1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * R-Car Gen2 Clock Pulse Generator 4 * 5 * Copyright (C) 2016 Cogent Embedded Inc. 6 */ 7 8 #include <linux/bug.h> 9 #include <linux/clk.h> 10 #include <linux/clk-provider.h> 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/init.h> 14 #include <linux/io.h> 15 #include <linux/slab.h> 16 #include <linux/sys_soc.h> 17 18 #include "renesas-cpg-mssr.h" 19 #include "rcar-gen2-cpg.h" 20 21 #define CPG_FRQCRB 0x0004 22 #define CPG_FRQCRB_KICK BIT(31) 23 #define CPG_SDCKCR 0x0074 24 #define CPG_PLL0CR 0x00d8 25 #define CPG_PLL0CR_STC_SHIFT 24 26 #define CPG_PLL0CR_STC_MASK (0x7f << CPG_PLL0CR_STC_SHIFT) 27 #define CPG_FRQCRC 0x00e0 28 #define CPG_FRQCRC_ZFC_SHIFT 8 29 #define CPG_FRQCRC_ZFC_MASK (0x1f << CPG_FRQCRC_ZFC_SHIFT) 30 #define CPG_ADSPCKCR 0x025c 31 #define CPG_RCANCKCR 0x0270 32 33 static DEFINE_SPINLOCK(cpg_lock); 34 35 /* 36 * Z Clock 37 * 38 * Traits of this clock: 39 * prepare - clk_prepare only ensures that parents are prepared 40 * enable - clk_enable only ensures that parents are enabled 41 * rate - rate is adjustable. clk->rate = parent->rate * mult / 32 42 * parent - fixed parent. No clk_set_parent support 43 */ 44 45 struct cpg_z_clk { 46 struct clk_hw hw; 47 void __iomem *reg; 48 void __iomem *kick_reg; 49 }; 50 51 #define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw) 52 53 static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw, 54 unsigned long parent_rate) 55 { 56 struct cpg_z_clk *zclk = to_z_clk(hw); 57 unsigned int mult; 58 unsigned int val; 59 60 val = (readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK) >> CPG_FRQCRC_ZFC_SHIFT; 61 mult = 32 - val; 62 63 return div_u64((u64)parent_rate * mult, 32); 64 } 65 66 static int cpg_z_clk_determine_rate(struct clk_hw *hw, 67 struct clk_rate_request *req) 68 { 69 unsigned long prate = req->best_parent_rate; 70 unsigned int min_mult, max_mult, mult; 71 72 min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL); 73 max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL); 74 if (max_mult < min_mult) 75 return -EINVAL; 76 77 mult = div64_ul(req->rate * 32ULL, prate); 78 mult = clamp(mult, min_mult, max_mult); 79 80 req->rate = div_u64((u64)prate * mult, 32); 81 return 0; 82 } 83 84 static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate, 85 unsigned long parent_rate) 86 { 87 struct cpg_z_clk *zclk = to_z_clk(hw); 88 unsigned int mult; 89 u32 val, kick; 90 unsigned int i; 91 92 mult = div64_ul(rate * 32ULL, parent_rate); 93 mult = clamp(mult, 1U, 32U); 94 95 if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK) 96 return -EBUSY; 97 98 val = readl(zclk->reg); 99 val &= ~CPG_FRQCRC_ZFC_MASK; 100 val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT; 101 writel(val, zclk->reg); 102 103 /* 104 * Set KICK bit in FRQCRB to update hardware setting and wait for 105 * clock change completion. 106 */ 107 kick = readl(zclk->kick_reg); 108 kick |= CPG_FRQCRB_KICK; 109 writel(kick, zclk->kick_reg); 110 111 /* 112 * Note: There is no HW information about the worst case latency. 113 * 114 * Using experimental measurements, it seems that no more than 115 * ~10 iterations are needed, independently of the CPU rate. 116 * Since this value might be dependent on external xtal rate, pll1 117 * rate or even the other emulation clocks rate, use 1000 as a 118 * "super" safe value. 119 */ 120 for (i = 1000; i; i--) { 121 if (!(readl(zclk->kick_reg) & CPG_FRQCRB_KICK)) 122 return 0; 123 124 cpu_relax(); 125 } 126 127 return -ETIMEDOUT; 128 } 129 130 static const struct clk_ops cpg_z_clk_ops = { 131 .recalc_rate = cpg_z_clk_recalc_rate, 132 .determine_rate = cpg_z_clk_determine_rate, 133 .set_rate = cpg_z_clk_set_rate, 134 }; 135 136 static struct clk * __init cpg_z_clk_register(const char *name, 137 const char *parent_name, 138 void __iomem *base) 139 { 140 struct clk_init_data init = {}; 141 struct cpg_z_clk *zclk; 142 struct clk *clk; 143 144 zclk = kzalloc(sizeof(*zclk), GFP_KERNEL); 145 if (!zclk) 146 return ERR_PTR(-ENOMEM); 147 148 init.name = name; 149 init.ops = &cpg_z_clk_ops; 150 init.parent_names = &parent_name; 151 init.num_parents = 1; 152 153 zclk->reg = base + CPG_FRQCRC; 154 zclk->kick_reg = base + CPG_FRQCRB; 155 zclk->hw.init = &init; 156 157 clk = clk_register(NULL, &zclk->hw); 158 if (IS_ERR(clk)) 159 kfree(zclk); 160 161 return clk; 162 } 163 164 static struct clk * __init cpg_rcan_clk_register(const char *name, 165 const char *parent_name, 166 void __iomem *base) 167 { 168 struct clk_fixed_factor *fixed; 169 struct clk_gate *gate; 170 struct clk *clk; 171 172 fixed = kzalloc(sizeof(*fixed), GFP_KERNEL); 173 if (!fixed) 174 return ERR_PTR(-ENOMEM); 175 176 fixed->mult = 1; 177 fixed->div = 6; 178 179 gate = kzalloc(sizeof(*gate), GFP_KERNEL); 180 if (!gate) { 181 kfree(fixed); 182 return ERR_PTR(-ENOMEM); 183 } 184 185 gate->reg = base + CPG_RCANCKCR; 186 gate->bit_idx = 8; 187 gate->flags = CLK_GATE_SET_TO_DISABLE; 188 gate->lock = &cpg_lock; 189 190 clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL, 191 &fixed->hw, &clk_fixed_factor_ops, 192 &gate->hw, &clk_gate_ops, 0); 193 if (IS_ERR(clk)) { 194 kfree(gate); 195 kfree(fixed); 196 } 197 198 return clk; 199 } 200 201 /* ADSP divisors */ 202 static const struct clk_div_table cpg_adsp_div_table[] = { 203 { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, 204 { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 }, 205 { 10, 36 }, { 11, 48 }, { 0, 0 }, 206 }; 207 208 static struct clk * __init cpg_adsp_clk_register(const char *name, 209 const char *parent_name, 210 void __iomem *base) 211 { 212 struct clk_divider *div; 213 struct clk_gate *gate; 214 struct clk *clk; 215 216 div = kzalloc(sizeof(*div), GFP_KERNEL); 217 if (!div) 218 return ERR_PTR(-ENOMEM); 219 220 div->reg = base + CPG_ADSPCKCR; 221 div->width = 4; 222 div->table = cpg_adsp_div_table; 223 div->lock = &cpg_lock; 224 225 gate = kzalloc(sizeof(*gate), GFP_KERNEL); 226 if (!gate) { 227 kfree(div); 228 return ERR_PTR(-ENOMEM); 229 } 230 231 gate->reg = base + CPG_ADSPCKCR; 232 gate->bit_idx = 8; 233 gate->flags = CLK_GATE_SET_TO_DISABLE; 234 gate->lock = &cpg_lock; 235 236 clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL, 237 &div->hw, &clk_divider_ops, 238 &gate->hw, &clk_gate_ops, 0); 239 if (IS_ERR(clk)) { 240 kfree(gate); 241 kfree(div); 242 } 243 244 return clk; 245 } 246 247 /* SDHI divisors */ 248 static const struct clk_div_table cpg_sdh_div_table[] = { 249 { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, 250 { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 }, 251 { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 }, 252 }; 253 254 static const struct clk_div_table cpg_sd01_div_table[] = { 255 { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 }, 256 { 8, 24 }, { 10, 36 }, { 11, 48 }, { 12, 10 }, 257 { 0, 0 }, 258 }; 259 260 static const struct rcar_gen2_cpg_pll_config *cpg_pll_config __initdata; 261 static unsigned int cpg_pll0_div __initdata; 262 static u32 cpg_mode __initdata; 263 static u32 cpg_quirks __initdata; 264 265 #define SD_SKIP_FIRST BIT(0) /* Skip first clock in SD table */ 266 267 static const struct soc_device_attribute cpg_quirks_match[] __initconst = { 268 { 269 .soc_id = "r8a77470", 270 .data = (void *)SD_SKIP_FIRST, 271 }, 272 { /* sentinel */ } 273 }; 274 275 struct clk * __init rcar_gen2_cpg_clk_register(struct device *dev, 276 const struct cpg_core_clk *core, const struct cpg_mssr_info *info, 277 struct clk **clks, void __iomem *base, 278 struct raw_notifier_head *notifiers) 279 { 280 const struct clk_div_table *table = NULL; 281 const struct clk *parent; 282 const char *parent_name; 283 unsigned int mult = 1; 284 unsigned int div = 1; 285 unsigned int shift; 286 287 parent = clks[core->parent]; 288 if (IS_ERR(parent)) 289 return ERR_CAST(parent); 290 291 parent_name = __clk_get_name(parent); 292 293 switch (core->type) { 294 /* R-Car Gen2 */ 295 case CLK_TYPE_GEN2_MAIN: 296 div = cpg_pll_config->extal_div; 297 break; 298 299 case CLK_TYPE_GEN2_PLL0: 300 /* 301 * PLL0 is a configurable multiplier clock except on R-Car 302 * V2H/E2. Register the PLL0 clock as a fixed factor clock for 303 * now as there's no generic multiplier clock implementation and 304 * we currently have no need to change the multiplier value. 305 */ 306 mult = cpg_pll_config->pll0_mult; 307 div = cpg_pll0_div; 308 if (!mult) { 309 u32 pll0cr = readl(base + CPG_PLL0CR); 310 311 mult = (((pll0cr & CPG_PLL0CR_STC_MASK) >> 312 CPG_PLL0CR_STC_SHIFT) + 1) * 2; 313 } 314 break; 315 316 case CLK_TYPE_GEN2_PLL1: 317 mult = cpg_pll_config->pll1_mult / 2; 318 break; 319 320 case CLK_TYPE_GEN2_PLL3: 321 mult = cpg_pll_config->pll3_mult; 322 break; 323 324 case CLK_TYPE_GEN2_Z: 325 return cpg_z_clk_register(core->name, parent_name, base); 326 327 case CLK_TYPE_GEN2_LB: 328 div = cpg_mode & BIT(18) ? 36 : 24; 329 break; 330 331 case CLK_TYPE_GEN2_ADSP: 332 return cpg_adsp_clk_register(core->name, parent_name, base); 333 334 case CLK_TYPE_GEN2_SDH: 335 table = cpg_sdh_div_table; 336 shift = 8; 337 break; 338 339 case CLK_TYPE_GEN2_SD0: 340 table = cpg_sd01_div_table; 341 if (cpg_quirks & SD_SKIP_FIRST) 342 table++; 343 344 shift = 4; 345 break; 346 347 case CLK_TYPE_GEN2_SD1: 348 table = cpg_sd01_div_table; 349 if (cpg_quirks & SD_SKIP_FIRST) 350 table++; 351 352 shift = 0; 353 break; 354 355 case CLK_TYPE_GEN2_QSPI: 356 div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) ? 357 8 : 10; 358 break; 359 360 case CLK_TYPE_GEN2_RCAN: 361 return cpg_rcan_clk_register(core->name, parent_name, base); 362 363 default: 364 return ERR_PTR(-EINVAL); 365 } 366 367 if (!table) 368 return clk_register_fixed_factor(NULL, core->name, parent_name, 369 0, mult, div); 370 else 371 return clk_register_divider_table(NULL, core->name, 372 parent_name, 0, 373 base + CPG_SDCKCR, shift, 4, 374 0, table, &cpg_lock); 375 } 376 377 int __init rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config, 378 unsigned int pll0_div, u32 mode) 379 { 380 const struct soc_device_attribute *attr; 381 382 cpg_pll_config = config; 383 cpg_pll0_div = pll0_div; 384 cpg_mode = mode; 385 attr = soc_device_match(cpg_quirks_match); 386 if (attr) 387 cpg_quirks = (uintptr_t)attr->data; 388 pr_debug("%s: mode = 0x%x quirks = 0x%x\n", __func__, mode, cpg_quirks); 389 390 return 0; 391 } 392