drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm_8960.c

   1 /*
   2  * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/clk-provider.h>
  15
  16 #include "dsi_pll.h"
  17 #include "dsi.xml.h"
  18
  19 /*
  20  * DSI PLL 28nm (8960/A family) - clock diagram (eg: DSI1):
  21  *
  22  *
  23  *                        +------+
  24  *  dsi1vco_clk ----o-----| DIV1 |---dsi1pllbit (not exposed as clock)
  25  *  F * byte_clk    |     +------+
  26  *                  | bit clock divider (F / 8)
  27  *                  |
  28  *                  |     +------+
  29  *                  o-----| DIV2 |---dsi0pllbyte---o---> To byte RCG
  30  *                  |     +------+                 | (sets parent rate)
  31  *                  | byte clock divider (F)       |
  32  *                  |                              |
  33  *                  |                              o---> To esc RCG
  34  *                  |                                (doesn't set parent rate)
  35  *                  |
  36  *                  |     +------+
  37  *                  o-----| DIV3 |----dsi0pll------o---> To dsi RCG
  38  *                        +------+                 | (sets parent rate)
  39  *                  dsi clock divider (F * magic)  |
  40  *                                                 |
  41  *                                                 o---> To pixel rcg
  42  *                                                  (doesn't set parent rate)
  43  */
  44
  45 #define POLL_MAX_READS          8000
  46 #define POLL_TIMEOUT_US         1
  47
  48 #define NUM_PROVIDED_CLKS       2
  49
  50 #define VCO_REF_CLK_RATE        27000000
  51 #define VCO_MIN_RATE            600000000
  52 #define VCO_MAX_RATE            1200000000
  53
  54 #define DSI_BYTE_PLL_CLK        0
  55 #define DSI_PIXEL_PLL_CLK       1
  56
  57 #define VCO_PREF_DIV_RATIO      27
  58
  59 struct pll_28nm_cached_state {
  60         unsigned long vco_rate;
  61         u8 postdiv3;
  62         u8 postdiv2;
  63         u8 postdiv1;
  64 };
  65
  66 struct clk_bytediv {
  67         struct clk_hw hw;
  68         void __iomem *reg;
  69 };
  70
  71 struct dsi_pll_28nm {
  72         struct msm_dsi_pll base;
  73
  74         int id;
  75         struct platform_device *pdev;
  76         void __iomem *mmio;
  77
  78         /* custom byte clock divider */
  79         struct clk_bytediv *bytediv;
  80
  81         /* private clocks: */
  82         struct clk *clks[NUM_DSI_CLOCKS_MAX];
  83         u32 num_clks;
  84
  85         /* clock-provider: */
  86         struct clk *provided_clks[NUM_PROVIDED_CLKS];
  87         struct clk_onecell_data clk_data;
  88
  89         struct pll_28nm_cached_state cached_state;
  90 };
  91
  92 #define to_pll_28nm(x)  container_of(x, struct dsi_pll_28nm, base)
  93
  94 static bool pll_28nm_poll_for_ready(struct dsi_pll_28nm *pll_28nm,
  95                                     int nb_tries, int timeout_us)
  96 {
  97         bool pll_locked = false;
  98         u32 val;
  99
 100         while (nb_tries--) {
 101                 val = pll_read(pll_28nm->mmio + REG_DSI_28nm_8960_PHY_PLL_RDY);
 102                 pll_locked = !!(val & DSI_28nm_8960_PHY_PLL_RDY_PLL_RDY);
 103
 104                 if (pll_locked)
 105                         break;
 106
 107                 udelay(timeout_us);
 108         }
 109         DBG("DSI PLL is %slocked", pll_locked ? "" : "*not* ");
 110
 111         return pll_locked;
 112 }
 113
 114 /*
 115  * Clock Callbacks
 116  */
 117 static int dsi_pll_28nm_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 118                                      unsigned long parent_rate)
 119 {
 120         struct msm_dsi_pll *pll = hw_clk_to_pll(hw);
 121         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 122         void __iomem *base = pll_28nm->mmio;
 123         u32 val, temp, fb_divider;
 124
 125         DBG("rate=%lu, parent's=%lu", rate, parent_rate);
 126
 127         temp = rate / 10;
 128         val = VCO_REF_CLK_RATE / 10;
 129         fb_divider = (temp * VCO_PREF_DIV_RATIO) / val;
 130         fb_divider = fb_divider / 2 - 1;
 131         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_1,
 132                         fb_divider & 0xff);
 133
 134         val = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_2);
 135
 136         val |= (fb_divider >> 8) & 0x07;
 137
 138         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_2,
 139                         val);
 140
 141         val = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_3);
 142
 143         val |= (VCO_PREF_DIV_RATIO - 1) & 0x3f;
 144
 145         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_3,
 146                         val);
 147
 148         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_6,
 149                         0xf);
 150
 151         val = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8);
 152         val |= 0x7 << 4;
 153         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8,
 154                         val);
 155
 156         return 0;
 157 }
 158
 159 static int dsi_pll_28nm_clk_is_enabled(struct clk_hw *hw)
 160 {
 161         struct msm_dsi_pll *pll = hw_clk_to_pll(hw);
 162         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 163
 164         return pll_28nm_poll_for_ready(pll_28nm, POLL_MAX_READS,
 165                                         POLL_TIMEOUT_US);
 166 }
 167
 168 static unsigned long dsi_pll_28nm_clk_recalc_rate(struct clk_hw *hw,
 169                                                   unsigned long parent_rate)
 170 {
 171         struct msm_dsi_pll *pll = hw_clk_to_pll(hw);
 172         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 173         void __iomem *base = pll_28nm->mmio;
 174         unsigned long vco_rate;
 175         u32 status, fb_divider, temp, ref_divider;
 176
 177         VERB("parent_rate=%lu", parent_rate);
 178
 179         status = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_0);
 180
 181         if (status & DSI_28nm_8960_PHY_PLL_CTRL_0_ENABLE) {
 182                 fb_divider = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_1);
 183                 fb_divider &= 0xff;
 184                 temp = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_2) & 0x07;
 185                 fb_divider = (temp << 8) | fb_divider;
 186                 fb_divider += 1;
 187
 188                 ref_divider = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_3);
 189                 ref_divider &= 0x3f;
 190                 ref_divider += 1;
 191
 192                 /* multiply by 2 */
 193                 vco_rate = (parent_rate / ref_divider) * fb_divider * 2;
 194         } else {
 195                 vco_rate = 0;
 196         }
 197
 198         DBG("returning vco rate = %lu", vco_rate);
 199
 200         return vco_rate;
 201 }
 202
 203 static const struct clk_ops clk_ops_dsi_pll_28nm_vco = {
 204         .round_rate = msm_dsi_pll_helper_clk_round_rate,
 205         .set_rate = dsi_pll_28nm_clk_set_rate,
 206         .recalc_rate = dsi_pll_28nm_clk_recalc_rate,
 207         .prepare = msm_dsi_pll_helper_clk_prepare,
 208         .unprepare = msm_dsi_pll_helper_clk_unprepare,
 209         .is_enabled = dsi_pll_28nm_clk_is_enabled,
 210 };
 211
 212 /*
 213  * Custom byte clock divier clk_ops
 214  *
 215  * This clock is the entry point to configuring the PLL. The user (dsi host)
 216  * will set this clock's rate to the desired byte clock rate. The VCO lock
 217  * frequency is a multiple of the byte clock rate. The multiplication factor
 218  * (shown as F in the diagram above) is a function of the byte clock rate.
 219  *
 220  * This custom divider clock ensures that its parent (VCO) is set to the
 221  * desired rate, and that the byte clock postdivider (POSTDIV2) is configured
 222  * accordingly
 223  */
 224 #define to_clk_bytediv(_hw) container_of(_hw, struct clk_bytediv, hw)
 225
 226 static unsigned long clk_bytediv_recalc_rate(struct clk_hw *hw,
 227                 unsigned long parent_rate)
 228 {
 229         struct clk_bytediv *bytediv = to_clk_bytediv(hw);
 230         unsigned int div;
 231
 232         div = pll_read(bytediv->reg) & 0xff;
 233
 234         return parent_rate / (div + 1);
 235 }
 236
 237 /* find multiplication factor(wrt byte clock) at which the VCO should be set */
 238 static unsigned int get_vco_mul_factor(unsigned long byte_clk_rate)
 239 {
 240         unsigned long bit_mhz;
 241
 242         /* convert to bit clock in Mhz */
 243         bit_mhz = (byte_clk_rate * 8) / 1000000;
 244
 245         if (bit_mhz < 125)
 246                 return 64;
 247         else if (bit_mhz < 250)
 248                 return 32;
 249         else if (bit_mhz < 600)
 250                 return 16;
 251         else
 252                 return 8;
 253 }
 254
 255 static long clk_bytediv_round_rate(struct clk_hw *hw, unsigned long rate,
 256                                    unsigned long *prate)
 257 {
 258         unsigned long best_parent;
 259         unsigned int factor;
 260
 261         factor = get_vco_mul_factor(rate);
 262
 263         best_parent = rate * factor;
 264         *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
 265
 266         return *prate / factor;
 267 }
 268
 269 static int clk_bytediv_set_rate(struct clk_hw *hw, unsigned long rate,
 270                                 unsigned long parent_rate)
 271 {
 272         struct clk_bytediv *bytediv = to_clk_bytediv(hw);
 273         u32 val;
 274         unsigned int factor;
 275
 276         factor = get_vco_mul_factor(rate);
 277
 278         val = pll_read(bytediv->reg);
 279         val |= (factor - 1) & 0xff;
 280         pll_write(bytediv->reg, val);
 281
 282         return 0;
 283 }
 284
 285 /* Our special byte clock divider ops */
 286 static const struct clk_ops clk_bytediv_ops = {
 287         .round_rate = clk_bytediv_round_rate,
 288         .set_rate = clk_bytediv_set_rate,
 289         .recalc_rate = clk_bytediv_recalc_rate,
 290 };
 291
 292 /*
 293  * PLL Callbacks
 294  */
 295 static int dsi_pll_28nm_enable_seq(struct msm_dsi_pll *pll)
 296 {
 297         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 298         struct device *dev = &pll_28nm->pdev->dev;
 299         void __iomem *base = pll_28nm->mmio;
 300         bool locked;
 301         unsigned int bit_div, byte_div;
 302         int max_reads = 1000, timeout_us = 100;
 303         u32 val;
 304
 305         DBG("id=%d", pll_28nm->id);
 306
 307         /*
 308          * before enabling the PLL, configure the bit clock divider since we
 309          * don't expose it as a clock to the outside world
 310          * 1: read back the byte clock divider that should already be set
 311          * 2: divide by 8 to get bit clock divider
 312          * 3: write it to POSTDIV1
 313          */
 314         val = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_9);
 315         byte_div = val + 1;
 316         bit_div = byte_div / 8;
 317
 318         val = pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8);
 319         val &= ~0xf;
 320         val |= (bit_div - 1);
 321         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8, val);
 322
 323         /* enable the PLL */
 324         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_0,
 325                         DSI_28nm_8960_PHY_PLL_CTRL_0_ENABLE);
 326
 327         locked = pll_28nm_poll_for_ready(pll_28nm, max_reads, timeout_us);
 328
 329         if (unlikely(!locked))
 330                 dev_err(dev, "DSI PLL lock failed\n");
 331         else
 332                 DBG("DSI PLL lock success");
 333
 334         return locked ? 0 : -EINVAL;
 335 }
 336
 337 static void dsi_pll_28nm_disable_seq(struct msm_dsi_pll *pll)
 338 {
 339         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 340
 341         DBG("id=%d", pll_28nm->id);
 342         pll_write(pll_28nm->mmio + REG_DSI_28nm_8960_PHY_PLL_CTRL_0, 0x00);
 343 }
 344
 345 static void dsi_pll_28nm_save_state(struct msm_dsi_pll *pll)
 346 {
 347         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 348         struct pll_28nm_cached_state *cached_state = &pll_28nm->cached_state;
 349         void __iomem *base = pll_28nm->mmio;
 350
 351         cached_state->postdiv3 =
 352                         pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_10);
 353         cached_state->postdiv2 =
 354                         pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_9);
 355         cached_state->postdiv1 =
 356                         pll_read(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8);
 357
 358         cached_state->vco_rate = clk_hw_get_rate(&pll->clk_hw);
 359 }
 360
 361 static int dsi_pll_28nm_restore_state(struct msm_dsi_pll *pll)
 362 {
 363         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 364         struct pll_28nm_cached_state *cached_state = &pll_28nm->cached_state;
 365         void __iomem *base = pll_28nm->mmio;
 366         int ret;
 367
 368         ret = dsi_pll_28nm_clk_set_rate(&pll->clk_hw,
 369                                         cached_state->vco_rate, 0);
 370         if (ret) {
 371                 dev_err(&pll_28nm->pdev->dev,
 372                         "restore vco rate failed. ret=%d\n", ret);
 373                 return ret;
 374         }
 375
 376         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_10,
 377                         cached_state->postdiv3);
 378         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_9,
 379                         cached_state->postdiv2);
 380         pll_write(base + REG_DSI_28nm_8960_PHY_PLL_CTRL_8,
 381                         cached_state->postdiv1);
 382
 383         return 0;
 384 }
 385
 386 static int dsi_pll_28nm_get_provider(struct msm_dsi_pll *pll,
 387                                 struct clk **byte_clk_provider,
 388                                 struct clk **pixel_clk_provider)
 389 {
 390         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 391
 392         if (byte_clk_provider)
 393                 *byte_clk_provider = pll_28nm->provided_clks[DSI_BYTE_PLL_CLK];
 394         if (pixel_clk_provider)
 395                 *pixel_clk_provider =
 396                                 pll_28nm->provided_clks[DSI_PIXEL_PLL_CLK];
 397
 398         return 0;
 399 }
 400
 401 static void dsi_pll_28nm_destroy(struct msm_dsi_pll *pll)
 402 {
 403         struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
 404
 405         msm_dsi_pll_helper_unregister_clks(pll_28nm->pdev,
 406                                         pll_28nm->clks, pll_28nm->num_clks);
 407 }
 408
 409 static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm)
 410 {
 411         char *clk_name, *parent_name, *vco_name;
 412         struct clk_init_data vco_init = {
 413                 .parent_names = (const char *[]){ "pxo" },
 414                 .num_parents = 1,
 415                 .flags = CLK_IGNORE_UNUSED,
 416                 .ops = &clk_ops_dsi_pll_28nm_vco,
 417         };
 418         struct device *dev = &pll_28nm->pdev->dev;
 419         struct clk **clks = pll_28nm->clks;
 420         struct clk **provided_clks = pll_28nm->provided_clks;
 421         struct clk_bytediv *bytediv;
 422         struct clk_init_data bytediv_init = { };
 423         int ret, num = 0;
 424
 425         DBG("%d", pll_28nm->id);
 426
 427         bytediv = devm_kzalloc(dev, sizeof(*bytediv), GFP_KERNEL);
 428         if (!bytediv)
 429                 return -ENOMEM;
 430
 431         vco_name = devm_kzalloc(dev, 32, GFP_KERNEL);
 432         if (!vco_name)
 433                 return -ENOMEM;
 434
 435         parent_name = devm_kzalloc(dev, 32, GFP_KERNEL);
 436         if (!parent_name)
 437                 return -ENOMEM;
 438
 439         clk_name = devm_kzalloc(dev, 32, GFP_KERNEL);
 440         if (!clk_name)
 441                 return -ENOMEM;
 442
 443         pll_28nm->bytediv = bytediv;
 444
 445         snprintf(vco_name, 32, "dsi%dvco_clk", pll_28nm->id);
 446         vco_init.name = vco_name;
 447
 448         pll_28nm->base.clk_hw.init = &vco_init;
 449
 450         clks[num++] = clk_register(dev, &pll_28nm->base.clk_hw);
 451
 452         /* prepare and register bytediv */
 453         bytediv->hw.init = &bytediv_init;
 454         bytediv->reg = pll_28nm->mmio + REG_DSI_28nm_8960_PHY_PLL_CTRL_9;
 455
 456         snprintf(parent_name, 32, "dsi%dvco_clk", pll_28nm->id);
 457         snprintf(clk_name, 32, "dsi%dpllbyte", pll_28nm->id);
 458
 459         bytediv_init.name = clk_name;
 460         bytediv_init.ops = &clk_bytediv_ops;
 461         bytediv_init.flags = CLK_SET_RATE_PARENT;
 462         bytediv_init.parent_names = (const char * const *) &parent_name;
 463         bytediv_init.num_parents = 1;
 464
 465         /* DIV2 */
 466         clks[num++] = provided_clks[DSI_BYTE_PLL_CLK] =
 467                         clk_register(dev, &bytediv->hw);
 468
 469         snprintf(clk_name, 32, "dsi%dpll", pll_28nm->id);
 470         /* DIV3 */
 471         clks[num++] = provided_clks[DSI_PIXEL_PLL_CLK] =
 472                         clk_register_divider(dev, clk_name,
 473                                 parent_name, 0, pll_28nm->mmio +
 474                                 REG_DSI_28nm_8960_PHY_PLL_CTRL_10,
 475                                 0, 8, 0, NULL);
 476
 477         pll_28nm->num_clks = num;
 478
 479         pll_28nm->clk_data.clk_num = NUM_PROVIDED_CLKS;
 480         pll_28nm->clk_data.clks = provided_clks;
 481
 482         ret = of_clk_add_provider(dev->of_node,
 483                         of_clk_src_onecell_get, &pll_28nm->clk_data);
 484         if (ret) {
 485                 dev_err(dev, "failed to register clk provider: %d\n", ret);
 486                 return ret;
 487         }
 488
 489         return 0;
 490 }
 491
 492 struct msm_dsi_pll *msm_dsi_pll_28nm_8960_init(struct platform_device *pdev,
 493                                                int id)
 494 {
 495         struct dsi_pll_28nm *pll_28nm;
 496         struct msm_dsi_pll *pll;
 497         int ret;
 498
 499         if (!pdev)
 500                 return ERR_PTR(-ENODEV);
 501
 502         pll_28nm = devm_kzalloc(&pdev->dev, sizeof(*pll_28nm), GFP_KERNEL);
 503         if (!pll_28nm)
 504                 return ERR_PTR(-ENOMEM);
 505
 506         pll_28nm->pdev = pdev;
 507         pll_28nm->id = id + 1;
 508
 509         pll_28nm->mmio = msm_ioremap(pdev, "dsi_pll", "DSI_PLL");
 510         if (IS_ERR_OR_NULL(pll_28nm->mmio)) {
 511                 dev_err(&pdev->dev, "%s: failed to map pll base\n", __func__);
 512                 return ERR_PTR(-ENOMEM);
 513         }
 514
 515         pll = &pll_28nm->base;
 516         pll->min_rate = VCO_MIN_RATE;
 517         pll->max_rate = VCO_MAX_RATE;
 518         pll->get_provider = dsi_pll_28nm_get_provider;
 519         pll->destroy = dsi_pll_28nm_destroy;
 520         pll->disable_seq = dsi_pll_28nm_disable_seq;
 521         pll->save_state = dsi_pll_28nm_save_state;
 522         pll->restore_state = dsi_pll_28nm_restore_state;
 523
 524         pll->en_seq_cnt = 1;
 525         pll->enable_seqs[0] = dsi_pll_28nm_enable_seq;
 526
 527         ret = pll_28nm_register(pll_28nm);
 528         if (ret) {
 529                 dev_err(&pdev->dev, "failed to register PLL: %d\n", ret);
 530                 return ERR_PTR(ret);
 531         }
 532
 533         return pll;
 534 }