arch/mips/ath79/clock.c

   1 /*
   2  *  Atheros AR71XX/AR724X/AR913X common routines
   3  *
   4  *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
   5  *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   6  *
   7  *  Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
   8  *
   9  *  This program is free software; you can redistribute it and/or modify it
  10  *  under the terms of the GNU General Public License version 2 as published
  11  *  by the Free Software Foundation.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/err.h>
  18 #include <linux/clk.h>
  19
  20 #include <asm/div64.h>
  21
  22 #include <asm/mach-ath79/ath79.h>
  23 #include <asm/mach-ath79/ar71xx_regs.h>
  24 #include "common.h"
  25
  26 #define AR71XX_BASE_FREQ        40000000
  27 #define AR724X_BASE_FREQ        5000000
  28 #define AR913X_BASE_FREQ        5000000
  29
  30 struct clk {
  31         unsigned long rate;
  32 };
  33
  34 static struct clk ath79_ref_clk;
  35 static struct clk ath79_cpu_clk;
  36 static struct clk ath79_ddr_clk;
  37 static struct clk ath79_ahb_clk;
  38 static struct clk ath79_wdt_clk;
  39 static struct clk ath79_uart_clk;
  40
  41 static void __init ar71xx_clocks_init(void)
  42 {
  43         u32 pll;
  44         u32 freq;
  45         u32 div;
  46
  47         ath79_ref_clk.rate = AR71XX_BASE_FREQ;
  48
  49         pll = ath79_pll_rr(AR71XX_PLL_REG_CPU_CONFIG);
  50
  51         div = ((pll >> AR71XX_PLL_DIV_SHIFT) & AR71XX_PLL_DIV_MASK) + 1;
  52         freq = div * ath79_ref_clk.rate;
  53
  54         div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
  55         ath79_cpu_clk.rate = freq / div;
  56
  57         div = ((pll >> AR71XX_DDR_DIV_SHIFT) & AR71XX_DDR_DIV_MASK) + 1;
  58         ath79_ddr_clk.rate = freq / div;
  59
  60         div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
  61         ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
  62
  63         ath79_wdt_clk.rate = ath79_ahb_clk.rate;
  64         ath79_uart_clk.rate = ath79_ahb_clk.rate;
  65 }
  66
  67 static void __init ar724x_clocks_init(void)
  68 {
  69         u32 pll;
  70         u32 freq;
  71         u32 div;
  72
  73         ath79_ref_clk.rate = AR724X_BASE_FREQ;
  74         pll = ath79_pll_rr(AR724X_PLL_REG_CPU_CONFIG);
  75
  76         div = ((pll >> AR724X_PLL_DIV_SHIFT) & AR724X_PLL_DIV_MASK);
  77         freq = div * ath79_ref_clk.rate;
  78
  79         div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK);
  80         freq *= div;
  81
  82         ath79_cpu_clk.rate = freq;
  83
  84         div = ((pll >> AR724X_DDR_DIV_SHIFT) & AR724X_DDR_DIV_MASK) + 1;
  85         ath79_ddr_clk.rate = freq / div;
  86
  87         div = (((pll >> AR724X_AHB_DIV_SHIFT) & AR724X_AHB_DIV_MASK) + 1) * 2;
  88         ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
  89
  90         ath79_wdt_clk.rate = ath79_ahb_clk.rate;
  91         ath79_uart_clk.rate = ath79_ahb_clk.rate;
  92 }
  93
  94 static void __init ar913x_clocks_init(void)
  95 {
  96         u32 pll;
  97         u32 freq;
  98         u32 div;
  99
 100         ath79_ref_clk.rate = AR913X_BASE_FREQ;
 101         pll = ath79_pll_rr(AR913X_PLL_REG_CPU_CONFIG);
 102
 103         div = ((pll >> AR913X_PLL_DIV_SHIFT) & AR913X_PLL_DIV_MASK);
 104         freq = div * ath79_ref_clk.rate;
 105
 106         ath79_cpu_clk.rate = freq;
 107
 108         div = ((pll >> AR913X_DDR_DIV_SHIFT) & AR913X_DDR_DIV_MASK) + 1;
 109         ath79_ddr_clk.rate = freq / div;
 110
 111         div = (((pll >> AR913X_AHB_DIV_SHIFT) & AR913X_AHB_DIV_MASK) + 1) * 2;
 112         ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
 113
 114         ath79_wdt_clk.rate = ath79_ahb_clk.rate;
 115         ath79_uart_clk.rate = ath79_ahb_clk.rate;
 116 }
 117
 118 static void __init ar933x_clocks_init(void)
 119 {
 120         u32 clock_ctrl;
 121         u32 cpu_config;
 122         u32 freq;
 123         u32 t;
 124
 125         t = ath79_reset_rr(AR933X_RESET_REG_BOOTSTRAP);
 126         if (t & AR933X_BOOTSTRAP_REF_CLK_40)
 127                 ath79_ref_clk.rate = (40 * 1000 * 1000);
 128         else
 129                 ath79_ref_clk.rate = (25 * 1000 * 1000);
 130
 131         clock_ctrl = ath79_pll_rr(AR933X_PLL_CLOCK_CTRL_REG);
 132         if (clock_ctrl & AR933X_PLL_CLOCK_CTRL_BYPASS) {
 133                 ath79_cpu_clk.rate = ath79_ref_clk.rate;
 134                 ath79_ahb_clk.rate = ath79_ref_clk.rate;
 135                 ath79_ddr_clk.rate = ath79_ref_clk.rate;
 136         } else {
 137                 cpu_config = ath79_pll_rr(AR933X_PLL_CPU_CONFIG_REG);
 138
 139                 t = (cpu_config >> AR933X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
 140                     AR933X_PLL_CPU_CONFIG_REFDIV_MASK;
 141                 freq = ath79_ref_clk.rate / t;
 142
 143                 t = (cpu_config >> AR933X_PLL_CPU_CONFIG_NINT_SHIFT) &
 144                     AR933X_PLL_CPU_CONFIG_NINT_MASK;
 145                 freq *= t;
 146
 147                 t = (cpu_config >> AR933X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
 148                     AR933X_PLL_CPU_CONFIG_OUTDIV_MASK;
 149                 if (t == 0)
 150                         t = 1;
 151
 152                 freq >>= t;
 153
 154                 t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_CPU_DIV_SHIFT) &
 155                      AR933X_PLL_CLOCK_CTRL_CPU_DIV_MASK) + 1;
 156                 ath79_cpu_clk.rate = freq / t;
 157
 158                 t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_DDR_DIV_SHIFT) &
 159                       AR933X_PLL_CLOCK_CTRL_DDR_DIV_MASK) + 1;
 160                 ath79_ddr_clk.rate = freq / t;
 161
 162                 t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_AHB_DIV_SHIFT) &
 163                      AR933X_PLL_CLOCK_CTRL_AHB_DIV_MASK) + 1;
 164                 ath79_ahb_clk.rate = freq / t;
 165         }
 166
 167         ath79_wdt_clk.rate = ath79_ref_clk.rate;
 168         ath79_uart_clk.rate = ath79_ref_clk.rate;
 169 }
 170
 171 static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac,
 172                                       u32 frac, u32 out_div)
 173 {
 174         u64 t;
 175         u32 ret;
 176
 177         t = ath79_ref_clk.rate;
 178         t *= nint;
 179         do_div(t, ref_div);
 180         ret = t;
 181
 182         t = ath79_ref_clk.rate;
 183         t *= nfrac;
 184         do_div(t, ref_div * frac);
 185         ret += t;
 186
 187         ret /= (1 << out_div);
 188         return ret;
 189 }
 190
 191 static void __init ar934x_clocks_init(void)
 192 {
 193         u32 pll, out_div, ref_div, nint, nfrac, frac, clk_ctrl, postdiv;
 194         u32 cpu_pll, ddr_pll;
 195         u32 bootstrap;
 196         void __iomem *dpll_base;
 197
 198         dpll_base = ioremap(AR934X_SRIF_BASE, AR934X_SRIF_SIZE);
 199
 200         bootstrap = ath79_reset_rr(AR934X_RESET_REG_BOOTSTRAP);
 201         if (bootstrap & AR934X_BOOTSTRAP_REF_CLK_40)
 202                 ath79_ref_clk.rate = 40 * 1000 * 1000;
 203         else
 204                 ath79_ref_clk.rate = 25 * 1000 * 1000;
 205
 206         pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG);
 207         if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
 208                 out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
 209                           AR934X_SRIF_DPLL2_OUTDIV_MASK;
 210                 pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL1_REG);
 211                 nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
 212                        AR934X_SRIF_DPLL1_NINT_MASK;
 213                 nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
 214                 ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
 215                           AR934X_SRIF_DPLL1_REFDIV_MASK;
 216                 frac = 1 << 18;
 217         } else {
 218                 pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG);
 219                 out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
 220                         AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
 221                 ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
 222                           AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
 223                 nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
 224                        AR934X_PLL_CPU_CONFIG_NINT_MASK;
 225                 nfrac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
 226                         AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
 227                 frac = 1 << 6;
 228         }
 229
 230         cpu_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
 231                                       nfrac, frac, out_div);
 232
 233         pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL2_REG);
 234         if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
 235                 out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
 236                           AR934X_SRIF_DPLL2_OUTDIV_MASK;
 237                 pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL1_REG);
 238                 nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
 239                        AR934X_SRIF_DPLL1_NINT_MASK;
 240                 nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
 241                 ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
 242                           AR934X_SRIF_DPLL1_REFDIV_MASK;
 243                 frac = 1 << 18;
 244         } else {
 245                 pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG);
 246                 out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
 247                           AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
 248                 ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
 249                            AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
 250                 nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
 251                        AR934X_PLL_DDR_CONFIG_NINT_MASK;
 252                 nfrac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
 253                         AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
 254                 frac = 1 << 10;
 255         }
 256
 257         ddr_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
 258                                       nfrac, frac, out_div);
 259
 260         clk_ctrl = ath79_pll_rr(AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
 261
 262         postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_SHIFT) &
 263                   AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_MASK;
 264
 265         if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_PLL_BYPASS)
 266                 ath79_cpu_clk.rate = ath79_ref_clk.rate;
 267         else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPUCLK_FROM_CPUPLL)
 268                 ath79_cpu_clk.rate = cpu_pll / (postdiv + 1);
 269         else
 270                 ath79_cpu_clk.rate = ddr_pll / (postdiv + 1);
 271
 272         postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_SHIFT) &
 273                   AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_MASK;
 274
 275         if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_PLL_BYPASS)
 276                 ath79_ddr_clk.rate = ath79_ref_clk.rate;
 277         else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDRCLK_FROM_DDRPLL)
 278                 ath79_ddr_clk.rate = ddr_pll / (postdiv + 1);
 279         else
 280                 ath79_ddr_clk.rate = cpu_pll / (postdiv + 1);
 281
 282         postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_SHIFT) &
 283                   AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_MASK;
 284
 285         if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_PLL_BYPASS)
 286                 ath79_ahb_clk.rate = ath79_ref_clk.rate;
 287         else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHBCLK_FROM_DDRPLL)
 288                 ath79_ahb_clk.rate = ddr_pll / (postdiv + 1);
 289         else
 290                 ath79_ahb_clk.rate = cpu_pll / (postdiv + 1);
 291
 292         ath79_wdt_clk.rate = ath79_ref_clk.rate;
 293         ath79_uart_clk.rate = ath79_ref_clk.rate;
 294
 295         iounmap(dpll_base);
 296 }
 297
 298 void __init ath79_clocks_init(void)
 299 {
 300         if (soc_is_ar71xx())
 301                 ar71xx_clocks_init();
 302         else if (soc_is_ar724x())
 303                 ar724x_clocks_init();
 304         else if (soc_is_ar913x())
 305                 ar913x_clocks_init();
 306         else if (soc_is_ar933x())
 307                 ar933x_clocks_init();
 308         else if (soc_is_ar934x())
 309                 ar934x_clocks_init();
 310         else
 311                 BUG();
 312
 313         pr_info("Clocks: CPU:%lu.%03luMHz, DDR:%lu.%03luMHz, AHB:%lu.%03luMHz, "
 314                 "Ref:%lu.%03luMHz",
 315                 ath79_cpu_clk.rate / 1000000,
 316                 (ath79_cpu_clk.rate / 1000) % 1000,
 317                 ath79_ddr_clk.rate / 1000000,
 318                 (ath79_ddr_clk.rate / 1000) % 1000,
 319                 ath79_ahb_clk.rate / 1000000,
 320                 (ath79_ahb_clk.rate / 1000) % 1000,
 321                 ath79_ref_clk.rate / 1000000,
 322                 (ath79_ref_clk.rate / 1000) % 1000);
 323 }
 324
 325 /*
 326  * Linux clock API
 327  */
 328 struct clk *clk_get(struct device *dev, const char *id)
 329 {
 330         if (!strcmp(id, "ref"))
 331                 return &ath79_ref_clk;
 332
 333         if (!strcmp(id, "cpu"))
 334                 return &ath79_cpu_clk;
 335
 336         if (!strcmp(id, "ddr"))
 337                 return &ath79_ddr_clk;
 338
 339         if (!strcmp(id, "ahb"))
 340                 return &ath79_ahb_clk;
 341
 342         if (!strcmp(id, "wdt"))
 343                 return &ath79_wdt_clk;
 344
 345         if (!strcmp(id, "uart"))
 346                 return &ath79_uart_clk;
 347
 348         return ERR_PTR(-ENOENT);
 349 }
 350 EXPORT_SYMBOL(clk_get);
 351
 352 int clk_enable(struct clk *clk)
 353 {
 354         return 0;
 355 }
 356 EXPORT_SYMBOL(clk_enable);
 357
 358 void clk_disable(struct clk *clk)
 359 {
 360 }
 361 EXPORT_SYMBOL(clk_disable);
 362
 363 unsigned long clk_get_rate(struct clk *clk)
 364 {
 365         return clk->rate;
 366 }
 367 EXPORT_SYMBOL(clk_get_rate);
 368
 369 void clk_put(struct clk *clk)
 370 {
 371 }
 372 EXPORT_SYMBOL(clk_put);