/*
* linux/arch/arm/mach-omap2/clock.c
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
* Copyright (C) 2004-2008 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.
*/
#undef DEBUG
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <mach/clock.h>
#include <mach/sram.h>
#include <asm/div64.h>
#include <asm/bitops.h>
#include "memory.h"
#include "clock.h"
#include "clock24xx.h"
#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
#define EN_APLL_STOPPED 0
#define EN_APLL_LOCKED 3
/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
#define APLLS_CLKIN_19_2MHZ 0
#define APLLS_CLKIN_13MHZ 2
#define APLLS_CLKIN_12MHZ 3
/* #define DOWN_VARIABLE_DPLL 1 */ /* Experimental */
static struct prcm_config *curr_prcm_set;
static struct clk *vclk;
static struct clk *sclk;
/*-------------------------------------------------------------------------
* Omap24xx specific clock functions
*-------------------------------------------------------------------------*/
/* This actually returns the rate of core_ck, not dpll_ck. */
static u32 omap2_get_dpll_rate_24xx(struct clk *tclk)
{
long long dpll_clk;
u8 amult;
dpll_clk = omap2_get_dpll_rate(tclk);
amult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
amult &= OMAP24XX_CORE_CLK_SRC_MASK;
dpll_clk *= amult;
return dpll_clk;
}
static int omap2_enable_osc_ck(struct clk *clk)
{
u32 pcc;
pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
__raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK,
OMAP24XX_PRCM_CLKSRC_CTRL);
return 0;
}
static void omap2_disable_osc_ck(struct clk *clk)
{
u32 pcc;
pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
__raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK,
OMAP24XX_PRCM_CLKSRC_CTRL);
}
#ifdef OLD_CK
/* Recalculate SYST_CLK */
static void omap2_sys_clk_recalc(struct clk * clk)
{
u32 div = PRCM_CLKSRC_CTRL;
div &= (1 << 7) | (1 << 6); /* Test if ext clk divided by 1 or 2 */
div >>= clk->rate_offset;
clk->rate = (clk->parent->rate / div);
propagate_rate(clk);
}
#endif /* OLD_CK */
/* Enable an APLL if off */
static int omap2_clk_fixed_enable(struct clk *clk)
{
u32 cval, apll_mask;
apll_mask = EN_APLL_LOCKED << clk->enable_bit;
cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
if ((cval & apll_mask) == apll_mask)
return 0; /* apll already enabled */
cval &= ~apll_mask;
cval |= apll_mask;
cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
if (clk == &apll96_ck)
cval = OMAP24XX_ST_96M_APLL;
else if (clk == &apll54_ck)
cval = OMAP24XX_ST_54M_APLL;
omap2_wait_clock_ready(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), cval,
clk->name);
/*
* REVISIT: Should we return an error code if omap2_wait_clock_ready()
* fails?
*/
return 0;
}
/* Stop APLL */
static void omap2_clk_fixed_disable(struct clk *clk)
{
u32 cval;
cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
}
/*
* Uses the current prcm set to tell if a rate is valid.
* You can go slower, but not faster within a given rate set.
*/
long omap2_dpllcore_round_rate(unsigned long target_rate)
{
u32 high, low, core_clk_src;
core_clk_src = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK;
if (core_clk_src == CORE_CLK_SRC_DPLL) { /* DPLL clockout */
high = curr_prcm_set->dpll_speed * 2;
low = curr_prcm_set->dpll_speed;
} else { /* DPLL clockout x 2 */
high = curr_prcm_set->dpll_speed;
low = curr_prcm_set->dpll_speed / 2;
}
#ifdef DOWN_VARIABLE_DPLL
if (target_rate > high)
return high;
else
return target_rate;
#else
if (target_rate > low)
return high;
else
return low;
#endif
}
static void omap2_dpllcore_recalc(struct clk *clk)
{
clk->rate = omap2_get_dpll_rate_24xx(clk);
propagate_rate(clk);
}
static int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate)
{
u32 cur_rate, low, mult, div, valid_rate, done_rate;
u32 bypass = 0;
struct prcm_config tmpset;
const struct dpll_data *dd;
unsigned long flags;
int ret = -EINVAL;
local_irq_save(flags);
cur_rate = omap2_get_dpll_rate_24xx(&dpll_ck);
mult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
mult &= OMAP24XX_CORE_CLK_SRC_MASK;
if ((rate == (cur_rate / 2)) && (mult == 2)) {
omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
} else if ((rate == (cur_rate * 2)) && (mult == 1)) {
omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
} else if (rate != cur_rate) {
valid_rate = omap2_dpllcore_round_rate(rate);
if (valid_rate != rate)
goto dpll_exit;
if (mult == 1)
low = curr_prcm_set->dpll_speed;
else
low = curr_prcm_set->dpll_speed / 2;
dd = clk->dpll_data;
if (!dd)
goto dpll_exit;
tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg);
tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
dd->div1_mask);
div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
tmpset.cm_clksel2_pll = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
if (rate > low) {
tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
mult = ((rate / 2) / 1000000);
done_rate = CORE_CLK_SRC_DPLL_X2;
} else {
tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
mult = (rate / 1000000);
done_rate = CORE_CLK_SRC_DPLL;
}
tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
/* Worst case */
tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
if (rate == curr_prcm_set->xtal_speed) /* If asking for 1-1 */
bypass = 1;
omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1); /* For init_mem */
/* Force dll lock mode */
omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
bypass);
/* Errata: ret dll entry state */
omap2_init_memory_params(omap2_dll_force_needed());
omap2_reprogram_sdrc(done_rate, 0);
}
omap2_dpllcore_recalc(&dpll_ck);
ret = 0;
dpll_exit:
local_irq_restore(flags);
return(ret);
}
/**
* 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.
*/
static void omap2_table_mpu_recalc(struct clk *clk)
{
clk->rate = 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.
*/
static long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
{
struct prcm_config *ptr;
long highest_rate;
if (clk != &virt_prcm_set)
return -EINVAL;
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 */
static int omap2_select_table_rate(struct clk *clk, unsigned long rate)
{
u32 cur_rate, done_rate, bypass = 0, tmp;
struct prcm_config *prcm;
unsigned long found_speed = 0;
unsigned long flags;
if (clk != &virt_prcm_set)
return -EINVAL;
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 = omap2_get_dpll_rate_24xx(&dpll_ck);
if (prcm->dpll_speed == cur_rate / 2) {
omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
} else if (prcm->dpll_speed == cur_rate * 2) {
omap2_reprogram_sdrc(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 */
cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
/* dsp + iva1 div(2420), iva2.1(2430) */
cm_write_mod_reg(prcm->cm_clksel_dsp,
OMAP24XX_DSP_MOD, CM_CLKSEL);
cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
/* Major subsystem dividers */
tmp = cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD, CM_CLKSEL1);
if (cpu_is_omap2430())
cm_write_mod_reg(prcm->cm_clksel_mdm,
OMAP2430_MDM_MOD, CM_CLKSEL);
/* x2 to enter init_mem */
omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
bypass);
omap2_init_memory_params(omap2_dll_force_needed());
omap2_reprogram_sdrc(done_rate, 0);
local_irq_restore(flags);
}
omap2_dpllcore_recalc(&dpll_ck);
return 0;
}
static struct clk_functions omap2_clk_functions = {
.clk_enable = omap2_clk_enable,
.clk_disable = omap2_clk_disable,
.clk_round_rate = omap2_clk_round_rate,
.clk_set_rate = omap2_clk_set_rate,
.clk_set_parent = omap2_clk_set_parent,
.clk_disable_unused = omap2_clk_disable_unused,
};
static u32 omap2_get_apll_clkin(void)
{
u32 aplls, sclk = 0;
aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
aplls &= OMAP24XX_APLLS_CLKIN_MASK;
aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;
if (aplls == APLLS_CLKIN_19_2MHZ)
sclk = 19200000;
else if (aplls == APLLS_CLKIN_13MHZ)
sclk = 13000000;
else if (aplls == APLLS_CLKIN_12MHZ)
sclk = 12000000;
return sclk;
}
static u32 omap2_get_sysclkdiv(void)
{
u32 div;
div = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
div &= OMAP_SYSCLKDIV_MASK;
div >>= OMAP_SYSCLKDIV_SHIFT;
return div;
}
static void omap2_osc_clk_recalc(struct clk *clk)
{
clk->rate = omap2_get_apll_clkin() * omap2_get_sysclkdiv();
propagate_rate(clk);
}
static void omap2_sys_clk_recalc(struct clk *clk)
{
clk->rate = clk->parent->rate / omap2_get_sysclkdiv();
propagate_rate(clk);
}
/*
* Set clocks for bypass mode for reboot to work.
*/
void omap2_clk_prepare_for_reboot(void)
{
u32 rate;
if (vclk == NULL || sclk == NULL)
return;
rate = clk_get_rate(sclk);
clk_set_rate(vclk, rate);
}
/*
* Switch the MPU rate if specified on cmdline.
* We cannot do this early until cmdline is parsed.
*/
static int __init omap2_clk_arch_init(void)
{
if (!mpurate)
return -EINVAL;
if (omap2_select_table_rate(&virt_prcm_set, mpurate))
printk(KERN_ERR "Could not find matching MPU rate\n");
recalculate_root_clocks();
printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL/MPU): "
"%ld.%01ld/%ld/%ld MHz\n",
(sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
(dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
return 0;
}
arch_initcall(omap2_clk_arch_init);
int __init omap2_clk_init(void)
{
struct prcm_config *prcm;
struct clk **clkp;
u32 clkrate;
if (cpu_is_omap242x())
cpu_mask = RATE_IN_242X;
else if (cpu_is_omap2430())
cpu_mask = RATE_IN_243X;
clk_init(&omap2_clk_functions);
omap2_osc_clk_recalc(&osc_ck);
omap2_sys_clk_recalc(&sys_ck);
for (clkp = onchip_24xx_clks;
clkp < onchip_24xx_clks + ARRAY_SIZE(onchip_24xx_clks);
clkp++) {
if ((*clkp)->flags & CLOCK_IN_OMAP242X && cpu_is_omap2420()) {
clk_register(*clkp);
continue;
}
if ((*clkp)->flags & CLOCK_IN_OMAP243X && cpu_is_omap2430()) {
clk_register(*clkp);
continue;
}
}
/* Check the MPU rate set by bootloader */
clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
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 <= clkrate)
break;
}
curr_prcm_set = prcm;
recalculate_root_clocks();
printk(KERN_INFO "Clocking rate (Crystal/DPLL/MPU): "
"%ld.%01ld/%ld/%ld MHz\n",
(sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
(dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
/*
* Only enable those clocks we will need, let the drivers
* enable other clocks as necessary
*/
clk_enable_init_clocks();
/* Avoid sleeping sleeping during omap2_clk_prepare_for_reboot() */
vclk = clk_get(NULL, "virt_prcm_set");
sclk = clk_get(NULL, "sys_ck");
return 0;
}