zynqmp: Do not alter system counter

On ZynqMP the FSBL will configure the system counter. Hence, remove the
initialization of the system counter with hardcoded values from the ATF
and use the setup provided by the bootloader.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

plat/xilinx/zynqmp/aarch64/zynqmp_common.c

@@ -77,22 +77,6 @@ unsigned int zynqmp_get_uart_clk(void)
 	return 100000000;
 }
 
-static unsigned int zynqmp_get_system_timer_freq(void)
-{
-	unsigned int ver = zynqmp_get_silicon_ver();
-
-	switch (ver) {
-	case ZYNQMP_CSU_VERSION_VELOCE:
-		return 10000;
-	case ZYNQMP_CSU_VERSION_EP108:
-		return 4000000;
-	case ZYNQMP_CSU_VERSION_QEMU:
-		return 50000000;
-	}
-
-	return 100000000;
-}
-
 unsigned int zynqmp_get_silicon_id(void)
 {
 	uint32_t id;
@@ -284,25 +268,21 @@ void zynqmp_config_setup(void)
 {
 	zynqmp_discover_pmufw();
 	zynqmp_print_platform_name();
-
-	/* Global timer init - Program time stamp reference clk */
-	uint32_t val = mmio_read_32(CRL_APB_TIMESTAMP_REF_CTRL);
-	val |= CRL_APB_TIMESTAMP_REF_CTRL_CLKACT_BIT;
-	mmio_write_32(CRL_APB_TIMESTAMP_REF_CTRL, val);
-
-	/* Program freq register in System counter and enable system counter. */
-	mmio_write_32(IOU_SCNTRS_BASEFREQ, zynqmp_get_system_timer_freq());
-	mmio_write_32(IOU_SCNTRS_CONTROL, IOU_SCNTRS_CONTROL_EN);
-
 	generic_delay_timer_init();
 }
 
 unsigned int plat_get_syscnt_freq2(void)
 {
-	unsigned int counter_base_frequency;
+	unsigned int ver = zynqmp_get_silicon_ver();
 
-	/* FIXME: Read the frequency from Frequency modes table */
-	counter_base_frequency = zynqmp_get_system_timer_freq();
+	switch (ver) {
+	case ZYNQMP_CSU_VERSION_VELOCE:
+		return 10000;
+	case ZYNQMP_CSU_VERSION_EP108:
+		return 4000000;
+	case ZYNQMP_CSU_VERSION_QEMU:
+		return 50000000;
+	}
 
-	return counter_base_frequency;
+	return mmio_read_32(IOU_SCNTRS_BASEFREQ);
 }

plat/xilinx/zynqmp/zynqmp_def.h

@@ -69,12 +69,9 @@
 /* CRL registers and bitfields */
 #define CRL_APB_BASE			0xFF5E0000
 #define CRL_APB_RPLL_CTRL		(CRL_APB_BASE + 0x30)
-#define CRL_APB_TIMESTAMP_REF_CTRL	(CRL_APB_BASE + 0x128)
 #define CRL_APB_BOOT_MODE_USER		(CRL_APB_BASE + 0x200)
 #define CRL_APB_RESET_CTRL		(CRL_APB_BASE + 0x218)
 
-#define CRL_APB_TIMESTAMP_REF_CTRL_CLKACT_BIT	(1 << 24)
-
 #define CRL_APB_RPLL_CTRL_BYPASS	(1 << 3)
 
 #define CRL_APB_RESET_CTRL_SOFT_RESET	(1 << 4)
@@ -84,11 +81,8 @@
 
 /* system counter registers and bitfields */
 #define IOU_SCNTRS_BASE			0xFF260000
-#define IOU_SCNTRS_CONTROL		(IOU_SCNTRS_BASE + 0)
 #define IOU_SCNTRS_BASEFREQ		(IOU_SCNTRS_BASE + 0x20)
 
-#define IOU_SCNTRS_CONTROL_EN		(1 << 0)
-
 /* APU registers and bitfields */
 #define APU_BASE		0xFD5C0000
 #define APU_CONFIG_0		(APU_BASE + 0x20)