/*
* OMAP2xxx DVFS virtual clock functions
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
* Copyright (C) 2004-2010 Nokia Corporation
*
* Contacts:
* Richard Woodruff <r-woodruff2@ti.com>
* Paul Walmsley
*
* Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
* Gordon McNutt and RidgeRun, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* XXX Some of this code should be replaceable by the upcoming OPP layer
* code. However, some notion of "rate set" is probably still necessary
* for OMAP2xxx at least. Rate sets should be generalized so they can be
* used for any OMAP chip, not just OMAP2xxx. In particular, Richard Woodruff
* has in the past expressed a preference to use rate sets for OPP changes,
* rather than dynamically recalculating the clock tree, so if someone wants
* this badly enough to write the code to handle it, we should support it
* as an option.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <plat/cpu.h>
#include <plat/clock.h>
#include <plat/sram.h>
#include <plat/sdrc.h>
#include "clock.h"
#include "clock2xxx.h"
#include "opp2xxx.h"
#include "cm2xxx_3xxx.h"
#include "cm-regbits-24xx.h"
const struct prcm_config *curr_prcm_set;
const struct prcm_config *rate_table;
/**
* omap2_table_mpu_recalc - just return the MPU speed
* @clk: virt_prcm_set struct clk
*
* Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
*/
unsigned long omap2_table_mpu_recalc(struct clk *clk)
{
return curr_prcm_set->mpu_speed;
}
/*
* Look for a rate equal or less than the target rate given a configuration set.
*
* What's not entirely clear is "which" field represents the key field.
* Some might argue L3-DDR, others ARM, others IVA. This code is simple and
* just uses the ARM rates.
*/
long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
{
const struct prcm_config *ptr;
long highest_rate;
highest_rate = -EINVAL;
for (ptr = rate_table; ptr->mpu_speed; ptr++) {
if (!(ptr->flags & cpu_mask))
continue;
if (ptr->xtal_speed != sclk->rate)
continue;
highest_rate = ptr->mpu_speed;
/* Can check only after xtal frequency check */
if (ptr->mpu_speed <= rate)
break;
}
return highest_rate;
}
/* Sets basic clocks based on the specified rate */
int omap2_select_table_rate(struct clk *clk, unsigned long rate)
{
u32 cur_rate, done_rate, bypass = 0, tmp;
const struct prcm_config *prcm;
unsigned long found_speed = 0;
unsigned long flags;
for (prcm = rate_table; prcm->mpu_speed; prcm++) {
if (!(prcm->flags & cpu_mask))
continue;
if (prcm->xtal_speed != sclk->rate)
continue;
if (prcm->mpu_speed <= rate) {
found_speed = prcm->mpu_speed;
break;
}
}
if (!found_speed) {
printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
rate / 1000000);
return -EINVAL;
}
curr_prcm_set = prcm;
cur_rate = omap2xxx_clk_get_core_rate(dclk);
if (prcm->dpll_speed == cur_rate / 2) {
omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
} else if (prcm->dpll_speed == cur_rate * 2) {
omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
} else if (prcm->dpll_speed != cur_rate) {
local_irq_save(flags);
if (prcm->dpll_speed == prcm->xtal_speed)
bypass = 1;
if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
CORE_CLK_SRC_DPLL_X2)
done_rate = CORE_CLK_SRC_DPLL_X2;
else
done_rate = CORE_CLK_SRC_DPLL;
/* MPU divider */
omap2_cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
/* dsp + iva1 div(2420), iva2.1(2430) */
omap2_cm_write_mod_reg(prcm->cm_clksel_dsp,
OMAP24XX_DSP_MOD, CM_CLKSEL);
omap2_cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
/* Major subsystem dividers */
tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
omap2_cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD,
CM_CLKSEL1);
if (cpu_is_omap2430())
omap2_cm_write_mod_reg(prcm->cm_clksel_mdm,
OMAP2430_MDM_MOD, CM_CLKSEL);
/* x2 to enter omap2xxx_sdrc_init_params() */
omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
bypass);
omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
omap2xxx_sdrc_reprogram(done_rate, 0);
local_irq_restore(flags);
}
return 0;
}
#ifdef CONFIG_CPU_FREQ
/*
* Walk PRCM rate table and fillout cpufreq freq_table
* XXX This should be replaced by an OPP layer in the near future
*/
static struct cpufreq_frequency_table *freq_table;
void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
{
const struct prcm_config *prcm;
int i = 0;
int tbl_sz = 0;
if (!cpu_is_omap24xx())
return;
for (prcm = rate_table; prcm->mpu_speed; prcm++) {
if (!(prcm->flags & cpu_mask))
continue;
if (prcm->xtal_speed != sclk->rate)
continue;
/* don't put bypass rates in table */
if (prcm->dpll_speed == prcm->xtal_speed)
continue;
tbl_sz++;
}
/*
* XXX Ensure that we're doing what CPUFreq expects for this error
* case and the following one
*/
if (tbl_sz == 0) {
pr_warning("%s: no matching entries in rate_table\n",
__func__);
return;
}
/* Include the CPUFREQ_TABLE_END terminator entry */
tbl_sz++;
freq_table = kzalloc(sizeof(struct cpufreq_frequency_table) * tbl_sz,
GFP_ATOMIC);
if (!freq_table) {
pr_err("%s: could not kzalloc frequency table\n", __func__);
return;
}
for (prcm = rate_table; prcm->mpu_speed; prcm++) {
if (!(prcm->flags & cpu_mask))
continue;
if (prcm->xtal_speed != sclk->rate)
continue;
/* don't put bypass rates in table */
if (prcm->dpll_speed == prcm->xtal_speed)
continue;
freq_table[i].index = i;
freq_table[i].frequency = prcm->mpu_speed / 1000;
i++;
}
freq_table[i].index = i;
freq_table[i].frequency = CPUFREQ_TABLE_END;
*table = &freq_table[0];
}
void omap2_clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
{
if (!cpu_is_omap24xx())
return;
kfree(freq_table);
}
#endif
