drivers/clk/clk-highbank.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2011-2012 Calxeda, Inc.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/slab.h>
   8 #include <linux/err.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/io.h>
  11 #include <linux/of.h>
  12 #include <linux/of_address.h>
  13
  14 #define HB_PLL_LOCK_500         0x20000000
  15 #define HB_PLL_LOCK             0x10000000
  16 #define HB_PLL_DIVF_SHIFT       20
  17 #define HB_PLL_DIVF_MASK        0x0ff00000
  18 #define HB_PLL_DIVQ_SHIFT       16
  19 #define HB_PLL_DIVQ_MASK        0x00070000
  20 #define HB_PLL_DIVR_SHIFT       8
  21 #define HB_PLL_DIVR_MASK        0x00001f00
  22 #define HB_PLL_RANGE_SHIFT      4
  23 #define HB_PLL_RANGE_MASK       0x00000070
  24 #define HB_PLL_BYPASS           0x00000008
  25 #define HB_PLL_RESET            0x00000004
  26 #define HB_PLL_EXT_BYPASS       0x00000002
  27 #define HB_PLL_EXT_ENA          0x00000001
  28
  29 #define HB_PLL_VCO_MIN_FREQ     2133000000
  30 #define HB_PLL_MAX_FREQ         HB_PLL_VCO_MIN_FREQ
  31 #define HB_PLL_MIN_FREQ         (HB_PLL_VCO_MIN_FREQ / 64)
  32
  33 #define HB_A9_BCLK_DIV_MASK     0x00000006
  34 #define HB_A9_BCLK_DIV_SHIFT    1
  35 #define HB_A9_PCLK_DIV          0x00000001
  36
  37 struct hb_clk {
  38         struct clk_hw   hw;
  39         void __iomem    *reg;
  40 };
  41 #define to_hb_clk(p) container_of(p, struct hb_clk, hw)
  42
  43 static int clk_pll_prepare(struct clk_hw *hwclk)
  44         {
  45         struct hb_clk *hbclk = to_hb_clk(hwclk);
  46         u32 reg;
  47
  48         reg = readl(hbclk->reg);
  49         reg &= ~HB_PLL_RESET;
  50         writel(reg, hbclk->reg);
  51
  52         while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
  53                 ;
  54         while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
  55                 ;
  56
  57         return 0;
  58 }
  59
  60 static void clk_pll_unprepare(struct clk_hw *hwclk)
  61 {
  62         struct hb_clk *hbclk = to_hb_clk(hwclk);
  63         u32 reg;
  64
  65         reg = readl(hbclk->reg);
  66         reg |= HB_PLL_RESET;
  67         writel(reg, hbclk->reg);
  68 }
  69
  70 static int clk_pll_enable(struct clk_hw *hwclk)
  71 {
  72         struct hb_clk *hbclk = to_hb_clk(hwclk);
  73         u32 reg;
  74
  75         reg = readl(hbclk->reg);
  76         reg |= HB_PLL_EXT_ENA;
  77         writel(reg, hbclk->reg);
  78
  79         return 0;
  80 }
  81
  82 static void clk_pll_disable(struct clk_hw *hwclk)
  83 {
  84         struct hb_clk *hbclk = to_hb_clk(hwclk);
  85         u32 reg;
  86
  87         reg = readl(hbclk->reg);
  88         reg &= ~HB_PLL_EXT_ENA;
  89         writel(reg, hbclk->reg);
  90 }
  91
  92 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
  93                                          unsigned long parent_rate)
  94 {
  95         struct hb_clk *hbclk = to_hb_clk(hwclk);
  96         unsigned long divf, divq, vco_freq, reg;
  97
  98         reg = readl(hbclk->reg);
  99         if (reg & HB_PLL_EXT_BYPASS)
 100                 return parent_rate;
 101
 102         divf = (reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT;
 103         divq = (reg & HB_PLL_DIVQ_MASK) >> HB_PLL_DIVQ_SHIFT;
 104         vco_freq = parent_rate * (divf + 1);
 105
 106         return vco_freq / (1 << divq);
 107 }
 108
 109 static void clk_pll_calc(unsigned long rate, unsigned long ref_freq,
 110                         u32 *pdivq, u32 *pdivf)
 111 {
 112         u32 divq, divf;
 113         unsigned long vco_freq;
 114
 115         if (rate < HB_PLL_MIN_FREQ)
 116                 rate = HB_PLL_MIN_FREQ;
 117         if (rate > HB_PLL_MAX_FREQ)
 118                 rate = HB_PLL_MAX_FREQ;
 119
 120         for (divq = 1; divq <= 6; divq++) {
 121                 if ((rate * (1 << divq)) >= HB_PLL_VCO_MIN_FREQ)
 122                         break;
 123         }
 124
 125         vco_freq = rate * (1 << divq);
 126         divf = (vco_freq + (ref_freq / 2)) / ref_freq;
 127         divf--;
 128
 129         *pdivq = divq;
 130         *pdivf = divf;
 131 }
 132
 133 static long clk_pll_round_rate(struct clk_hw *hwclk, unsigned long rate,
 134                                unsigned long *parent_rate)
 135 {
 136         u32 divq, divf;
 137         unsigned long ref_freq = *parent_rate;
 138
 139         clk_pll_calc(rate, ref_freq, &divq, &divf);
 140
 141         return (ref_freq * (divf + 1)) / (1 << divq);
 142 }
 143
 144 static int clk_pll_set_rate(struct clk_hw *hwclk, unsigned long rate,
 145                             unsigned long parent_rate)
 146 {
 147         struct hb_clk *hbclk = to_hb_clk(hwclk);
 148         u32 divq, divf;
 149         u32 reg;
 150
 151         clk_pll_calc(rate, parent_rate, &divq, &divf);
 152
 153         reg = readl(hbclk->reg);
 154         if (divf != ((reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT)) {
 155                 /* Need to re-lock PLL, so put it into bypass mode */
 156                 reg |= HB_PLL_EXT_BYPASS;
 157                 writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
 158
 159                 writel(reg | HB_PLL_RESET, hbclk->reg);
 160                 reg &= ~(HB_PLL_DIVF_MASK | HB_PLL_DIVQ_MASK);
 161                 reg |= (divf << HB_PLL_DIVF_SHIFT) | (divq << HB_PLL_DIVQ_SHIFT);
 162                 writel(reg | HB_PLL_RESET, hbclk->reg);
 163                 writel(reg, hbclk->reg);
 164
 165                 while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
 166                         ;
 167                 while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
 168                         ;
 169                 reg |= HB_PLL_EXT_ENA;
 170                 reg &= ~HB_PLL_EXT_BYPASS;
 171         } else {
 172                 writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
 173                 reg &= ~HB_PLL_DIVQ_MASK;
 174                 reg |= divq << HB_PLL_DIVQ_SHIFT;
 175                 writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
 176         }
 177         writel(reg, hbclk->reg);
 178
 179         return 0;
 180 }
 181
 182 static const struct clk_ops clk_pll_ops = {
 183         .prepare = clk_pll_prepare,
 184         .unprepare = clk_pll_unprepare,
 185         .enable = clk_pll_enable,
 186         .disable = clk_pll_disable,
 187         .recalc_rate = clk_pll_recalc_rate,
 188         .round_rate = clk_pll_round_rate,
 189         .set_rate = clk_pll_set_rate,
 190 };
 191
 192 static unsigned long clk_cpu_periphclk_recalc_rate(struct clk_hw *hwclk,
 193                                                    unsigned long parent_rate)
 194 {
 195         struct hb_clk *hbclk = to_hb_clk(hwclk);
 196         u32 div = (readl(hbclk->reg) & HB_A9_PCLK_DIV) ? 8 : 4;
 197         return parent_rate / div;
 198 }
 199
 200 static const struct clk_ops a9periphclk_ops = {
 201         .recalc_rate = clk_cpu_periphclk_recalc_rate,
 202 };
 203
 204 static unsigned long clk_cpu_a9bclk_recalc_rate(struct clk_hw *hwclk,
 205                                                 unsigned long parent_rate)
 206 {
 207         struct hb_clk *hbclk = to_hb_clk(hwclk);
 208         u32 div = (readl(hbclk->reg) & HB_A9_BCLK_DIV_MASK) >> HB_A9_BCLK_DIV_SHIFT;
 209
 210         return parent_rate / (div + 2);
 211 }
 212
 213 static const struct clk_ops a9bclk_ops = {
 214         .recalc_rate = clk_cpu_a9bclk_recalc_rate,
 215 };
 216
 217 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
 218                                              unsigned long parent_rate)
 219 {
 220         struct hb_clk *hbclk = to_hb_clk(hwclk);
 221         u32 div;
 222
 223         div = readl(hbclk->reg) & 0x1f;
 224         div++;
 225         div *= 2;
 226
 227         return parent_rate / div;
 228 }
 229
 230 static long clk_periclk_round_rate(struct clk_hw *hwclk, unsigned long rate,
 231                                    unsigned long *parent_rate)
 232 {
 233         u32 div;
 234
 235         div = *parent_rate / rate;
 236         div++;
 237         div &= ~0x1;
 238
 239         return *parent_rate / div;
 240 }
 241
 242 static int clk_periclk_set_rate(struct clk_hw *hwclk, unsigned long rate,
 243                                 unsigned long parent_rate)
 244 {
 245         struct hb_clk *hbclk = to_hb_clk(hwclk);
 246         u32 div;
 247
 248         div = parent_rate / rate;
 249         if (div & 0x1)
 250                 return -EINVAL;
 251
 252         writel(div >> 1, hbclk->reg);
 253         return 0;
 254 }
 255
 256 static const struct clk_ops periclk_ops = {
 257         .recalc_rate = clk_periclk_recalc_rate,
 258         .round_rate = clk_periclk_round_rate,
 259         .set_rate = clk_periclk_set_rate,
 260 };
 261
 262 static void __init hb_clk_init(struct device_node *node, const struct clk_ops *ops, unsigned long clkflags)
 263 {
 264         u32 reg;
 265         struct hb_clk *hb_clk;
 266         const char *clk_name = node->name;
 267         const char *parent_name;
 268         struct clk_init_data init;
 269         struct device_node *srnp;
 270         int rc;
 271
 272         rc = of_property_read_u32(node, "reg", &reg);
 273         if (WARN_ON(rc))
 274                 return;
 275
 276         hb_clk = kzalloc(sizeof(*hb_clk), GFP_KERNEL);
 277         if (WARN_ON(!hb_clk))
 278                 return;
 279
 280         /* Map system registers */
 281         srnp = of_find_compatible_node(NULL, NULL, "calxeda,hb-sregs");
 282         hb_clk->reg = of_iomap(srnp, 0);
 283         of_node_put(srnp);
 284         BUG_ON(!hb_clk->reg);
 285         hb_clk->reg += reg;
 286
 287         of_property_read_string(node, "clock-output-names", &clk_name);
 288
 289         init.name = clk_name;
 290         init.ops = ops;
 291         init.flags = clkflags;
 292         parent_name = of_clk_get_parent_name(node, 0);
 293         init.parent_names = &parent_name;
 294         init.num_parents = 1;
 295
 296         hb_clk->hw.init = &init;
 297
 298         rc = clk_hw_register(NULL, &hb_clk->hw);
 299         if (WARN_ON(rc)) {
 300                 kfree(hb_clk);
 301                 return;
 302         }
 303         of_clk_add_hw_provider(node, of_clk_hw_simple_get, &hb_clk->hw);
 304 }
 305
 306 static void __init hb_pll_init(struct device_node *node)
 307 {
 308         hb_clk_init(node, &clk_pll_ops, 0);
 309 }
 310 CLK_OF_DECLARE(hb_pll, "calxeda,hb-pll-clock", hb_pll_init);
 311
 312 static void __init hb_a9periph_init(struct device_node *node)
 313 {
 314         hb_clk_init(node, &a9periphclk_ops, 0);
 315 }
 316 CLK_OF_DECLARE(hb_a9periph, "calxeda,hb-a9periph-clock", hb_a9periph_init);
 317
 318 static void __init hb_a9bus_init(struct device_node *node)
 319 {
 320         hb_clk_init(node, &a9bclk_ops, CLK_IS_CRITICAL);
 321 }
 322 CLK_OF_DECLARE(hb_a9bus, "calxeda,hb-a9bus-clock", hb_a9bus_init);
 323
 324 static void __init hb_emmc_init(struct device_node *node)
 325 {
 326         hb_clk_init(node, &periclk_ops, 0);
 327 }
 328 CLK_OF_DECLARE(hb_emmc, "calxeda,hb-emmc-clock", hb_emmc_init);