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