2 * OMAP2xxx DVFS virtual clock functions
4 * Copyright (C) 2005-2008 Texas Instruments, Inc.
5 * Copyright (C) 2004-2010 Nokia Corporation
8 * Richard Woodruff <r-woodruff2@ti.com>
11 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
12 * Gordon McNutt and RidgeRun, Inc.
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.
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
29 #include <linux/kernel.h>
30 #include <linux/errno.h>
31 #include <linux/clk.h>
33 #include <linux/cpufreq.h>
34 #include <linux/slab.h>
36 #include "../plat-omap/sram.h"
40 #include "clock2xxx.h"
42 #include "cm2xxx_3xxx.h"
43 #include "cm-regbits-24xx.h"
46 const struct prcm_config *curr_prcm_set;
47 const struct prcm_config *rate_table;
50 * omap2_table_mpu_recalc - just return the MPU speed
51 * @clk: virt_prcm_set struct clk
53 * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
55 unsigned long omap2_table_mpu_recalc(struct clk *clk)
57 return curr_prcm_set->mpu_speed;
61 * Look for a rate equal or less than the target rate given a configuration set.
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.
67 long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
69 const struct prcm_config *ptr;
70 long highest_rate, sys_clk_rate;
72 highest_rate = -EINVAL;
73 sys_clk_rate = __clk_get_rate(sclk);
75 for (ptr = rate_table; ptr->mpu_speed; ptr++) {
76 if (!(ptr->flags & cpu_mask))
78 if (ptr->xtal_speed != sys_clk_rate)
81 highest_rate = ptr->mpu_speed;
83 /* Can check only after xtal frequency check */
84 if (ptr->mpu_speed <= rate)
90 /* Sets basic clocks based on the specified rate */
91 int omap2_select_table_rate(struct clk *clk, unsigned long rate)
93 u32 cur_rate, done_rate, bypass = 0, tmp;
94 const struct prcm_config *prcm;
95 unsigned long found_speed = 0;
99 sys_clk_rate = __clk_get_rate(sclk);
101 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
102 if (!(prcm->flags & cpu_mask))
105 if (prcm->xtal_speed != sys_clk_rate)
108 if (prcm->mpu_speed <= rate) {
109 found_speed = prcm->mpu_speed;
115 printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
120 curr_prcm_set = prcm;
121 cur_rate = omap2xxx_clk_get_core_rate(dclk);
123 if (prcm->dpll_speed == cur_rate / 2) {
124 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
125 } else if (prcm->dpll_speed == cur_rate * 2) {
126 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
127 } else if (prcm->dpll_speed != cur_rate) {
128 local_irq_save(flags);
130 if (prcm->dpll_speed == prcm->xtal_speed)
133 if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
134 CORE_CLK_SRC_DPLL_X2)
135 done_rate = CORE_CLK_SRC_DPLL_X2;
137 done_rate = CORE_CLK_SRC_DPLL;
140 omap2_cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
142 /* dsp + iva1 div(2420), iva2.1(2430) */
143 omap2_cm_write_mod_reg(prcm->cm_clksel_dsp,
144 OMAP24XX_DSP_MOD, CM_CLKSEL);
146 omap2_cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
148 /* Major subsystem dividers */
149 tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
150 omap2_cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD,
153 if (cpu_is_omap2430())
154 omap2_cm_write_mod_reg(prcm->cm_clksel_mdm,
155 OMAP2430_MDM_MOD, CM_CLKSEL);
157 /* x2 to enter omap2xxx_sdrc_init_params() */
158 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
160 omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
163 omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
164 omap2xxx_sdrc_reprogram(done_rate, 0);
166 local_irq_restore(flags);