Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / arch / arm / mach-omap2 / clkt2xxx_virt_prcm_set.c
blobb935ed2922d806725cd6916ce18bd429acf8e926
1 /*
2 * OMAP2xxx DVFS virtual clock functions
4 * Copyright (C) 2005-2008, 2012 Texas Instruments, Inc.
5 * Copyright (C) 2004-2010 Nokia Corporation
7 * Contacts:
8 * Richard Woodruff <r-woodruff2@ti.com>
9 * Paul Walmsley
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
25 * as an option.
27 #undef DEBUG
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>
36 #include "soc.h"
37 #include "clock.h"
38 #include "clock2xxx.h"
39 #include "opp2xxx.h"
40 #include "cm2xxx.h"
41 #include "cm-regbits-24xx.h"
42 #include "sdrc.h"
43 #include "sram.h"
45 const struct prcm_config *curr_prcm_set;
46 const struct prcm_config *rate_table;
49 * sys_ck_rate: the rate of the external high-frequency clock
50 * oscillator on the board. Set by the SoC-specific clock init code.
51 * Once set during a boot, will not change.
53 static unsigned long sys_ck_rate;
55 /**
56 * omap2_table_mpu_recalc - just return the MPU speed
57 * @clk: virt_prcm_set struct clk
59 * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
61 unsigned long omap2_table_mpu_recalc(struct clk_hw *clk,
62 unsigned long parent_rate)
64 return curr_prcm_set->mpu_speed;
68 * Look for a rate equal or less than the target rate given a configuration set.
70 * What's not entirely clear is "which" field represents the key field.
71 * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
72 * just uses the ARM rates.
74 long omap2_round_to_table_rate(struct clk_hw *hw, unsigned long rate,
75 unsigned long *parent_rate)
77 const struct prcm_config *ptr;
78 long highest_rate;
80 highest_rate = -EINVAL;
82 for (ptr = rate_table; ptr->mpu_speed; ptr++) {
83 if (!(ptr->flags & cpu_mask))
84 continue;
85 if (ptr->xtal_speed != sys_ck_rate)
86 continue;
88 highest_rate = ptr->mpu_speed;
90 /* Can check only after xtal frequency check */
91 if (ptr->mpu_speed <= rate)
92 break;
94 return highest_rate;
97 /* Sets basic clocks based on the specified rate */
98 int omap2_select_table_rate(struct clk_hw *hw, unsigned long rate,
99 unsigned long parent_rate)
101 u32 cur_rate, done_rate, bypass = 0;
102 const struct prcm_config *prcm;
103 unsigned long found_speed = 0;
104 unsigned long flags;
106 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
107 if (!(prcm->flags & cpu_mask))
108 continue;
110 if (prcm->xtal_speed != sys_ck_rate)
111 continue;
113 if (prcm->mpu_speed <= rate) {
114 found_speed = prcm->mpu_speed;
115 break;
119 if (!found_speed) {
120 printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
121 rate / 1000000);
122 return -EINVAL;
125 curr_prcm_set = prcm;
126 cur_rate = omap2xxx_clk_get_core_rate();
128 if (prcm->dpll_speed == cur_rate / 2) {
129 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
130 } else if (prcm->dpll_speed == cur_rate * 2) {
131 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
132 } else if (prcm->dpll_speed != cur_rate) {
133 local_irq_save(flags);
135 if (prcm->dpll_speed == prcm->xtal_speed)
136 bypass = 1;
138 if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
139 CORE_CLK_SRC_DPLL_X2)
140 done_rate = CORE_CLK_SRC_DPLL_X2;
141 else
142 done_rate = CORE_CLK_SRC_DPLL;
144 omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
145 prcm->cm_clksel_dsp,
146 prcm->cm_clksel_gfx,
147 prcm->cm_clksel1_core,
148 prcm->cm_clksel_mdm);
150 /* x2 to enter omap2xxx_sdrc_init_params() */
151 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
153 omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
154 bypass);
156 omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
157 omap2xxx_sdrc_reprogram(done_rate, 0);
159 local_irq_restore(flags);
162 return 0;
166 * omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
167 * table sets matches the current CORE DPLL hardware rate
169 * Check the MPU rate set by bootloader. Sets the 'curr_prcm_set'
170 * global to point to the active rate set when found; otherwise, sets
171 * it to NULL. No return value;
173 void omap2xxx_clkt_vps_check_bootloader_rates(void)
175 const struct prcm_config *prcm = NULL;
176 unsigned long rate;
178 rate = omap2xxx_clk_get_core_rate();
179 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
180 if (!(prcm->flags & cpu_mask))
181 continue;
182 if (prcm->xtal_speed != sys_ck_rate)
183 continue;
184 if (prcm->dpll_speed <= rate)
185 break;
187 curr_prcm_set = prcm;
191 * omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
193 * Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
194 * code. (The sys_ck rate does not -- or rather, must not -- change
195 * during kernel runtime.) Must be called after we have a valid
196 * sys_ck rate, but before the virt_prcm_set clock rate is
197 * recalculated. No return value.
199 void omap2xxx_clkt_vps_late_init(void)
201 struct clk *c;
203 c = clk_get(NULL, "sys_ck");
204 if (IS_ERR(c)) {
205 WARN(1, "could not locate sys_ck\n");
206 } else {
207 sys_ck_rate = clk_get_rate(c);
208 clk_put(c);