1 /* 2 * OMAP APLL clock support 3 * 4 * Copyright (C) 2013 Texas Instruments, Inc. 5 * 6 * J Keerthy <j-keerthy@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 13 * kind, whether express or implied; without even the implied warranty 14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/clk.h> 19 #include <linux/clk-provider.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/io.h> 23 #include <linux/err.h> 24 #include <linux/string.h> 25 #include <linux/log2.h> 26 #include <linux/of.h> 27 #include <linux/of_address.h> 28 #include <linux/clk/ti.h> 29 #include <linux/delay.h> 30 31 #include "clock.h" 32 33 #define APLL_FORCE_LOCK 0x1 34 #define APLL_AUTO_IDLE 0x2 35 #define MAX_APLL_WAIT_TRIES 1000000 36 37 #undef pr_fmt 38 #define pr_fmt(fmt) "%s: " fmt, __func__ 39 40 static int dra7_apll_enable(struct clk_hw *hw) 41 { 42 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 43 int r = 0, i = 0; 44 struct dpll_data *ad; 45 const char *clk_name; 46 u8 state = 1; 47 u32 v; 48 49 ad = clk->dpll_data; 50 if (!ad) 51 return -EINVAL; 52 53 clk_name = clk_hw_get_name(&clk->hw); 54 55 state <<= __ffs(ad->idlest_mask); 56 57 /* Check is already locked */ 58 v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg); 59 60 if ((v & ad->idlest_mask) == state) 61 return r; 62 63 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 64 v &= ~ad->enable_mask; 65 v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask); 66 ti_clk_ll_ops->clk_writel(v, &ad->control_reg); 67 68 state <<= __ffs(ad->idlest_mask); 69 70 while (1) { 71 v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg); 72 if ((v & ad->idlest_mask) == state) 73 break; 74 if (i > MAX_APLL_WAIT_TRIES) 75 break; 76 i++; 77 udelay(1); 78 } 79 80 if (i == MAX_APLL_WAIT_TRIES) { 81 pr_warn("clock: %s failed transition to '%s'\n", 82 clk_name, (state) ? "locked" : "bypassed"); 83 r = -EBUSY; 84 } else 85 pr_debug("clock: %s transition to '%s' in %d loops\n", 86 clk_name, (state) ? "locked" : "bypassed", i); 87 88 return r; 89 } 90 91 static void dra7_apll_disable(struct clk_hw *hw) 92 { 93 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 94 struct dpll_data *ad; 95 u8 state = 1; 96 u32 v; 97 98 ad = clk->dpll_data; 99 100 state <<= __ffs(ad->idlest_mask); 101 102 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 103 v &= ~ad->enable_mask; 104 v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask); 105 ti_clk_ll_ops->clk_writel(v, &ad->control_reg); 106 } 107 108 static int dra7_apll_is_enabled(struct clk_hw *hw) 109 { 110 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 111 struct dpll_data *ad; 112 u32 v; 113 114 ad = clk->dpll_data; 115 116 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 117 v &= ad->enable_mask; 118 119 v >>= __ffs(ad->enable_mask); 120 121 return v == APLL_AUTO_IDLE ? 0 : 1; 122 } 123 124 static u8 dra7_init_apll_parent(struct clk_hw *hw) 125 { 126 return 0; 127 } 128 129 static const struct clk_ops apll_ck_ops = { 130 .enable = &dra7_apll_enable, 131 .disable = &dra7_apll_disable, 132 .is_enabled = &dra7_apll_is_enabled, 133 .get_parent = &dra7_init_apll_parent, 134 }; 135 136 static void __init omap_clk_register_apll(struct clk_hw *hw, 137 struct device_node *node) 138 { 139 struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw); 140 struct dpll_data *ad = clk_hw->dpll_data; 141 struct clk *clk; 142 143 clk = of_clk_get(node, 0); 144 if (IS_ERR(clk)) { 145 pr_debug("clk-ref for %s not ready, retry\n", 146 node->name); 147 if (!ti_clk_retry_init(node, hw, omap_clk_register_apll)) 148 return; 149 150 goto cleanup; 151 } 152 153 ad->clk_ref = __clk_get_hw(clk); 154 155 clk = of_clk_get(node, 1); 156 if (IS_ERR(clk)) { 157 pr_debug("clk-bypass for %s not ready, retry\n", 158 node->name); 159 if (!ti_clk_retry_init(node, hw, omap_clk_register_apll)) 160 return; 161 162 goto cleanup; 163 } 164 165 ad->clk_bypass = __clk_get_hw(clk); 166 167 clk = ti_clk_register(NULL, &clk_hw->hw, node->name); 168 if (!IS_ERR(clk)) { 169 of_clk_add_provider(node, of_clk_src_simple_get, clk); 170 kfree(clk_hw->hw.init->parent_names); 171 kfree(clk_hw->hw.init); 172 return; 173 } 174 175 cleanup: 176 kfree(clk_hw->dpll_data); 177 kfree(clk_hw->hw.init->parent_names); 178 kfree(clk_hw->hw.init); 179 kfree(clk_hw); 180 } 181 182 static void __init of_dra7_apll_setup(struct device_node *node) 183 { 184 struct dpll_data *ad = NULL; 185 struct clk_hw_omap *clk_hw = NULL; 186 struct clk_init_data *init = NULL; 187 const char **parent_names = NULL; 188 int ret; 189 190 ad = kzalloc(sizeof(*ad), GFP_KERNEL); 191 clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); 192 init = kzalloc(sizeof(*init), GFP_KERNEL); 193 if (!ad || !clk_hw || !init) 194 goto cleanup; 195 196 clk_hw->dpll_data = ad; 197 clk_hw->hw.init = init; 198 199 init->name = node->name; 200 init->ops = &apll_ck_ops; 201 202 init->num_parents = of_clk_get_parent_count(node); 203 if (init->num_parents < 1) { 204 pr_err("dra7 apll %s must have parent(s)\n", node->name); 205 goto cleanup; 206 } 207 208 parent_names = kzalloc(sizeof(char *) * init->num_parents, GFP_KERNEL); 209 if (!parent_names) 210 goto cleanup; 211 212 of_clk_parent_fill(node, parent_names, init->num_parents); 213 214 init->parent_names = parent_names; 215 216 ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg); 217 ret |= ti_clk_get_reg_addr(node, 1, &ad->idlest_reg); 218 219 if (ret) 220 goto cleanup; 221 222 ad->idlest_mask = 0x1; 223 ad->enable_mask = 0x3; 224 225 omap_clk_register_apll(&clk_hw->hw, node); 226 return; 227 228 cleanup: 229 kfree(parent_names); 230 kfree(ad); 231 kfree(clk_hw); 232 kfree(init); 233 } 234 CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup); 235 236 #define OMAP2_EN_APLL_LOCKED 0x3 237 #define OMAP2_EN_APLL_STOPPED 0x0 238 239 static int omap2_apll_is_enabled(struct clk_hw *hw) 240 { 241 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 242 struct dpll_data *ad = clk->dpll_data; 243 u32 v; 244 245 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 246 v &= ad->enable_mask; 247 248 v >>= __ffs(ad->enable_mask); 249 250 return v == OMAP2_EN_APLL_LOCKED ? 1 : 0; 251 } 252 253 static unsigned long omap2_apll_recalc(struct clk_hw *hw, 254 unsigned long parent_rate) 255 { 256 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 257 258 if (omap2_apll_is_enabled(hw)) 259 return clk->fixed_rate; 260 261 return 0; 262 } 263 264 static int omap2_apll_enable(struct clk_hw *hw) 265 { 266 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 267 struct dpll_data *ad = clk->dpll_data; 268 u32 v; 269 int i = 0; 270 271 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 272 v &= ~ad->enable_mask; 273 v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask); 274 ti_clk_ll_ops->clk_writel(v, &ad->control_reg); 275 276 while (1) { 277 v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg); 278 if (v & ad->idlest_mask) 279 break; 280 if (i > MAX_APLL_WAIT_TRIES) 281 break; 282 i++; 283 udelay(1); 284 } 285 286 if (i == MAX_APLL_WAIT_TRIES) { 287 pr_warn("%s failed to transition to locked\n", 288 clk_hw_get_name(&clk->hw)); 289 return -EBUSY; 290 } 291 292 return 0; 293 } 294 295 static void omap2_apll_disable(struct clk_hw *hw) 296 { 297 struct clk_hw_omap *clk = to_clk_hw_omap(hw); 298 struct dpll_data *ad = clk->dpll_data; 299 u32 v; 300 301 v = ti_clk_ll_ops->clk_readl(&ad->control_reg); 302 v &= ~ad->enable_mask; 303 v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask); 304 ti_clk_ll_ops->clk_writel(v, &ad->control_reg); 305 } 306 307 static struct clk_ops omap2_apll_ops = { 308 .enable = &omap2_apll_enable, 309 .disable = &omap2_apll_disable, 310 .is_enabled = &omap2_apll_is_enabled, 311 .recalc_rate = &omap2_apll_recalc, 312 }; 313 314 static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val) 315 { 316 struct dpll_data *ad = clk->dpll_data; 317 u32 v; 318 319 v = ti_clk_ll_ops->clk_readl(&ad->autoidle_reg); 320 v &= ~ad->autoidle_mask; 321 v |= val << __ffs(ad->autoidle_mask); 322 ti_clk_ll_ops->clk_writel(v, &ad->control_reg); 323 } 324 325 #define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP 0x3 326 #define OMAP2_APLL_AUTOIDLE_DISABLE 0x0 327 328 static void omap2_apll_allow_idle(struct clk_hw_omap *clk) 329 { 330 omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP); 331 } 332 333 static void omap2_apll_deny_idle(struct clk_hw_omap *clk) 334 { 335 omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE); 336 } 337 338 static const struct clk_hw_omap_ops omap2_apll_hwops = { 339 .allow_idle = &omap2_apll_allow_idle, 340 .deny_idle = &omap2_apll_deny_idle, 341 }; 342 343 static void __init of_omap2_apll_setup(struct device_node *node) 344 { 345 struct dpll_data *ad = NULL; 346 struct clk_hw_omap *clk_hw = NULL; 347 struct clk_init_data *init = NULL; 348 struct clk *clk; 349 const char *parent_name; 350 u32 val; 351 int ret; 352 353 ad = kzalloc(sizeof(*ad), GFP_KERNEL); 354 clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); 355 init = kzalloc(sizeof(*init), GFP_KERNEL); 356 357 if (!ad || !clk_hw || !init) 358 goto cleanup; 359 360 clk_hw->dpll_data = ad; 361 clk_hw->hw.init = init; 362 init->ops = &omap2_apll_ops; 363 init->name = node->name; 364 clk_hw->ops = &omap2_apll_hwops; 365 366 init->num_parents = of_clk_get_parent_count(node); 367 if (init->num_parents != 1) { 368 pr_err("%s must have one parent\n", node->name); 369 goto cleanup; 370 } 371 372 parent_name = of_clk_get_parent_name(node, 0); 373 init->parent_names = &parent_name; 374 375 if (of_property_read_u32(node, "ti,clock-frequency", &val)) { 376 pr_err("%s missing clock-frequency\n", node->name); 377 goto cleanup; 378 } 379 clk_hw->fixed_rate = val; 380 381 if (of_property_read_u32(node, "ti,bit-shift", &val)) { 382 pr_err("%s missing bit-shift\n", node->name); 383 goto cleanup; 384 } 385 386 clk_hw->enable_bit = val; 387 ad->enable_mask = 0x3 << val; 388 ad->autoidle_mask = 0x3 << val; 389 390 if (of_property_read_u32(node, "ti,idlest-shift", &val)) { 391 pr_err("%s missing idlest-shift\n", node->name); 392 goto cleanup; 393 } 394 395 ad->idlest_mask = 1 << val; 396 397 ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg); 398 ret |= ti_clk_get_reg_addr(node, 1, &ad->autoidle_reg); 399 ret |= ti_clk_get_reg_addr(node, 2, &ad->idlest_reg); 400 401 if (ret) 402 goto cleanup; 403 404 clk = clk_register(NULL, &clk_hw->hw); 405 if (!IS_ERR(clk)) { 406 of_clk_add_provider(node, of_clk_src_simple_get, clk); 407 kfree(init); 408 return; 409 } 410 cleanup: 411 kfree(ad); 412 kfree(clk_hw); 413 kfree(init); 414 } 415 CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock", 416 of_omap2_apll_setup); 417