arm: socfpga: Fix delay in freeze controller

Based on observation, this udelay(20) was apparently too high and caused
subsequent failure to calibrate DDR when U-Boot was compiled with certain
toolchains. Lowering this delay fixed the problem.

Instead of permanently lowering the delay, calculate the correct delay
based on the original comment, that is, obtain EOSC1 frequency and use
it to calculate the precise delay.

Signed-off-by: Marek Vasut <marex@denx.de>

arch/arm/mach-socfpga/freeze_controller.c

@@ -7,8 +7,8 @@
 
 #include <common.h>
 #include <asm/io.h>
+#include <asm/arch/clock_manager.h>
 #include <asm/arch/freeze_controller.h>
-#include <asm/arch/timer.h>
 #include <asm/errno.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -112,6 +112,7 @@ void sys_mgr_frzctrl_thaw_req(void)
 	u32 reg_cfg_mask;
 	u32 reg_value;
 	u32 channel_id;
+	unsigned long eosc1_freq;
 
 	/* select software FSM */
 	writel(SYSMGR_FRZCTRL_SRC_VIO1_ENUM_SW,	&freeze_controller_base->src);
@@ -162,12 +163,9 @@ void sys_mgr_frzctrl_thaw_req(void)
 	setbits_le32(&freeze_controller_base->hioctrl,
 		SYSMGR_FRZCTRL_HIOCTRL_OCT_CFGEN_CALSTART_MASK);
 
-	/*
-	 * Delay 1000 intosc. intosc is based on eosc1
-	 * Use worst case which is fatest eosc1=50MHz, delay required
-	 * is 1/50MHz * 1000 = 20us
-	 */
-	udelay(20);
+	/* Delay 1000 intosc cycles. The intosc is based on eosc1. */
+	eosc1_freq = cm_get_osc_clk_hz(1) / 1000;	/* kHz */
+	udelay(DIV_ROUND_UP(1000000, eosc1_freq));
 
 	/*
 	 * de-assert active low bhniotri signals,