drivers/clk/mvebu/clk-corediv.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MVEBU Core divider clock
   4  *
   5  * Copyright (C) 2013 Marvell
   6  *
   7  * Ezequiel Garcia <[email protected]>
   8  *
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/clk-provider.h>
  13 #include <linux/io.h>
  14 #include <linux/of_address.h>
  15 #include <linux/slab.h>
  16 #include <linux/delay.h>
  17 #include "common.h"
  18
  19 #define CORE_CLK_DIV_RATIO_MASK         0xff
  20
  21 /*
  22  * This structure describes the hardware details (bit offset and mask)
  23  * to configure one particular core divider clock. Those hardware
  24  * details may differ from one SoC to another. This structure is
  25  * therefore typically instantiated statically to describe the
  26  * hardware details.
  27  */
  28 struct clk_corediv_desc {
  29         unsigned int mask;
  30         unsigned int offset;
  31         unsigned int fieldbit;
  32 };
  33
  34 /*
  35  * This structure describes the hardware details to configure the core
  36  * divider clocks on a given SoC. Amongst others, it points to the
  37  * array of core divider clock descriptors for this SoC, as well as
  38  * the corresponding operations to manipulate them.
  39  */
  40 struct clk_corediv_soc_desc {
  41         const struct clk_corediv_desc *descs;
  42         unsigned int ndescs;
  43         const struct clk_ops ops;
  44         u32 ratio_reload;
  45         u32 enable_bit_offset;
  46         u32 ratio_offset;
  47 };
  48
  49 /*
  50  * This structure represents one core divider clock for the clock
  51  * framework, and is dynamically allocated for each core divider clock
  52  * existing in the current SoC.
  53  */
  54 struct clk_corediv {
  55         struct clk_hw hw;
  56         void __iomem *reg;
  57         const struct clk_corediv_desc *desc;
  58         const struct clk_corediv_soc_desc *soc_desc;
  59         spinlock_t lock;
  60 };
  61
  62 static struct clk_onecell_data clk_data;
  63
  64 /*
  65  * Description of the core divider clocks available. For now, we
  66  * support only NAND, and it is available at the same register
  67  * locations regardless of the SoC.
  68  */
  69 static const struct clk_corediv_desc mvebu_corediv_desc[] = {
  70         { .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */
  71 };
  72
  73 static const struct clk_corediv_desc mv98dx3236_corediv_desc[] = {
  74         { .mask = 0x0f, .offset = 6, .fieldbit = 27 }, /* NAND clock */
  75 };
  76
  77 #define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)
  78
  79 static int clk_corediv_is_enabled(struct clk_hw *hwclk)
  80 {
  81         struct clk_corediv *corediv = to_corediv_clk(hwclk);
  82         const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
  83         const struct clk_corediv_desc *desc = corediv->desc;
  84         u32 enable_mask = BIT(desc->fieldbit) << soc_desc->enable_bit_offset;
  85
  86         return !!(readl(corediv->reg) & enable_mask);
  87 }
  88
  89 static int clk_corediv_enable(struct clk_hw *hwclk)
  90 {
  91         struct clk_corediv *corediv = to_corediv_clk(hwclk);
  92         const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
  93         const struct clk_corediv_desc *desc = corediv->desc;
  94         unsigned long flags = 0;
  95         u32 reg;
  96
  97         spin_lock_irqsave(&corediv->lock, flags);
  98
  99         reg = readl(corediv->reg);
 100         reg |= (BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
 101         writel(reg, corediv->reg);
 102
 103         spin_unlock_irqrestore(&corediv->lock, flags);
 104
 105         return 0;
 106 }
 107
 108 static void clk_corediv_disable(struct clk_hw *hwclk)
 109 {
 110         struct clk_corediv *corediv = to_corediv_clk(hwclk);
 111         const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 112         const struct clk_corediv_desc *desc = corediv->desc;
 113         unsigned long flags = 0;
 114         u32 reg;
 115
 116         spin_lock_irqsave(&corediv->lock, flags);
 117
 118         reg = readl(corediv->reg);
 119         reg &= ~(BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
 120         writel(reg, corediv->reg);
 121
 122         spin_unlock_irqrestore(&corediv->lock, flags);
 123 }
 124
 125 static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk,
 126                                          unsigned long parent_rate)
 127 {
 128         struct clk_corediv *corediv = to_corediv_clk(hwclk);
 129         const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 130         const struct clk_corediv_desc *desc = corediv->desc;
 131         u32 reg, div;
 132
 133         reg = readl(corediv->reg + soc_desc->ratio_offset);
 134         div = (reg >> desc->offset) & desc->mask;
 135         return parent_rate / div;
 136 }
 137
 138 static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate,
 139                                unsigned long *parent_rate)
 140 {
 141         /* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
 142         u32 div;
 143
 144         div = *parent_rate / rate;
 145         if (div < 4)
 146                 div = 4;
 147         else if (div > 6)
 148                 div = 8;
 149
 150         return *parent_rate / div;
 151 }
 152
 153 static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
 154                             unsigned long parent_rate)
 155 {
 156         struct clk_corediv *corediv = to_corediv_clk(hwclk);
 157         const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 158         const struct clk_corediv_desc *desc = corediv->desc;
 159         unsigned long flags = 0;
 160         u32 reg, div;
 161
 162         div = parent_rate / rate;
 163
 164         spin_lock_irqsave(&corediv->lock, flags);
 165
 166         /* Write new divider to the divider ratio register */
 167         reg = readl(corediv->reg + soc_desc->ratio_offset);
 168         reg &= ~(desc->mask << desc->offset);
 169         reg |= (div & desc->mask) << desc->offset;
 170         writel(reg, corediv->reg + soc_desc->ratio_offset);
 171
 172         /* Set reload-force for this clock */
 173         reg = readl(corediv->reg) | BIT(desc->fieldbit);
 174         writel(reg, corediv->reg);
 175
 176         /* Now trigger the clock update */
 177         reg = readl(corediv->reg) | soc_desc->ratio_reload;
 178         writel(reg, corediv->reg);
 179
 180         /*
 181          * Wait for clocks to settle down, and then clear all the
 182          * ratios request and the reload request.
 183          */
 184         udelay(1000);
 185         reg &= ~(CORE_CLK_DIV_RATIO_MASK | soc_desc->ratio_reload);
 186         writel(reg, corediv->reg);
 187         udelay(1000);
 188
 189         spin_unlock_irqrestore(&corediv->lock, flags);
 190
 191         return 0;
 192 }
 193
 194 static const struct clk_corediv_soc_desc armada370_corediv_soc = {
 195         .descs = mvebu_corediv_desc,
 196         .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 197         .ops = {
 198                 .enable = clk_corediv_enable,
 199                 .disable = clk_corediv_disable,
 200                 .is_enabled = clk_corediv_is_enabled,
 201                 .recalc_rate = clk_corediv_recalc_rate,
 202                 .round_rate = clk_corediv_round_rate,
 203                 .set_rate = clk_corediv_set_rate,
 204         },
 205         .ratio_reload = BIT(8),
 206         .enable_bit_offset = 24,
 207         .ratio_offset = 0x8,
 208 };
 209
 210 static const struct clk_corediv_soc_desc armada380_corediv_soc = {
 211         .descs = mvebu_corediv_desc,
 212         .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 213         .ops = {
 214                 .enable = clk_corediv_enable,
 215                 .disable = clk_corediv_disable,
 216                 .is_enabled = clk_corediv_is_enabled,
 217                 .recalc_rate = clk_corediv_recalc_rate,
 218                 .round_rate = clk_corediv_round_rate,
 219                 .set_rate = clk_corediv_set_rate,
 220         },
 221         .ratio_reload = BIT(8),
 222         .enable_bit_offset = 16,
 223         .ratio_offset = 0x4,
 224 };
 225
 226 static const struct clk_corediv_soc_desc armada375_corediv_soc = {
 227         .descs = mvebu_corediv_desc,
 228         .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 229         .ops = {
 230                 .recalc_rate = clk_corediv_recalc_rate,
 231                 .round_rate = clk_corediv_round_rate,
 232                 .set_rate = clk_corediv_set_rate,
 233         },
 234         .ratio_reload = BIT(8),
 235         .ratio_offset = 0x4,
 236 };
 237
 238 static const struct clk_corediv_soc_desc mv98dx3236_corediv_soc = {
 239         .descs = mv98dx3236_corediv_desc,
 240         .ndescs = ARRAY_SIZE(mv98dx3236_corediv_desc),
 241         .ops = {
 242                 .recalc_rate = clk_corediv_recalc_rate,
 243                 .round_rate = clk_corediv_round_rate,
 244                 .set_rate = clk_corediv_set_rate,
 245         },
 246         .ratio_reload = BIT(10),
 247         .ratio_offset = 0x8,
 248 };
 249
 250 static void __init
 251 mvebu_corediv_clk_init(struct device_node *node,
 252                        const struct clk_corediv_soc_desc *soc_desc)
 253 {
 254         struct clk_init_data init;
 255         struct clk_corediv *corediv;
 256         struct clk **clks;
 257         void __iomem *base;
 258         const char *parent_name;
 259         const char *clk_name;
 260         int i;
 261
 262         base = of_iomap(node, 0);
 263         if (WARN_ON(!base))
 264                 return;
 265
 266         parent_name = of_clk_get_parent_name(node, 0);
 267
 268         clk_data.clk_num = soc_desc->ndescs;
 269
 270         /* clks holds the clock array */
 271         clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
 272                                 GFP_KERNEL);
 273         if (WARN_ON(!clks))
 274                 goto err_unmap;
 275         /* corediv holds the clock specific array */
 276         corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
 277                                 GFP_KERNEL);
 278         if (WARN_ON(!corediv))
 279                 goto err_free_clks;
 280
 281         spin_lock_init(&corediv->lock);
 282
 283         for (i = 0; i < clk_data.clk_num; i++) {
 284                 of_property_read_string_index(node, "clock-output-names",
 285                                               i, &clk_name);
 286                 init.num_parents = 1;
 287                 init.parent_names = &parent_name;
 288                 init.name = clk_name;
 289                 init.ops = &soc_desc->ops;
 290                 init.flags = 0;
 291
 292                 corediv[i].soc_desc = soc_desc;
 293                 corediv[i].desc = soc_desc->descs + i;
 294                 corediv[i].reg = base;
 295                 corediv[i].hw.init = &init;
 296
 297                 clks[i] = clk_register(NULL, &corediv[i].hw);
 298                 WARN_ON(IS_ERR(clks[i]));
 299         }
 300
 301         clk_data.clks = clks;
 302         of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
 303         return;
 304
 305 err_free_clks:
 306         kfree(clks);
 307 err_unmap:
 308         iounmap(base);
 309 }
 310
 311 static void __init armada370_corediv_clk_init(struct device_node *node)
 312 {
 313         return mvebu_corediv_clk_init(node, &armada370_corediv_soc);
 314 }
 315 CLK_OF_DECLARE(armada370_corediv_clk, "marvell,armada-370-corediv-clock",
 316                armada370_corediv_clk_init);
 317
 318 static void __init armada375_corediv_clk_init(struct device_node *node)
 319 {
 320         return mvebu_corediv_clk_init(node, &armada375_corediv_soc);
 321 }
 322 CLK_OF_DECLARE(armada375_corediv_clk, "marvell,armada-375-corediv-clock",
 323                armada375_corediv_clk_init);
 324
 325 static void __init armada380_corediv_clk_init(struct device_node *node)
 326 {
 327         return mvebu_corediv_clk_init(node, &armada380_corediv_soc);
 328 }
 329 CLK_OF_DECLARE(armada380_corediv_clk, "marvell,armada-380-corediv-clock",
 330                armada380_corediv_clk_init);
 331
 332 static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
 333 {
 334         return mvebu_corediv_clk_init(node, &mv98dx3236_corediv_soc);
 335 }
 336 CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
 337                mv98dx3236_corediv_clk_init);