drivers/clk/clk-hsdk-pll.c

   1 /*
   2  * Synopsys HSDK 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/clk-provider.h>
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/err.h>
  15 #include <linux/io.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_device.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/slab.h>
  21
  22 #define CGU_PLL_CTRL    0x000 /* ARC PLL control register */
  23 #define CGU_PLL_STATUS  0x004 /* ARC PLL status register */
  24 #define CGU_PLL_FMEAS   0x008 /* ARC PLL frequency measurement register */
  25 #define CGU_PLL_MON     0x00C /* ARC PLL monitor register */
  26
  27 #define CGU_PLL_CTRL_ODIV_SHIFT         2
  28 #define CGU_PLL_CTRL_IDIV_SHIFT         4
  29 #define CGU_PLL_CTRL_FBDIV_SHIFT        9
  30 #define CGU_PLL_CTRL_BAND_SHIFT         20
  31
  32 #define CGU_PLL_CTRL_ODIV_MASK          GENMASK(3, CGU_PLL_CTRL_ODIV_SHIFT)
  33 #define CGU_PLL_CTRL_IDIV_MASK          GENMASK(8, CGU_PLL_CTRL_IDIV_SHIFT)
  34 #define CGU_PLL_CTRL_FBDIV_MASK         GENMASK(15, CGU_PLL_CTRL_FBDIV_SHIFT)
  35
  36 #define CGU_PLL_CTRL_PD                 BIT(0)
  37 #define CGU_PLL_CTRL_BYPASS             BIT(1)
  38
  39 #define CGU_PLL_STATUS_LOCK             BIT(0)
  40 #define CGU_PLL_STATUS_ERR              BIT(1)
  41
  42 #define HSDK_PLL_MAX_LOCK_TIME          100 /* 100 us */
  43
  44 #define CGU_PLL_SOURCE_MAX              1
  45
  46 #define CORE_IF_CLK_THRESHOLD_HZ        500000000
  47 #define CREG_CORE_IF_CLK_DIV_1          0x0
  48 #define CREG_CORE_IF_CLK_DIV_2          0x1
  49
  50 struct hsdk_pll_cfg {
  51         u32 rate;
  52         u32 idiv;
  53         u32 fbdiv;
  54         u32 odiv;
  55         u32 band;
  56 };
  57
  58 static const struct hsdk_pll_cfg asdt_pll_cfg[] = {
  59         { 100000000,  0, 11, 3, 0 },
  60         { 133000000,  0, 15, 3, 0 },
  61         { 200000000,  1, 47, 3, 0 },
  62         { 233000000,  1, 27, 2, 0 },
  63         { 300000000,  1, 35, 2, 0 },
  64         { 333000000,  1, 39, 2, 0 },
  65         { 400000000,  1, 47, 2, 0 },
  66         { 500000000,  0, 14, 1, 0 },
  67         { 600000000,  0, 17, 1, 0 },
  68         { 700000000,  0, 20, 1, 0 },
  69         { 800000000,  0, 23, 1, 0 },
  70         { 900000000,  1, 26, 0, 0 },
  71         { 1000000000, 1, 29, 0, 0 },
  72         { 1100000000, 1, 32, 0, 0 },
  73         { 1200000000, 1, 35, 0, 0 },
  74         { 1300000000, 1, 38, 0, 0 },
  75         { 1400000000, 1, 41, 0, 0 },
  76         { 1500000000, 1, 44, 0, 0 },
  77         { 1600000000, 1, 47, 0, 0 },
  78         {}
  79 };
  80
  81 static const struct hsdk_pll_cfg hdmi_pll_cfg[] = {
  82         { 297000000,  0, 21, 2, 0 },
  83         { 540000000,  0, 19, 1, 0 },
  84         { 594000000,  0, 21, 1, 0 },
  85         {}
  86 };
  87
  88 struct hsdk_pll_clk {
  89         struct clk_hw hw;
  90         void __iomem *regs;
  91         void __iomem *spec_regs;
  92         const struct hsdk_pll_devdata *pll_devdata;
  93         struct device *dev;
  94 };
  95
  96 struct hsdk_pll_devdata {
  97         const struct hsdk_pll_cfg *pll_cfg;
  98         int (*update_rate)(struct hsdk_pll_clk *clk, unsigned long rate,
  99                            const struct hsdk_pll_cfg *cfg);
 100 };
 101
 102 static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *, unsigned long,
 103                                      const struct hsdk_pll_cfg *);
 104 static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *, unsigned long,
 105                                      const struct hsdk_pll_cfg *);
 106
 107 static const struct hsdk_pll_devdata core_pll_devdata = {
 108         .pll_cfg = asdt_pll_cfg,
 109         .update_rate = hsdk_pll_core_update_rate,
 110 };
 111
 112 static const struct hsdk_pll_devdata sdt_pll_devdata = {
 113         .pll_cfg = asdt_pll_cfg,
 114         .update_rate = hsdk_pll_comm_update_rate,
 115 };
 116
 117 static const struct hsdk_pll_devdata hdmi_pll_devdata = {
 118         .pll_cfg = hdmi_pll_cfg,
 119         .update_rate = hsdk_pll_comm_update_rate,
 120 };
 121
 122 static inline void hsdk_pll_write(struct hsdk_pll_clk *clk, u32 reg, u32 val)
 123 {
 124         iowrite32(val, clk->regs + reg);
 125 }
 126
 127 static inline u32 hsdk_pll_read(struct hsdk_pll_clk *clk, u32 reg)
 128 {
 129         return ioread32(clk->regs + reg);
 130 }
 131
 132 static inline void hsdk_pll_set_cfg(struct hsdk_pll_clk *clk,
 133                                     const struct hsdk_pll_cfg *cfg)
 134 {
 135         u32 val = 0;
 136
 137         /* Powerdown and Bypass bits should be cleared */
 138         val |= cfg->idiv << CGU_PLL_CTRL_IDIV_SHIFT;
 139         val |= cfg->fbdiv << CGU_PLL_CTRL_FBDIV_SHIFT;
 140         val |= cfg->odiv << CGU_PLL_CTRL_ODIV_SHIFT;
 141         val |= cfg->band << CGU_PLL_CTRL_BAND_SHIFT;
 142
 143         dev_dbg(clk->dev, "write configuration: %#x\n", val);
 144
 145         hsdk_pll_write(clk, CGU_PLL_CTRL, val);
 146 }
 147
 148 static inline bool hsdk_pll_is_locked(struct hsdk_pll_clk *clk)
 149 {
 150         return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK);
 151 }
 152
 153 static inline bool hsdk_pll_is_err(struct hsdk_pll_clk *clk)
 154 {
 155         return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR);
 156 }
 157
 158 static inline struct hsdk_pll_clk *to_hsdk_pll_clk(struct clk_hw *hw)
 159 {
 160         return container_of(hw, struct hsdk_pll_clk, hw);
 161 }
 162
 163 static unsigned long hsdk_pll_recalc_rate(struct clk_hw *hw,
 164                                           unsigned long parent_rate)
 165 {
 166         u32 val;
 167         u64 rate;
 168         u32 idiv, fbdiv, odiv;
 169         struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
 170
 171         val = hsdk_pll_read(clk, CGU_PLL_CTRL);
 172
 173         dev_dbg(clk->dev, "current configuration: %#x\n", val);
 174
 175         /* Check if PLL is disabled */
 176         if (val & CGU_PLL_CTRL_PD)
 177                 return 0;
 178
 179         /* Check if PLL is bypassed */
 180         if (val & CGU_PLL_CTRL_BYPASS)
 181                 return parent_rate;
 182
 183         /* input divider = reg.idiv + 1 */
 184         idiv = 1 + ((val & CGU_PLL_CTRL_IDIV_MASK) >> CGU_PLL_CTRL_IDIV_SHIFT);
 185         /* fb divider = 2*(reg.fbdiv + 1) */
 186         fbdiv = 2 * (1 + ((val & CGU_PLL_CTRL_FBDIV_MASK) >> CGU_PLL_CTRL_FBDIV_SHIFT));
 187         /* output divider = 2^(reg.odiv) */
 188         odiv = 1 << ((val & CGU_PLL_CTRL_ODIV_MASK) >> CGU_PLL_CTRL_ODIV_SHIFT);
 189
 190         rate = (u64)parent_rate * fbdiv;
 191         do_div(rate, idiv * odiv);
 192
 193         return rate;
 194 }
 195
 196 static long hsdk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 197                                 unsigned long *prate)
 198 {
 199         int i;
 200         unsigned long best_rate;
 201         struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
 202         const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg;
 203
 204         if (pll_cfg[0].rate == 0)
 205                 return -EINVAL;
 206
 207         best_rate = pll_cfg[0].rate;
 208
 209         for (i = 1; pll_cfg[i].rate != 0; i++) {
 210                 if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
 211                         best_rate = pll_cfg[i].rate;
 212         }
 213
 214         dev_dbg(clk->dev, "chosen best rate: %lu\n", best_rate);
 215
 216         return best_rate;
 217 }
 218
 219 static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *clk,
 220                                      unsigned long rate,
 221                                      const struct hsdk_pll_cfg *cfg)
 222 {
 223         hsdk_pll_set_cfg(clk, cfg);
 224
 225         /*
 226          * Wait until CGU relocks and check error status.
 227          * If after timeout CGU is unlocked yet return error.
 228          */
 229         udelay(HSDK_PLL_MAX_LOCK_TIME);
 230         if (!hsdk_pll_is_locked(clk))
 231                 return -ETIMEDOUT;
 232
 233         if (hsdk_pll_is_err(clk))
 234                 return -EINVAL;
 235
 236         return 0;
 237 }
 238
 239 static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *clk,
 240                                      unsigned long rate,
 241                                      const struct hsdk_pll_cfg *cfg)
 242 {
 243         /*
 244          * When core clock exceeds 500MHz, the divider for the interface
 245          * clock must be programmed to div-by-2.
 246          */
 247         if (rate > CORE_IF_CLK_THRESHOLD_HZ)
 248                 iowrite32(CREG_CORE_IF_CLK_DIV_2, clk->spec_regs);
 249
 250         hsdk_pll_set_cfg(clk, cfg);
 251
 252         /*
 253          * Wait until CGU relocks and check error status.
 254          * If after timeout CGU is unlocked yet return error.
 255          */
 256         udelay(HSDK_PLL_MAX_LOCK_TIME);
 257         if (!hsdk_pll_is_locked(clk))
 258                 return -ETIMEDOUT;
 259
 260         if (hsdk_pll_is_err(clk))
 261                 return -EINVAL;
 262
 263         /*
 264          * Program divider to div-by-1 if we succesfuly set core clock below
 265          * 500MHz threshold.
 266          */
 267         if (rate <= CORE_IF_CLK_THRESHOLD_HZ)
 268                 iowrite32(CREG_CORE_IF_CLK_DIV_1, clk->spec_regs);
 269
 270         return 0;
 271 }
 272
 273 static int hsdk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 274                              unsigned long parent_rate)
 275 {
 276         int i;
 277         struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
 278         const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg;
 279
 280         for (i = 0; pll_cfg[i].rate != 0; i++) {
 281                 if (pll_cfg[i].rate == rate) {
 282                         return clk->pll_devdata->update_rate(clk, rate,
 283                                                              &pll_cfg[i]);
 284                 }
 285         }
 286
 287         dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
 288                         parent_rate);
 289
 290         return -EINVAL;
 291 }
 292
 293 static const struct clk_ops hsdk_pll_ops = {
 294         .recalc_rate = hsdk_pll_recalc_rate,
 295         .round_rate = hsdk_pll_round_rate,
 296         .set_rate = hsdk_pll_set_rate,
 297 };
 298
 299 static int hsdk_pll_clk_probe(struct platform_device *pdev)
 300 {
 301         int ret;
 302         struct resource *mem;
 303         const char *parent_name;
 304         unsigned int num_parents;
 305         struct hsdk_pll_clk *pll_clk;
 306         struct clk_init_data init = { };
 307         struct device *dev = &pdev->dev;
 308
 309         pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
 310         if (!pll_clk)
 311                 return -ENOMEM;
 312
 313         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 314         pll_clk->regs = devm_ioremap_resource(dev, mem);
 315         if (IS_ERR(pll_clk->regs))
 316                 return PTR_ERR(pll_clk->regs);
 317
 318         init.name = dev->of_node->name;
 319         init.ops = &hsdk_pll_ops;
 320         parent_name = of_clk_get_parent_name(dev->of_node, 0);
 321         init.parent_names = &parent_name;
 322         num_parents = of_clk_get_parent_count(dev->of_node);
 323         if (num_parents == 0 || num_parents > CGU_PLL_SOURCE_MAX) {
 324                 dev_err(dev, "wrong clock parents number: %u\n", num_parents);
 325                 return -EINVAL;
 326         }
 327         init.num_parents = num_parents;
 328
 329         pll_clk->hw.init = &init;
 330         pll_clk->dev = dev;
 331         pll_clk->pll_devdata = of_device_get_match_data(dev);
 332
 333         if (!pll_clk->pll_devdata) {
 334                 dev_err(dev, "No OF match data provided\n");
 335                 return -EINVAL;
 336         }
 337
 338         ret = devm_clk_hw_register(dev, &pll_clk->hw);
 339         if (ret) {
 340                 dev_err(dev, "failed to register %s clock\n", init.name);
 341                 return ret;
 342         }
 343
 344         return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
 345                         &pll_clk->hw);
 346 }
 347
 348 static int hsdk_pll_clk_remove(struct platform_device *pdev)
 349 {
 350         of_clk_del_provider(pdev->dev.of_node);
 351         return 0;
 352 }
 353
 354 static void __init of_hsdk_pll_clk_setup(struct device_node *node)
 355 {
 356         int ret;
 357         const char *parent_name;
 358         unsigned int num_parents;
 359         struct hsdk_pll_clk *pll_clk;
 360         struct clk_init_data init = { };
 361
 362         pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
 363         if (!pll_clk)
 364                 return;
 365
 366         pll_clk->regs = of_iomap(node, 0);
 367         if (!pll_clk->regs) {
 368                 pr_err("failed to map pll registers\n");
 369                 goto err_free_pll_clk;
 370         }
 371
 372         pll_clk->spec_regs = of_iomap(node, 1);
 373         if (!pll_clk->spec_regs) {
 374                 pr_err("failed to map pll registers\n");
 375                 goto err_unmap_comm_regs;
 376         }
 377
 378         init.name = node->name;
 379         init.ops = &hsdk_pll_ops;
 380         parent_name = of_clk_get_parent_name(node, 0);
 381         init.parent_names = &parent_name;
 382         num_parents = of_clk_get_parent_count(node);
 383         if (num_parents > CGU_PLL_SOURCE_MAX) {
 384                 pr_err("too much clock parents: %u\n", num_parents);
 385                 goto err_unmap_spec_regs;
 386         }
 387         init.num_parents = num_parents;
 388
 389         pll_clk->hw.init = &init;
 390         pll_clk->pll_devdata = &core_pll_devdata;
 391
 392         ret = clk_hw_register(NULL, &pll_clk->hw);
 393         if (ret) {
 394                 pr_err("failed to register %pOFn clock\n", node);
 395                 goto err_unmap_spec_regs;
 396         }
 397
 398         ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
 399         if (ret) {
 400                 pr_err("failed to add hw provider for %pOFn clock\n", node);
 401                 goto err_unmap_spec_regs;
 402         }
 403
 404         return;
 405
 406 err_unmap_spec_regs:
 407         iounmap(pll_clk->spec_regs);
 408 err_unmap_comm_regs:
 409         iounmap(pll_clk->regs);
 410 err_free_pll_clk:
 411         kfree(pll_clk);
 412 }
 413
 414 /* Core PLL needed early for ARC cpus timers */
 415 CLK_OF_DECLARE(hsdk_pll_clock, "snps,hsdk-core-pll-clock",
 416 of_hsdk_pll_clk_setup);
 417
 418 static const struct of_device_id hsdk_pll_clk_id[] = {
 419         { .compatible = "snps,hsdk-gp-pll-clock", .data = &sdt_pll_devdata},
 420         { .compatible = "snps,hsdk-hdmi-pll-clock", .data = &hdmi_pll_devdata},
 421         { }
 422 };
 423
 424 static struct platform_driver hsdk_pll_clk_driver = {
 425         .driver = {
 426                 .name = "hsdk-gp-pll-clock",
 427                 .of_match_table = hsdk_pll_clk_id,
 428         },
 429         .probe = hsdk_pll_clk_probe,
 430         .remove = hsdk_pll_clk_remove,
 431 };
 432 builtin_platform_driver(hsdk_pll_clk_driver);