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MIPS: Alchemy: move calc_clock function.

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Now that nothing in time.c depends on calc_clock, it can
be moved to clocks.c where it belongs.
While at it, give it a better non-generic name and call it
as soon as possible in plat_mem_init.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Manuel Lauss 2008-12-21 09:26:24 +01:00 committed by Ralf Baechle
parent 0c694de12b
commit 2699cdfb76
4 changed files with 64 additions and 54 deletions
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54
arch/mips/alchemy/common/clocks.c
View File

@ -27,11 +27,21 @@
*/
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/time.h>
#include <asm/mach-au1x00/au1000.h>
/*
* I haven't found anyone that doesn't use a 12 MHz source clock,
* but just in case.....
*/
#define AU1000_SRC_CLK 12000000
static unsigned int au1x00_clock; /* Hz */
static unsigned long uart_baud_base;
static DEFINE_SPINLOCK(time_lock);
/*
* Set the au1000_clock
*/
@ -60,3 +70,47 @@ void set_au1x00_uart_baud_base(unsigned long new_baud_base)
{
uart_baud_base = new_baud_base;
}
/*
* We read the real processor speed from the PLL. This is important
* because it is more accurate than computing it from the 32 KHz
* counter, if it exists. If we don't have an accurate processor
* speed, all of the peripherals that derive their clocks based on
* this advertised speed will introduce error and sometimes not work
* properly. This function is futher convoluted to still allow configurations
* to do that in case they have really, really old silicon with a
* write-only PLL register. -- Dan
*/
unsigned long au1xxx_calc_clock(void)
{
unsigned long cpu_speed;
unsigned long flags;
spin_lock_irqsave(&time_lock, flags);
/*
* On early Au1000, sys_cpupll was write-only. Since these
* silicon versions of Au1000 are not sold by AMD, we don't bend
* over backwards trying to determine the frequency.
*/
if (au1xxx_cpu_has_pll_wo())
#ifdef CONFIG_SOC_AU1000_FREQUENCY
cpu_speed = CONFIG_SOC_AU1000_FREQUENCY;
#else
cpu_speed = 396000000;
#endif
else
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
/* On Alchemy CPU:counter ratio is 1:1 */
mips_hpt_frequency = cpu_speed;
/* Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16) */
set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)
& 0x03) + 2) * 16));
spin_unlock_irqrestore(&time_lock, flags);
set_au1x00_speed(cpu_speed);
return cpu_speed;
}

9
arch/mips/alchemy/common/setup.c
View File

@ -44,6 +44,15 @@ extern void set_cpuspec(void);
void __init plat_mem_setup(void)
{
unsigned long est_freq;
/* determine core clock */
est_freq = au1xxx_calc_clock();
est_freq += 5000; /* round */
est_freq -= est_freq % 10000;
printk(KERN_INFO "(PRId %08x) @ %lu.%02lu MHz\n", read_c0_prid(),
est_freq / 1000000, ((est_freq % 1000000) * 100) / 1000000);
_machine_restart = au1000_restart;
_machine_halt = au1000_halt;
pm_power_off = au1000_power_off;

54
arch/mips/alchemy/common/time.c
View File

@ -44,53 +44,6 @@
extern int allow_au1k_wait; /* default off for CP0 Counter */
static DEFINE_SPINLOCK(time_lock);
/*
* I haven't found anyone that doesn't use a 12 MHz source clock,
* but just in case.....
*/
#define AU1000_SRC_CLK 12000000
/*
* We read the real processor speed from the PLL. This is important
* because it is more accurate than computing it from the 32 KHz
* counter, if it exists. If we don't have an accurate processor
* speed, all of the peripherals that derive their clocks based on
* this advertised speed will introduce error and sometimes not work
* properly. This function is futher convoluted to still allow configurations
* to do that in case they have really, really old silicon with a
* write-only PLL register. -- Dan
*/
unsigned long calc_clock(void)
{
unsigned long cpu_speed;
unsigned long flags;
spin_lock_irqsave(&time_lock, flags);
/*
* On early Au1000, sys_cpupll was write-only. Since these
* silicon versions of Au1000 are not sold by AMD, we don't bend
* over backwards trying to determine the frequency.
*/
if (au1xxx_cpu_has_pll_wo())
#ifdef CONFIG_SOC_AU1000_FREQUENCY
cpu_speed = CONFIG_SOC_AU1000_FREQUENCY;
#else
cpu_speed = 396000000;
#endif
else
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
/* On Alchemy CPU:counter ratio is 1:1 */
mips_hpt_frequency = cpu_speed;
/* Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16) */
set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)
& 0x03) + 2) * 16));
spin_unlock_irqrestore(&time_lock, flags);
return cpu_speed;
}
static cycle_t au1x_counter1_read(void)
{
return au_readl(SYS_RTCREAD);
@ -150,13 +103,6 @@ void __init plat_time_init(void)
{
struct clock_event_device *cd = &au1x_rtcmatch2_clockdev;
unsigned long t;
unsigned int est_freq = calc_clock();
est_freq += 5000; /* round */
est_freq -= est_freq%10000;
printk(KERN_INFO "(PRId %08x) @ %u.%02u MHz\n", read_c0_prid(),
est_freq / 1000000, ((est_freq % 1000000) * 100) / 1000000);
set_au1x00_speed(est_freq);
/* Check if firmware (YAMON, ...) has enabled 32kHz and clock
* has been detected. If so install the rtcmatch2 clocksource,

1
arch/mips/include/asm/mach-au1x00/au1000.h
View File

@ -135,6 +135,7 @@ extern void set_au1x00_speed(unsigned int new_freq);
extern unsigned int get_au1x00_speed(void);
extern void set_au1x00_uart_baud_base(unsigned long new_baud_base);
extern unsigned long get_au1x00_uart_baud_base(void);
extern unsigned long au1xxx_calc_clock(void);
/*
* Every board describes its IRQ mapping with this table.