AT91 clock/timer: move static data to global_data struct
authorReinhard Meyer <u-boot@emk-elektronik.de>
Tue, 5 Oct 2010 14:54:35 +0000 (16:54 +0200)
committerReinhard Meyer <u-boot@emk-elektronik.de>
Tue, 19 Oct 2010 13:12:29 +0000 (15:12 +0200)
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@emk-elektronik.de>
arch/arm/cpu/arm926ejs/at91/clock.c
arch/arm/cpu/arm926ejs/at91/timer.c
arch/arm/include/asm/global_data.h

index ecf91f5187419871c9b375e8e9d34921a45d3b1b..7a10a77877eb7257695a80e389c244e4dfe14f6a 100644 (file)
  * (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;
 }
index 8efc34bcf12061d81244e6736c45b38b54e32b17..82b8d7e7d7f65bc39023444270feff720f20b13d 100644 (file)
 #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;
 }
index 6152f348f3389239744e08ab7045aa435f6ed2d8..6dae4328e68e2c12a95dda30f701fd65dd47c396 100644 (file)
@@ -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 */