drivers/clk/tegra/clk-sdmmc-mux.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018 NVIDIA CORPORATION.  All rights reserved.
   4  *
   5  * based on clk-mux.c
   6  *
   7  * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
   8  * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
   9  * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
  10  *
  11  */
  12
  13 #include <linux/clk-provider.h>
  14 #include <linux/err.h>
  15 #include <linux/io.h>
  16 #include <linux/types.h>
  17
  18 #include "clk.h"
  19
  20 #define DIV_MASK GENMASK(7, 0)
  21 #define MUX_SHIFT 29
  22 #define MUX_MASK GENMASK(MUX_SHIFT + 2, MUX_SHIFT)
  23 #define SDMMC_MUL 2
  24
  25 #define get_max_div(d) DIV_MASK
  26 #define get_div_field(val) ((val) & DIV_MASK)
  27 #define get_mux_field(val) (((val) & MUX_MASK) >> MUX_SHIFT)
  28
  29 static const char * const mux_sdmmc_parents[] = {
  30         "pll_p", "pll_c4_out2", "pll_c4_out0", "pll_c4_out1", "clk_m"
  31 };
  32
  33 static const u8 mux_lj_idx[] = {
  34         [0] = 0, [1] = 1, [2] = 2, [3] = 5, [4] = 6
  35 };
  36
  37 static const u8 mux_non_lj_idx[] = {
  38         [0] = 0, [1] = 3, [2] = 7, [3] = 4, [4] = 6
  39 };
  40
  41 static u8 clk_sdmmc_mux_get_parent(struct clk_hw *hw)
  42 {
  43         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
  44         int num_parents, i;
  45         u32 src, val;
  46         const u8 *mux_idx;
  47
  48         num_parents = clk_hw_get_num_parents(hw);
  49
  50         val = readl_relaxed(sdmmc_mux->reg);
  51         src = get_mux_field(val);
  52         if (get_div_field(val))
  53                 mux_idx = mux_non_lj_idx;
  54         else
  55                 mux_idx = mux_lj_idx;
  56
  57         for (i = 0; i < num_parents; i++) {
  58                 if (mux_idx[i] == src)
  59                         return i;
  60         }
  61
  62         WARN(1, "Unknown parent selector %d\n", src);
  63
  64         return 0;
  65 }
  66
  67 static int clk_sdmmc_mux_set_parent(struct clk_hw *hw, u8 index)
  68 {
  69         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
  70         u32 val;
  71
  72
  73         val = readl_relaxed(sdmmc_mux->reg);
  74         if (get_div_field(val))
  75                 index = mux_non_lj_idx[index];
  76         else
  77                 index = mux_lj_idx[index];
  78
  79         val &= ~MUX_MASK;
  80         val |= index << MUX_SHIFT;
  81
  82         writel(val, sdmmc_mux->reg);
  83
  84         return 0;
  85 }
  86
  87 static unsigned long clk_sdmmc_mux_recalc_rate(struct clk_hw *hw,
  88                                                unsigned long parent_rate)
  89 {
  90         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
  91         u32 val;
  92         int div;
  93         u64 rate = parent_rate;
  94
  95         val = readl_relaxed(sdmmc_mux->reg);
  96         div = get_div_field(val);
  97
  98         div += SDMMC_MUL;
  99
 100         rate *= SDMMC_MUL;
 101         rate += div - 1;
 102         do_div(rate, div);
 103
 104         return rate;
 105 }
 106
 107 static int clk_sdmmc_mux_determine_rate(struct clk_hw *hw,
 108                                         struct clk_rate_request *req)
 109 {
 110         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
 111         int div;
 112         unsigned long output_rate = req->best_parent_rate;
 113
 114         req->rate = max(req->rate, req->min_rate);
 115         req->rate = min(req->rate, req->max_rate);
 116
 117         if (!req->rate)
 118                 return output_rate;
 119
 120         div = div_frac_get(req->rate, output_rate, 8, 1, sdmmc_mux->div_flags);
 121         if (div < 0)
 122                 div = 0;
 123
 124         if (sdmmc_mux->div_flags & TEGRA_DIVIDER_ROUND_UP)
 125                 req->rate =  DIV_ROUND_UP(output_rate * SDMMC_MUL,
 126                                           div + SDMMC_MUL);
 127         else
 128                 req->rate =  output_rate * SDMMC_MUL / (div + SDMMC_MUL);
 129
 130         return 0;
 131 }
 132
 133 static int clk_sdmmc_mux_set_rate(struct clk_hw *hw, unsigned long rate,
 134                                   unsigned long parent_rate)
 135 {
 136         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
 137         int div;
 138         unsigned long flags = 0;
 139         u32 val;
 140         u8 src;
 141
 142         div = div_frac_get(rate, parent_rate, 8, 1, sdmmc_mux->div_flags);
 143         if (div < 0)
 144                 return div;
 145
 146         if (sdmmc_mux->lock)
 147                 spin_lock_irqsave(sdmmc_mux->lock, flags);
 148
 149         src = clk_sdmmc_mux_get_parent(hw);
 150         if (div)
 151                 src = mux_non_lj_idx[src];
 152         else
 153                 src = mux_lj_idx[src];
 154
 155         val = src << MUX_SHIFT;
 156         val |= div;
 157         writel(val, sdmmc_mux->reg);
 158         fence_udelay(2, sdmmc_mux->reg);
 159
 160         if (sdmmc_mux->lock)
 161                 spin_unlock_irqrestore(sdmmc_mux->lock, flags);
 162
 163         return 0;
 164 }
 165
 166 static int clk_sdmmc_mux_is_enabled(struct clk_hw *hw)
 167 {
 168         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
 169         const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
 170         struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
 171
 172         __clk_hw_set_clk(gate_hw, hw);
 173
 174         return gate_ops->is_enabled(gate_hw);
 175 }
 176
 177 static int clk_sdmmc_mux_enable(struct clk_hw *hw)
 178 {
 179         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
 180         const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
 181         struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
 182
 183         __clk_hw_set_clk(gate_hw, hw);
 184
 185         return gate_ops->enable(gate_hw);
 186 }
 187
 188 static void clk_sdmmc_mux_disable(struct clk_hw *hw)
 189 {
 190         struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
 191         const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
 192         struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
 193
 194         gate_ops->disable(gate_hw);
 195 }
 196
 197 static void clk_sdmmc_mux_restore_context(struct clk_hw *hw)
 198 {
 199         struct clk_hw *parent = clk_hw_get_parent(hw);
 200         unsigned long parent_rate = clk_hw_get_rate(parent);
 201         unsigned long rate = clk_hw_get_rate(hw);
 202         int parent_id;
 203
 204         parent_id = clk_hw_get_parent_index(hw);
 205         if (WARN_ON(parent_id < 0))
 206                 return;
 207
 208         clk_sdmmc_mux_set_parent(hw, parent_id);
 209         clk_sdmmc_mux_set_rate(hw, rate, parent_rate);
 210 }
 211
 212 static const struct clk_ops tegra_clk_sdmmc_mux_ops = {
 213         .get_parent = clk_sdmmc_mux_get_parent,
 214         .set_parent = clk_sdmmc_mux_set_parent,
 215         .determine_rate = clk_sdmmc_mux_determine_rate,
 216         .recalc_rate = clk_sdmmc_mux_recalc_rate,
 217         .set_rate = clk_sdmmc_mux_set_rate,
 218         .is_enabled = clk_sdmmc_mux_is_enabled,
 219         .enable = clk_sdmmc_mux_enable,
 220         .disable = clk_sdmmc_mux_disable,
 221         .restore_context = clk_sdmmc_mux_restore_context,
 222 };
 223
 224 struct clk *tegra_clk_register_sdmmc_mux_div(const char *name,
 225         void __iomem *clk_base, u32 offset, u32 clk_num, u8 div_flags,
 226         unsigned long flags, void *lock)
 227 {
 228         struct clk *clk;
 229         struct clk_init_data init;
 230         const struct tegra_clk_periph_regs *bank;
 231         struct tegra_sdmmc_mux *sdmmc_mux;
 232
 233         init.ops = &tegra_clk_sdmmc_mux_ops;
 234         init.name = name;
 235         init.flags = flags;
 236         init.parent_names = mux_sdmmc_parents;
 237         init.num_parents = ARRAY_SIZE(mux_sdmmc_parents);
 238
 239         bank = get_reg_bank(clk_num);
 240         if (!bank)
 241                 return ERR_PTR(-EINVAL);
 242
 243         sdmmc_mux = kzalloc(sizeof(*sdmmc_mux), GFP_KERNEL);
 244         if (!sdmmc_mux)
 245                 return ERR_PTR(-ENOMEM);
 246
 247         /* Data in .init is copied by clk_register(), so stack variable OK */
 248         sdmmc_mux->hw.init = &init;
 249         sdmmc_mux->reg = clk_base + offset;
 250         sdmmc_mux->lock = lock;
 251         sdmmc_mux->gate.clk_base = clk_base;
 252         sdmmc_mux->gate.regs = bank;
 253         sdmmc_mux->gate.enable_refcnt = periph_clk_enb_refcnt;
 254         sdmmc_mux->gate.clk_num = clk_num;
 255         sdmmc_mux->gate.flags = TEGRA_PERIPH_ON_APB;
 256         sdmmc_mux->div_flags = div_flags;
 257         sdmmc_mux->gate_ops = &tegra_clk_periph_gate_ops;
 258
 259         clk = clk_register(NULL, &sdmmc_mux->hw);
 260         if (IS_ERR(clk)) {
 261                 kfree(sdmmc_mux);
 262                 return clk;
 263         }
 264
 265         sdmmc_mux->gate.hw.clk = clk;
 266
 267         return clk;
 268 }