linux/drivers/clk/sprd/pll.c
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   1// SPDX-License-Identifier: GPL-2.0
   2//
   3// Spreadtrum pll clock driver
   4//
   5// Copyright (C) 2015~2017 Spreadtrum, Inc.
   6// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
   7
   8#include <linux/delay.h>
   9#include <linux/err.h>
  10#include <linux/regmap.h>
  11#include <linux/slab.h>
  12
  13#include "pll.h"
  14
  15#define CLK_PLL_1M      1000000
  16#define CLK_PLL_10M     (CLK_PLL_1M * 10)
  17
  18#define pindex(pll, member)             \
  19        (pll->factors[member].shift / (8 * sizeof(pll->regs_num)))
  20
  21#define pshift(pll, member)             \
  22        (pll->factors[member].shift % (8 * sizeof(pll->regs_num)))
  23
  24#define pwidth(pll, member)             \
  25        pll->factors[member].width
  26
  27#define pmask(pll, member)                                      \
  28        ((pwidth(pll, member)) ?                                \
  29        GENMASK(pwidth(pll, member) + pshift(pll, member) - 1,  \
  30        pshift(pll, member)) : 0)
  31
  32#define pinternal(pll, cfg, member)     \
  33        (cfg[pindex(pll, member)] & pmask(pll, member))
  34
  35#define pinternal_val(pll, cfg, member) \
  36        (pinternal(pll, cfg, member) >> pshift(pll, member))
  37
  38static inline unsigned int
  39sprd_pll_read(const struct sprd_pll *pll, u8 index)
  40{
  41        const struct sprd_clk_common *common = &pll->common;
  42        unsigned int val = 0;
  43
  44        if (WARN_ON(index >= pll->regs_num))
  45                return 0;
  46
  47        regmap_read(common->regmap, common->reg + index * 4, &val);
  48
  49        return val;
  50}
  51
  52static inline void
  53sprd_pll_write(const struct sprd_pll *pll, u8 index,
  54                                  u32 msk, u32 val)
  55{
  56        const struct sprd_clk_common *common = &pll->common;
  57        unsigned int offset, reg;
  58        int ret = 0;
  59
  60        if (WARN_ON(index >= pll->regs_num))
  61                return;
  62
  63        offset = common->reg + index * 4;
  64        ret = regmap_read(common->regmap, offset, &reg);
  65        if (!ret)
  66                regmap_write(common->regmap, offset, (reg & ~msk) | val);
  67}
  68
  69static unsigned long pll_get_refin(const struct sprd_pll *pll)
  70{
  71        u32 shift, mask, index, refin_id = 3;
  72        const unsigned long refin[4] = { 2, 4, 13, 26 };
  73
  74        if (pwidth(pll, PLL_REFIN)) {
  75                index = pindex(pll, PLL_REFIN);
  76                shift = pshift(pll, PLL_REFIN);
  77                mask = pmask(pll, PLL_REFIN);
  78                refin_id = (sprd_pll_read(pll, index) & mask) >> shift;
  79                if (refin_id > 3)
  80                        refin_id = 3;
  81        }
  82
  83        return refin[refin_id];
  84}
  85
  86static u32 pll_get_ibias(u64 rate, const u64 *table)
  87{
  88        u32 i, num = table[0];
  89
  90        /* table[0] indicates the number of items in this table */
  91        for (i = 0; i < num; i++)
  92                if (rate <= table[i + 1])
  93                        break;
  94
  95        return i == num ? num - 1 : i;
  96}
  97
  98static unsigned long _sprd_pll_recalc_rate(const struct sprd_pll *pll,
  99                                           unsigned long parent_rate)
 100{
 101        u32 *cfg;
 102        u32 i, mask, regs_num = pll->regs_num;
 103        unsigned long rate, nint, kint = 0;
 104        u64 refin;
 105        u16 k1, k2;
 106
 107        cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);
 108        if (!cfg)
 109                return parent_rate;
 110
 111        for (i = 0; i < regs_num; i++)
 112                cfg[i] = sprd_pll_read(pll, i);
 113
 114        refin = pll_get_refin(pll);
 115
 116        if (pinternal(pll, cfg, PLL_PREDIV))
 117                refin = refin * 2;
 118
 119        if (pwidth(pll, PLL_POSTDIV) &&
 120            ((pll->fflag == 1 && pinternal(pll, cfg, PLL_POSTDIV)) ||
 121             (!pll->fflag && !pinternal(pll, cfg, PLL_POSTDIV))))
 122                refin = refin / 2;
 123
 124        if (!pinternal(pll, cfg, PLL_DIV_S)) {
 125                rate = refin * pinternal_val(pll, cfg, PLL_N) * CLK_PLL_10M;
 126        } else {
 127                nint = pinternal_val(pll, cfg, PLL_NINT);
 128                if (pinternal(pll, cfg, PLL_SDM_EN))
 129                        kint = pinternal_val(pll, cfg, PLL_KINT);
 130
 131                mask = pmask(pll, PLL_KINT);
 132
 133                k1 = pll->k1;
 134                k2 = pll->k2;
 135                rate = DIV_ROUND_CLOSEST_ULL(refin * kint * k1,
 136                                         ((mask >> __ffs(mask)) + 1)) *
 137                                         k2 + refin * nint * CLK_PLL_1M;
 138        }
 139
 140        kfree(cfg);
 141        return rate;
 142}
 143
 144#define SPRD_PLL_WRITE_CHECK(pll, i, mask, val)         \
 145        (((sprd_pll_read(pll, i) & mask) == val) ? 0 : (-EFAULT))
 146
 147static int _sprd_pll_set_rate(const struct sprd_pll *pll,
 148                              unsigned long rate,
 149                              unsigned long parent_rate)
 150{
 151        struct reg_cfg *cfg;
 152        int ret = 0;
 153        u32 mask, shift, width, ibias_val, index;
 154        u32 regs_num = pll->regs_num, i = 0;
 155        unsigned long kint, nint;
 156        u64 tmp, refin, fvco = rate;
 157
 158        cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);
 159        if (!cfg)
 160                return -ENOMEM;
 161
 162        refin = pll_get_refin(pll);
 163
 164        mask = pmask(pll, PLL_PREDIV);
 165        index = pindex(pll, PLL_PREDIV);
 166        width = pwidth(pll, PLL_PREDIV);
 167        if (width && (sprd_pll_read(pll, index) & mask))
 168                refin = refin * 2;
 169
 170        mask = pmask(pll, PLL_POSTDIV);
 171        index = pindex(pll, PLL_POSTDIV);
 172        width = pwidth(pll, PLL_POSTDIV);
 173        cfg[index].msk = mask;
 174        if (width && ((pll->fflag == 1 && fvco <= pll->fvco) ||
 175                      (pll->fflag == 0 && fvco > pll->fvco)))
 176                cfg[index].val |= mask;
 177
 178        if (width && fvco <= pll->fvco)
 179                fvco = fvco * 2;
 180
 181        mask = pmask(pll, PLL_DIV_S);
 182        index = pindex(pll, PLL_DIV_S);
 183        cfg[index].val |= mask;
 184        cfg[index].msk |= mask;
 185
 186        mask = pmask(pll, PLL_SDM_EN);
 187        index = pindex(pll, PLL_SDM_EN);
 188        cfg[index].val |= mask;
 189        cfg[index].msk |= mask;
 190
 191        nint = do_div(fvco, refin * CLK_PLL_1M);
 192        mask = pmask(pll, PLL_NINT);
 193        index = pindex(pll, PLL_NINT);
 194        shift = pshift(pll, PLL_NINT);
 195        cfg[index].val |= (nint << shift) & mask;
 196        cfg[index].msk |= mask;
 197
 198        mask = pmask(pll, PLL_KINT);
 199        index = pindex(pll, PLL_KINT);
 200        width = pwidth(pll, PLL_KINT);
 201        shift = pshift(pll, PLL_KINT);
 202        tmp = fvco - refin * nint * CLK_PLL_1M;
 203        tmp = do_div(tmp, 10000) * ((mask >> shift) + 1);
 204        kint = DIV_ROUND_CLOSEST_ULL(tmp, refin * 100);
 205        cfg[index].val |= (kint << shift) & mask;
 206        cfg[index].msk |= mask;
 207
 208        ibias_val = pll_get_ibias(fvco, pll->itable);
 209
 210        mask = pmask(pll, PLL_IBIAS);
 211        index = pindex(pll, PLL_IBIAS);
 212        shift = pshift(pll, PLL_IBIAS);
 213        cfg[index].val |= ibias_val << shift & mask;
 214        cfg[index].msk |= mask;
 215
 216        for (i = 0; i < regs_num; i++) {
 217                if (cfg[i].msk) {
 218                        sprd_pll_write(pll, i, cfg[i].msk, cfg[i].val);
 219                        ret |= SPRD_PLL_WRITE_CHECK(pll, i, cfg[i].msk,
 220                                                   cfg[i].val);
 221                }
 222        }
 223
 224        if (!ret)
 225                udelay(pll->udelay);
 226
 227        kfree(cfg);
 228        return ret;
 229}
 230
 231static unsigned long sprd_pll_recalc_rate(struct clk_hw *hw,
 232                                          unsigned long parent_rate)
 233{
 234        struct sprd_pll *pll = hw_to_sprd_pll(hw);
 235
 236        return _sprd_pll_recalc_rate(pll, parent_rate);
 237}
 238
 239static int sprd_pll_set_rate(struct clk_hw *hw,
 240                             unsigned long rate,
 241                             unsigned long parent_rate)
 242{
 243        struct sprd_pll *pll = hw_to_sprd_pll(hw);
 244
 245        return _sprd_pll_set_rate(pll, rate, parent_rate);
 246}
 247
 248static int sprd_pll_clk_prepare(struct clk_hw *hw)
 249{
 250        struct sprd_pll *pll = hw_to_sprd_pll(hw);
 251
 252        udelay(pll->udelay);
 253
 254        return 0;
 255}
 256
 257static long sprd_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 258                                unsigned long *prate)
 259{
 260        return rate;
 261}
 262
 263const struct clk_ops sprd_pll_ops = {
 264        .prepare = sprd_pll_clk_prepare,
 265        .recalc_rate = sprd_pll_recalc_rate,
 266        .round_rate = sprd_pll_round_rate,
 267        .set_rate = sprd_pll_set_rate,
 268};
 269EXPORT_SYMBOL_GPL(sprd_pll_ops);
 270