clk: fixed: add devm helper for clk_hw_register_fixed_factor()

Add a devm helper for clk_hw_register_fixed_factor() so that drivers that internally
register fixed factor clocks for things like dividers don't need to manually unregister
them on remove or if probe fails.

Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Link: https://lore.kernel.org/r/20210211052206.2955988-4-daniel@0x0f.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: fifteenhex

drivers/clk/clk-fixed-factor.c

@@ -64,18 +64,32 @@ const struct clk_ops clk_fixed_factor_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
 
+static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
+{
+	clk_hw_unregister_fixed_factor(&((struct clk_fixed_factor *)res)->hw);
+}
+
 static struct clk_hw *
 __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
 		const char *name, const char *parent_name, int index,
-		unsigned long flags, unsigned int mult, unsigned int div)
+		unsigned long flags, unsigned int mult, unsigned int div,
+		bool devm)
 {
 	struct clk_fixed_factor *fix;
 	struct clk_init_data init = { };
 	struct clk_parent_data pdata = { .index = index };
 	struct clk_hw *hw;
 	int ret;
 
-	fix = kmalloc(sizeof(*fix), GFP_KERNEL);
+	/* You can't use devm without a dev */
+	if (devm && !dev)
+		return ERR_PTR(-EINVAL);
+
+	if (devm)
+		fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
+				sizeof(*fix), GFP_KERNEL);
+	else
+		fix = kmalloc(sizeof(*fix), GFP_KERNEL);
 	if (!fix)
 		return ERR_PTR(-ENOMEM);
 
@@ -99,9 +113,13 @@ __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
 	else
 		ret = of_clk_hw_register(np, hw);
 	if (ret) {
-		kfree(fix);
+		if (devm)
+			devres_free(fix);
+		else
+			kfree(fix);
 		hw = ERR_PTR(ret);
-	}
+	} else if (devm)
+		devres_add(dev, fix);
 
 	return hw;
 }
@@ -111,7 +129,7 @@ struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
 		unsigned int mult, unsigned int div)
 {
 	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
-					      flags, mult, div);
+					      flags, mult, div, false);
 }
 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
 
@@ -153,6 +171,15 @@ void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
 }
 EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
 
+struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
+			flags, mult, div, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
+
 #ifdef CONFIG_OF
 static const struct of_device_id set_rate_parent_matches[] = {
 	{ .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
@@ -185,7 +212,7 @@ static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
 		flags |= CLK_SET_RATE_PARENT;
 
 	hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, 0,
-					    flags, mult, div);
+					    flags, mult, div, false);
 	if (IS_ERR(hw)) {
 		/*
 		 * Clear OF_POPULATED flag so that clock registration can be

include/linux/clk-provider.h

@@ -941,7 +941,9 @@ struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
 		const char *name, const char *parent_name, unsigned long flags,
 		unsigned int mult, unsigned int div);
 void clk_hw_unregister_fixed_factor(struct clk_hw *hw);
-
+struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div);
 /**
  * struct clk_fractional_divider - adjustable fractional divider clock
  *