- 根目录:
- arch
- mips
- ar7
- clock.c
/*
* Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
* Copyright (C) 2009 Florian Fainelli <florian@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/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/gcd.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <asm/addrspace.h>
#include <asm/mach-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
#define TNETD7200_CLOCK_ID_CPU 0
#define TNETD7200_CLOCK_ID_DSP 1
#define TNETD7200_CLOCK_ID_USB 2
#define TNETD7200_DEF_CPU_CLK 211000000
#define TNETD7200_DEF_DSP_CLK 125000000
#define TNETD7200_DEF_USB_CLK 48000000
struct tnetd7300_clock {
u32 ctrl;
#define PREDIV_MASK 0x001f0000
#define PREDIV_SHIFT 16
#define POSTDIV_MASK 0x0000001f
u32 unused1[3];
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];
};
struct tnetd7300_clocks {
struct tnetd7300_clock bus;
struct tnetd7300_clock cpu;
struct tnetd7300_clock usb;
struct tnetd7300_clock dsp;
};
struct tnetd7200_clock {
u32 ctrl;
u32 unused1[3];
#define DIVISOR_ENABLE_MASK 0x00008000
u32 mul;
u32 prediv;
u32 postdiv;
u32 postdiv2;
u32 unused2[6];
u32 cmd;
u32 status;
u32 cmden;
u32 padding[15];
};
struct tnetd7200_clocks {
struct tnetd7200_clock cpu;
struct tnetd7200_clock dsp;
struct tnetd7200_clock usb;
};
static struct clk bus_clk = {
.rate = 125000000,
};
static struct clk cpu_clk = {
.rate = 150000000,
};
static struct clk dsp_clk;
static struct clk vbus_clk;
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 = readl(&clock->ctrl);
u32 pll = readl(&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 = cpu_clk.rate;
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)
{
int prediv, postdiv, mul;
int base_clock = bus_clk.rate;
switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
case BOOT_PLL_SOURCE_BUS:
base_clock = bus_clk.rate;
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 = cpu_clk.rate;
break;
}
calculate(base_clock, frequency, &prediv, &postdiv, &mul);
writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
mdelay(1);
writel(4, &clock->pll);
while (readl(&clock->pll) & PLL_STATUS)
;
writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
mdelay(75);
}
static void __init tnetd7300_init_clocks(void)
{
u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
struct tnetd7300_clocks *clocks =
ioremap_nocache(UR8_REGS_CLOCKS,
sizeof(struct tnetd7300_clocks));
bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
&clocks->bus, bootcr, AR7_AFE_CLOCK);
if (*bootcr & BOOT_PLL_ASYNC_MODE)
cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
&clocks->cpu, bootcr, AR7_AFE_CLOCK);
else
cpu_clk.rate = bus_clk.rate;
if (dsp_clk.rate == 250000000)
tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
bootcr, dsp_clk.rate);
iounmap(clocks);
iounmap(bootcr);
}
static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
{
printk(KERN_INFO
"Clocks: base = %d, frequency = %u, prediv = %d, "
"postdiv = %d, postdiv2 = %d, mul = %d\n",
base, frequency, prediv, postdiv, postdiv2, mul);
writel(0, &clock->ctrl);
writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
writel((mul - 1) & 0xF, &clock->mul);
while (readl(&clock->status) & 0x1)
; /* nop */
writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
writel(readl(&clock->cmden) | 1, &clock->cmden);
writel(readl(&clock->cmd) | 1, &clock->cmd);
while (readl(&clock->status) & 0x1)
; /* nop */
writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
writel(readl(&clock->cmden) | 1, &clock->cmden);
writel(readl(&clock->cmd) | 1, &clock->cmd);
while (readl(&clock->status) & 0x1)
; /* nop */
writel(readl(&clock->ctrl) | 1, &clock->ctrl);
}
static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
{
if (*bootcr & BOOT_PLL_ASYNC_MODE)
/* Async */
switch (clock_id) {
case TNETD7200_CLOCK_ID_DSP:
return AR7_REF_CLOCK;
default:
return AR7_AFE_CLOCK;
}
else
/* Sync */
if (*bootcr & BOOT_PLL_2TO1_MODE)
/* 2:1 */
switch (clock_id) {
case TNETD7200_CLOCK_ID_DSP:
return AR7_REF_CLOCK;
default:
return AR7_AFE_CLOCK;
}
else
/* 1:1 */
return AR7_REF_CLOCK;
}
static void __init tnetd7200_init_clocks(void)
{
u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
struct tnetd7200_clocks *clocks =
ioremap_nocache(AR7_REGS_CLOCKS,
sizeof(struct tnetd7200_clocks));
int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
int usb_base, usb_mul, usb_prediv, usb_postdiv;
cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
if (*bootcr & BOOT_PLL_ASYNC_MODE) {
printk(KERN_INFO "Clocks: Async mode\n");
printk(KERN_INFO "Clocks: Setting DSP clock\n");
calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
&dsp_prediv, &dsp_postdiv, &dsp_mul);
bus_clk.rate =
((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
tnetd7200_set_clock(dsp_base, &clocks->dsp,
dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
bus_clk.rate);
printk(KERN_INFO "Clocks: Setting CPU clock\n");
calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
&cpu_postdiv, &cpu_mul);
cpu_clk.rate =
((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
tnetd7200_set_clock(cpu_base, &clocks->cpu,
cpu_prediv, cpu_postdiv, -1, cpu_mul,
cpu_clk.rate);
} else
if (*bootcr & BOOT_PLL_2TO1_MODE) {
printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
printk(KERN_INFO "Clocks: Setting CPU clock\n");
calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
&cpu_postdiv, &cpu_mul);
cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
/ cpu_postdiv;
tnetd7200_set_clock(cpu_base, &clocks->cpu,
cpu_prediv, cpu_postdiv, -1, cpu_mul,
cpu_clk.rate);
printk(KERN_INFO "Clocks: Setting DSP clock\n");
calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
&dsp_postdiv, &dsp_mul);
bus_clk.rate = cpu_clk.rate / 2;
tnetd7200_set_clock(dsp_base, &clocks->dsp,
dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
dsp_mul * 2, bus_clk.rate);
} else {
printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
printk(KERN_INFO "Clocks: Setting DSP clock\n");
calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
&dsp_postdiv, &dsp_mul);
bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
/ dsp_postdiv;
tnetd7200_set_clock(dsp_base, &clocks->dsp,
dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
dsp_mul * 2, bus_clk.rate);
cpu_clk.rate = bus_clk.rate;
}
printk(KERN_INFO "Clocks: Setting USB clock\n");
usb_base = bus_clk.rate;
calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
&usb_postdiv, &usb_mul);
tnetd7200_set_clock(usb_base, &clocks->usb,
usb_prediv, usb_postdiv, -1, usb_mul,
TNETD7200_DEF_USB_CLK);
dsp_clk.rate = cpu_clk.rate;
iounmap(clocks);
iounmap(bootcr);
}
/*
* Linux clock API
*/
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
struct clk *clk_get(struct device *dev, const char *id)
{
if (!strcmp(id, "bus"))
return &bus_clk;
/* cpmac and vbus share the same rate */
if (!strcmp(id, "cpmac"))
return &vbus_clk;
if (!strcmp(id, "cpu"))
return &cpu_clk;
if (!strcmp(id, "dsp"))
return &dsp_clk;
if (!strcmp(id, "vbus"))
return &vbus_clk;
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);
void __init ar7_init_clocks(void)
{
switch (ar7_chip_id()) {
case AR7_CHIP_7100:
case AR7_CHIP_7200:
tnetd7200_init_clocks();
break;
case AR7_CHIP_7300:
dsp_clk.rate = tnetd7300_dsp_clock();
tnetd7300_init_clocks();
break;
default:
break;
}
/* adjust vbus clock rate */
vbus_clk.rate = bus_clk.rate / 2;
}