linux/arch/arm/mach-omap1/clock.c

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/*
* linux/arch/arm/mach-omap1/clock.c
*
* Copyright (C) 2004 - 2005, 2009-2010 Nokia Corporation
* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
*
* Modified to use omap shared clock framework by
* Tony Lindgren <tony@atomide.com>
*
* 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <asm/mach-types.h>
#include <asm/clkdev.h>
#include <plat/cpu.h>
#include <plat/usb.h>
#include <plat/clock.h>
#include <plat/sram.h>
#include <plat/clkdev_omap.h>
#include "clock.h"
#include "opp.h"
__u32 arm_idlect1_mask;
struct clk *api_ck_p, *ck_dpll1_p, *ck_ref_p;
/*-------------------------------------------------------------------------
* Omap1 specific clock functions
*-------------------------------------------------------------------------*/
unsigned long omap1_uart_recalc(struct clk *clk)
{
unsigned int val = __raw_readl(clk->enable_reg);
return val & clk->enable_bit ? 48000000 : 12000000;
}
unsigned long omap1_sossi_recalc(struct clk *clk)
{
u32 div = omap_readl(MOD_CONF_CTRL_1);
div = (div >> 17) & 0x7;
div++;
return clk->parent->rate / div;
}
static void omap1_clk_allow_idle(struct clk *clk)
{
struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;
if (!(clk->flags & CLOCK_IDLE_CONTROL))
return;
if (iclk->no_idle_count > 0 && !(--iclk->no_idle_count))
arm_idlect1_mask |= 1 << iclk->idlect_shift;
}
static void omap1_clk_deny_idle(struct clk *clk)
{
struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;
if (!(clk->flags & CLOCK_IDLE_CONTROL))
return;
if (iclk->no_idle_count++ == 0)
arm_idlect1_mask &= ~(1 << iclk->idlect_shift);
}
static __u16 verify_ckctl_value(__u16 newval)
{
/* This function checks for following limitations set
* by the hardware (all conditions must be true):
* DSPMMU_CK == DSP_CK or DSPMMU_CK == DSP_CK/2
* ARM_CK >= TC_CK
* DSP_CK >= TC_CK
* DSPMMU_CK >= TC_CK
*
* In addition following rules are enforced:
* LCD_CK <= TC_CK
* ARMPER_CK <= TC_CK
*
* However, maximum frequencies are not checked for!
*/
__u8 per_exp;
__u8 lcd_exp;
__u8 arm_exp;
__u8 dsp_exp;
__u8 tc_exp;
__u8 dspmmu_exp;
per_exp = (newval >> CKCTL_PERDIV_OFFSET) & 3;
lcd_exp = (newval >> CKCTL_LCDDIV_OFFSET) & 3;
arm_exp = (newval >> CKCTL_ARMDIV_OFFSET) & 3;
dsp_exp = (newval >> CKCTL_DSPDIV_OFFSET) & 3;
tc_exp = (newval >> CKCTL_TCDIV_OFFSET) & 3;
dspmmu_exp = (newval >> CKCTL_DSPMMUDIV_OFFSET) & 3;
if (dspmmu_exp < dsp_exp)
dspmmu_exp = dsp_exp;
if (dspmmu_exp > dsp_exp+1)
dspmmu_exp = dsp_exp+1;
if (tc_exp < arm_exp)
tc_exp = arm_exp;
if (tc_exp < dspmmu_exp)
tc_exp = dspmmu_exp;
if (tc_exp > lcd_exp)
lcd_exp = tc_exp;
if (tc_exp > per_exp)
per_exp = tc_exp;
newval &= 0xf000;
newval |= per_exp << CKCTL_PERDIV_OFFSET;
newval |= lcd_exp << CKCTL_LCDDIV_OFFSET;
newval |= arm_exp << CKCTL_ARMDIV_OFFSET;
newval |= dsp_exp << CKCTL_DSPDIV_OFFSET;
newval |= tc_exp << CKCTL_TCDIV_OFFSET;
newval |= dspmmu_exp << CKCTL_DSPMMUDIV_OFFSET;
return newval;
}
static int calc_dsor_exp(struct clk *clk, unsigned long rate)
{
/* Note: If target frequency is too low, this function will return 4,
* which is invalid value. Caller must check for this value and act
* accordingly.
*
* Note: This function does not check for following limitations set
* by the hardware (all conditions must be true):
* DSPMMU_CK == DSP_CK or DSPMMU_CK == DSP_CK/2
* ARM_CK >= TC_CK
* DSP_CK >= TC_CK
* DSPMMU_CK >= TC_CK
*/
unsigned long realrate;
struct clk * parent;
unsigned dsor_exp;
parent = clk->parent;
if (unlikely(parent == NULL))
return -EIO;
realrate = parent->rate;
for (dsor_exp=0; dsor_exp<4; dsor_exp++) {
if (realrate <= rate)
break;
realrate /= 2;
}
return dsor_exp;
}
unsigned long omap1_ckctl_recalc(struct clk *clk)
{
/* Calculate divisor encoded as 2-bit exponent */
int dsor = 1 << (3 & (omap_readw(ARM_CKCTL) >> clk->rate_offset));
return clk->parent->rate / dsor;
}
unsigned long omap1_ckctl_recalc_dsp_domain(struct clk *clk)
{
int dsor;
/* Calculate divisor encoded as 2-bit exponent
*
* The clock control bits are in DSP domain,
* so api_ck is needed for access.
* Note that DSP_CKCTL virt addr = phys addr, so
* we must use __raw_readw() instead of omap_readw().
*/
omap1_clk_enable(api_ck_p);
dsor = 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset));
omap1_clk_disable(api_ck_p);
return clk->parent->rate / dsor;
}
/* MPU virtual clock functions */
int omap1_select_table_rate(struct clk *clk, unsigned long rate)
{
/* Find the highest supported frequency <= rate and switch to it */
struct mpu_rate * ptr;
unsigned long dpll1_rate, ref_rate;
dpll1_rate = ck_dpll1_p->rate;
ref_rate = ck_ref_p->rate;
for (ptr = omap1_rate_table; ptr->rate; ptr++) {
if (ptr->xtal != ref_rate)
continue;
/* DPLL1 cannot be reprogrammed without risking system crash */
if (likely(dpll1_rate != 0) && ptr->pll_rate != dpll1_rate)
continue;
/* Can check only after xtal frequency check */
if (ptr->rate <= rate)
break;
}
if (!ptr->rate)
return -EINVAL;
/*
* In most cases we should not need to reprogram DPLL.
* Reprogramming the DPLL is tricky, it must be done from SRAM.
* (on 730, bit 13 must always be 1)
*/
if (cpu_is_omap7xx())
omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val | 0x2000);
else
omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);
/* XXX Do we need to recalculate the tree below DPLL1 at this point? */
ck_dpll1_p->rate = ptr->pll_rate;
return 0;
}
int omap1_clk_set_rate_dsp_domain(struct clk *clk, unsigned long rate)
{
int dsor_exp;
u16 regval;
dsor_exp = calc_dsor_exp(clk, rate);
if (dsor_exp > 3)
dsor_exp = -EINVAL;
if (dsor_exp < 0)
return dsor_exp;
regval = __raw_readw(DSP_CKCTL);
regval &= ~(3 << clk->rate_offset);
regval |= dsor_exp << clk->rate_offset;
__raw_writew(regval, DSP_CKCTL);
clk->rate = clk->parent->rate / (1 << dsor_exp);
return 0;
}
long omap1_clk_round_rate_ckctl_arm(struct clk *clk, unsigned long rate)
{
int dsor_exp = calc_dsor_exp(clk, rate);
if (dsor_exp < 0)
return dsor_exp;
if (dsor_exp > 3)
dsor_exp = 3;
return clk->parent->rate / (1 << dsor_exp);
}
int omap1_clk_set_rate_ckctl_arm(struct clk *clk, unsigned long rate)
{
int dsor_exp;
u16 regval;
dsor_exp = calc_dsor_exp(clk, rate);
if (dsor_exp > 3)
dsor_exp = -EINVAL;
if (dsor_exp < 0)
return dsor_exp;
regval = omap_readw(ARM_CKCTL);
regval &= ~(3 << clk->rate_offset);
regval |= dsor_exp << clk->rate_offset;
regval = verify_ckctl_value(regval);
omap_writew(regval, ARM_CKCTL);
clk->rate = clk->parent->rate / (1 << dsor_exp);
return 0;
}
long omap1_round_to_table_rate(struct clk *clk, unsigned long rate)
{
/* Find the highest supported frequency <= rate */
struct mpu_rate * ptr;
long highest_rate;
unsigned long ref_rate;
ref_rate = ck_ref_p->rate;
highest_rate = -EINVAL;
for (ptr = omap1_rate_table; ptr->rate; ptr++) {
if (ptr->xtal != ref_rate)
continue;
highest_rate = ptr->rate;
/* Can check only after xtal frequency check */
if (ptr->rate <= rate)
break;
}
return highest_rate;
}
static unsigned calc_ext_dsor(unsigned long rate)
{
unsigned dsor;
/* MCLK and BCLK divisor selection is not linear:
* freq = 96MHz / dsor
*
* RATIO_SEL range: dsor <-> RATIO_SEL
* 0..6: (RATIO_SEL+2) <-> (dsor-2)
* 6..48: (8+(RATIO_SEL-6)*2) <-> ((dsor-8)/2+6)
* Minimum dsor is 2 and maximum is 96. Odd divisors starting from 9
* can not be used.
*/
for (dsor = 2; dsor < 96; ++dsor) {
if ((dsor & 1) && dsor > 8)
continue;
if (rate >= 96000000 / dsor)
break;
}
return dsor;
}
/* XXX Only needed on 1510 */
int omap1_set_uart_rate(struct clk *clk, unsigned long rate)
{
unsigned int val;
val = __raw_readl(clk->enable_reg);
if (rate == 12000000)
val &= ~(1 << clk->enable_bit);
else if (rate == 48000000)
val |= (1 << clk->enable_bit);
else
return -EINVAL;
__raw_writel(val, clk->enable_reg);
clk->rate = rate;
return 0;
}
/* External clock (MCLK & BCLK) functions */
int omap1_set_ext_clk_rate(struct clk *clk, unsigned long rate)
{
unsigned dsor;
__u16 ratio_bits;
dsor = calc_ext_dsor(rate);
clk->rate = 96000000 / dsor;
if (dsor > 8)
ratio_bits = ((dsor - 8) / 2 + 6) << 2;
else
ratio_bits = (dsor - 2) << 2;
ratio_bits |= __raw_readw(clk->enable_reg) & ~0xfd;
__raw_writew(ratio_bits, clk->enable_reg);
return 0;
}
int omap1_set_sossi_rate(struct clk *clk, unsigned long rate)
{
u32 l;
int div;
unsigned long p_rate;
p_rate = clk->parent->rate;
/* Round towards slower frequency */
div = (p_rate + rate - 1) / rate;
div--;
if (div < 0 || div > 7)
return -EINVAL;
l = omap_readl(MOD_CONF_CTRL_1);
l &= ~(7 << 17);
l |= div << 17;
omap_writel(l, MOD_CONF_CTRL_1);
clk->rate = p_rate / (div + 1);
return 0;
}
long omap1_round_ext_clk_rate(struct clk *clk, unsigned long rate)
{
return 96000000 / calc_ext_dsor(rate);
}
void omap1_init_ext_clk(struct clk *clk)
{
unsigned dsor;
__u16 ratio_bits;
/* Determine current rate and ensure clock is based on 96MHz APLL */
ratio_bits = __raw_readw(clk->enable_reg) & ~1;
__raw_writew(ratio_bits, clk->enable_reg);
ratio_bits = (ratio_bits & 0xfc) >> 2;
if (ratio_bits > 6)
dsor = (ratio_bits - 6) * 2 + 8;
else
dsor = ratio_bits + 2;
clk-> rate = 96000000 / dsor;
}
int omap1_clk_enable(struct clk *clk)
{
int ret = 0;
if (clk->usecount++ == 0) {
if (clk->parent) {
ret = omap1_clk_enable(clk->parent);
if (ret)
goto err;
if (clk->flags & CLOCK_NO_IDLE_PARENT)
omap1_clk_deny_idle(clk->parent);
}
ret = clk->ops->enable(clk);
if (ret) {
if (clk->parent)
omap1_clk_disable(clk->parent);
goto err;
}
}
return ret;
err:
clk->usecount--;
return ret;
}
void omap1_clk_disable(struct clk *clk)
{
if (clk->usecount > 0 && !(--clk->usecount)) {
clk->ops->disable(clk);
if (likely(clk->parent)) {
omap1_clk_disable(clk->parent);
if (clk->flags & CLOCK_NO_IDLE_PARENT)
omap1_clk_allow_idle(clk->parent);
}
}
}
static int omap1_clk_enable_generic(struct clk *clk)
{
__u16 regval16;
__u32 regval32;
if (unlikely(clk->enable_reg == NULL)) {
printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
clk->name);
return -EINVAL;
}
if (clk->flags & ENABLE_REG_32BIT) {
regval32 = __raw_readl(clk->enable_reg);
regval32 |= (1 << clk->enable_bit);
__raw_writel(regval32, clk->enable_reg);
} else {
regval16 = __raw_readw(clk->enable_reg);
regval16 |= (1 << clk->enable_bit);
__raw_writew(regval16, clk->enable_reg);
}
return 0;
}
static void omap1_clk_disable_generic(struct clk *clk)
{
__u16 regval16;
__u32 regval32;
if (clk->enable_reg == NULL)
return;
if (clk->flags & ENABLE_REG_32BIT) {
regval32 = __raw_readl(clk->enable_reg);
regval32 &= ~(1 << clk->enable_bit);
__raw_writel(regval32, clk->enable_reg);
} else {
regval16 = __raw_readw(clk->enable_reg);
regval16 &= ~(1 << clk->enable_bit);
__raw_writew(regval16, clk->enable_reg);
}
}
const struct clkops clkops_generic = {
.enable = omap1_clk_enable_generic,
.disable = omap1_clk_disable_generic,
};
static int omap1_clk_enable_dsp_domain(struct clk *clk)
{
int retval;
retval = omap1_clk_enable(api_ck_p);
if (!retval) {
retval = omap1_clk_enable_generic(clk);
omap1_clk_disable(api_ck_p);
}
return retval;
}
static void omap1_clk_disable_dsp_domain(struct clk *clk)
{
if (omap1_clk_enable(api_ck_p) == 0) {
omap1_clk_disable_generic(clk);
omap1_clk_disable(api_ck_p);
}
}
const struct clkops clkops_dspck = {
.enable = omap1_clk_enable_dsp_domain,
.disable = omap1_clk_disable_dsp_domain,
};
static int omap1_clk_enable_uart_functional(struct clk *clk)
{
int ret;
struct uart_clk *uclk;
ret = omap1_clk_enable_generic(clk);
if (ret == 0) {
/* Set smart idle acknowledgement mode */
uclk = (struct uart_clk *)clk;
omap_writeb((omap_readb(uclk->sysc_addr) & ~0x10) | 8,
uclk->sysc_addr);
}
return ret;
}
static void omap1_clk_disable_uart_functional(struct clk *clk)
{
struct uart_clk *uclk;
/* Set force idle acknowledgement mode */
uclk = (struct uart_clk *)clk;
omap_writeb((omap_readb(uclk->sysc_addr) & ~0x18), uclk->sysc_addr);
omap1_clk_disable_generic(clk);
}
const struct clkops clkops_uart = {
.enable = omap1_clk_enable_uart_functional,
.disable = omap1_clk_disable_uart_functional,
};
long omap1_clk_round_rate(struct clk *clk, unsigned long rate)
{
if (clk->round_rate != NULL)
return clk->round_rate(clk, rate);
return clk->rate;
}
int omap1_clk_set_rate(struct clk *clk, unsigned long rate)
{
int ret = -EINVAL;
if (clk->set_rate)
ret = clk->set_rate(clk, rate);
return ret;
}
/*-------------------------------------------------------------------------
* Omap1 clock reset and init functions
*-------------------------------------------------------------------------*/
#ifdef CONFIG_OMAP_RESET_CLOCKS
void __init omap1_clk_disable_unused(struct clk *clk)
{
__u32 regval32;
/* Clocks in the DSP domain need api_ck. Just assume bootloader
* has not enabled any DSP clocks */
if (clk->enable_reg == DSP_IDLECT2) {
printk(KERN_INFO "Skipping reset check for DSP domain "
"clock \"%s\"\n", clk->name);
return;
}
/* Is the clock already disabled? */
if (clk->flags & ENABLE_REG_32BIT)
regval32 = __raw_readl(clk->enable_reg);
else
regval32 = __raw_readw(clk->enable_reg);
if ((regval32 & (1 << clk->enable_bit)) == 0)
return;
printk(KERN_INFO "Disabling unused clock \"%s\"... ", clk->name);
clk->ops->disable(clk);
printk(" done\n");
}
#endif