arm: uniphier: use DM_TIMER of arm a9 global timer

All uniphier v7 SoCs have cortex-a9 and use cortex-a9 global timer
in a simple implementation. Now DM_TIMER of it is available
on 35751c7f3f ("timer: sti: convert sti-timer to arm a9 global timer"),
so let's switch to it.

The old driver reads the lower 32bits of counter field
and sets the prescaler as 50 with PERIPHCLK(=50MHz),
so the global timer works as a 32-bit 1MHz timer.

The DM_TIMER uses the whole 64bits with no prescaler,
so the global timer works as a 64-bit PERIPHCLK timer.

CONFIG_SYS_HZ_CLOCK is set as the default PERIPHCLK frequency,
if there is no 'clocks' property in devicetree.

Signed-off-by: Dai Okamura <okamura.dai@socionext.com>

arch/arm/dts/uniphier-v7-u-boot.dtsi

@@ -2,6 +2,10 @@
 	soc {
 		u-boot,dm-pre-reloc;
 
+		timer@60000200 {
+			u-boot,dm-pre-reloc;
+		};
+
 		serial@54006800 {
 			u-boot,dm-pre-reloc;
 		};

arch/arm/mach-uniphier/Kconfig

@@ -12,6 +12,7 @@ config ARCH_UNIPHIER_V7_MULTI
 	select ARMV7_NONSEC
 	select CPU_V7A
 	select CPU_V7_HAS_NONSEC
+	select ARM_GLOBAL_TIMER if TIMER
 
 config ARCH_UNIPHIER_V8_MULTI
 	bool "UniPhier V8 SoCs"

arch/arm/mach-uniphier/arm32/Makefile

@@ -8,5 +8,3 @@ obj-y += late_lowlevel_init.o
 obj-y += cache-uniphier.o
 obj-$(CONFIG_ARMV7_PSCI) += psci.o psci_smp.o
 endif
-
-obj-y += timer.o

arch/arm/mach-uniphier/arm32/timer.c

@@ -1,39 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
- */
-
-#include <config.h>
-#include <init.h>
-#include <linux/io.h>
-
-#include "arm-mpcore.h"
-
-#define PERIPHCLK (50 * 1000 * 1000) /* 50 MHz */
-#define PRESCALER ((PERIPHCLK) / (CFG_SYS_TIMER_RATE) - 1)
-
-static void *get_global_timer_base(void)
-{
-	void *val;
-
-	asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (val) : : "memory");
-
-	return val + GLOBAL_TIMER_OFFSET;
-}
-
-unsigned long timer_read_counter(void)
-{
-	/*
-	 * ARM 64bit Global Timer is too much for our purpose.
-	 * We use only lower 32 bit of the timer counter.
-	 */
-	return readl(get_global_timer_base() + GTIMER_CNT_L);
-}
-
-int timer_init(void)
-{
-	/* enable timer */
-	writel(PRESCALER << 8 | 1, get_global_timer_base() + GTIMER_CTRL);
-
-	return 0;
-}

configs/uniphier_ld4_sld8_defconfig

@@ -13,6 +13,8 @@ CONFIG_SYS_LOAD_ADDR=0x85000000
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x84000000
 CONFIG_SYS_MONITOR_LEN=2097152
+CONFIG_TIMER=y
+CONFIG_SPL_TIMER=y
 CONFIG_TIMESTAMP=y
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
 CONFIG_BOOTCOMMAND="run ${bootdev}script; run ${bootdev}boot"

configs/uniphier_v7_defconfig

@@ -13,6 +13,8 @@ CONFIG_SYS_LOAD_ADDR=0x85000000
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x84000000
 CONFIG_SYS_MONITOR_LEN=2097152
+CONFIG_TIMER=y
+CONFIG_SPL_TIMER=y
 CONFIG_TIMESTAMP=y
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
 CONFIG_BOOTCOMMAND="run ${bootdev}script; run ${bootdev}boot"

include/configs/uniphier.h

@@ -36,8 +36,7 @@
 	BOOT_TARGET_DEVICE_USB(func)
 
 #if !defined(CONFIG_ARM64)
-/* Time clock 1MHz */
+#define CFG_SYS_HZ_CLOCK			50000000
-#define CFG_SYS_TIMER_RATE			1000000
 #endif
 
 #define CFG_SYS_NAND_REGS_BASE			0x68100000