[U-Boot] [PATCH] arm: pxa: use common timer functions

[U-Boot] [PATCH] arm: pxa: use common timer functions

[Andrew Ruder]

This patch moves pxa to the common timer functions added in commit

  8dfafdd - Introduce common timer functions <Rob Herring>

The (removed) pxa timer code (specifically __udelay()) could deadlock at
the 32-bit boundary of get_ticks().  get_ticks() returned a 32-bit value
cast up to a 64-bit value.  If get_ticks() + tmo in __udelay() crossed
the 32-bit boundary, the while condition became unconditionally true and
locked the processor.  Rather than patch the specific pxa issues, simply
move everything over to the common code.

Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@konsuiko.com>
---

Tom,

You had asked me to fix up this patch back on August 30, 2014.  It broke
compilation on some PXA ports.  I have compile-tested on every PXA board in the
tree, I believe.  I have tested it on a yet-to-be-upstreamed board port based
on the PXA270.

 arch/arm/cpu/pxa/timer.c               | 69 +---------------------------------
 arch/arm/include/asm/arch-pxa/config.h | 25 ++++++++++++
 arch/arm/include/asm/config.h          |  5 ++-
 3 files changed, 30 insertions(+), 69 deletions(-)
 create mode 100644 arch/arm/include/asm/arch-pxa/config.h

diff --git a/arch/arm/cpu/pxa/timer.c b/arch/arm/cpu/pxa/timer.c
index c4717de..11fefd5 100644
--- a/arch/arm/cpu/pxa/timer.c
+++ b/arch/arm/cpu/pxa/timer.c
@@ -6,80 +6,13 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-#include <asm/arch/pxa-regs.h>
 #include <asm/io.h>
 #include <common.h>
-#include <div64.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#define	TIMER_LOAD_VAL	0xffffffff
-
-#define	timestamp	(gd->arch.tbl)
-#define	lastinc		(gd->arch.lastinc)
-
-#if defined(CONFIG_CPU_PXA27X) || defined(CONFIG_CPU_MONAHANS)
-#define	TIMER_FREQ_HZ	3250000
-#elif defined(CONFIG_CPU_PXA25X)
-#define	TIMER_FREQ_HZ	3686400
-#else
-#error "Timer frequency unknown - please config PXA CPU type"
-#endif
-
-static unsigned long long tick_to_time(unsigned long long tick)
-{
-	return lldiv(tick * CONFIG_SYS_HZ, TIMER_FREQ_HZ);
-}
-
-static unsigned long long us_to_tick(unsigned long long us)
-{
-	return lldiv(us * TIMER_FREQ_HZ, 1000000);
-}
-
 int timer_init(void)
 {
-	writel(0, OSCR);
+	writel(0, CONFIG_SYS_TIMER_COUNTER);
 	return 0;
 }
-
-unsigned long long get_ticks(void)
-{
-	/* Current tick value */
-	uint32_t now = readl(OSCR);
-
-	if (now >= lastinc) {
-		/*
-		 * Normal mode (non roll)
-		 * Move stamp forward with absolute diff ticks
-		 */
-		timestamp += (now - lastinc);
-	} else {
-		/* We have rollover of incrementer */
-		timestamp += (TIMER_LOAD_VAL - lastinc) + now;
-	}
-
-	lastinc = now;
-	return timestamp;
-}
-
-ulong get_timer(ulong base)
-{
-	return tick_to_time(get_ticks()) - base;
-}
-
-void __udelay(unsigned long usec)
-{
-	unsigned long long tmp;
-	ulong tmo;
-
-	tmo = us_to_tick(usec);
-	tmp = get_ticks() + tmo;	/* get current timestamp */
-
-	while (get_ticks() < tmp)	/* loop till event */
-		 /*NOP*/;
-}
-
-ulong get_tbclk(void)
-{
-	return TIMER_FREQ_HZ;
-}
diff --git a/arch/arm/include/asm/arch-pxa/config.h b/arch/arm/include/asm/arch-pxa/config.h
new file mode 100644
index 0000000..5836945
--- /dev/null
+++ b/arch/arm/include/asm/arch-pxa/config.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2014 Andrew Ruder <andrew.ruder@elecsyscorp.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _ASM_ARM_PXA_CONFIG_
+#define _ASM_ARM_PXA_CONFIG_
+
+#include <asm/arch/pxa-regs.h>
+
+/*
+ * Generic timer support
+ */
+#if defined(CONFIG_CPU_PXA27X) || defined(CONFIG_CPU_MONAHANS)
+#define	CONFIG_SYS_TIMER_RATE	3250000
+#elif defined(CONFIG_CPU_PXA25X)
+#define	CONFIG_SYS_TIMER_RATE	3686400
+#else
+#error "Timer frequency unknown - please config PXA CPU type"
+#endif
+
+#define CONFIG_SYS_TIMER_COUNTER	OSCR
+
+#endif /* _ASM_ARM_PXA_CONFIG_ */
diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
index 7a34a01..22fff02 100644
--- a/arch/arm/include/asm/config.h
+++ b/arch/arm/include/asm/config.h
@@ -19,7 +19,10 @@
 #include <asm/arch-fsl-lsch3/config.h>
 #endif
 
-#ifdef CONFIG_LS102XA
+#if defined(CONFIG_LS102XA) || \
+	defined(CONFIG_CPU_PXA27X) || \
+	defined(CONFIG_CPU_MONAHANS) || \
+	defined(CONFIG_CPU_PXA25X)
 #include <asm/arch/config.h>
 #endif
 
-- 
2.1.4

[U-Boot] [PATCH] arm: pxa: use common timer functions

[Andrew Ruder]

Tom,

Just replying so you see this since apparently I should have used 
copy-paste on your e-mail address for the Cc: and not attempted to read 
after 45 cups of tea.

- Andy

[U-Boot] [PATCH] arm: pxa: use common timer functions

[Marek Vasut]

On Wednesday, August 12, 2015 at 08:18:31 PM, Andrew Ruder wrote:
> This patch moves pxa to the common timer functions added in commit
> 
>   8dfafdd - Introduce common timer functions <Rob Herring>
> 
> The (removed) pxa timer code (specifically __udelay()) could deadlock at
> the 32-bit boundary of get_ticks().  get_ticks() returned a 32-bit value
> cast up to a 64-bit value.  If get_ticks() + tmo in __udelay() crossed
> the 32-bit boundary, the while condition became unconditionally true and
> locked the processor.  Rather than patch the specific pxa issues, simply
> move everything over to the common code.
> 
> Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
> Cc: Marek Vasut <marex@denx.de>
> Cc: Tom Rini <trini@konsuiko.com>

Applied to u-boot-pxa/master, thanks.

Best regards,
Marek Vasut