peng Fan <peng.fan@nxp.com>
   6  */
   7
   8 #include <linux/clk-provider.h>
   9 #include <linux/errno.h>
  10 #include <linux/export.h>
  11 #include <linux/io.h>
  12 #include <linux/iopoll.h>
  13 #include <linux/slab.h>
  14
  15 #include "clk.h"
  16
  17 #define DIRECT_OFFSET           0x0
  18
  19 /*
  20  * 0b000 - LPCG will be OFF in any CPU mode.
  21  * 0b100 - LPCG will be ON in any CPU mode.
  22  */
  23 #define LPM_SETTING_OFF         0x0
  24 #define LPM_SETTING_ON          0x4
  25
  26 #define LPM_CUR_OFFSET          0x1c
  27
  28 #define AUTHEN_OFFSET           0x30
  29 #define CPULPM_EN               BIT(2)
  30 #define TZ_NS_SHIFT             9
  31 #define TZ_NS_MASK              BIT(9)
  32
  33 #define WHITE_LIST_SHIFT        16
  34
  35 struct imx93_clk_gate {
  36         struct clk_hw hw;
  37         void __iomem    *reg;
  38         u32             bit_idx;
  39         u32             val;
  40         u32             mask;
  41         spinlock_t      *lock;
  42         unsigned int    *share_count;
  43 };
  44
  45 #define to_imx93_clk_gate(_hw) container_of(_hw, struct imx93_clk_gate, hw)
  46
  47 static void imx93_clk_gate_do_hardware(struct clk_hw *hw, bool enable)
  48 {
  49         struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
  50         u32 val;
  51
  52         val = readl(gate->reg + AUTHEN_OFFSET);
  53         if (val & CPULPM_EN) {
  54                 val = enable ? LPM_SETTING_ON : LPM_SETTING_OFF;
  55                 writel(val, gate->reg + LPM_CUR_OFFSET);
  56         } else {
  57                 val = readl(gate->reg + DIRECT_OFFSET);
  58                 val &= ~(gate->mask << gate->bit_idx);
  59                 if (enable)
  60                         val |= (gate->val & gate->mask) << gate->bit_idx;
  61                 writel(val, gate->reg + DIRECT_OFFSET);
  62         }
  63 }
  64
  65 static int imx93_clk_gate_enable(struct clk_hw *hw)
  66 {
  67         struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
  68         unsigned long flags;
  69
  70         spin_lock_irqsave(gate->lock, flags);
  71
  72         if (gate->share_count && (*gate->share_count)++ > 0)
  73                 goto out;
  74
  75         imx93_clk_gate_do_hardware(hw, true);
  76 out:
  77         spin_unlock_irqrestore(gate->lock, flags);
  78
  79         return 0;
  80 }
  81
  82 static void imx93_clk_gate_disable(struct clk_hw *hw)
  83 {
  84         struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
  85         unsigned long flags;
  86
  87         spin_lock_irqsave(gate->lock, flags);
  88
  89         if (gate->share_count) {
  90                 if (WARN_ON(*gate->share_count == 0))
  91                         goto out;
  92                 else if (--(*gate->share_count) > 0)
  93                         goto out;
  94         }
  95
  96         imx93_clk_gate_do_hardware(hw, false);
  97 out:
  98         spin_unlock_irqrestore(gate->lock, flags);
  99 }
 100
 101 static int imx93_clk_gate_reg_is_enabled(struct imx93_clk_gate *gate)
 102 {
 103         u32 val = readl(gate->reg + AUTHEN_OFFSET);
 104
 105         if (val & CPULPM_EN) {
 106                 val = readl(gate->reg + LPM_CUR_OFFSET);
 107                 if (val == LPM_SETTING_ON)
 108                         return 1;
 109         } else {
 110                 val = readl(gate->reg);
 111                 if (((val >> gate->bit_idx) & gate->mask) == gate->val)
 112                         return 1;
 113         }
 114
 115         return 0;
 116 }
 117
 118 static int imx93_clk_gate_is_enabled(struct clk_hw *hw)
 119 {
 120         struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
 121         unsigned long flags;
 122         int ret;
 123
 124         spin_lock_irqsave(gate->lock, flags);
 125
 126         ret = imx93_clk_gate_reg_is_enabled(gate);
 127
 128         spin_unlock_irqrestore(gate->lock, flags);
 129
 130         return ret;
 131 }
 132
 133 static void imx93_clk_gate_disable_unused(struct clk_hw *hw)
 134 {
 135         struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
 136         unsigned long flags;
 137
 138         spin_lock_irqsave(gate->lock, flags);
 139
 140         if (!gate->share_count || *gate->share_count == 0)
 141                 imx93_clk_gate_do_hardware(hw, false);
 142
 143         spin_unlock_irqrestore(gate->lock, flags);
 144 }
 145
 146 static const struct clk_ops imx93_clk_gate_ops = {
 147         .enable = imx93_clk_gate_enable,
 148         .disable = imx93_clk_gate_disable,
 149         .disable_unused = imx93_clk_gate_disable_unused,
 150         .is_enabled = imx93_clk_gate_is_enabled,
 151 };
 152
 153 static const struct clk_ops imx93_clk_gate_ro_ops = {
 154         .is_enabled = imx93_clk_gate_is_enabled,
 155 };
 156
 157 struct clk_hw *imx93_clk_gate(struct device *dev, const char *name, const char *parent_name,
 158                               unsigned long flags, void __iomem *reg, u32 bit_idx, u32 val,
 159                               u32 mask, u32 domain_id, unsigned int *share_count)
 160 {
 161         struct imx93_clk_gate *gate;
 162         struct clk_hw *hw;
 163         struct clk_init_data init;
 164         int ret;
 165         u32 authen;
 166
 167         gate = kzalloc(sizeof(struct imx93_clk_gate), GFP_KERNEL);
 168         if (!gate)
 169                 return ERR_PTR(-ENOMEM);
 170
 171         gate->reg = reg;
 172         gate->lock = &imx_ccm_lock;
 173         gate->bit_idx = bit_idx;
 174         gate->val = val;
 175         gate->mask = mask;
 176         gate->share_count = share_count;
 177
 178         init.name = name;
 179         init.ops = &imx93_clk_gate_ops;
 180         init.flags = flags | CLK_SET_RATE_PARENT | CLK_OPS_PARENT_ENABLE;
 181         init.parent_names = parent_name ? &parent_name : NULL;
 182         init.num_parents = parent_name ? 1 : 0;
 183
 184         gate->hw.init = &init;
 185         hw = &gate->hw;
 186
 187         authen = readl(reg + AUTHEN_OFFSET);
 188         if (!(authen & TZ_NS_MASK) || !(authen & BIT(WHITE_LIST_SHIFT + domain_id)))
 189                 init.ops = &imx93_clk_gate_ro_ops;
 190
 191         ret = clk_hw_register(dev, hw);
 192         if (ret) {
 193                 kfree(gate);
 194                 return ERR_PTR(ret);
 195         }
 196
 197         return hw;
 198 }
 199 EXPORT_SYMBOL_GPL(imx93_clk_gate);