clk: sunxi: Give sunxi_factors_register a registers parameter

Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
the clk registers. The sun6i prcm has factor clocks, for which we want to
use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
factor clocks, because the prcm uses the mfd framework, so the registers
are not part of the dt-node, instead they are added to the platform_device,
as platform_device resources.

This commit makes getting the registers the callers duty, so that
sunxi_factors_register can be used with mfd instantiated platform device too.

While at it also add error checking to the of_iomap calls.

This commit also drops the __init function from sunxi_factors_register since
platform driver probe functions are not __init.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/clk/sunxi/clk-mod0.c

@@ -79,7 +79,17 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
 
 static void __init sun4i_a10_mod0_setup(struct device_node *node)
 {
-	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
+	void __iomem *reg;
+
+	reg = of_iomap(node, 0);
+	if (!reg) {
+		pr_err("Could not get registers for mod0-clk: %s\n",
+		       node->name);
+		return;
+	}
+
+	sunxi_factors_register(node, &sun4i_a10_mod0_data,
+			       &sun4i_a10_mod0_lock, reg);
 }
 CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup);
 
@@ -87,7 +97,17 @@ static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
 
 static void __init sun5i_a13_mbus_setup(struct device_node *node)
 {
-	struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock);
+	struct clk *mbus;
+	void __iomem *reg;
+
+	reg = of_iomap(node, 0);
+	if (!reg) {
+		pr_err("Could not get registers for a13-mbus-clk\n");
+		return;
+	}
+
+	mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data,
+				      &sun5i_a13_mbus_lock, reg);
 
 	/* The MBUS clocks needs to be always enabled */
 	__clk_get(mbus);