clk: rockchip: add rk3399 ddr clock support

add ddrc clock setting, so we can do ddr frequency
scaling on rk3399 platform in future.
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

drivers/clk/rockchip/clk-rk3399.c

@@ -120,6 +120,10 @@ PNAME(mux_armclkb_p)				= { "clk_core_b_lpll_src",
 						    "clk_core_b_bpll_src",
 						    "clk_core_b_dpll_src",
 						    "clk_core_b_gpll_src" };
+PNAME(mux_ddrclk_p)				= { "clk_ddrc_lpll_src",
+						    "clk_ddrc_bpll_src",
+						    "clk_ddrc_dpll_src",
+						    "clk_ddrc_gpll_src" };
 PNAME(mux_aclk_cci_p)				= { "cpll_aclk_cci_src",
 						    "gpll_aclk_cci_src",
 						    "npll_aclk_cci_src",
@@ -1379,6 +1383,18 @@ static struct rockchip_clk_branch rk3399_clk_branches[] __initdata = {
 	COMPOSITE_NOMUX(0, "clk_test", "clk_test_pre", CLK_IGNORE_UNUSED,
 			RK3368_CLKSEL_CON(58), 0, 5, DFLAGS,
 			RK3368_CLKGATE_CON(13), 11, GFLAGS),
+
+	/* ddrc */
+	GATE(0, "clk_ddrc_lpll_src", "lpll", 0, RK3399_CLKGATE_CON(3),
+	     0, GFLAGS),
+	GATE(0, "clk_ddrc_bpll_src", "bpll", 0, RK3399_CLKGATE_CON(3),
+	     1, GFLAGS),
+	GATE(0, "clk_ddrc_dpll_src", "dpll", 0, RK3399_CLKGATE_CON(3),
+	     2, GFLAGS),
+	GATE(0, "clk_ddrc_gpll_src", "gpll", 0, RK3399_CLKGATE_CON(3),
+	     3, GFLAGS),
+	COMPOSITE_DDRCLK(SCLK_DDRC, "sclk_ddrc", mux_ddrclk_p, 0,
+		       RK3399_CLKSEL_CON(6), 4, 2, 0, 0, ROCKCHIP_DDRCLK_SIP),
 };
 
 static struct rockchip_clk_branch rk3399_clk_pmu_branches[] __initdata = {
@@ -1493,6 +1509,9 @@ static const char *const rk3399_cru_critical_clocks[] __initconst = {
 	"gpll_aclk_perilp0_src",
 	"gpll_aclk_perihp_src",
 	"aclk_vio_noc",
+
+	/* ddrc */
+	"sclk_ddrc"
 };
 
 static const char *const rk3399_pmucru_critical_clocks[] __initconst = {