drivers/clk/axs10x/pll_clock.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Synopsys AXS10X SDP Generic PLL clock driver
   4  *
   5  * Copyright (C) 2017 Synopsys
   6  */
   7
   8 #include <linux/platform_device.h>
   9 #include <linux/module.h>
  10 #include <linux/clk-provider.h>
  11 #include <linux/delay.h>
  12 #include <linux/err.h>
  13 #include <linux/device.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/slab.h>
  18
  19 /* PLL registers addresses */
  20 #define PLL_REG_IDIV    0x0
  21 #define PLL_REG_FBDIV   0x4
  22 #define PLL_REG_ODIV    0x8
  23
  24 /*
  25  * Bit fields of the PLL IDIV/FBDIV/ODIV registers:
  26  *  ________________________________________________________________________
  27  * |31                15|    14    |   13   |  12  |11         6|5         0|
  28  * |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|--LOWTIME--|
  29  * |____________________|__________|________|______|____________|___________|
  30  *
  31  * Following macros determine the way of access to these registers
  32  * They should be set up only using the macros.
  33  * reg should be an u32 variable.
  34  */
  35
  36 #define PLL_REG_GET_LOW(reg)                    \
  37         (((reg) & (0x3F << 0)) >> 0)
  38 #define PLL_REG_GET_HIGH(reg)                   \
  39         (((reg) & (0x3F << 6)) >> 6)
  40 #define PLL_REG_GET_EDGE(reg)                   \
  41         (((reg) & (BIT(12))) ? 1 : 0)
  42 #define PLL_REG_GET_BYPASS(reg)                 \
  43         (((reg) & (BIT(13))) ? 1 : 0)
  44 #define PLL_REG_GET_NOUPD(reg)                  \
  45         (((reg) & (BIT(14))) ? 1 : 0)
  46 #define PLL_REG_GET_PAD(reg)                    \
  47         (((reg) & (0x1FFFF << 15)) >> 15)
  48
  49 #define PLL_REG_SET_LOW(reg, value)             \
  50         { reg |= (((value) & 0x3F) << 0); }
  51 #define PLL_REG_SET_HIGH(reg, value)            \
  52         { reg |= (((value) & 0x3F) << 6); }
  53 #define PLL_REG_SET_EDGE(reg, value)            \
  54         { reg |= (((value) & 0x01) << 12); }
  55 #define PLL_REG_SET_BYPASS(reg, value)          \
  56         { reg |= (((value) & 0x01) << 13); }
  57 #define PLL_REG_SET_NOUPD(reg, value)           \
  58         { reg |= (((value) & 0x01) << 14); }
  59 #define PLL_REG_SET_PAD(reg, value)             \
  60         { reg |= (((value) & 0x1FFFF) << 15); }
  61
  62 #define PLL_LOCK        BIT(0)
  63 #define PLL_ERROR       BIT(1)
  64 #define PLL_MAX_LOCK_TIME 100 /* 100 us */
  65
  66 struct axs10x_pll_cfg {
  67         u32 rate;
  68         u32 idiv;
  69         u32 fbdiv;
  70         u32 odiv;
  71 };
  72
  73 static const struct axs10x_pll_cfg arc_pll_cfg[] = {
  74         { 33333333,  1, 1,  1 },
  75         { 50000000,  1, 30, 20 },
  76         { 75000000,  2, 45, 10 },
  77         { 90000000,  2, 54, 10 },
  78         { 100000000, 1, 30, 10 },
  79         { 125000000, 2, 45, 6 },
  80         {}
  81 };
  82
  83 static const struct axs10x_pll_cfg pgu_pll_cfg[] = {
  84         { 25200000, 1, 84, 90 },
  85         { 50000000, 1, 100, 54 },
  86         { 74250000, 1, 44, 16 },
  87         {}
  88 };
  89
  90 struct axs10x_pll_clk {
  91         struct clk_hw hw;
  92         void __iomem *base;
  93         void __iomem *lock;
  94         const struct axs10x_pll_cfg *pll_cfg;
  95         struct device *dev;
  96 };
  97
  98 static inline void axs10x_pll_write(struct axs10x_pll_clk *clk, u32 reg,
  99                                     u32 val)
 100 {
 101         iowrite32(val, clk->base + reg);
 102 }
 103
 104 static inline u32 axs10x_pll_read(struct axs10x_pll_clk *clk, u32 reg)
 105 {
 106         return ioread32(clk->base + reg);
 107 }
 108
 109 static inline struct axs10x_pll_clk *to_axs10x_pll_clk(struct clk_hw *hw)
 110 {
 111         return container_of(hw, struct axs10x_pll_clk, hw);
 112 }
 113
 114 static inline u32 axs10x_div_get_value(u32 reg)
 115 {
 116         if (PLL_REG_GET_BYPASS(reg))
 117                 return 1;
 118
 119         return PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg);
 120 }
 121
 122 static inline u32 axs10x_encode_div(unsigned int id, int upd)
 123 {
 124         u32 div = 0;
 125
 126         PLL_REG_SET_LOW(div, (id % 2 == 0) ? id >> 1 : (id >> 1) + 1);
 127         PLL_REG_SET_HIGH(div, id >> 1);
 128         PLL_REG_SET_EDGE(div, id % 2);
 129         PLL_REG_SET_BYPASS(div, id == 1 ? 1 : 0);
 130         PLL_REG_SET_NOUPD(div, upd == 0 ? 1 : 0);
 131
 132         return div;
 133 }
 134
 135 static unsigned long axs10x_pll_recalc_rate(struct clk_hw *hw,
 136                                             unsigned long parent_rate)
 137 {
 138         u64 rate;
 139         u32 idiv, fbdiv, odiv;
 140         struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 141
 142         idiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_IDIV));
 143         fbdiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_FBDIV));
 144         odiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_ODIV));
 145
 146         rate = (u64)parent_rate * fbdiv;
 147         do_div(rate, idiv * odiv);
 148
 149         return rate;
 150 }
 151
 152 static long axs10x_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 153                                   unsigned long *prate)
 154 {
 155         int i;
 156         long best_rate;
 157         struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 158         const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
 159
 160         if (pll_cfg[0].rate == 0)
 161                 return -EINVAL;
 162
 163         best_rate = pll_cfg[0].rate;
 164
 165         for (i = 1; pll_cfg[i].rate != 0; i++) {
 166                 if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
 167                         best_rate = pll_cfg[i].rate;
 168         }
 169
 170         return best_rate;
 171 }
 172
 173 static int axs10x_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 174                                unsigned long parent_rate)
 175 {
 176         int i;
 177         struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
 178         const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
 179
 180         for (i = 0; pll_cfg[i].rate != 0; i++) {
 181                 if (pll_cfg[i].rate == rate) {
 182                         axs10x_pll_write(clk, PLL_REG_IDIV,
 183                                          axs10x_encode_div(pll_cfg[i].idiv, 0));
 184                         axs10x_pll_write(clk, PLL_REG_FBDIV,
 185                                          axs10x_encode_div(pll_cfg[i].fbdiv, 0));
 186                         axs10x_pll_write(clk, PLL_REG_ODIV,
 187                                          axs10x_encode_div(pll_cfg[i].odiv, 1));
 188
 189                         /*
 190                          * Wait until CGU relocks and check error status.
 191                          * If after timeout CGU is unlocked yet return error
 192                          */
 193                         udelay(PLL_MAX_LOCK_TIME);
 194                         if (!(ioread32(clk->lock) & PLL_LOCK))
 195                                 return -ETIMEDOUT;
 196
 197                         if (ioread32(clk->lock) & PLL_ERROR)
 198                                 return -EINVAL;
 199
 200                         return 0;
 201                 }
 202         }
 203
 204         dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
 205                         parent_rate);
 206         return -EINVAL;
 207 }
 208
 209 static const struct clk_ops axs10x_pll_ops = {
 210         .recalc_rate = axs10x_pll_recalc_rate,
 211         .round_rate = axs10x_pll_round_rate,
 212         .set_rate = axs10x_pll_set_rate,
 213 };
 214
 215 static int axs10x_pll_clk_probe(struct platform_device *pdev)
 216 {
 217         struct device *dev = &pdev->dev;
 218         const char *parent_name;
 219         struct axs10x_pll_clk *pll_clk;
 220         struct clk_init_data init = { };
 221         int ret;
 222
 223         pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
 224         if (!pll_clk)
 225                 return -ENOMEM;
 226
 227         pll_clk->base = devm_platform_ioremap_resource(pdev, 0);
 228         if (IS_ERR(pll_clk->base))
 229                 return PTR_ERR(pll_clk->base);
 230
 231         pll_clk->lock = devm_platform_ioremap_resource(pdev, 1);
 232         if (IS_ERR(pll_clk->lock))
 233                 return PTR_ERR(pll_clk->lock);
 234
 235         init.name = dev->of_node->name;
 236         init.ops = &axs10x_pll_ops;
 237         parent_name = of_clk_get_parent_name(dev->of_node, 0);
 238         init.parent_names = &parent_name;
 239         init.num_parents = 1;
 240         pll_clk->hw.init = &init;
 241         pll_clk->dev = dev;
 242         pll_clk->pll_cfg = of_device_get_match_data(dev);
 243
 244         if (!pll_clk->pll_cfg) {
 245                 dev_err(dev, "No OF match data provided\n");
 246                 return -EINVAL;
 247         }
 248
 249         ret = devm_clk_hw_register(dev, &pll_clk->hw);
 250         if (ret) {
 251                 dev_err(dev, "failed to register %s clock\n", init.name);
 252                 return ret;
 253         }
 254
 255         return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
 256                                            &pll_clk->hw);
 257 }
 258
 259 static void __init of_axs10x_pll_clk_setup(struct device_node *node)
 260 {
 261         const char *parent_name;
 262         struct axs10x_pll_clk *pll_clk;
 263         struct clk_init_data init = { };
 264         int ret;
 265
 266         pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
 267         if (!pll_clk)
 268                 return;
 269
 270         pll_clk->base = of_iomap(node, 0);
 271         if (!pll_clk->base) {
 272                 pr_err("failed to map pll div registers\n");
 273                 goto err_free_pll_clk;
 274         }
 275
 276         pll_clk->lock = of_iomap(node, 1);
 277         if (!pll_clk->lock) {
 278                 pr_err("failed to map pll lock register\n");
 279                 goto err_unmap_base;
 280         }
 281
 282         init.name = node->name;
 283         init.ops = &axs10x_pll_ops;
 284         parent_name = of_clk_get_parent_name(node, 0);
 285         init.parent_names = &parent_name;
 286         init.num_parents = parent_name ? 1 : 0;
 287         pll_clk->hw.init = &init;
 288         pll_clk->pll_cfg = arc_pll_cfg;
 289
 290         ret = clk_hw_register(NULL, &pll_clk->hw);
 291         if (ret) {
 292                 pr_err("failed to register %pOFn clock\n", node);
 293                 goto err_unmap_lock;
 294         }
 295
 296         ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
 297         if (ret) {
 298                 pr_err("failed to add hw provider for %pOFn clock\n", node);
 299                 goto err_unregister_clk;
 300         }
 301
 302         return;
 303
 304 err_unregister_clk:
 305         clk_hw_unregister(&pll_clk->hw);
 306 err_unmap_lock:
 307         iounmap(pll_clk->lock);
 308 err_unmap_base:
 309         iounmap(pll_clk->base);
 310 err_free_pll_clk:
 311         kfree(pll_clk);
 312 }
 313 CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock",
 314                of_axs10x_pll_clk_setup);
 315
 316 static const struct of_device_id axs10x_pll_clk_id[] = {
 317         { .compatible = "snps,axs10x-pgu-pll-clock", .data = &pgu_pll_cfg},
 318         { }
 319 };
 320 MODULE_DEVICE_TABLE(of, axs10x_pll_clk_id);
 321
 322 static struct platform_driver axs10x_pll_clk_driver = {
 323         .driver = {
 324                 .name = "axs10x-pll-clock",
 325                 .of_match_table = axs10x_pll_clk_id,
 326         },
 327         .probe = axs10x_pll_clk_probe,
 328 };
 329 builtin_platform_driver(axs10x_pll_clk_driver);
 330
 331 MODULE_AUTHOR("Vlad Zakharov <vzakhar@synopsys.com>");
 332 MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
 333 MODULE_LICENSE("GPL v2");