clk: basic: improve parent_names & return errors

This patch is the basic clk version of 'clk: core: copy parent_names &
return error codes'.

The registration functions are changed to allow the core code to copy
the array of strings and allow platforms to declare those arrays as
__initdata.

This patch also converts all of the basic clk registration functions to
return error codes which better aligns them with the existing clk.h api.

Signed-off-by: Mike Turquette <mturquette@linaro.org>

5 files changed, 64 insertions, 56 deletions

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index b1c4b02aaaf1..5fc541d017f1 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -153,6 +153,18 @@ const struct clk_ops clk_divider_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_divider_ops);
 
+/**
+ * clk_register_divider - register a divider clock with the clock framework
+ * @dev: device registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust divider
+ * @shift: number of bits to shift the bitfield
+ * @width: width of the bitfield
+ * @clk_divider_flags: divider-specific flags for this clock
+ * @lock: shared register lock for this clock
+ */
 struct clk *clk_register_divider(struct device *dev, const char *name,
                 const char *parent_name, unsigned long flags,
                 void __iomem *reg, u8 shift, u8 width,
@@ -161,11 +173,11 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
         struct clk_divider *div;
         struct clk *clk;
 
+        /* allocate the divider */
         div = kzalloc(sizeof(struct clk_divider), GFP_KERNEL);
-
         if (!div) {
                 pr_err("%s: could not allocate divider clk\n", __func__);
-                return NULL;
+                return ERR_PTR(-ENOMEM);
         }
 
         /* struct clk_divider assignments */
@@ -175,23 +187,15 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
         div->flags = clk_divider_flags;
         div->lock = lock;
 
-        if (parent_name) {
-                div->parent[0] = kstrdup(parent_name, GFP_KERNEL);
-                if (!div->parent[0])
-                        goto out;
-        }
-
+        /* register the clock */
         clk = clk_register(dev, name,
                         &clk_divider_ops, &div->hw,
-                        div->parent,
+                        (parent_name ? &parent_name: NULL),
                         (parent_name ? 1 : 0),
                         flags);
-        if (clk)
-                return clk;
 
-out:
-        kfree(div->parent[0]);
-        kfree(div);
+        if (IS_ERR(clk))
+                kfree(div);
 
-        return NULL;
+        return clk;
 }
diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c
index 027e47704de9..b555a04c8df8 100644
--- a/drivers/clk/clk-fixed-rate.c
+++ b/drivers/clk/clk-fixed-rate.c
@@ -38,16 +38,23 @@ const struct clk_ops clk_fixed_rate_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
 
+/**
+ * clk_register_fixed_rate - register fixed-rate clock with the clock framework
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @fixed_rate: non-adjustable clock rate
+ */
 struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
                 const char *parent_name, unsigned long flags,
                 unsigned long fixed_rate)
 {
         struct clk_fixed_rate *fixed;
-        char **parent_names = NULL;
-        u8 len;
+        struct clk *clk;
 
+        /* allocate fixed-rate clock */
         fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL);
-
         if (!fixed) {
                 pr_err("%s: could not allocate fixed clk\n", __func__);
                 return ERR_PTR(-ENOMEM);
@@ -56,26 +63,15 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
         /* struct clk_fixed_rate assignments */
         fixed->fixed_rate = fixed_rate;
 
-        if (parent_name) {
-                parent_names = kmalloc(sizeof(char *), GFP_KERNEL);
-
-                if (! parent_names)
-                        goto out;
-
-                len = sizeof(char) * strlen(parent_name);
-
-                parent_names[0] = kmalloc(len, GFP_KERNEL);
-
-                if (!parent_names[0])
-                        goto out;
-
-                strncpy(parent_names[0], parent_name, len);
-        }
-
-out:
-        return clk_register(dev, name,
+        /* register the clock */
+        clk = clk_register(dev, name,
                         &clk_fixed_rate_ops, &fixed->hw,
-                        parent_names,
+                        (parent_name ? &parent_name : NULL),
                         (parent_name ? 1 : 0),
                         flags);
+
+        if (IS_ERR(clk))
+                kfree(fixed);
+
+        return clk;
 }
diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c
index fe2ff9e774c2..42a4b941b6e7 100644
--- a/drivers/clk/clk-gate.c
+++ b/drivers/clk/clk-gate.c
@@ -105,6 +105,17 @@ const struct clk_ops clk_gate_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_gate_ops);
 
+/**
+ * clk_register_gate - register a gate clock with the clock framework
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_name: name of this clock's parent
+ * @flags: framework-specific flags for this clock
+ * @reg: register address to control gating of this clock
+ * @bit_idx: which bit in the register controls gating of this clock
+ * @clk_gate_flags: gate-specific flags for this clock
+ * @lock: shared register lock for this clock
+ */
 struct clk *clk_register_gate(struct device *dev, const char *name,
                 const char *parent_name, unsigned long flags,
                 void __iomem *reg, u8 bit_idx,
@@ -113,11 +124,11 @@ struct clk *clk_register_gate(struct device *dev, const char *name,
         struct clk_gate *gate;
         struct clk *clk;
 
+        /* allocate the gate */
         gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
-
         if (!gate) {
                 pr_err("%s: could not allocate gated clk\n", __func__);
-                return NULL;
+                return ERR_PTR(-ENOMEM);
         }
 
         /* struct clk_gate assignments */
@@ -126,22 +137,15 @@ struct clk *clk_register_gate(struct device *dev, const char *name,
         gate->flags = clk_gate_flags;
         gate->lock = lock;
 
-        if (parent_name) {
-                gate->parent[0] = kstrdup(parent_name, GFP_KERNEL);
-                if (!gate->parent[0])
-                        goto out;
-        }
-
+        /* register the clock */
         clk = clk_register(dev, name,
                         &clk_gate_ops, &gate->hw,
-                        gate->parent,
+                        (parent_name ? &parent_name : NULL),
                         (parent_name ? 1 : 0),
                         flags);
-        if (clk)
-                return clk;
-out:
-        kfree(gate->parent[0]);
-        kfree(gate);
 
-        return NULL;
+        if (IS_ERR(clk))
+                kfree(gate);
+
+        return clk;
 }
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index bd5e598b9f1e..6e58f11ab81f 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -94,9 +94,10 @@ struct clk *clk_register_mux(struct device *dev, const char *name,
                 u8 clk_mux_flags, spinlock_t *lock)
 {
         struct clk_mux *mux;
+        struct clk *clk;
 
+        /* allocate the mux */
         mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
-
         if (!mux) {
                 pr_err("%s: could not allocate mux clk\n", __func__);
                 return ERR_PTR(-ENOMEM);
@@ -109,6 +110,11 @@ struct clk *clk_register_mux(struct device *dev, const char *name,
         mux->flags = clk_mux_flags;
         mux->lock = lock;
 
-        return clk_register(dev, name, &clk_mux_ops, &mux->hw,
+        clk = clk_register(dev, name, &clk_mux_ops, &mux->hw,
                         parent_names, num_parents, flags);
+
+        if (IS_ERR(clk))
+                kfree(mux);
+
+        return clk;
 }
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 97f9fabf3be2..3323d24a7be4 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -176,7 +176,6 @@ struct clk_gate {
         u8              bit_idx;
         u8              flags;
         spinlock_t      *lock;
-        const char      *parent[1];
 };
 
 #define CLK_GATE_SET_TO_DISABLE         BIT(0)
@@ -214,7 +213,6 @@ struct clk_divider {
         u8              width;
         u8              flags;
         spinlock_t      *lock;
-        const char      *parent[1];
 };
 
 #define CLK_DIVIDER_ONE_BASED           BIT(0)