drivers/clk/mediatek/clk-pll.c

   1 /*
   2  * Copyright (c) 2014 MediaTek Inc.
   3  * Author: James Liao <jamesjj.liao@mediatek.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/io.h>
  18 #include <linux/slab.h>
  19 #include <linux/clkdev.h>
  20 #include <linux/delay.h>
  21
  22 #include "clk-mtk.h"
  23
  24 #define REG_CON0                0
  25 #define REG_CON1                4
  26
  27 #define CON0_BASE_EN            BIT(0)
  28 #define CON0_PWR_ON             BIT(0)
  29 #define CON0_ISO_EN             BIT(1)
  30 #define CON0_PCW_CHG            BIT(31)
  31
  32 #define AUDPLL_TUNER_EN         BIT(31)
  33
  34 #define POSTDIV_MASK            0x7
  35 #define INTEGER_BITS            7
  36
  37 /*
  38  * MediaTek PLLs are configured through their pcw value. The pcw value describes
  39  * a divider in the PLL feedback loop which consists of 7 bits for the integer
  40  * part and the remaining bits (if present) for the fractional part. Also they
  41  * have a 3 bit power-of-two post divider.
  42  */
  43
  44 struct mtk_clk_pll {
  45         struct clk_hw   hw;
  46         void __iomem    *base_addr;
  47         void __iomem    *pd_addr;
  48         void __iomem    *pwr_addr;
  49         void __iomem    *tuner_addr;
  50         void __iomem    *pcw_addr;
  51         const struct mtk_pll_data *data;
  52 };
  53
  54 static inline struct mtk_clk_pll *to_mtk_clk_pll(struct clk_hw *hw)
  55 {
  56         return container_of(hw, struct mtk_clk_pll, hw);
  57 }
  58
  59 static int mtk_pll_is_prepared(struct clk_hw *hw)
  60 {
  61         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
  62
  63         return (readl(pll->base_addr + REG_CON0) & CON0_BASE_EN) != 0;
  64 }
  65
  66 static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
  67                 u32 pcw, int postdiv)
  68 {
  69         int pcwbits = pll->data->pcwbits;
  70         int pcwfbits;
  71         u64 vco;
  72         u8 c = 0;
  73
  74         /* The fractional part of the PLL divider. */
  75         pcwfbits = pcwbits > INTEGER_BITS ? pcwbits - INTEGER_BITS : 0;
  76
  77         vco = (u64)fin * pcw;
  78
  79         if (pcwfbits && (vco & GENMASK(pcwfbits - 1, 0)))
  80                 c = 1;
  81
  82         vco >>= pcwfbits;
  83
  84         if (c)
  85                 vco++;
  86
  87         return ((unsigned long)vco + postdiv - 1) / postdiv;
  88 }
  89
  90 static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
  91                 int postdiv)
  92 {
  93         u32 con1, val;
  94         int pll_en;
  95
  96         pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;
  97
  98         /* set postdiv */
  99         val = readl(pll->pd_addr);
 100         val &= ~(POSTDIV_MASK << pll->data->pd_shift);
 101         val |= (ffs(postdiv) - 1) << pll->data->pd_shift;
 102
 103         /* postdiv and pcw need to set at the same time if on same register */
 104         if (pll->pd_addr != pll->pcw_addr) {
 105                 writel(val, pll->pd_addr);
 106                 val = readl(pll->pcw_addr);
 107         }
 108
 109         /* set pcw */
 110         val &= ~GENMASK(pll->data->pcw_shift + pll->data->pcwbits - 1,
 111                         pll->data->pcw_shift);
 112         val |= pcw << pll->data->pcw_shift;
 113         writel(val, pll->pcw_addr);
 114
 115         con1 = readl(pll->base_addr + REG_CON1);
 116
 117         if (pll_en)
 118                 con1 |= CON0_PCW_CHG;
 119
 120         writel(con1, pll->base_addr + REG_CON1);
 121         if (pll->tuner_addr)
 122                 writel(con1 + 1, pll->tuner_addr);
 123
 124         if (pll_en)
 125                 udelay(20);
 126 }
 127
 128 /*
 129  * mtk_pll_calc_values - calculate good values for a given input frequency.
 130  * @pll:        The pll
 131  * @pcw:        The pcw value (output)
 132  * @postdiv:    The post divider (output)
 133  * @freq:       The desired target frequency
 134  * @fin:        The input frequency
 135  *
 136  */
 137 static void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv,
 138                 u32 freq, u32 fin)
 139 {
 140         unsigned long fmin = 1000 * MHZ;
 141         const struct mtk_pll_div_table *div_table = pll->data->div_table;
 142         u64 _pcw;
 143         u32 val;
 144
 145         if (freq > pll->data->fmax)
 146                 freq = pll->data->fmax;
 147
 148         if (div_table) {
 149                 if (freq > div_table[0].freq)
 150                         freq = div_table[0].freq;
 151
 152                 for (val = 0; div_table[val + 1].freq != 0; val++) {
 153                         if (freq > div_table[val + 1].freq)
 154                                 break;
 155                 }
 156                 *postdiv = 1 << val;
 157         } else {
 158                 for (val = 0; val < 5; val++) {
 159                         *postdiv = 1 << val;
 160                         if ((u64)freq * *postdiv >= fmin)
 161                                 break;
 162                 }
 163         }
 164
 165         /* _pcw = freq * postdiv / fin * 2^pcwfbits */
 166         _pcw = ((u64)freq << val) << (pll->data->pcwbits - INTEGER_BITS);
 167         do_div(_pcw, fin);
 168
 169         *pcw = (u32)_pcw;
 170 }
 171
 172 static int mtk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 173                 unsigned long parent_rate)
 174 {
 175         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 176         u32 pcw = 0;
 177         u32 postdiv;
 178
 179         mtk_pll_calc_values(pll, &pcw, &postdiv, rate, parent_rate);
 180         mtk_pll_set_rate_regs(pll, pcw, postdiv);
 181
 182         return 0;
 183 }
 184
 185 static unsigned long mtk_pll_recalc_rate(struct clk_hw *hw,
 186                 unsigned long parent_rate)
 187 {
 188         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 189         u32 postdiv;
 190         u32 pcw;
 191
 192         postdiv = (readl(pll->pd_addr) >> pll->data->pd_shift) & POSTDIV_MASK;
 193         postdiv = 1 << postdiv;
 194
 195         pcw = readl(pll->pcw_addr) >> pll->data->pcw_shift;
 196         pcw &= GENMASK(pll->data->pcwbits - 1, 0);
 197
 198         return __mtk_pll_recalc_rate(pll, parent_rate, pcw, postdiv);
 199 }
 200
 201 static long mtk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 202                 unsigned long *prate)
 203 {
 204         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 205         u32 pcw = 0;
 206         int postdiv;
 207
 208         mtk_pll_calc_values(pll, &pcw, &postdiv, rate, *prate);
 209
 210         return __mtk_pll_recalc_rate(pll, *prate, pcw, postdiv);
 211 }
 212
 213 static int mtk_pll_prepare(struct clk_hw *hw)
 214 {
 215         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 216         u32 r;
 217
 218         r = readl(pll->pwr_addr) | CON0_PWR_ON;
 219         writel(r, pll->pwr_addr);
 220         udelay(1);
 221
 222         r = readl(pll->pwr_addr) & ~CON0_ISO_EN;
 223         writel(r, pll->pwr_addr);
 224         udelay(1);
 225
 226         r = readl(pll->base_addr + REG_CON0);
 227         r |= pll->data->en_mask;
 228         writel(r, pll->base_addr + REG_CON0);
 229
 230         if (pll->tuner_addr) {
 231                 r = readl(pll->tuner_addr) | AUDPLL_TUNER_EN;
 232                 writel(r, pll->tuner_addr);
 233         }
 234
 235         udelay(20);
 236
 237         if (pll->data->flags & HAVE_RST_BAR) {
 238                 r = readl(pll->base_addr + REG_CON0);
 239                 r |= pll->data->rst_bar_mask;
 240                 writel(r, pll->base_addr + REG_CON0);
 241         }
 242
 243         return 0;
 244 }
 245
 246 static void mtk_pll_unprepare(struct clk_hw *hw)
 247 {
 248         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 249         u32 r;
 250
 251         if (pll->data->flags & HAVE_RST_BAR) {
 252                 r = readl(pll->base_addr + REG_CON0);
 253                 r &= ~pll->data->rst_bar_mask;
 254                 writel(r, pll->base_addr + REG_CON0);
 255         }
 256
 257         if (pll->tuner_addr) {
 258                 r = readl(pll->tuner_addr) & ~AUDPLL_TUNER_EN;
 259                 writel(r, pll->tuner_addr);
 260         }
 261
 262         r = readl(pll->base_addr + REG_CON0);
 263         r &= ~CON0_BASE_EN;
 264         writel(r, pll->base_addr + REG_CON0);
 265
 266         r = readl(pll->pwr_addr) | CON0_ISO_EN;
 267         writel(r, pll->pwr_addr);
 268
 269         r = readl(pll->pwr_addr) & ~CON0_PWR_ON;
 270         writel(r, pll->pwr_addr);
 271 }
 272
 273 static const struct clk_ops mtk_pll_ops = {
 274         .is_prepared    = mtk_pll_is_prepared,
 275         .prepare        = mtk_pll_prepare,
 276         .unprepare      = mtk_pll_unprepare,
 277         .recalc_rate    = mtk_pll_recalc_rate,
 278         .round_rate     = mtk_pll_round_rate,
 279         .set_rate       = mtk_pll_set_rate,
 280 };
 281
 282 static struct clk *mtk_clk_register_pll(const struct mtk_pll_data *data,
 283                 void __iomem *base)
 284 {
 285         struct mtk_clk_pll *pll;
 286         struct clk_init_data init = {};
 287         struct clk *clk;
 288         const char *parent_name = "clk26m";
 289
 290         pll = kzalloc(sizeof(*pll), GFP_KERNEL);
 291         if (!pll)
 292                 return ERR_PTR(-ENOMEM);
 293
 294         pll->base_addr = base + data->reg;
 295         pll->pwr_addr = base + data->pwr_reg;
 296         pll->pd_addr = base + data->pd_reg;
 297         pll->pcw_addr = base + data->pcw_reg;
 298         if (data->tuner_reg)
 299                 pll->tuner_addr = base + data->tuner_reg;
 300         pll->hw.init = &init;
 301         pll->data = data;
 302
 303         init.name = data->name;
 304         init.flags = (data->flags & PLL_AO) ? CLK_IS_CRITICAL : 0;
 305         init.ops = &mtk_pll_ops;
 306         init.parent_names = &parent_name;
 307         init.num_parents = 1;
 308
 309         clk = clk_register(NULL, &pll->hw);
 310
 311         if (IS_ERR(clk))
 312                 kfree(pll);
 313
 314         return clk;
 315 }
 316
 317 void mtk_clk_register_plls(struct device_node *node,
 318                 const struct mtk_pll_data *plls, int num_plls, struct clk_onecell_data *clk_data)
 319 {
 320         void __iomem *base;
 321         int i;
 322         struct clk *clk;
 323
 324         base = of_iomap(node, 0);
 325         if (!base) {
 326                 pr_err("%s(): ioremap failed\n", __func__);
 327                 return;
 328         }
 329
 330         for (i = 0; i < num_plls; i++) {
 331                 const struct mtk_pll_data *pll = &plls[i];
 332
 333                 clk = mtk_clk_register_pll(pll, base);
 334
 335                 if (IS_ERR(clk)) {
 336                         pr_err("Failed to register clk %s: %ld\n",
 337                                         pll->name, PTR_ERR(clk));
 338                         continue;
 339                 }
 340
 341                 clk_data->clks[pll->id] = clk;
 342         }
 343 }