[U-Boot] [PATCH] AT91 clock/timer: move static data to global_data struct
Reinhard Meyer
u-boot at emk-elektronik.de
Tue Oct 5 16:54:35 CEST 2010
clock.c / timer.c used static data and are called before relocation.
Move all static variables into global_data structure. Also cleanup
timer.c from unused stubs and make it truly use 64 bit tick values.
Signed-off-by: Reinhard Meyer <u-boot at emk-elektronik.de>
---
arch/arm/cpu/arm926ejs/at91/clock.c | 55 +++++++++++-----------
arch/arm/cpu/arm926ejs/at91/timer.c | 85 +++++++++++++++++------------------
arch/arm/include/asm/global_data.h | 14 ++++++
3 files changed, 83 insertions(+), 71 deletions(-)
diff --git a/arch/arm/cpu/arm926ejs/at91/clock.c b/arch/arm/cpu/arm926ejs/at91/clock.c
index ecf91f5..7a10a77 100644
--- a/arch/arm/cpu/arm926ejs/at91/clock.c
+++ b/arch/arm/cpu/arm926ejs/at91/clock.c
@@ -11,47 +11,46 @@
* (at your option) any later version.
*/
-#include <config.h>
+#include <common.h>
#include <asm/arch/hardware.h>
#include <asm/arch/io.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/clk.h>
-static unsigned long cpu_clk_rate_hz;
-static unsigned long main_clk_rate_hz;
-static unsigned long mck_rate_hz;
-static unsigned long plla_rate_hz;
-static unsigned long pllb_rate_hz;
-static u32 at91_pllb_usb_init;
+#if !defined(CONFIG_AT91FAMILY)
+# error You need to define CONFIG_AT91FAMILY in your board config!
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
unsigned long get_cpu_clk_rate(void)
{
- return cpu_clk_rate_hz;
+ return gd->cpu_clk_rate_hz;
}
unsigned long get_main_clk_rate(void)
{
- return main_clk_rate_hz;
+ return gd->main_clk_rate_hz;
}
unsigned long get_mck_clk_rate(void)
{
- return mck_rate_hz;
+ return gd->mck_rate_hz;
}
unsigned long get_plla_clk_rate(void)
{
- return plla_rate_hz;
+ return gd->plla_rate_hz;
}
unsigned long get_pllb_clk_rate(void)
{
- return pllb_rate_hz;
+ return gd->pllb_rate_hz;
}
u32 get_pllb_init(void)
{
- return at91_pllb_usb_init;
+ return gd->at91_pllb_usb_init;
}
static unsigned long at91_css_to_rate(unsigned long css)
@@ -60,11 +59,11 @@ static unsigned long at91_css_to_rate(unsigned long css)
case AT91_PMC_MCKR_CSS_SLOW:
return AT91_SLOW_CLOCK;
case AT91_PMC_MCKR_CSS_MAIN:
- return main_clk_rate_hz;
+ return gd->main_clk_rate_hz;
case AT91_PMC_MCKR_CSS_PLLA:
- return plla_rate_hz;
+ return gd->plla_rate_hz;
case AT91_PMC_MCKR_CSS_PLLB:
- return pllb_rate_hz;
+ return gd->pllb_rate_hz;
}
return 0;
@@ -163,10 +162,10 @@ int at91_clock_init(unsigned long main_clock)
main_clock = tmp * (AT91_SLOW_CLOCK / 16);
}
#endif
- main_clk_rate_hz = main_clock;
+ gd->main_clk_rate_hz = main_clock;
/* report if PLLA is more than mildly overclocked */
- plla_rate_hz = at91_pll_rate(main_clock, readl(&pmc->pllar));
+ gd->plla_rate_hz = at91_pll_rate(main_clock, readl(&pmc->pllar));
#ifdef CONFIG_USB_ATMEL
/*
@@ -175,9 +174,9 @@ int at91_clock_init(unsigned long main_clock)
*
* REVISIT: assumes MCK doesn't derive from PLLB!
*/
- at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) |
+ gd->at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) |
AT91_PMC_PLLBR_USBDIV_2;
- pllb_rate_hz = at91_pll_rate(main_clock, at91_pllb_usb_init);
+ gd->pllb_rate_hz = at91_pll_rate(main_clock, gd->at91_pllb_usb_init);
#endif
/*
@@ -187,30 +186,30 @@ int at91_clock_init(unsigned long main_clock)
mckr = readl(&pmc->mckr);
#if defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45)
/* plla divisor by 2 */
- plla_rate_hz /= (1 << ((mckr & 1 << 12) >> 12));
+ gd->plla_rate_hz /= (1 << ((mckr & 1 << 12) >> 12));
#endif
- mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK);
- freq = mck_rate_hz;
+ gd->mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK);
+ freq = gd->mck_rate_hz;
freq /= (1 << ((mckr & AT91_PMC_MCKR_PRES_MASK) >> 2)); /* prescale */
#if defined(CONFIG_AT91RM9200)
/* mdiv */
- mck_rate_hz = freq / (1 + ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
+ gd->mck_rate_hz = freq / (1 + ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
#elif defined(CONFIG_AT91SAM9G20)
/* mdiv ; (x >> 7) = ((x >> 8) * 2) */
- mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ?
+ gd->mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ?
freq / ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 7) : freq;
if (mckr & AT91_PMC_MCKR_MDIV_MASK)
freq /= 2; /* processor clock division */
#elif defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45)
- mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ==
+ gd->mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ==
(AT91_PMC_MCKR_MDIV_2 | AT91_PMC_MCKR_MDIV_4)
? freq / 3
: freq / (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
#else
- mck_rate_hz = freq / (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
+ gd->mck_rate_hz = freq / (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
#endif
- cpu_clk_rate_hz = freq;
+ gd->cpu_clk_rate_hz = freq;
return 0;
}
diff --git a/arch/arm/cpu/arm926ejs/at91/timer.c b/arch/arm/cpu/arm926ejs/at91/timer.c
index 8efc34b..82b8d7e 100644
--- a/arch/arm/cpu/arm926ejs/at91/timer.c
+++ b/arch/arm/cpu/arm926ejs/at91/timer.c
@@ -30,55 +30,63 @@
#include <asm/arch/io.h>
#include <div64.h>
+#if !defined(CONFIG_AT91FAMILY)
+# error You need to define CONFIG_AT91FAMILY in your board config!
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
/*
* We're using the AT91CAP9/SAM9 PITC in 32 bit mode, by
* setting the 20 bit counter period to its maximum (0xfffff).
+ * (See the relevant data sheets to understand that this really works)
+ *
+ * We do also mimic the typical powerpc way of incrementing
+ * two 32 bit registers called tbl and tbu.
+ *
+ * Those registers increment at 1/16 the main clock rate.
*/
-#define TIMER_LOAD_VAL 0xfffff
-static ulong timestamp;
-static ulong lastinc;
-static ulong timer_freq;
+#define TIMER_LOAD_VAL 0xfffff
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
- do_div(tick, timer_freq);
+ do_div(tick, gd->timer_rate_hz);
return tick;
}
static inline unsigned long long usec_to_tick(unsigned long long usec)
{
- usec *= timer_freq;
+ usec *= gd->timer_rate_hz;
do_div(usec, 1000000);
return usec;
}
-/* nothing really to do with interrupts, just starts up a counter. */
+/*
+ * Use the PITC in full 32 bit incrementing mode
+ */
int timer_init(void)
{
at91_pmc_t *pmc = (at91_pmc_t *) AT91_PMC_BASE;
at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE;
- /*
- * Enable PITC Clock
- * The clock is already enabled for system controller in boot
- */
+
+ /* Enable PITC Clock */
writel(1 << AT91_ID_SYS, &pmc->pcer);
/* Enable PITC */
writel(TIMER_LOAD_VAL | AT91_PIT_MR_EN , &pit->mr);
- reset_timer_masked();
-
- timer_freq = get_mck_clk_rate() >> 4;
+ gd->timer_rate_hz = gd->mck_rate_hz / 16;
+ gd->tbu = gd->tbl = 0;
return 0;
}
/*
- * timer without interrupts
+ * Get the current 64 bit timer tick count
*/
unsigned long long get_ticks(void)
{
@@ -86,28 +94,11 @@ unsigned long long get_ticks(void)
ulong now = readl(&pit->piir);
- if (now >= lastinc) /* normal mode (non roll) */
- /* move stamp forward with absolut diff ticks */
- timestamp += (now - lastinc);
- else /* we have rollover of incrementer */
- timestamp += (0xFFFFFFFF - lastinc) + now;
- lastinc = now;
- return timestamp;
-}
-
-void reset_timer_masked(void)
-{
- /* reset time */
- at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE;
-
- /* capture current incrementer value time */
- lastinc = readl(&pit->piir);
- timestamp = 0; /* start "advancing" time stamp from 0 */
-}
-
-ulong get_timer_masked(void)
-{
- return tick_to_time(get_ticks());
+ /* increment tbu if tbl has rolled over */
+ if (now < gd->tbl)
+ gd->tbu++;
+ gd->tbl = now;
+ return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
}
void __udelay(unsigned long usec)
@@ -119,24 +110,32 @@ void __udelay(unsigned long usec)
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
- /*NOP*/;
+ ;
}
+/*
+ * reset_timer() and get_timer(base) are a pair of functions that are used by
+ * some timeout/sleep mechanisms in u-boot.
+ *
+ * reset_timer() marks the current time as epoch and
+ * get_timer(base) works relative to that epoch.
+ *
+ * The time is used in CONFIG_SYS_HZ units!
+ */
void reset_timer(void)
{
- reset_timer_masked();
+ gd->timer_reset_value = get_ticks();
}
ulong get_timer(ulong base)
{
- return get_timer_masked () - base;
+ return tick_to_time(get_ticks() - gd->timer_reset_value) - base;
}
/*
- * This function is derived from PowerPC code (timebase clock frequency).
- * On ARM it returns the number of timer ticks per second.
+ * Return the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
- return timer_freq;
+ return gd->timer_rate_hz;
}
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 6152f34..b173ea5 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -47,6 +47,20 @@ typedef struct global_data {
#ifdef CONFIG_FSL_ESDHC
unsigned long sdhc_clk;
#endif
+#ifdef CONFIG_AT91FAMILY
+ /* "static data" needed by at91's clock.c */
+ unsigned long cpu_clk_rate_hz;
+ unsigned long main_clk_rate_hz;
+ unsigned long mck_rate_hz;
+ unsigned long plla_rate_hz;
+ unsigned long pllb_rate_hz;
+ unsigned long at91_pllb_usb_init;
+ /* "static data" needed by at91's timer.c */
+ unsigned long timer_rate_hz;
+ unsigned long tbl;
+ unsigned long tbu;
+ unsigned long long timer_reset_value;
+#endif
#if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
unsigned long relocaddr; /* Start address of U-Boot in RAM */
phys_size_t ram_size; /* RAM size */
--
1.5.6.5
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