xilinx: versal-net: Add support for timer and start it

Add support for starting timer by setting up time stamp generator
registers. This is done only for EL3 i.e. mini U-Boot case.
For other cases, it will be done TF-A.

Add COUNTER_FREQUENCY and IOU_SWITCH_DIVISOR0 to Kconfig so that they
can be tuned as required.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/fcd8b0dc4b45a11f5e753afff42f84738ac813da.1673336645.git.michal.simek@amd.com
diff --git a/arch/arm/mach-versal-net/Kconfig b/arch/arm/mach-versal-net/Kconfig
index 62825e1..edff5b0 100644
--- a/arch/arm/mach-versal-net/Kconfig
+++ b/arch/arm/mach-versal-net/Kconfig
@@ -21,6 +21,18 @@
 	  Based on this option include/configs/<CONFIG_SYS_CONFIG_NAME>.h header
 	  will be used for board configuration.
 
+config COUNTER_FREQUENCY
+	int "Timer clock frequency"
+	default 0
+	help
+	  Setup time clock frequency for certain platform
+
+config IOU_SWITCH_DIVISOR0
+	hex "IOU switch divisor0"
+	default 0x20
+	help
+	  Setup time clock divisor for input clock.
+
 config SYS_MEM_RSVD_FOR_MMU
 	bool "Reserve memory for MMU Table"
 	help
diff --git a/arch/arm/mach-versal-net/include/mach/hardware.h b/arch/arm/mach-versal-net/include/mach/hardware.h
index 808ce48..c5e4e22 100644
--- a/arch/arm/mach-versal-net/include/mach/hardware.h
+++ b/arch/arm/mach-versal-net/include/mach/hardware.h
@@ -8,6 +8,36 @@
 #include <linux/bitops.h>
 #endif
 
+struct crlapb_regs {
+	u32 reserved0[67];
+	u32 cpu_r5_ctrl;
+	u32 reserved;
+	u32 iou_switch_ctrl; /* 0x114 */
+	u32 reserved1[13];
+	u32 timestamp_ref_ctrl; /* 0x14c */
+	u32 reserved3[108];
+	u32 rst_cpu_r5;
+	u32 reserved2[17];
+	u32 rst_timestamp; /* 0x348 */
+};
+
+struct iou_scntrs_regs {
+	u32 counter_control_register; /* 0x0 */
+	u32 reserved0[7];
+	u32 base_frequency_id_register; /* 0x20 */
+};
+
+#define VERSAL_NET_CRL_APB_BASEADDR		0xEB5E0000
+#define VERSAL_NET_IOU_SCNTR_SECURE		0xEC920000
+
+#define CRL_APB_TIMESTAMP_REF_CTRL_CLKACT_BIT	BIT(25)
+#define IOU_SWITCH_CTRL_CLKACT_BIT		BIT(25)
+#define IOU_SWITCH_CTRL_DIVISOR0_SHIFT		8
+#define IOU_SCNTRS_CONTROL_EN			1
+
+#define crlapb_base ((struct crlapb_regs *)VERSAL_NET_CRL_APB_BASEADDR)
+#define iou_scntr_secure ((struct iou_scntrs_regs *)VERSAL_NET_IOU_SCNTR_SECURE)
+
 #define PMC_TAP	0xF11A0000
 
 #define PMC_TAP_IDCODE		(PMC_TAP + 0)