openwrtv4/target/linux/ar7-2.6/files/arch/mips/ar7/clock.c

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/*
* $Id$
*
* Copyright (C) 2007 OpenWrt.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/ar7/ar7.h>
#define BOOT_PLL_SOURCE_MASK 0x3
#define CPU_PLL_SOURCE_SHIFT 16
#define BUS_PLL_SOURCE_SHIFT 14
#define USB_PLL_SOURCE_SHIFT 18
#define DSP_PLL_SOURCE_SHIFT 22
#define BOOT_PLL_SOURCE_AFE 0
#define BOOT_PLL_SOURCE_BUS 0
#define BOOT_PLL_SOURCE_REF 1
#define BOOT_PLL_SOURCE_XTAL 2
#define BOOT_PLL_SOURCE_CPU 3
#define BOOT_PLL_BYPASS 0x00000020
#define BOOT_PLL_ASYNC_MODE 0x02000000
#define BOOT_PLL_2TO1_MODE 0x00008000
struct tnetd7300_clock {
volatile u32 ctrl;
#define PREDIV_MASK 0x001f0000
#define PREDIV_SHIFT 16
#define POSTDIV_MASK 0x0000001f
u32 unused1[3];
volatile u32 pll;
#define MUL_MASK 0x0000f000
#define MUL_SHIFT 12
#define PLL_MODE_MASK 0x00000001
#define PLL_NDIV 0x00000800
#define PLL_DIV 0x00000002
#define PLL_STATUS 0x00000001
u32 unused2[3];
} __attribute__ ((packed));
struct tnetd7300_clocks {
struct tnetd7300_clock bus;
struct tnetd7300_clock cpu;
struct tnetd7300_clock usb;
struct tnetd7300_clock dsp;
} __attribute__ ((packed));
struct tnetd7200_clock {
volatile u32 ctrl;
u32 unused1[3];
#define DIVISOR_ENABLE_MASK 0x00008000
volatile u32 mul;
volatile u32 prediv;
volatile u32 postdiv;
u32 unused2[7];
volatile u32 cmd;
volatile u32 status;
volatile u32 cmden;
u32 padding[15];
};
struct tnetd7200_clocks {
struct tnetd7200_clock cpu;
struct tnetd7200_clock dsp;
struct tnetd7200_clock usb;
};
int ar7_afe_clock = 35328000;
int ar7_ref_clock = 25000000;
int ar7_xtal_clock = 24000000;
int ar7_cpu_clock = 150000000;
EXPORT_SYMBOL(ar7_cpu_clock);
int ar7_bus_clock = 125000000;
EXPORT_SYMBOL(ar7_bus_clock);
int ar7_dsp_clock = 0;
EXPORT_SYMBOL(ar7_dsp_clock);
static int gcd(int x, int y)
{
if (x > y)
return (x % y) ? gcd(y, x % y) : y;
return (y % x) ? gcd(x, y % x) : x;
}
static inline int ABS(int x)
{
return (x >= 0) ? x : -x;
}
static void approximate(int base, int target, int *prediv,
int *postdiv, int *mul)
{
int i, j, k, freq, res = target;
for (i = 1; i <= 16; i++) {
for (j = 1; j <= 32; j++) {
for (k = 1; k <= 32; k++) {
freq = ABS(base / j * i / k - target);
if (freq < res) {
res = freq;
*mul = i;
*prediv = j;
*postdiv = k;
}
}
}
}
}
static void calculate(int base, int target, int *prediv, int *postdiv,
int *mul)
{
int tmp_gcd, tmp_base, tmp_freq;
for (*prediv = 1; *prediv <= 32; (*prediv)++) {
tmp_base = base / *prediv;
tmp_gcd = gcd(target, tmp_base);
*mul = target / tmp_gcd;
*postdiv = tmp_base / tmp_gcd;
if ((*mul < 1) || (*mul >= 16))
continue;
if ((*postdiv > 0) & (*postdiv <= 32))
break;
}
if (base / (*prediv) * (*mul) / (*postdiv) != target) {
approximate(base, target, prediv, postdiv, mul);
tmp_freq = base / (*prediv) * (*mul) / (*postdiv);
printk(KERN_WARNING
"Adjusted requested frequency %d to %d\n",
target, tmp_freq);
}
printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
*prediv, *postdiv, *mul);
}
static int tnetd7300_dsp_clock(void)
{
u32 didr1, didr2;
u8 rev = ar7_chip_rev();
didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
if (didr2 & (1 << 23))
return 0;
if ((rev >= 0x23) && (rev != 0x57))
return 250000000;
if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
> 4208000)
return 250000000;
return 0;
}
static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
u32 *bootcr, u32 bus_clock)
{
int product;
int base_clock = ar7_ref_clock;
u32 ctrl = clock->ctrl;
u32 pll = clock->pll;
int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
int postdiv = (ctrl & POSTDIV_MASK) + 1;
int divisor = prediv * postdiv;
int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
case BOOT_PLL_SOURCE_BUS:
base_clock = bus_clock;
break;
case BOOT_PLL_SOURCE_REF:
base_clock = ar7_ref_clock;
break;
case BOOT_PLL_SOURCE_XTAL:
base_clock = ar7_xtal_clock;
break;
case BOOT_PLL_SOURCE_CPU:
base_clock = ar7_cpu_clock;
break;
}
if (*bootcr & BOOT_PLL_BYPASS)
return base_clock / divisor;
if ((pll & PLL_MODE_MASK) == 0)
return (base_clock >> (mul / 16 + 1)) / divisor;
if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
product = (mul & 1) ?
(base_clock * mul) >> 1 :
(base_clock * (mul - 1)) >> 2;
return product / divisor;
}
if (mul == 16)
return base_clock / divisor;
return base_clock * mul / divisor;
}
static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
u32 *bootcr, u32 frequency)
{
u32 status;
int prediv, postdiv, mul;
int base_clock = ar7_bus_clock;
switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
case BOOT_PLL_SOURCE_BUS:
base_clock = ar7_bus_clock;
break;
case BOOT_PLL_SOURCE_REF:
base_clock = ar7_ref_clock;
break;
case BOOT_PLL_SOURCE_XTAL:
base_clock = ar7_xtal_clock;
break;
case BOOT_PLL_SOURCE_CPU:
base_clock = ar7_cpu_clock;
break;
}
calculate(base_clock, frequency, &prediv, &postdiv, &mul);
clock->ctrl = ((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1);
mdelay(1);
clock->pll = 4;
do {
status = clock->pll;
} while (status & PLL_STATUS);
clock->pll = ((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e;
mdelay(75);
}
static void __init tnetd7300_init_clocks(void)
{
u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
struct tnetd7300_clocks *clocks = (struct tnetd7300_clocks *)ioremap_nocache(AR7_REGS_POWER + 0x20, sizeof(struct tnetd7300_clocks));
ar7_bus_clock = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
&clocks->bus, bootcr,
ar7_afe_clock);
if (*bootcr & BOOT_PLL_ASYNC_MODE) {
ar7_cpu_clock = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
&clocks->cpu,
bootcr, ar7_afe_clock);
} else {
ar7_cpu_clock = ar7_bus_clock;
}
tnetd7300_set_clock(USB_PLL_SOURCE_SHIFT, &clocks->usb,
bootcr, 48000000);
if (ar7_dsp_clock == 250000000)
tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
bootcr, ar7_dsp_clock);
iounmap(clocks);
iounmap(bootcr);
}
static int tnetd7200_get_clock(int base, struct tnetd7200_clock *clock,
u32 *bootcr, u32 bus_clock)
{
int divisor = ((clock->prediv & 0x1f) + 1) *
((clock->postdiv & 0x1f) + 1);
if (*bootcr & BOOT_PLL_BYPASS)
return base / divisor;
return base * ((clock->mul & 0xf) + 1) / divisor;
}
static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
u32 *bootcr, u32 frequency)
{
u32 status;
int prediv, postdiv, mul;
calculate(base, frequency, &prediv, &postdiv, &mul);
clock->ctrl = 0;
clock->prediv = DIVISOR_ENABLE_MASK | prediv;
clock->mul = mul;
mdelay(1);
do {
status = clock->status;
} while (status & PLL_STATUS);
clock->postdiv = DIVISOR_ENABLE_MASK | postdiv;
clock->cmden = 1;
clock->cmd = 1;
do {
status = clock->status;
} while (status & PLL_STATUS);
clock->ctrl = 1;
}
static void __init tnetd7200_init_clocks(void)
{
u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
struct tnetd7200_clocks *clocks = (struct tnetd7200_clocks *)ioremap_nocache(AR7_REGS_POWER + 0x80, sizeof(struct tnetd7200_clocks));
ar7_cpu_clock = tnetd7200_get_clock(ar7_afe_clock,
&clocks->cpu,
bootcr, ar7_afe_clock);
if (*bootcr & BOOT_PLL_ASYNC_MODE) {
ar7_bus_clock = 125000000;
} else {
if (*bootcr & BOOT_PLL_2TO1_MODE) {
ar7_bus_clock = ar7_cpu_clock / 2;
} else {
ar7_bus_clock = ar7_cpu_clock;
}
}
tnetd7200_set_clock(ar7_ref_clock * 5, &clocks->usb,
bootcr, 48000000);
if (ar7_dsp_clock == 250000000)
tnetd7200_set_clock(ar7_ref_clock, &clocks->dsp,
bootcr, ar7_dsp_clock);
iounmap(clocks);
iounmap(bootcr);
}
void __init ar7_init_clocks(void)
{
switch (ar7_chip_id()) {
case AR7_CHIP_7100:
tnetd7200_init_clocks();
break;
case AR7_CHIP_7200:
#warning FIXME: check revision
ar7_dsp_clock = 250000000;
tnetd7200_init_clocks();
break;
case AR7_CHIP_7300:
ar7_dsp_clock = tnetd7300_dsp_clock();
tnetd7300_init_clocks();
break;
default:
break;
}
}