478 lines · c
1/*2 * Helper routines for SuperH Clock Pulse Generator blocks (CPG).3 *4 * Copyright (C) 2010 Magnus Damm5 * Copyright (C) 2010 - 2012 Paul Mundt6 *7 * This file is subject to the terms and conditions of the GNU General Public8 * License. See the file "COPYING" in the main directory of this archive9 * for more details.10 */11#include <linux/clk.h>12#include <linux/compiler.h>13#include <linux/slab.h>14#include <linux/io.h>15#include <linux/sh_clk.h>16 17#define CPG_CKSTP_BIT BIT(8)18 19static unsigned int sh_clk_read(struct clk *clk)20{21 if (clk->flags & CLK_ENABLE_REG_8BIT)22 return ioread8(clk->mapped_reg);23 else if (clk->flags & CLK_ENABLE_REG_16BIT)24 return ioread16(clk->mapped_reg);25 26 return ioread32(clk->mapped_reg);27}28 29static void sh_clk_write(int value, struct clk *clk)30{31 if (clk->flags & CLK_ENABLE_REG_8BIT)32 iowrite8(value, clk->mapped_reg);33 else if (clk->flags & CLK_ENABLE_REG_16BIT)34 iowrite16(value, clk->mapped_reg);35 else36 iowrite32(value, clk->mapped_reg);37}38 39static int sh_clk_mstp_enable(struct clk *clk)40{41 sh_clk_write(sh_clk_read(clk) & ~(1 << clk->enable_bit), clk);42 if (clk->status_reg) {43 unsigned int (*read)(const void __iomem *addr);44 int i;45 void __iomem *mapped_status = (phys_addr_t)clk->status_reg -46 (phys_addr_t)clk->enable_reg + clk->mapped_reg;47 48 if (clk->flags & CLK_ENABLE_REG_8BIT)49 read = ioread8;50 else if (clk->flags & CLK_ENABLE_REG_16BIT)51 read = ioread16;52 else53 read = ioread32;54 55 for (i = 1000;56 (read(mapped_status) & (1 << clk->enable_bit)) && i;57 i--)58 cpu_relax();59 if (!i) {60 pr_err("cpg: failed to enable %p[%d]\n",61 clk->enable_reg, clk->enable_bit);62 return -ETIMEDOUT;63 }64 }65 return 0;66}67 68static void sh_clk_mstp_disable(struct clk *clk)69{70 sh_clk_write(sh_clk_read(clk) | (1 << clk->enable_bit), clk);71}72 73static struct sh_clk_ops sh_clk_mstp_clk_ops = {74 .enable = sh_clk_mstp_enable,75 .disable = sh_clk_mstp_disable,76 .recalc = followparent_recalc,77};78 79int __init sh_clk_mstp_register(struct clk *clks, int nr)80{81 struct clk *clkp;82 int ret = 0;83 int k;84 85 for (k = 0; !ret && (k < nr); k++) {86 clkp = clks + k;87 clkp->ops = &sh_clk_mstp_clk_ops;88 ret |= clk_register(clkp);89 }90 91 return ret;92}93 94/*95 * Div/mult table lookup helpers96 */97static inline struct clk_div_table *clk_to_div_table(struct clk *clk)98{99 return clk->priv;100}101 102static inline struct clk_div_mult_table *clk_to_div_mult_table(struct clk *clk)103{104 return clk_to_div_table(clk)->div_mult_table;105}106 107/*108 * Common div ops109 */110static long sh_clk_div_round_rate(struct clk *clk, unsigned long rate)111{112 return clk_rate_table_round(clk, clk->freq_table, rate);113}114 115static unsigned long sh_clk_div_recalc(struct clk *clk)116{117 struct clk_div_mult_table *table = clk_to_div_mult_table(clk);118 unsigned int idx;119 120 clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,121 table, clk->arch_flags ? &clk->arch_flags : NULL);122 123 idx = (sh_clk_read(clk) >> clk->enable_bit) & clk->div_mask;124 125 return clk->freq_table[idx].frequency;126}127 128static int sh_clk_div_set_rate(struct clk *clk, unsigned long rate)129{130 struct clk_div_table *dt = clk_to_div_table(clk);131 unsigned long value;132 int idx;133 134 idx = clk_rate_table_find(clk, clk->freq_table, rate);135 if (idx < 0)136 return idx;137 138 value = sh_clk_read(clk);139 value &= ~(clk->div_mask << clk->enable_bit);140 value |= (idx << clk->enable_bit);141 sh_clk_write(value, clk);142 143 /* XXX: Should use a post-change notifier */144 if (dt->kick)145 dt->kick(clk);146 147 return 0;148}149 150static int sh_clk_div_enable(struct clk *clk)151{152 if (clk->div_mask == SH_CLK_DIV6_MSK) {153 int ret = sh_clk_div_set_rate(clk, clk->rate);154 if (ret < 0)155 return ret;156 }157 158 sh_clk_write(sh_clk_read(clk) & ~CPG_CKSTP_BIT, clk);159 return 0;160}161 162static void sh_clk_div_disable(struct clk *clk)163{164 unsigned int val;165 166 val = sh_clk_read(clk);167 val |= CPG_CKSTP_BIT;168 169 /*170 * div6 clocks require the divisor field to be non-zero or the171 * above CKSTP toggle silently fails. Ensure that the divisor172 * array is reset to its initial state on disable.173 */174 if (clk->flags & CLK_MASK_DIV_ON_DISABLE)175 val |= clk->div_mask;176 177 sh_clk_write(val, clk);178}179 180static struct sh_clk_ops sh_clk_div_clk_ops = {181 .recalc = sh_clk_div_recalc,182 .set_rate = sh_clk_div_set_rate,183 .round_rate = sh_clk_div_round_rate,184};185 186static struct sh_clk_ops sh_clk_div_enable_clk_ops = {187 .recalc = sh_clk_div_recalc,188 .set_rate = sh_clk_div_set_rate,189 .round_rate = sh_clk_div_round_rate,190 .enable = sh_clk_div_enable,191 .disable = sh_clk_div_disable,192};193 194static int __init sh_clk_init_parent(struct clk *clk)195{196 u32 val;197 198 if (clk->parent)199 return 0;200 201 if (!clk->parent_table || !clk->parent_num)202 return 0;203 204 if (!clk->src_width) {205 pr_err("sh_clk_init_parent: cannot select parent clock\n");206 return -EINVAL;207 }208 209 val = (sh_clk_read(clk) >> clk->src_shift);210 val &= (1 << clk->src_width) - 1;211 212 if (val >= clk->parent_num) {213 pr_err("sh_clk_init_parent: parent table size failed\n");214 return -EINVAL;215 }216 217 clk_reparent(clk, clk->parent_table[val]);218 if (!clk->parent) {219 pr_err("sh_clk_init_parent: unable to set parent");220 return -EINVAL;221 }222 223 return 0;224}225 226static int __init sh_clk_div_register_ops(struct clk *clks, int nr,227 struct clk_div_table *table, struct sh_clk_ops *ops)228{229 struct clk *clkp;230 void *freq_table;231 int nr_divs = table->div_mult_table->nr_divisors;232 int freq_table_size = sizeof(struct cpufreq_frequency_table);233 int ret = 0;234 int k;235 236 freq_table_size *= (nr_divs + 1);237 freq_table = kcalloc(nr, freq_table_size, GFP_KERNEL);238 if (!freq_table) {239 pr_err("%s: unable to alloc memory\n", __func__);240 return -ENOMEM;241 }242 243 for (k = 0; !ret && (k < nr); k++) {244 clkp = clks + k;245 246 clkp->ops = ops;247 clkp->priv = table;248 249 clkp->freq_table = freq_table + (k * freq_table_size);250 clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;251 252 ret = clk_register(clkp);253 if (ret == 0)254 ret = sh_clk_init_parent(clkp);255 }256 257 return ret;258}259 260/*261 * div6 support262 */263static int sh_clk_div6_divisors[64] = {264 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,265 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,266 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,267 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64268};269 270static struct clk_div_mult_table div6_div_mult_table = {271 .divisors = sh_clk_div6_divisors,272 .nr_divisors = ARRAY_SIZE(sh_clk_div6_divisors),273};274 275static struct clk_div_table sh_clk_div6_table = {276 .div_mult_table = &div6_div_mult_table,277};278 279static int sh_clk_div6_set_parent(struct clk *clk, struct clk *parent)280{281 struct clk_div_mult_table *table = clk_to_div_mult_table(clk);282 u32 value;283 int ret, i;284 285 if (!clk->parent_table || !clk->parent_num)286 return -EINVAL;287 288 /* Search the parent */289 for (i = 0; i < clk->parent_num; i++)290 if (clk->parent_table[i] == parent)291 break;292 293 if (i == clk->parent_num)294 return -ENODEV;295 296 ret = clk_reparent(clk, parent);297 if (ret < 0)298 return ret;299 300 value = sh_clk_read(clk) &301 ~(((1 << clk->src_width) - 1) << clk->src_shift);302 303 sh_clk_write(value | (i << clk->src_shift), clk);304 305 /* Rebuild the frequency table */306 clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,307 table, NULL);308 309 return 0;310}311 312static struct sh_clk_ops sh_clk_div6_reparent_clk_ops = {313 .recalc = sh_clk_div_recalc,314 .round_rate = sh_clk_div_round_rate,315 .set_rate = sh_clk_div_set_rate,316 .enable = sh_clk_div_enable,317 .disable = sh_clk_div_disable,318 .set_parent = sh_clk_div6_set_parent,319};320 321int __init sh_clk_div6_register(struct clk *clks, int nr)322{323 return sh_clk_div_register_ops(clks, nr, &sh_clk_div6_table,324 &sh_clk_div_enable_clk_ops);325}326 327int __init sh_clk_div6_reparent_register(struct clk *clks, int nr)328{329 return sh_clk_div_register_ops(clks, nr, &sh_clk_div6_table,330 &sh_clk_div6_reparent_clk_ops);331}332 333/*334 * div4 support335 */336static int sh_clk_div4_set_parent(struct clk *clk, struct clk *parent)337{338 struct clk_div_mult_table *table = clk_to_div_mult_table(clk);339 u32 value;340 int ret;341 342 /* we really need a better way to determine parent index, but for343 * now assume internal parent comes with CLK_ENABLE_ON_INIT set,344 * no CLK_ENABLE_ON_INIT means external clock...345 */346 347 if (parent->flags & CLK_ENABLE_ON_INIT)348 value = sh_clk_read(clk) & ~(1 << 7);349 else350 value = sh_clk_read(clk) | (1 << 7);351 352 ret = clk_reparent(clk, parent);353 if (ret < 0)354 return ret;355 356 sh_clk_write(value, clk);357 358 /* Rebiuld the frequency table */359 clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,360 table, &clk->arch_flags);361 362 return 0;363}364 365static struct sh_clk_ops sh_clk_div4_reparent_clk_ops = {366 .recalc = sh_clk_div_recalc,367 .set_rate = sh_clk_div_set_rate,368 .round_rate = sh_clk_div_round_rate,369 .enable = sh_clk_div_enable,370 .disable = sh_clk_div_disable,371 .set_parent = sh_clk_div4_set_parent,372};373 374int __init sh_clk_div4_register(struct clk *clks, int nr,375 struct clk_div4_table *table)376{377 return sh_clk_div_register_ops(clks, nr, table, &sh_clk_div_clk_ops);378}379 380int __init sh_clk_div4_enable_register(struct clk *clks, int nr,381 struct clk_div4_table *table)382{383 return sh_clk_div_register_ops(clks, nr, table,384 &sh_clk_div_enable_clk_ops);385}386 387int __init sh_clk_div4_reparent_register(struct clk *clks, int nr,388 struct clk_div4_table *table)389{390 return sh_clk_div_register_ops(clks, nr, table,391 &sh_clk_div4_reparent_clk_ops);392}393 394/* FSI-DIV */395static unsigned long fsidiv_recalc(struct clk *clk)396{397 u32 value;398 399 value = __raw_readl(clk->mapping->base);400 401 value >>= 16;402 if (value < 2)403 return clk->parent->rate;404 405 return clk->parent->rate / value;406}407 408static long fsidiv_round_rate(struct clk *clk, unsigned long rate)409{410 return clk_rate_div_range_round(clk, 1, 0xffff, rate);411}412 413static void fsidiv_disable(struct clk *clk)414{415 __raw_writel(0, clk->mapping->base);416}417 418static int fsidiv_enable(struct clk *clk)419{420 u32 value;421 422 value = __raw_readl(clk->mapping->base) >> 16;423 if (value < 2)424 return 0;425 426 __raw_writel((value << 16) | 0x3, clk->mapping->base);427 428 return 0;429}430 431static int fsidiv_set_rate(struct clk *clk, unsigned long rate)432{433 int idx;434 435 idx = (clk->parent->rate / rate) & 0xffff;436 if (idx < 2)437 __raw_writel(0, clk->mapping->base);438 else439 __raw_writel(idx << 16, clk->mapping->base);440 441 return 0;442}443 444static struct sh_clk_ops fsidiv_clk_ops = {445 .recalc = fsidiv_recalc,446 .round_rate = fsidiv_round_rate,447 .set_rate = fsidiv_set_rate,448 .enable = fsidiv_enable,449 .disable = fsidiv_disable,450};451 452int __init sh_clk_fsidiv_register(struct clk *clks, int nr)453{454 struct clk_mapping *map;455 int i;456 457 for (i = 0; i < nr; i++) {458 459 map = kzalloc(sizeof(struct clk_mapping), GFP_KERNEL);460 if (!map) {461 pr_err("%s: unable to alloc memory\n", __func__);462 return -ENOMEM;463 }464 465 /* clks[i].enable_reg came from SH_CLK_FSIDIV() */466 map->phys = (phys_addr_t)clks[i].enable_reg;467 map->len = 8;468 469 clks[i].enable_reg = 0; /* remove .enable_reg */470 clks[i].ops = &fsidiv_clk_ops;471 clks[i].mapping = map;472 473 clk_register(&clks[i]);474 }475 476 return 0;477}478