drivers/clk/actions/owl-pll.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // OWL pll clock driver
   4 //
   5 // Copyright (c) 2014 Actions Semi Inc.
   6 // Author: David Liu <liuwei@actions-semi.com>
   7 //
   8 // Copyright (c) 2018 Linaro Ltd.
   9 // Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/slab.h>
  13 #include <linux/io.h>
  14 #include <linux/delay.h>
  15
  16 #include "owl-pll.h"
  17
  18 static u32 owl_pll_calculate_mul(struct owl_pll_hw *pll_hw, unsigned long rate)
  19 {
  20         u32 mul;
  21
  22         mul = DIV_ROUND_CLOSEST(rate, pll_hw->bfreq);
  23         if (mul < pll_hw->min_mul)
  24                 mul = pll_hw->min_mul;
  25         else if (mul > pll_hw->max_mul)
  26                 mul = pll_hw->max_mul;
  27
  28         return mul &= mul_mask(pll_hw);
  29 }
  30
  31 static unsigned long _get_table_rate(const struct clk_pll_table *table,
  32                 unsigned int val)
  33 {
  34         const struct clk_pll_table *clkt;
  35
  36         for (clkt = table; clkt->rate; clkt++)
  37                 if (clkt->val == val)
  38                         return clkt->rate;
  39
  40         return 0;
  41 }
  42
  43 static const struct clk_pll_table *_get_pll_table(
  44                 const struct clk_pll_table *table, unsigned long rate)
  45 {
  46         const struct clk_pll_table *clkt;
  47
  48         for (clkt = table; clkt->rate; clkt++) {
  49                 if (clkt->rate == rate) {
  50                         table = clkt;
  51                         break;
  52                 } else if (clkt->rate < rate)
  53                         table = clkt;
  54         }
  55
  56         return table;
  57 }
  58
  59 static long owl_pll_round_rate(struct clk_hw *hw, unsigned long rate,
  60                 unsigned long *parent_rate)
  61 {
  62         struct owl_pll *pll = hw_to_owl_pll(hw);
  63         struct owl_pll_hw *pll_hw = &pll->pll_hw;
  64         const struct clk_pll_table *clkt;
  65         u32 mul;
  66
  67         if (pll_hw->table) {
  68                 clkt = _get_pll_table(pll_hw->table, rate);
  69                 return clkt->rate;
  70         }
  71
  72         /* fixed frequency */
  73         if (pll_hw->width == 0)
  74                 return pll_hw->bfreq;
  75
  76         mul = owl_pll_calculate_mul(pll_hw, rate);
  77
  78         return pll_hw->bfreq * mul;
  79 }
  80
  81 static unsigned long owl_pll_recalc_rate(struct clk_hw *hw,
  82                 unsigned long parent_rate)
  83 {
  84         struct owl_pll *pll = hw_to_owl_pll(hw);
  85         struct owl_pll_hw *pll_hw = &pll->pll_hw;
  86         const struct owl_clk_common *common = &pll->common;
  87         u32 val;
  88
  89         if (pll_hw->table) {
  90                 regmap_read(common->regmap, pll_hw->reg, &val);
  91
  92                 val = val >> pll_hw->shift;
  93                 val &= mul_mask(pll_hw);
  94
  95                 return _get_table_rate(pll_hw->table, val);
  96         }
  97
  98         /* fixed frequency */
  99         if (pll_hw->width == 0)
 100                 return pll_hw->bfreq;
 101
 102         regmap_read(common->regmap, pll_hw->reg, &val);
 103
 104         val = val >> pll_hw->shift;
 105         val &= mul_mask(pll_hw);
 106
 107         return pll_hw->bfreq * val;
 108 }
 109
 110 static int owl_pll_is_enabled(struct clk_hw *hw)
 111 {
 112         struct owl_pll *pll = hw_to_owl_pll(hw);
 113         struct owl_pll_hw *pll_hw = &pll->pll_hw;
 114         const struct owl_clk_common *common = &pll->common;
 115         u32 reg;
 116
 117         regmap_read(common->regmap, pll_hw->reg, &reg);
 118
 119         return !!(reg & BIT(pll_hw->bit_idx));
 120 }
 121
 122 static void owl_pll_set(const struct owl_clk_common *common,
 123                        const struct owl_pll_hw *pll_hw, bool enable)
 124 {
 125         u32 reg;
 126
 127         regmap_read(common->regmap, pll_hw->reg, &reg);
 128
 129         if (enable)
 130                 reg |= BIT(pll_hw->bit_idx);
 131         else
 132                 reg &= ~BIT(pll_hw->bit_idx);
 133
 134         regmap_write(common->regmap, pll_hw->reg, reg);
 135 }
 136
 137 static int owl_pll_enable(struct clk_hw *hw)
 138 {
 139         struct owl_pll *pll = hw_to_owl_pll(hw);
 140         const struct owl_clk_common *common = &pll->common;
 141
 142         owl_pll_set(common, &pll->pll_hw, true);
 143
 144         return 0;
 145 }
 146
 147 static void owl_pll_disable(struct clk_hw *hw)
 148 {
 149         struct owl_pll *pll = hw_to_owl_pll(hw);
 150         const struct owl_clk_common *common = &pll->common;
 151
 152         owl_pll_set(common, &pll->pll_hw, false);
 153 }
 154
 155 static int owl_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 156                 unsigned long parent_rate)
 157 {
 158         struct owl_pll *pll = hw_to_owl_pll(hw);
 159         struct owl_pll_hw *pll_hw = &pll->pll_hw;
 160         const struct owl_clk_common *common = &pll->common;
 161         const struct clk_pll_table *clkt;
 162         u32 val, reg;
 163
 164         /* fixed frequency */
 165         if (pll_hw->width == 0)
 166                 return 0;
 167
 168         if (pll_hw->table) {
 169                 clkt = _get_pll_table(pll_hw->table, rate);
 170                 val = clkt->val;
 171         } else {
 172                 val = owl_pll_calculate_mul(pll_hw, rate);
 173         }
 174
 175         regmap_read(common->regmap, pll_hw->reg, &reg);
 176
 177         reg &= ~mul_mask(pll_hw);
 178         reg |= val << pll_hw->shift;
 179
 180         regmap_write(common->regmap, pll_hw->reg, reg);
 181
 182         udelay(PLL_STABILITY_WAIT_US);
 183
 184         return 0;
 185 }
 186
 187 const struct clk_ops owl_pll_ops = {
 188         .enable = owl_pll_enable,
 189         .disable = owl_pll_disable,
 190         .is_enabled = owl_pll_is_enabled,
 191         .round_rate = owl_pll_round_rate,
 192         .recalc_rate = owl_pll_recalc_rate,
 193         .set_rate = owl_pll_set_rate,
 194 };