linux/drivers/clk/axs10x/pll_clock.c
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   1/*
   2 * Synopsys AXS10X SDP Generic PLL clock driver
   3 *
   4 * Copyright (C) 2017 Synopsys
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2. This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#include <linux/platform_device.h>
  12#include <linux/module.h>
  13#include <linux/clk-provider.h>
  14#include <linux/delay.h>
  15#include <linux/err.h>
  16#include <linux/device.h>
  17#include <linux/io.h>
  18#include <linux/of_address.h>
  19#include <linux/of_device.h>
  20#include <linux/slab.h>
  21#include <linux/of.h>
  22
  23/* PLL registers addresses */
  24#define PLL_REG_IDIV    0x0
  25#define PLL_REG_FBDIV   0x4
  26#define PLL_REG_ODIV    0x8
  27
  28/*
  29 * Bit fields of the PLL IDIV/FBDIV/ODIV registers:
  30 *  ________________________________________________________________________
  31 * |31                15|    14    |   13   |  12  |11         6|5         0|
  32 * |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|--LOWTIME--|
  33 * |____________________|__________|________|______|____________|___________|
  34 *
  35 * Following macros determine the way of access to these registers
  36 * They should be set up only using the macros.
  37 * reg should be an u32 variable.
  38 */
  39
  40#define PLL_REG_GET_LOW(reg)                    \
  41        (((reg) & (0x3F << 0)) >> 0)
  42#define PLL_REG_GET_HIGH(reg)                   \
  43        (((reg) & (0x3F << 6)) >> 6)
  44#define PLL_REG_GET_EDGE(reg)                   \
  45        (((reg) & (BIT(12))) ? 1 : 0)
  46#define PLL_REG_GET_BYPASS(reg)                 \
  47        (((reg) & (BIT(13))) ? 1 : 0)
  48#define PLL_REG_GET_NOUPD(reg)                  \
  49        (((reg) & (BIT(14))) ? 1 : 0)
  50#define PLL_REG_GET_PAD(reg)                    \
  51        (((reg) & (0x1FFFF << 15)) >> 15)
  52
  53#define PLL_REG_SET_LOW(reg, value)             \
  54        { reg |= (((value) & 0x3F) << 0); }
  55#define PLL_REG_SET_HIGH(reg, value)            \
  56        { reg |= (((value) & 0x3F) << 6); }
  57#define PLL_REG_SET_EDGE(reg, value)            \
  58        { reg |= (((value) & 0x01) << 12); }
  59#define PLL_REG_SET_BYPASS(reg, value)          \
  60        { reg |= (((value) & 0x01) << 13); }
  61#define PLL_REG_SET_NOUPD(reg, value)           \
  62        { reg |= (((value) & 0x01) << 14); }
  63#define PLL_REG_SET_PAD(reg, value)             \
  64        { reg |= (((value) & 0x1FFFF) << 15); }
  65
  66#define PLL_LOCK        BIT(0)
  67#define PLL_ERROR       BIT(1)
  68#define PLL_MAX_LOCK_TIME 100 /* 100 us */
  69
  70struct axs10x_pll_cfg {
  71        u32 rate;
  72        u32 idiv;
  73        u32 fbdiv;
  74        u32 odiv;
  75};
  76
  77static const struct axs10x_pll_cfg arc_pll_cfg[] = {
  78        { 33333333,  1, 1,  1 },
  79        { 50000000,  1, 30, 20 },
  80        { 75000000,  2, 45, 10 },
  81        { 90000000,  2, 54, 10 },
  82        { 100000000, 1, 30, 10 },
  83        { 125000000, 2, 45, 6 },
  84        {}
  85};
  86
  87static const struct axs10x_pll_cfg pgu_pll_cfg[] = {
  88        { 25200000, 1, 84, 90 },
  89        { 50000000, 1, 100, 54 },
  90        { 74250000, 1, 44, 16 },
  91        {}
  92};
  93
  94struct axs10x_pll_clk {
  95        struct clk_hw hw;
  96        void __iomem *base;
  97        void __iomem *lock;
  98        const struct axs10x_pll_cfg *pll_cfg;
  99        struct device *dev;
 100};
 101
 102static inline void axs10x_pll_write(struct axs10x_pll_clk *clk, u32 reg,
 103                                    u32 val)
 104{
 105        iowrite32(val, clk->base + reg);
 106}
 107
 108static inline u32 axs10x_pll_read(struct axs10x_pll_clk *clk, u32 reg)
 109{
 110        return ioread32(clk->base + reg);
 111}
 112
 113static inline struct axs10x_pll_clk *to_axs10x_pll_clk(struct clk_hw *hw)
 114{
 115        return container_of(hw, struct axs10x_pll_clk, hw);
 116}
 117
 118static inline u32 axs10x_div_get_value(u32 reg)
 119{
 120        if (PLL_REG_GET_BYPASS(reg))
 121                return 1;
 122
 123        return PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg);
 124}
 125
 126static inline u32 axs10x_encode_div(unsigned int id, int upd)
 127{
 128        u32 div = 0;
 129
 130        PLL_REG_SET_LOW(div, (id % 2 == 0) ? id >> 1 : (id >> 1) + 1);
 131        PLL_REG_SET_HIGH(div, id >> 1);
 132        PLL_REG_SET_EDGE(div, id % 2);
 133        PLL_REG_SET_BYPASS(div, id == 1 ? 1 : 0);
 134        PLL_REG_SET_NOUPD(div, upd == 0 ? 1 : 0);
 135
 136        return div;
 137}
 138
 139static unsigned long axs10x_pll_recalc_rate(struct clk_hw *hw,
 140                                            unsigned long parent_rate)
 141{
 142        u64 rate;
 143        u32 idiv, fbdiv, odiv;
 144        struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 145
 146        idiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_IDIV));
 147        fbdiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_FBDIV));
 148        odiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_ODIV));
 149
 150        rate = (u64)parent_rate * fbdiv;
 151        do_div(rate, idiv * odiv);
 152
 153        return rate;
 154}
 155
 156static long axs10x_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 157                                  unsigned long *prate)
 158{
 159        int i;
 160        long best_rate;
 161        struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 162        const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
 163
 164        if (pll_cfg[0].rate == 0)
 165                return -EINVAL;
 166
 167        best_rate = pll_cfg[0].rate;
 168
 169        for (i = 1; pll_cfg[i].rate != 0; i++) {
 170                if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
 171                        best_rate = pll_cfg[i].rate;
 172        }
 173
 174        return best_rate;
 175}
 176
 177static int axs10x_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 178                               unsigned long parent_rate)
 179{
 180        int i;
 181        struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 182        const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
 183
 184        for (i = 0; pll_cfg[i].rate != 0; i++) {
 185                if (pll_cfg[i].rate == rate) {
 186                        axs10x_pll_write(clk, PLL_REG_IDIV,
 187                                         axs10x_encode_div(pll_cfg[i].idiv, 0));
 188                        axs10x_pll_write(clk, PLL_REG_FBDIV,
 189                                         axs10x_encode_div(pll_cfg[i].fbdiv, 0));
 190                        axs10x_pll_write(clk, PLL_REG_ODIV,
 191                                         axs10x_encode_div(pll_cfg[i].odiv, 1));
 192
 193                        /*
 194                         * Wait until CGU relocks and check error status.
 195                         * If after timeout CGU is unlocked yet return error
 196                         */
 197                        udelay(PLL_MAX_LOCK_TIME);
 198                        if (!(ioread32(clk->lock) & PLL_LOCK))
 199                                return -ETIMEDOUT;
 200
 201                        if (ioread32(clk->lock) & PLL_ERROR)
 202                                return -EINVAL;
 203
 204                        return 0;
 205                }
 206        }
 207
 208        dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
 209                        parent_rate);
 210        return -EINVAL;
 211}
 212
 213static const struct clk_ops axs10x_pll_ops = {
 214        .recalc_rate = axs10x_pll_recalc_rate,
 215        .round_rate = axs10x_pll_round_rate,
 216        .set_rate = axs10x_pll_set_rate,
 217};
 218
 219static int axs10x_pll_clk_probe(struct platform_device *pdev)
 220{
 221        struct device *dev = &pdev->dev;
 222        const char *parent_name;
 223        struct axs10x_pll_clk *pll_clk;
 224        struct clk_init_data init = { };
 225        int ret;
 226
 227        pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
 228        if (!pll_clk)
 229                return -ENOMEM;
 230
 231        pll_clk->base = devm_platform_ioremap_resource(pdev, 0);
 232        if (IS_ERR(pll_clk->base))
 233                return PTR_ERR(pll_clk->base);
 234
 235        pll_clk->lock = devm_platform_ioremap_resource(pdev, 1);
 236        if (IS_ERR(pll_clk->lock))
 237                return PTR_ERR(pll_clk->lock);
 238
 239        init.name = dev->of_node->name;
 240        init.ops = &axs10x_pll_ops;
 241        parent_name = of_clk_get_parent_name(dev->of_node, 0);
 242        init.parent_names = &parent_name;
 243        init.num_parents = 1;
 244        pll_clk->hw.init = &init;
 245        pll_clk->dev = dev;
 246        pll_clk->pll_cfg = of_device_get_match_data(dev);
 247
 248        if (!pll_clk->pll_cfg) {
 249                dev_err(dev, "No OF match data provided\n");
 250                return -EINVAL;
 251        }
 252
 253        ret = devm_clk_hw_register(dev, &pll_clk->hw);
 254        if (ret) {
 255                dev_err(dev, "failed to register %s clock\n", init.name);
 256                return ret;
 257        }
 258
 259        return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
 260                        &pll_clk->hw);
 261}
 262
 263static int axs10x_pll_clk_remove(struct platform_device *pdev)
 264{
 265        of_clk_del_provider(pdev->dev.of_node);
 266        return 0;
 267}
 268
 269static void __init of_axs10x_pll_clk_setup(struct device_node *node)
 270{
 271        const char *parent_name;
 272        struct axs10x_pll_clk *pll_clk;
 273        struct clk_init_data init = { };
 274        int ret;
 275
 276        pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
 277        if (!pll_clk)
 278                return;
 279
 280        pll_clk->base = of_iomap(node, 0);
 281        if (!pll_clk->base) {
 282                pr_err("failed to map pll div registers\n");
 283                goto err_free_pll_clk;
 284        }
 285
 286        pll_clk->lock = of_iomap(node, 1);
 287        if (!pll_clk->lock) {
 288                pr_err("failed to map pll lock register\n");
 289                goto err_unmap_base;
 290        }
 291
 292        init.name = node->name;
 293        init.ops = &axs10x_pll_ops;
 294        parent_name = of_clk_get_parent_name(node, 0);
 295        init.parent_names = &parent_name;
 296        init.num_parents = parent_name ? 1 : 0;
 297        pll_clk->hw.init = &init;
 298        pll_clk->pll_cfg = arc_pll_cfg;
 299
 300        ret = clk_hw_register(NULL, &pll_clk->hw);
 301        if (ret) {
 302                pr_err("failed to register %pOFn clock\n", node);
 303                goto err_unmap_lock;
 304        }
 305
 306        ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
 307        if (ret) {
 308                pr_err("failed to add hw provider for %pOFn clock\n", node);
 309                goto err_unregister_clk;
 310        }
 311
 312        return;
 313
 314err_unregister_clk:
 315        clk_hw_unregister(&pll_clk->hw);
 316err_unmap_lock:
 317        iounmap(pll_clk->lock);
 318err_unmap_base:
 319        iounmap(pll_clk->base);
 320err_free_pll_clk:
 321        kfree(pll_clk);
 322}
 323CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock",
 324               of_axs10x_pll_clk_setup);
 325
 326static const struct of_device_id axs10x_pll_clk_id[] = {
 327        { .compatible = "snps,axs10x-pgu-pll-clock", .data = &pgu_pll_cfg},
 328        { }
 329};
 330MODULE_DEVICE_TABLE(of, axs10x_pll_clk_id);
 331
 332static struct platform_driver axs10x_pll_clk_driver = {
 333        .driver = {
 334                .name = "axs10x-pll-clock",
 335                .of_match_table = axs10x_pll_clk_id,
 336        },
 337        .probe = axs10x_pll_clk_probe,
 338        .remove = axs10x_pll_clk_remove,
 339};
 340builtin_platform_driver(axs10x_pll_clk_driver);
 341
 342MODULE_AUTHOR("Vlad Zakharov <vzakhar@synopsys.com>");
 343MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
 344MODULE_LICENSE("GPL v2");
 345