arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c

   1 /*
   2  * OMAP2xxx DVFS virtual clock functions
   3  *
   4  * Copyright (C) 2005-2008 Texas Instruments, Inc.
   5  * Copyright (C) 2004-2010 Nokia Corporation
   6  *
   7  * Contacts:
   8  * Richard Woodruff <r-woodruff2@ti.com>
   9  * Paul Walmsley
  10  *
  11  * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
  12  * Gordon McNutt and RidgeRun, Inc.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  *
  18  * XXX Some of this code should be replaceable by the upcoming OPP layer
  19  * code.  However, some notion of "rate set" is probably still necessary
  20  * for OMAP2xxx at least.  Rate sets should be generalized so they can be
  21  * used for any OMAP chip, not just OMAP2xxx.  In particular, Richard Woodruff
  22  * has in the past expressed a preference to use rate sets for OPP changes,
  23  * rather than dynamically recalculating the clock tree, so if someone wants
  24  * this badly enough to write the code to handle it, we should support it
  25  * as an option.
  26  */
  27 #undef DEBUG
  28
  29 #include <linux/kernel.h>
  30 #include <linux/errno.h>
  31 #include <linux/clk.h>
  32 #include <linux/io.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/slab.h>
  35
  36 #include <plat/clock.h>
  37 #include <plat/sram.h>
  38 #include <plat/sdrc.h>
  39
  40 #include "clock.h"
  41 #include "clock2xxx.h"
  42 #include "opp2xxx.h"
  43 #include "cm2xxx_3xxx.h"
  44 #include "cm-regbits-24xx.h"
  45
  46 const struct prcm_config *curr_prcm_set;
  47 const struct prcm_config *rate_table;
  48
  49 /**
  50  * omap2_table_mpu_recalc - just return the MPU speed
  51  * @clk: virt_prcm_set struct clk
  52  *
  53  * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
  54  */
  55 unsigned long omap2_table_mpu_recalc(struct clk *clk)
  56 {
  57         return curr_prcm_set->mpu_speed;
  58 }
  59
  60 /*
  61  * Look for a rate equal or less than the target rate given a configuration set.
  62  *
  63  * What's not entirely clear is "which" field represents the key field.
  64  * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
  65  * just uses the ARM rates.
  66  */
  67 long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
  68 {
  69         const struct prcm_config *ptr;
  70         long highest_rate;
  71
  72         highest_rate = -EINVAL;
  73
  74         for (ptr = rate_table; ptr->mpu_speed; ptr++) {
  75                 if (!(ptr->flags & cpu_mask))
  76                         continue;
  77                 if (ptr->xtal_speed != sclk->rate)
  78                         continue;
  79
  80                 highest_rate = ptr->mpu_speed;
  81
  82                 /* Can check only after xtal frequency check */
  83                 if (ptr->mpu_speed <= rate)
  84                         break;
  85         }
  86         return highest_rate;
  87 }
  88
  89 /* Sets basic clocks based on the specified rate */
  90 int omap2_select_table_rate(struct clk *clk, unsigned long rate)
  91 {
  92         u32 cur_rate, done_rate, bypass = 0, tmp;
  93         const struct prcm_config *prcm;
  94         unsigned long found_speed = 0;
  95         unsigned long flags;
  96
  97         for (prcm = rate_table; prcm->mpu_speed; prcm++) {
  98                 if (!(prcm->flags & cpu_mask))
  99                         continue;
 100
 101                 if (prcm->xtal_speed != sclk->rate)
 102                         continue;
 103
 104                 if (prcm->mpu_speed <= rate) {
 105                         found_speed = prcm->mpu_speed;
 106                         break;
 107                 }
 108         }
 109
 110         if (!found_speed) {
 111                 printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
 112                        rate / 1000000);
 113                 return -EINVAL;
 114         }
 115
 116         curr_prcm_set = prcm;
 117         cur_rate = omap2xxx_clk_get_core_rate(dclk);
 118
 119         if (prcm->dpll_speed == cur_rate / 2) {
 120                 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
 121         } else if (prcm->dpll_speed == cur_rate * 2) {
 122                 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
 123         } else if (prcm->dpll_speed != cur_rate) {
 124                 local_irq_save(flags);
 125
 126                 if (prcm->dpll_speed == prcm->xtal_speed)
 127                         bypass = 1;
 128
 129                 if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
 130                     CORE_CLK_SRC_DPLL_X2)
 131                         done_rate = CORE_CLK_SRC_DPLL_X2;
 132                 else
 133                         done_rate = CORE_CLK_SRC_DPLL;
 134
 135                 /* MPU divider */
 136                 omap2_cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
 137
 138                 /* dsp + iva1 div(2420), iva2.1(2430) */
 139                 omap2_cm_write_mod_reg(prcm->cm_clksel_dsp,
 140                                  OMAP24XX_DSP_MOD, CM_CLKSEL);
 141
 142                 omap2_cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
 143
 144                 /* Major subsystem dividers */
 145                 tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
 146                 omap2_cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD,
 147                                  CM_CLKSEL1);
 148
 149                 if (cpu_is_omap2430())
 150                         omap2_cm_write_mod_reg(prcm->cm_clksel_mdm,
 151                                          OMAP2430_MDM_MOD, CM_CLKSEL);
 152
 153                 /* x2 to enter omap2xxx_sdrc_init_params() */
 154                 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
 155
 156                 omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
 157                                bypass);
 158
 159                 omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
 160                 omap2xxx_sdrc_reprogram(done_rate, 0);
 161
 162                 local_irq_restore(flags);
 163         }
 164
 165         return 0;
 166 }
 167
 168 #ifdef CONFIG_CPU_FREQ
 169 /*
 170  * Walk PRCM rate table and fillout cpufreq freq_table
 171  * XXX This should be replaced by an OPP layer in the near future
 172  */
 173 static struct cpufreq_frequency_table *freq_table;
 174
 175 void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 176 {
 177         const struct prcm_config *prcm;
 178         int i = 0;
 179         int tbl_sz = 0;
 180
 181         if (!cpu_is_omap24xx())
 182                 return;
 183
 184         for (prcm = rate_table; prcm->mpu_speed; prcm++) {
 185                 if (!(prcm->flags & cpu_mask))
 186                         continue;
 187                 if (prcm->xtal_speed != sclk->rate)
 188                         continue;
 189
 190                 /* don't put bypass rates in table */
 191                 if (prcm->dpll_speed == prcm->xtal_speed)
 192                         continue;
 193
 194                 tbl_sz++;
 195         }
 196
 197         /*
 198          * XXX Ensure that we're doing what CPUFreq expects for this error
 199          * case and the following one
 200          */
 201         if (tbl_sz == 0) {
 202                 pr_warning("%s: no matching entries in rate_table\n",
 203                            __func__);
 204                 return;
 205         }
 206
 207         /* Include the CPUFREQ_TABLE_END terminator entry */
 208         tbl_sz++;
 209
 210         freq_table = kzalloc(sizeof(struct cpufreq_frequency_table) * tbl_sz,
 211                              GFP_ATOMIC);
 212         if (!freq_table) {
 213                 pr_err("%s: could not kzalloc frequency table\n", __func__);
 214                 return;
 215         }
 216
 217         for (prcm = rate_table; prcm->mpu_speed; prcm++) {
 218                 if (!(prcm->flags & cpu_mask))
 219                         continue;
 220                 if (prcm->xtal_speed != sclk->rate)
 221                         continue;
 222
 223                 /* don't put bypass rates in table */
 224                 if (prcm->dpll_speed == prcm->xtal_speed)
 225                         continue;
 226
 227                 freq_table[i].index = i;
 228                 freq_table[i].frequency = prcm->mpu_speed / 1000;
 229                 i++;
 230         }
 231
 232         freq_table[i].index = i;
 233         freq_table[i].frequency = CPUFREQ_TABLE_END;
 234
 235         *table = &freq_table[0];
 236 }
 237
 238 void omap2_clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
 239 {
 240         if (!cpu_is_omap24xx())
 241                 return;
 242
 243         kfree(freq_table);
 244 }
 245
 246 #endif