sunxi: clock: Add clock_get_pll3() helper function

Add a helper function to get the pll3 clock rate.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/arch/arm/cpu/armv7/sunxi/clock_sun4i.c b/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
index c3e04af..7c8eff9 100644
--- a/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
+++ b/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
@@ -198,6 +198,15 @@
 	       CCM_PLL3_CTRL_M(clk / 3000000), &ccm->pll3_cfg);
 }
 
+unsigned int clock_get_pll3(void)
+{
+	struct sunxi_ccm_reg *const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	uint32_t rval = readl(&ccm->pll3_cfg);
+	int m = ((rval & CCM_PLL3_CTRL_M_MASK) >> CCM_PLL3_CTRL_M_SHIFT);
+	return 3000000 * m;
+}
+
 unsigned int clock_get_pll5p(void)
 {
 	struct sunxi_ccm_reg *const ccm =