armv8/ls2085a: Fix generic timer clock source

The timer clock is system clock divided by 4, not fixed 12MHz.
This is common to the SoC, not board specific. Primary core is
fixed when u-boot still runs in board_f. Secondary cores are
fixed by reading a variable set by u-boot.

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Mark Rutland <mark.rutland@arm.com>

README

@@ -690,6 +690,14 @@ The following options need to be configured:
 		exists, unlike the similar options in the Linux kernel. Do not
 		set these options unless they apply!
 
+		COUNTER_FREQUENCY
+		Generic timer clock source frequency.
+
+		COUNTER_FREQUENCY_REAL
+		Generic timer clock source frequency if the real clock is
+		different from COUNTER_FREQUENCY, and can only be determined
+		at run time.
+
 		NOTE: The following can be machine specific errata. These
 		do have ability to provide rudimentary version and machine
 		specific checks, but expect no product checks.

arch/arm/cpu/armv8/fsl-lsch3/cpu.c

@@ -395,3 +395,27 @@ int arch_early_init_r(void)
 
 	return 0;
 }
+
+int timer_init(void)
+{
+	u32 __iomem *cntcr = (u32 *)CONFIG_SYS_FSL_TIMER_ADDR;
+	u32 __iomem *cltbenr = (u32 *)CONFIG_SYS_FSL_PMU_CLTBENR;
+#ifdef COUNTER_FREQUENCY_REAL
+	unsigned long cntfrq = COUNTER_FREQUENCY_REAL;
+
+	/* Update with accurate clock frequency */
+	asm volatile("msr cntfrq_el0, %0" : : "r" (cntfrq) : "memory");
+#endif
+
+	/* Enable timebase for all clusters.
+	 * It is safe to do so even some clusters are not enabled.
+	 */
+	out_le32(cltbenr, 0xf);
+
+	/* Enable clock for timer
+	 * This is a global setting.
+	 */
+	out_le32(cntcr, 0x1);
+
+	return 0;
+}

arch/arm/cpu/armv8/fsl-lsch3/lowlevel.S

@@ -224,6 +224,9 @@ ENTRY(secondary_boot_func)
 	/* physical address of this cpus spin table element */
 	add	x11, x1, x0
 
+	ldr	x0, =__real_cntfrq
+	ldr	x0, [x0]
+	msr	cntfrq_el0, x0	/* set with real frequency */
 	str	x9, [x11, #16]	/* LPID */
 	mov	x4, #1
 	str	x4, [x11, #8]	/* STATUS */
@@ -275,6 +278,9 @@ ENDPROC(secondary_switch_to_el1)
 
 	/* 64 bit alignment for elements accessed as data */
 	.align 4
+	.global __real_cntfrq
+__real_cntfrq:
+	.quad COUNTER_FREQUENCY
 	.globl __secondary_boot_code_size
 	.type __secondary_boot_code_size, %object
 	/* Secondary Boot Code ends here */

arch/arm/cpu/armv8/fsl-lsch3/mp.c

@@ -31,6 +31,13 @@ int fsl_lsch3_wake_seconday_cores(void)
 	int i, timeout = 10;
 	u64 *table = get_spin_tbl_addr();
 
+#ifdef COUNTER_FREQUENCY_REAL
+	/* update for secondary cores */
+	__real_cntfrq = COUNTER_FREQUENCY_REAL;
+	flush_dcache_range((unsigned long)&__real_cntfrq,
+			   (unsigned long)&__real_cntfrq + 8);
+#endif
+
 	cores = cpu_mask();
 	/* Clear spin table so that secondary processors
 	 * observe the correct value after waking up from wfe.

arch/arm/cpu/armv8/fsl-lsch3/mp.h

@@ -26,6 +26,7 @@
 #define id_to_core(x)	((x & 3) | (x >> 6))
 #ifndef __ASSEMBLY__
 extern u64 __spin_table[];
+extern u64 __real_cntfrq;
 extern u64 *secondary_boot_code;
 extern size_t __secondary_boot_code_size;
 int fsl_lsch3_wake_seconday_cores(void);

board/freescale/ls2085a/ls2085a.c

@@ -55,24 +55,6 @@ int dram_init(void)
 	return 0;
 }
 
-int timer_init(void)
-{
-	u32 __iomem *cntcr = (u32 *)CONFIG_SYS_FSL_TIMER_ADDR;
-	u32 __iomem *cltbenr = (u32 *)CONFIG_SYS_FSL_PMU_CLTBENR;
-
-	/* Enable timebase for all clusters.
-	 * It is safe to do so even some clusters are not enabled.
-	 */
-	out_le32(cltbenr, 0xf);
-
-	/* Enable clock for timer
-	 * This is a global setting.
-	 */
-	out_le32(cntcr, 0x1);
-
-	return 0;
-}
-
 /*
  * Board specific reset that is system reset.
  */

include/configs/ls2085a_common.h

@@ -72,7 +72,11 @@
 #define CONFIG_DP_DDR_NUM_CTRLS		1
 
 /* Generic Timer Definitions */
-#define COUNTER_FREQUENCY		12000000	/* 12MHz */
+/*
+ * This is not an accurate number. It is used in start.S. The frequency
+ * will be udpated later when get_bus_freq(0) is available.
+ */
+#define COUNTER_FREQUENCY		25000000	/* 25MHz */
 
 /* Size of malloc() pool */
 #define CONFIG_SYS_MALLOC_LEN		(CONFIG_ENV_SIZE + 2048 * 1024)