linux/arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c
Tero Kristo cd6e9db277 ARM: OMAP2: CM/PM: remove direct register accesses outside CM code
Users of the CM funtionality should not access the CM registers directly
by themselves. Thus, added new CM driver APIs for the OMAP2 specific
functionalities which support the existing direct register accesses, and
changed the platform code to use these. This is done in preparation
for moving the CM code into its own individual driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2013-10-19 10:11:51 -06:00

211 lines
5.6 KiB
C

/*
* 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;
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;
omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
prcm->cm_clksel_dsp,
prcm->cm_clksel_gfx,
prcm->cm_clksel1_core,
prcm->cm_clksel_mdm);
/* 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);
}
}