Pieter Voorthuijsen wrote:

Hi Dirk, Troy,

Still some troubles on the DVEVM, i2c and flash are too fast, also dhcp is racing like h#ll. See log below.

Currently the timer rolls over every 1 ms, this means get_timer should be called at least every ms to detect a roll over... Is it better to have a static variable timer than read the timer register directly?

I see that this is standard behavior in other timer code in u-boot, but we don't need it I think. I'll try to implement the 64-bit timer without roll over this afternoon.

I don't love the idea of 64-bit timer! We *should* get it working with 32bit timer. Do you like spending the time to implement the 64-bit timer instead in thinking/debugging the 32-bit timer?

E.g. what happens if you use

#define TIMER_LOAD_VAL 0xffffffff

instead in patch below?

Dirk

Best regards, Pieter

U-Boot > era 03EC0000 +20000

Flash erase timeout at address 3ec0000 data b4f0b4f Flash erase timeout at address 3ed0000 data f4f0f4f done Erased 2 sectors U-Boot > iprobe Valid chip addresses: 00 01 02 03 04 05 06 07 08 09 0B 0C 0D 0E 0F 10 11 12 13 1 4 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60 61 62 63 6 4 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F U-Boot >

-----Original Message----- From: dirk.behme@googlemail.com [mailto:dirk.behme@googlemail.com] Sent: maandag 24 maart 2008 15:58 To: u-boot-users@lists.sourceforge.net Cc: troy.kisky@boundarydevices.com; Pieter Voorthuijsen Subject: [PATCH] ARM: Davinci: Fix DM644x timer overflow handling and cleanup

Fix ARM based DaVinci DM644x timer overflow handling and cleanup timer code.

Changes:

• Remove *_masked() functions as noted by Wolfgang

• Adapt register naming to recent TI spec (sprue26, March 2007)

• Fix reset_timer() handling

• As reported by Pieter [1] the overflow fix introduced a delay of factor 16 (e.g 2 seconds became 32). While the overflow fix is basically okay, it missed to divide CFG_HZ_CLOCK by 16, too. Fix this.

[1] http://article.gmane.org/gmane.comp.boot-loaders.u-boot/38179

• Remove software division of timer count value (DIV(x) macro) and do it in hardware (TIM_CLK_DIV).

Many thanks to Troy Kisky troy.kisky@boundarydevices.com for his hints!

Patch is compile tested with davinci_dvevm & sonata & schmoogie configuration. Anybody can test it on real hardware? Pieter?

Signed-off-by: Dirk Behme dirk.behme@gmail.com

Index: uboot_davinci/cpu/arm926ejs/davinci/timer.c

--- uboot_davinci.orig/cpu/arm926ejs/davinci/timer.c +++ uboot_davinci/cpu/arm926ejs/davinci/timer.c @@ -42,9 +42,9 @@

typedef volatile struct { u_int32_t pid12;

• u_int32_t emumgt_clksped;
• u_int32_t gpint_en;
• u_int32_t gpdir_dat;

• u_int32_t emumgt;
• u_int32_t na1;
• u_int32_t na2; u_int32_t tim12; u_int32_t tim34; u_int32_t prd12;

@@ -52,21 +52,11 @@ typedef volatile struct { u_int32_t tcr; u_int32_t tgcr; u_int32_t wdtcr;

• u_int32_t tlgc;
• u_int32_t tlmr;

} davinci_timer;

davinci_timer *timer = (davinci_timer *)CFG_TIMERBASE;

#define TIMER_LOAD_VAL (CFG_HZ_CLOCK / CFG_HZ) -#define READ_TIMER timer->tim34

-/*

• • Timer runs with CFG_HZ_CLOCK, currently 27MHz. To avoid wrap
• • around of timestamp already after min ~159s, divide it, e.g. by 16.
• • timestamp will then wrap around all min ~42min
• */

-#define DIV(x) ((x) >> 4)

static ulong timestamp; static ulong lastinc; @@ -76,63 +66,51 @@ int timer_init(void) /* We are using timer34 in unchained 32-bit mode, full speed */ timer->tcr = 0x0; timer->tgcr = 0x0;

• timer->tgcr = 0x06;

• timer->tgcr = 0x06 | ((TIM_CLK_DIV - 1) << 8); timer->tim34 = 0x0; timer->prd34 = TIMER_LOAD_VAL; lastinc = 0;

• timer->tcr = 0x80 << 16; timestamp = 0;

• timer->tcr = 2 << 22;

  return(0);

}

void reset_timer(void) {

• reset_timer_masked();

-}

-ulong get_timer(ulong base) -{

• return(get_timer_masked() - base);

-}

-void set_timer(ulong t) -{

• timestamp = t;

-}

-void udelay(unsigned long usec) -{

• udelay_masked(usec);

-}

-void reset_timer_masked(void) -{

• lastinc = DIV(READ_TIMER);

• timer->tcr = 0x0;
• timer->tim34 = 0;
• lastinc = 0; timestamp = 0;
• timer->tcr = 2 << 22;

}

-ulong get_timer_raw(void) +static ulong get_timer_raw(void) {

• ulong now = DIV(READ_TIMER);

• ulong now = timer->tim34;

  if (now >= lastinc) { /* normal mode */ timestamp += now - lastinc; } else { /* overflow ... */

• timestamp += now + DIV(TIMER_LOAD_VAL) - lastinc;
  

• timestamp += now + TIMER_LOAD_VAL - lastinc;
  

  } lastinc = now; return timestamp;

}

-ulong get_timer_masked(void) +ulong get_timer(ulong base) +{

• return(get_timer_raw() - base);

+}

+void set_timer(ulong t) {

• return(get_timer_raw() / DIV(TIMER_LOAD_VAL));

• timestamp = t;

}

-void udelay_masked(unsigned long usec) +void udelay(unsigned long usec) { ulong tmo; ulong endtime; @@ -165,8 +143,5 @@ unsigned long long get_ticks(void) */ ulong get_tbclk(void) {

• ulong tbclk;
• tbclk = CFG_HZ;
• return(tbclk);

• return CFG_HZ;

} Index: uboot_davinci/include/configs/davinci_dvevm.h =================================================================== --- uboot_davinci.orig/include/configs/davinci_dvevm.h +++ uboot_davinci/include/configs/davinci_dvevm.h @@ -58,7 +58,8 @@ #define CONFIG_ARM926EJS /* arm926ejs CPU core */ #define CONFIG_SYS_CLK_FREQ 297000000 /* Arm Clock frequency */ #define CFG_TIMERBASE 0x01c21400 /* use timer 0 */ -#define CFG_HZ_CLOCK 27000000 /* Timer Input clock freq */ +#define TIM_CLK_DIV 16 +#define CFG_HZ_CLOCK (27000000/TIM_CLK_DIV) /* Timer clock freq */ #define CFG_HZ 1000 /*====================================================*/ /* EEPROM definitions for Atmel 24C256BN SEEPROM chip */ Index: uboot_davinci/include/configs/davinci_schmoogie.h =================================================================== --- uboot_davinci.orig/include/configs/davinci_schmoogie.h +++ uboot_davinci/include/configs/davinci_schmoogie.h @@ -33,7 +33,8 @@ #define CONFIG_ARM926EJS /* arm926ejs CPU core */ #define CONFIG_SYS_CLK_FREQ 297000000 /* Arm Clock frequency */ #define CFG_TIMERBASE 0x01c21400 /* use timer 0 */ -#define CFG_HZ_CLOCK 27000000 /* Timer Input clock freq */ +#define TIM_CLK_DIV 16 +#define CFG_HZ_CLOCK (27000000/TIM_CLK_DIV) /* Timer clock freq */ #define CFG_HZ 1000 /*=============*/ /* Memory Info */ Index: uboot_davinci/include/configs/davinci_sonata.h =================================================================== --- uboot_davinci.orig/include/configs/davinci_sonata.h +++ uboot_davinci/include/configs/davinci_sonata.h @@ -58,7 +58,8 @@ #define CONFIG_ARM926EJS /* arm926ejs CPU core */ #define CONFIG_SYS_CLK_FREQ 297000000 /* Arm Clock frequency */ #define CFG_TIMERBASE 0x01c21400 /* use timer 0 */ -#define CFG_HZ_CLOCK 27000000 /* Timer Input clock freq */ +#define TIM_CLK_DIV 16 +#define CFG_HZ_CLOCK (27000000/TIM_CLK_DIV) /* Timer clock freq */ #define CFG_HZ 1000 /*====================================================*/ /* EEPROM definitions for Atmel 24C256BN SEEPROM chip */