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linux/arch/mips/ar7/clock.c
Florian Fainelli 0bc6791707 MIPS: AR7: Fix loops per jiffies on TNETD7200 devices 
TNETD7200 run their CPU clock faster than the default CPU clock we assume.
In order to have the correct loops per jiffies settings, initialize clocks right
before setting mips_hpt_frequency. As a side effect, we can no longer use
msleep in clocks.c which requires other parts of the kernel to be initialized,
so replace these with mdelay.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1749/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-12-16 18:10:56 +00:00

476 lines
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/*
* 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;
}
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