/*
* OMAP2xxx DVFS virtual clock functions
*
* Copyright (C) 2005-2008, 2012 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 "soc.h"
#include "clock.h"
#include "clock2xxx.h"
#include "opp2xxx.h"
#include "cm2xxx.h"
#include "cm-regbits-24xx.h"
#include "sdrc.h"
#include "sram.h"
const struct prcm_config *curr_prcm_set;
const struct prcm_config *rate_table;
/*
* sys_ck_rate: the rate of the external high-frequency clock
* oscillator on the board. Set by the SoC-specific clock init code.
* Once set during a boot, will not change.
*/
static unsigned long sys_ck_rate;
/**
* 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_hw *clk,
unsigned long parent_rate)
{
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_hw *hw, unsigned long rate,
unsigned long *parent_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 != sys_ck_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_hw *hw, unsigned long rate,
unsigned long parent_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 != sys_ck_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();
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;
}
/**
* omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
* table sets matches the current CORE DPLL hardware rate
*
* Check the MPU rate set by bootloader. Sets the 'curr_prcm_set'
* global to point to the active rate set when found; otherwise, sets
* it to NULL. No return value;
*/
void omap2xxx_clkt_vps_check_bootloader_rates(void)
{
const struct prcm_config *prcm = NULL;
unsigned long rate;
rate = omap2xxx_clk_get_core_rate();
for (prcm = rate_table; prcm->mpu_speed; prcm++) {
if (!(prcm->flags & cpu_mask))
continue;
if (prcm->xtal_speed != sys_ck_rate)
continue;
if (prcm->dpll_speed <= rate)
break;
}
curr_prcm_set = prcm;
}
/**
* omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
*
* Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
* code. (The sys_ck rate does not -- or rather, must not -- change
* during kernel runtime.) Must be called after we have a valid
* sys_ck rate, but before the virt_prcm_set clock rate is
* recalculated. No return value.
*/
void omap2xxx_clkt_vps_late_init(void)
{
struct clk *c;
c = clk_get(NULL, "sys_ck");
if (IS_ERR(c)) {
WARN(1, "could not locate sys_ck\n");
} else {
sys_ck_rate = clk_get_rate(c);
clk_put(c);
}
}
