drivers/clk/tegra/clk-super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/io.h>
   8 #include <linux/delay.h>
   9 #include <linux/err.h>
  10 #include <linux/slab.h>
  11 #include <linux/clk-provider.h>
  12
  13 #include "clk.h"
  14
  15 #define SUPER_STATE_IDLE 0
  16 #define SUPER_STATE_RUN 1
  17 #define SUPER_STATE_IRQ 2
  18 #define SUPER_STATE_FIQ 3
  19
  20 #define SUPER_STATE_SHIFT 28
  21 #define SUPER_STATE_MASK ((BIT(SUPER_STATE_IDLE) | BIT(SUPER_STATE_RUN) | \
  22                            BIT(SUPER_STATE_IRQ) | BIT(SUPER_STATE_FIQ)) \
  23                           << SUPER_STATE_SHIFT)
  24
  25 #define SUPER_LP_DIV2_BYPASS (1 << 16)
  26
  27 #define super_state(s) (BIT(s) << SUPER_STATE_SHIFT)
  28 #define super_state_to_src_shift(m, s) ((m->width * s))
  29 #define super_state_to_src_mask(m) (((1 << m->width) - 1))
  30
  31 #define CCLK_SRC_PLLP_OUT0 4
  32 #define CCLK_SRC_PLLP_OUT4 5
  33
  34 static u8 clk_super_get_parent(struct clk_hw *hw)
  35 {
  36         struct tegra_clk_super_mux *mux = to_clk_super_mux(hw);
  37         u32 val, state;
  38         u8 source, shift;
  39
  40         val = readl_relaxed(mux->reg);
  41
  42         state = val & SUPER_STATE_MASK;
  43
  44         BUG_ON((state != super_state(SUPER_STATE_RUN)) &&
  45                (state != super_state(SUPER_STATE_IDLE)));
  46         shift = (state == super_state(SUPER_STATE_IDLE)) ?
  47                 super_state_to_src_shift(mux, SUPER_STATE_IDLE) :
  48                 super_state_to_src_shift(mux, SUPER_STATE_RUN);
  49
  50         source = (val >> shift) & super_state_to_src_mask(mux);
  51
  52         /*
  53          * If LP_DIV2_BYPASS is not set and PLLX is current parent then
  54          * PLLX/2 is the input source to CCLKLP.
  55          */
  56         if ((mux->flags & TEGRA_DIVIDER_2) && !(val & SUPER_LP_DIV2_BYPASS) &&
  57             (source == mux->pllx_index))
  58                 source = mux->div2_index;
  59
  60         return source;
  61 }
  62
  63 static int clk_super_set_parent(struct clk_hw *hw, u8 index)
  64 {
  65         struct tegra_clk_super_mux *mux = to_clk_super_mux(hw);
  66         u32 val, state;
  67         int err = 0;
  68         u8 parent_index, shift;
  69         unsigned long flags = 0;
  70
  71         if (mux->lock)
  72                 spin_lock_irqsave(mux->lock, flags);
  73
  74         val = readl_relaxed(mux->reg);
  75         state = val & SUPER_STATE_MASK;
  76         BUG_ON((state != super_state(SUPER_STATE_RUN)) &&
  77                (state != super_state(SUPER_STATE_IDLE)));
  78         shift = (state == super_state(SUPER_STATE_IDLE)) ?
  79                 super_state_to_src_shift(mux, SUPER_STATE_IDLE) :
  80                 super_state_to_src_shift(mux, SUPER_STATE_RUN);
  81
  82         /*
  83          * For LP mode super-clock switch between PLLX direct
  84          * and divided-by-2 outputs is allowed only when other
  85          * than PLLX clock source is current parent.
  86          */
  87         if ((mux->flags & TEGRA_DIVIDER_2) && ((index == mux->div2_index) ||
  88                                                (index == mux->pllx_index))) {
  89                 parent_index = clk_super_get_parent(hw);
  90                 if ((parent_index == mux->div2_index) ||
  91                     (parent_index == mux->pllx_index)) {
  92                         err = -EINVAL;
  93                         goto out;
  94                 }
  95
  96                 val ^= SUPER_LP_DIV2_BYPASS;
  97                 writel_relaxed(val, mux->reg);
  98                 udelay(2);
  99
 100                 if (index == mux->div2_index)
 101                         index = mux->pllx_index;
 102         }
 103
 104         /* enable PLLP branches to CPU before selecting PLLP source */
 105         if ((mux->flags & TEGRA210_CPU_CLK) &&
 106             (index == CCLK_SRC_PLLP_OUT0 || index == CCLK_SRC_PLLP_OUT4))
 107                 tegra_clk_set_pllp_out_cpu(true);
 108
 109         val &= ~((super_state_to_src_mask(mux)) << shift);
 110         val |= (index & (super_state_to_src_mask(mux))) << shift;
 111
 112         writel_relaxed(val, mux->reg);
 113         udelay(2);
 114
 115         /* disable PLLP branches to CPU if not used */
 116         if ((mux->flags & TEGRA210_CPU_CLK) &&
 117             index != CCLK_SRC_PLLP_OUT0 && index != CCLK_SRC_PLLP_OUT4)
 118                 tegra_clk_set_pllp_out_cpu(false);
 119
 120 out:
 121         if (mux->lock)
 122                 spin_unlock_irqrestore(mux->lock, flags);
 123
 124         return err;
 125 }
 126
 127 static void clk_super_mux_restore_context(struct clk_hw *hw)
 128 {
 129         int parent_id;
 130
 131         parent_id = clk_hw_get_parent_index(hw);
 132         if (WARN_ON(parent_id < 0))
 133                 return;
 134
 135         clk_super_set_parent(hw, parent_id);
 136 }
 137
 138 static const struct clk_ops tegra_clk_super_mux_ops = {
 139         .determine_rate = clk_hw_determine_rate_no_reparent,
 140         .get_parent = clk_super_get_parent,
 141         .set_parent = clk_super_set_parent,
 142         .restore_context = clk_super_mux_restore_context,
 143 };
 144
 145 static int clk_super_determine_rate(struct clk_hw *hw,
 146                                     struct clk_rate_request *req)
 147 {
 148         struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
 149         struct clk_hw *div_hw = &super->frac_div.hw;
 150         unsigned long rate;
 151
 152         __clk_hw_set_clk(div_hw, hw);
 153
 154         rate = super->div_ops->round_rate(div_hw, req->rate,
 155                                           &req->best_parent_rate);
 156         if (rate < 0)
 157                 return rate;
 158
 159         req->rate = rate;
 160         return 0;
 161 }
 162
 163 static unsigned long clk_super_recalc_rate(struct clk_hw *hw,
 164                                            unsigned long parent_rate)
 165 {
 166         struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
 167         struct clk_hw *div_hw = &super->frac_div.hw;
 168
 169         __clk_hw_set_clk(div_hw, hw);
 170
 171         return super->div_ops->recalc_rate(div_hw, parent_rate);
 172 }
 173
 174 static int clk_super_set_rate(struct clk_hw *hw, unsigned long rate,
 175                               unsigned long parent_rate)
 176 {
 177         struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
 178         struct clk_hw *div_hw = &super->frac_div.hw;
 179
 180         __clk_hw_set_clk(div_hw, hw);
 181
 182         return super->div_ops->set_rate(div_hw, rate, parent_rate);
 183 }
 184
 185 static void clk_super_restore_context(struct clk_hw *hw)
 186 {
 187         struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
 188         struct clk_hw *div_hw = &super->frac_div.hw;
 189         int parent_id;
 190
 191         parent_id = clk_hw_get_parent_index(hw);
 192         if (WARN_ON(parent_id < 0))
 193                 return;
 194
 195         super->div_ops->restore_context(div_hw);
 196         clk_super_set_parent(hw, parent_id);
 197 }
 198
 199 const struct clk_ops tegra_clk_super_ops = {
 200         .get_parent = clk_super_get_parent,
 201         .set_parent = clk_super_set_parent,
 202         .set_rate = clk_super_set_rate,
 203         .determine_rate = clk_super_determine_rate,
 204         .recalc_rate = clk_super_recalc_rate,
 205         .restore_context = clk_super_restore_context,
 206 };
 207
 208 struct clk *tegra_clk_register_super_mux(const char *name,
 209                 const char **parent_names, u8 num_parents,
 210                 unsigned long flags, void __iomem *reg, u8 clk_super_flags,
 211                 u8 width, u8 pllx_index, u8 div2_index, spinlock_t *lock)
 212 {
 213         struct tegra_clk_super_mux *super;
 214         struct clk *clk;
 215         struct clk_init_data init;
 216
 217         super = kzalloc(sizeof(*super), GFP_KERNEL);
 218         if (!super)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         init.name = name;
 222         init.ops = &tegra_clk_super_mux_ops;
 223         init.flags = flags;
 224         init.parent_names = parent_names;
 225         init.num_parents = num_parents;
 226
 227         super->reg = reg;
 228         super->pllx_index = pllx_index;
 229         super->div2_index = div2_index;
 230         super->lock = lock;
 231         super->width = width;
 232         super->flags = clk_super_flags;
 233
 234         /* Data in .init is copied by clk_register(), so stack variable OK */
 235         super->hw.init = &init;
 236
 237         clk = tegra_clk_dev_register(&super->hw);
 238         if (IS_ERR(clk))
 239                 kfree(super);
 240
 241         return clk;
 242 }
 243
 244 struct clk *tegra_clk_register_super_clk(const char *name,
 245                 const char * const *parent_names, u8 num_parents,
 246                 unsigned long flags, void __iomem *reg, u8 clk_super_flags,
 247                 spinlock_t *lock)
 248 {
 249         struct tegra_clk_super_mux *super;
 250         struct clk *clk;
 251         struct clk_init_data init;
 252
 253         super = kzalloc(sizeof(*super), GFP_KERNEL);
 254         if (!super)
 255                 return ERR_PTR(-ENOMEM);
 256
 257         init.name = name;
 258         init.ops = &tegra_clk_super_ops;
 259         init.flags = flags;
 260         init.parent_names = parent_names;
 261         init.num_parents = num_parents;
 262
 263         super->reg = reg;
 264         super->lock = lock;
 265         super->width = 4;
 266         super->flags = clk_super_flags;
 267         super->frac_div.reg = reg + 4;
 268         super->frac_div.shift = 16;
 269         super->frac_div.width = 8;
 270         super->frac_div.frac_width = 1;
 271         super->frac_div.lock = lock;
 272         super->div_ops = &tegra_clk_frac_div_ops;
 273
 274         /* Data in .init is copied by clk_register(), so stack variable OK */
 275         super->hw.init = &init;
 276
 277         clk = clk_register(NULL, &super->hw);
 278         if (IS_ERR(clk))
 279                 kfree(super);
 280
 281         return clk;
 282 }