rockchip/rk3399: fix DRAM gate training issue

The differential signal of DQS need keep low level
before gate training. It need enable RPULL and disable
PHY side ODT to ensure it when do gate training.
But it can not access the PHY registers to do it when
perform DFS.So the workaroud as below: It is ensure that
the PHY's read gate is landing somewhere in the incoming
DQS's pulses before it starts searching for pre-amble window.
It need get the rddqs_delay_ps to calculate the start point
of gate training for DFS.

Change-Id: I79eabcf4ec9a9c8f4539f68a51f22afba49c72fe
Signed-off-by: Lin Huang <hl@rock-chips.com>

plat/rockchip/rk3399/drivers/dram/dfs.c

@@ -54,6 +54,7 @@ struct rk3399_saved_status {
 static struct rk3399_dram_status rk3399_dram_status;
 static struct rk3399_saved_status rk3399_suspend_status;
 static uint32_t wrdqs_delay_val[2][2][4];
+static uint32_t rddqs_delay_ps;
 
 static struct rk3399_sdram_default_config ddr3_default_config = {
 	.bl = 8,
@@ -1599,7 +1600,7 @@ static void gen_rk3399_phy_params(struct timing_related_config *timing_config,
 		mmio_clrsetbits_32(PHY_REG(i, 394), 0xf, tmp);
 		/* PHY_GTLVL_LAT_ADJ_START */
 		/* DENALI_PHY_80/208/336/464 4bits offset_16 */
-		tmp = delay_frac_ps / 1000;
+		tmp = rddqs_delay_ps / (1000000 / pdram_timing->mhz) + 2;
 		mmio_clrsetbits_32(PHY_REG(i, 80), 0xf << 16, tmp << 16);
 		mmio_clrsetbits_32(PHY_REG(i, 208), 0xf << 16, tmp << 16);
 		mmio_clrsetbits_32(PHY_REG(i, 336), 0xf << 16, tmp << 16);
@@ -1830,6 +1831,7 @@ static void dram_low_power_config(void)
 void dram_dfs_init(void)
 {
 	uint32_t trefi0, trefi1, boot_freq;
+	uint32_t rddqs_adjust, rddqs_slave;
 
 	/* get sdram config for os reg */
 	get_dram_drv_odt_val(sdram_config.dramtype,
@@ -1875,8 +1877,31 @@ void dram_dfs_init(void)
 	/* Disable multicast */
 	mmio_clrbits_32(PHY_REG(0, 896), 1);
 	mmio_clrbits_32(PHY_REG(1, 896), 1);
-
 	dram_low_power_config();
+
+	/*
+	 * If boot_freq isn't in the bypass mode, it can get the
+	 * rddqs_delay_ps from the result of gate training
+	 */
+	if (((mmio_read_32(PHY_REG(0, 86)) >> 8) & 0xf) != 0xc) {
+
+		/*
+		 * Select PHY's frequency set to current_index
+		 * index for get the result of gate Training
+		 * from registers
+		 */
+		mmio_clrsetbits_32(PHY_REG(0, 896), 0x3 << 8,
+				   rk3399_dram_status.current_index << 8);
+		rddqs_slave = (mmio_read_32(PHY_REG(0, 77)) >> 16) & 0x3ff;
+		rddqs_slave = rddqs_slave * 1000000 / boot_freq / 512;
+
+		rddqs_adjust = mmio_read_32(PHY_REG(0, 78)) & 0xf;
+		rddqs_adjust = rddqs_adjust * 1000000 / boot_freq;
+		rddqs_delay_ps = rddqs_slave + rddqs_adjust -
+				(1000000 / boot_freq / 2);
+	} else {
+		rddqs_delay_ps = 3500;
+	}
 }
 
 /*