1 /* 2 * AXI clkgen driver 3 * 4 * Copyright 2012-2013 Analog Devices Inc. 5 * Author: Lars-Peter Clausen <lars@metafoo.de> 6 * 7 * Licensed under the GPL-2. 8 * 9 */ 10 11 #include <linux/platform_device.h> 12 #include <linux/clk-provider.h> 13 #include <linux/slab.h> 14 #include <linux/io.h> 15 #include <linux/of.h> 16 #include <linux/module.h> 17 #include <linux/err.h> 18 19 #define AXI_CLKGEN_V2_REG_RESET 0x40 20 #define AXI_CLKGEN_V2_REG_CLKSEL 0x44 21 #define AXI_CLKGEN_V2_REG_DRP_CNTRL 0x70 22 #define AXI_CLKGEN_V2_REG_DRP_STATUS 0x74 23 24 #define AXI_CLKGEN_V2_RESET_MMCM_ENABLE BIT(1) 25 #define AXI_CLKGEN_V2_RESET_ENABLE BIT(0) 26 27 #define AXI_CLKGEN_V2_DRP_CNTRL_SEL BIT(29) 28 #define AXI_CLKGEN_V2_DRP_CNTRL_READ BIT(28) 29 30 #define AXI_CLKGEN_V2_DRP_STATUS_BUSY BIT(16) 31 32 #define MMCM_REG_CLKOUT0_1 0x08 33 #define MMCM_REG_CLKOUT0_2 0x09 34 #define MMCM_REG_CLK_FB1 0x14 35 #define MMCM_REG_CLK_FB2 0x15 36 #define MMCM_REG_CLK_DIV 0x16 37 #define MMCM_REG_LOCK1 0x18 38 #define MMCM_REG_LOCK2 0x19 39 #define MMCM_REG_LOCK3 0x1a 40 #define MMCM_REG_FILTER1 0x4e 41 #define MMCM_REG_FILTER2 0x4f 42 43 struct axi_clkgen { 44 void __iomem *base; 45 struct clk_hw clk_hw; 46 }; 47 48 static uint32_t axi_clkgen_lookup_filter(unsigned int m) 49 { 50 switch (m) { 51 case 0: 52 return 0x01001990; 53 case 1: 54 return 0x01001190; 55 case 2: 56 return 0x01009890; 57 case 3: 58 return 0x01001890; 59 case 4: 60 return 0x01008890; 61 case 5 ... 8: 62 return 0x01009090; 63 case 9 ... 11: 64 return 0x01000890; 65 case 12: 66 return 0x08009090; 67 case 13 ... 22: 68 return 0x01001090; 69 case 23 ... 36: 70 return 0x01008090; 71 case 37 ... 46: 72 return 0x08001090; 73 default: 74 return 0x08008090; 75 } 76 } 77 78 static const uint32_t axi_clkgen_lock_table[] = { 79 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8, 80 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8, 81 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339, 82 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271, 83 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4, 84 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190, 85 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e, 86 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c, 87 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113, 88 }; 89 90 static uint32_t axi_clkgen_lookup_lock(unsigned int m) 91 { 92 if (m < ARRAY_SIZE(axi_clkgen_lock_table)) 93 return axi_clkgen_lock_table[m]; 94 return 0x1f1f00fa; 95 } 96 97 static const unsigned int fpfd_min = 10000; 98 static const unsigned int fpfd_max = 300000; 99 static const unsigned int fvco_min = 600000; 100 static const unsigned int fvco_max = 1200000; 101 102 static void axi_clkgen_calc_params(unsigned long fin, unsigned long fout, 103 unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout) 104 { 105 unsigned long d, d_min, d_max, _d_min, _d_max; 106 unsigned long m, m_min, m_max; 107 unsigned long f, dout, best_f, fvco; 108 109 fin /= 1000; 110 fout /= 1000; 111 112 best_f = ULONG_MAX; 113 *best_d = 0; 114 *best_m = 0; 115 *best_dout = 0; 116 117 d_min = max_t(unsigned long, DIV_ROUND_UP(fin, fpfd_max), 1); 118 d_max = min_t(unsigned long, fin / fpfd_min, 80); 119 120 m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min, fin) * d_min, 1); 121 m_max = min_t(unsigned long, fvco_max * d_max / fin, 64); 122 123 for (m = m_min; m <= m_max; m++) { 124 _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max)); 125 _d_max = min(d_max, fin * m / fvco_min); 126 127 for (d = _d_min; d <= _d_max; d++) { 128 fvco = fin * m / d; 129 130 dout = DIV_ROUND_CLOSEST(fvco, fout); 131 dout = clamp_t(unsigned long, dout, 1, 128); 132 f = fvco / dout; 133 if (abs(f - fout) < abs(best_f - fout)) { 134 best_f = f; 135 *best_d = d; 136 *best_m = m; 137 *best_dout = dout; 138 if (best_f == fout) 139 return; 140 } 141 } 142 } 143 } 144 145 static void axi_clkgen_calc_clk_params(unsigned int divider, unsigned int *low, 146 unsigned int *high, unsigned int *edge, unsigned int *nocount) 147 { 148 if (divider == 1) 149 *nocount = 1; 150 else 151 *nocount = 0; 152 153 *high = divider / 2; 154 *edge = divider % 2; 155 *low = divider - *high; 156 } 157 158 static void axi_clkgen_write(struct axi_clkgen *axi_clkgen, 159 unsigned int reg, unsigned int val) 160 { 161 writel(val, axi_clkgen->base + reg); 162 } 163 164 static void axi_clkgen_read(struct axi_clkgen *axi_clkgen, 165 unsigned int reg, unsigned int *val) 166 { 167 *val = readl(axi_clkgen->base + reg); 168 } 169 170 static int axi_clkgen_wait_non_busy(struct axi_clkgen *axi_clkgen) 171 { 172 unsigned int timeout = 10000; 173 unsigned int val; 174 175 do { 176 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_STATUS, &val); 177 } while ((val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) && --timeout); 178 179 if (val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) 180 return -EIO; 181 182 return val & 0xffff; 183 } 184 185 static int axi_clkgen_mmcm_read(struct axi_clkgen *axi_clkgen, 186 unsigned int reg, unsigned int *val) 187 { 188 unsigned int reg_val; 189 int ret; 190 191 ret = axi_clkgen_wait_non_busy(axi_clkgen); 192 if (ret < 0) 193 return ret; 194 195 reg_val = AXI_CLKGEN_V2_DRP_CNTRL_SEL | AXI_CLKGEN_V2_DRP_CNTRL_READ; 196 reg_val |= (reg << 16); 197 198 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val); 199 200 ret = axi_clkgen_wait_non_busy(axi_clkgen); 201 if (ret < 0) 202 return ret; 203 204 *val = ret; 205 206 return 0; 207 } 208 209 static int axi_clkgen_mmcm_write(struct axi_clkgen *axi_clkgen, 210 unsigned int reg, unsigned int val, unsigned int mask) 211 { 212 unsigned int reg_val = 0; 213 int ret; 214 215 ret = axi_clkgen_wait_non_busy(axi_clkgen); 216 if (ret < 0) 217 return ret; 218 219 if (mask != 0xffff) { 220 axi_clkgen_mmcm_read(axi_clkgen, reg, ®_val); 221 reg_val &= ~mask; 222 } 223 224 reg_val |= AXI_CLKGEN_V2_DRP_CNTRL_SEL | (reg << 16) | (val & mask); 225 226 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val); 227 228 return 0; 229 } 230 231 static void axi_clkgen_mmcm_enable(struct axi_clkgen *axi_clkgen, 232 bool enable) 233 { 234 unsigned int val = AXI_CLKGEN_V2_RESET_ENABLE; 235 236 if (enable) 237 val |= AXI_CLKGEN_V2_RESET_MMCM_ENABLE; 238 239 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_RESET, val); 240 } 241 242 static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw) 243 { 244 return container_of(clk_hw, struct axi_clkgen, clk_hw); 245 } 246 247 static int axi_clkgen_set_rate(struct clk_hw *clk_hw, 248 unsigned long rate, unsigned long parent_rate) 249 { 250 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 251 unsigned int d, m, dout; 252 unsigned int nocount; 253 unsigned int high; 254 unsigned int edge; 255 unsigned int low; 256 uint32_t filter; 257 uint32_t lock; 258 259 if (parent_rate == 0 || rate == 0) 260 return -EINVAL; 261 262 axi_clkgen_calc_params(parent_rate, rate, &d, &m, &dout); 263 264 if (d == 0 || dout == 0 || m == 0) 265 return -EINVAL; 266 267 filter = axi_clkgen_lookup_filter(m - 1); 268 lock = axi_clkgen_lookup_lock(m - 1); 269 270 axi_clkgen_calc_clk_params(dout, &low, &high, &edge, &nocount); 271 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_1, 272 (high << 6) | low, 0xefff); 273 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_2, 274 (edge << 7) | (nocount << 6), 0x03ff); 275 276 axi_clkgen_calc_clk_params(d, &low, &high, &edge, &nocount); 277 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_DIV, 278 (edge << 13) | (nocount << 12) | (high << 6) | low, 0x3fff); 279 280 axi_clkgen_calc_clk_params(m, &low, &high, &edge, &nocount); 281 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB1, 282 (high << 6) | low, 0xefff); 283 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB2, 284 (edge << 7) | (nocount << 6), 0x03ff); 285 286 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK1, lock & 0x3ff, 0x3ff); 287 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK2, 288 (((lock >> 16) & 0x1f) << 10) | 0x1, 0x7fff); 289 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK3, 290 (((lock >> 24) & 0x1f) << 10) | 0x3e9, 0x7fff); 291 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER1, filter >> 16, 0x9900); 292 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER2, filter, 0x9900); 293 294 return 0; 295 } 296 297 static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate, 298 unsigned long *parent_rate) 299 { 300 unsigned int d, m, dout; 301 302 axi_clkgen_calc_params(*parent_rate, rate, &d, &m, &dout); 303 304 if (d == 0 || dout == 0 || m == 0) 305 return -EINVAL; 306 307 return *parent_rate / d * m / dout; 308 } 309 310 static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw, 311 unsigned long parent_rate) 312 { 313 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 314 unsigned int d, m, dout; 315 unsigned int reg; 316 unsigned long long tmp; 317 318 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); 319 dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); 320 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, ®); 321 d = (reg & 0x3f) + ((reg >> 6) & 0x3f); 322 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); 323 m = (reg & 0x3f) + ((reg >> 6) & 0x3f); 324 325 if (d == 0 || dout == 0) 326 return 0; 327 328 tmp = (unsigned long long)(parent_rate / d) * m; 329 do_div(tmp, dout); 330 331 return min_t(unsigned long long, tmp, ULONG_MAX); 332 } 333 334 static int axi_clkgen_enable(struct clk_hw *clk_hw) 335 { 336 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 337 338 axi_clkgen_mmcm_enable(axi_clkgen, true); 339 340 return 0; 341 } 342 343 static void axi_clkgen_disable(struct clk_hw *clk_hw) 344 { 345 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 346 347 axi_clkgen_mmcm_enable(axi_clkgen, false); 348 } 349 350 static int axi_clkgen_set_parent(struct clk_hw *clk_hw, u8 index) 351 { 352 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 353 354 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, index); 355 356 return 0; 357 } 358 359 static u8 axi_clkgen_get_parent(struct clk_hw *clk_hw) 360 { 361 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 362 unsigned int parent; 363 364 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, &parent); 365 366 return parent; 367 } 368 369 static const struct clk_ops axi_clkgen_ops = { 370 .recalc_rate = axi_clkgen_recalc_rate, 371 .round_rate = axi_clkgen_round_rate, 372 .set_rate = axi_clkgen_set_rate, 373 .enable = axi_clkgen_enable, 374 .disable = axi_clkgen_disable, 375 .set_parent = axi_clkgen_set_parent, 376 .get_parent = axi_clkgen_get_parent, 377 }; 378 379 static const struct of_device_id axi_clkgen_ids[] = { 380 { 381 .compatible = "adi,axi-clkgen-2.00.a", 382 }, 383 { }, 384 }; 385 MODULE_DEVICE_TABLE(of, axi_clkgen_ids); 386 387 static int axi_clkgen_probe(struct platform_device *pdev) 388 { 389 const struct of_device_id *id; 390 struct axi_clkgen *axi_clkgen; 391 struct clk_init_data init; 392 const char *parent_names[2]; 393 const char *clk_name; 394 struct resource *mem; 395 struct clk *clk; 396 unsigned int i; 397 398 if (!pdev->dev.of_node) 399 return -ENODEV; 400 401 id = of_match_node(axi_clkgen_ids, pdev->dev.of_node); 402 if (!id) 403 return -ENODEV; 404 405 axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL); 406 if (!axi_clkgen) 407 return -ENOMEM; 408 409 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 410 axi_clkgen->base = devm_ioremap_resource(&pdev->dev, mem); 411 if (IS_ERR(axi_clkgen->base)) 412 return PTR_ERR(axi_clkgen->base); 413 414 init.num_parents = of_clk_get_parent_count(pdev->dev.of_node); 415 if (init.num_parents < 1 || init.num_parents > 2) 416 return -EINVAL; 417 418 for (i = 0; i < init.num_parents; i++) { 419 parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i); 420 if (!parent_names[i]) 421 return -EINVAL; 422 } 423 424 clk_name = pdev->dev.of_node->name; 425 of_property_read_string(pdev->dev.of_node, "clock-output-names", 426 &clk_name); 427 428 init.name = clk_name; 429 init.ops = &axi_clkgen_ops; 430 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; 431 init.parent_names = parent_names; 432 433 axi_clkgen_mmcm_enable(axi_clkgen, false); 434 435 axi_clkgen->clk_hw.init = &init; 436 clk = devm_clk_register(&pdev->dev, &axi_clkgen->clk_hw); 437 if (IS_ERR(clk)) 438 return PTR_ERR(clk); 439 440 return of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, 441 clk); 442 } 443 444 static int axi_clkgen_remove(struct platform_device *pdev) 445 { 446 of_clk_del_provider(pdev->dev.of_node); 447 448 return 0; 449 } 450 451 static struct platform_driver axi_clkgen_driver = { 452 .driver = { 453 .name = "adi-axi-clkgen", 454 .of_match_table = axi_clkgen_ids, 455 }, 456 .probe = axi_clkgen_probe, 457 .remove = axi_clkgen_remove, 458 }; 459 module_platform_driver(axi_clkgen_driver); 460 461 MODULE_LICENSE("GPL v2"); 462 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 463 MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator"); 464