[U-Boot] [PATCH v4 04/28] armv8/ls2085a: Fix generic timer clock source

Fri Mar 20 20:21:00 CET 2015

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 at freescale.com>
CC: Mark Rutland <mark.rutland at arm.com>

---

Changes in v4:
  Remove temporary variable cntfrq.

Changes in v3:
  Move secondary core fix to mp.c.
  Replace hard-coded value with COUNTER_FREQUENCY.

Changes in v2:
  Fix CNTFRQ for secondary cores when COUNTER_FREQUENCY_REAL is defined.

 README                                  |    8 ++++++++
 arch/arm/cpu/armv8/fsl-lsch3/cpu.c      |   24 ++++++++++++++++++++++++
 arch/arm/cpu/armv8/fsl-lsch3/lowlevel.S |    6 ++++++
 arch/arm/cpu/armv8/fsl-lsch3/mp.c       |    7 +++++++
 arch/arm/cpu/armv8/fsl-lsch3/mp.h       |    1 +
 board/freescale/ls2085a/ls2085a.c       |   18 ------------------
 include/configs/ls2085a_common.h        |    6 +++++-
 7 files changed, 51 insertions(+), 19 deletions(-)

diff --git a/README b/README
index e710226..f063a74 100644
--- a/README
+++ b/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.
diff --git a/arch/arm/cpu/armv8/fsl-lsch3/cpu.c b/arch/arm/cpu/armv8/fsl-lsch3/cpu.c
index 94fd147..e985181 100644
--- a/arch/arm/cpu/armv8/fsl-lsch3/cpu.c
+++ b/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;
+}
diff --git a/arch/arm/cpu/armv8/fsl-lsch3/lowlevel.S b/arch/arm/cpu/armv8/fsl-lsch3/lowlevel.S
index 886576e..53bdb44 100644
--- a/arch/arm/cpu/armv8/fsl-lsch3/lowlevel.S
+++ b/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 */
diff --git a/arch/arm/cpu/armv8/fsl-lsch3/mp.c b/arch/arm/cpu/armv8/fsl-lsch3/mp.c
index ce9c0c1..da7853a 100644
--- a/arch/arm/cpu/armv8/fsl-lsch3/mp.c
+++ b/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.
diff --git a/arch/arm/cpu/armv8/fsl-lsch3/mp.h b/arch/arm/cpu/armv8/fsl-lsch3/mp.h
index 66144d6..c985d6a 100644
--- a/arch/arm/cpu/armv8/fsl-lsch3/mp.h
+++ b/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);
diff --git a/board/freescale/ls2085a/ls2085a.c b/board/freescale/ls2085a/ls2085a.c
index e78c63a..bd016e9 100644
--- a/board/freescale/ls2085a/ls2085a.c
+++ b/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.
  */
diff --git a/include/configs/ls2085a_common.h b/include/configs/ls2085a_common.h
index 5721b18..f6b3ed0 100644
--- a/include/configs/ls2085a_common.h
+++ b/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)
-- 
1.7.9.5

