Current clock wrappers assume simple and direct mapped hardware register
access. Improve this support by adding functionality for registering
platform specific clock I/O wrappers, which can be used to support
various features needed like endianess conversions, indexed regmap support,
etc. Default I/O wrapper provided also which uses the existing direct
I/O mapped behavior.
Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
---
drivers/clk/clk.c | 68 ++++++++++++++++++++++++++++++++++++++++++
include/linux/clk-provider.h | 15 +++++-----
2 files changed, 75 insertions(+), 8 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 2cf2ea6..c331386 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -34,6 +34,74 @@ static HLIST_HEAD(clk_root_list);
static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);
+/**
+ * clk_readl_default - default clock register read support function
+ * @reg: register to read
+ *
+ * Default implementation for reading a clock register.
+ */
+static u32 clk_readl_default(u32 __iomem *reg)
+{
+ return readl(reg);
+}
+
+/**
+ * clk_writel_default - default clock register write support function
+ * @val: value to write
+ * @reg: register to write to
+ *
+ * Default implementation for writing a clock register.
+ */
+static void clk_writel_default(u32 val, u32 __iomem *reg)
+{
+ writel(val, reg);
+}
+
+struct clk_reg_ops clk_reg_ops_default = {
+ .clk_readl = clk_readl_default,
+ .clk_writel = clk_writel_default
+};
+
+static struct clk_reg_ops *clk_reg_ops = &clk_reg_ops_default;
+
+/**
+ * clk_register_reg_ops - register access functions for clock registers
+ * @ops: register level ops
+ *
+ * Registers platform or SoC specific operations for reading / writing
+ * clock registers.
+ */
+int clk_register_reg_ops(struct clk_reg_ops *ops)
+{
+ if (!ops)
+ return -EINVAL;
+ clk_reg_ops = ops;
+ return 0;
+}
+
+/**
+ * clk_readl - read a clock register value from hardware
+ * @reg: register to read
+ *
+ * Uses the registered clk_reg_ops to read a hardware clock register value.
+ */
+u32 clk_readl(u32 __iomem *reg)
+{
+ return clk_reg_ops->clk_readl(reg);
+}
+
+/**
+ * clk_writel - write a clock register value to hardware
+ * @val: value to write
+ * @reg: register to write
+ *
+ * Uses the registered clk_reg_ops to write a hardware clock register value.
+ */
+void clk_writel(u32 val, u32 __iomem *reg)
+{
+ clk_reg_ops->clk_writel(val, reg);
+}
+
/*** locking ***/
static void clk_prepare_lock(void)
{
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 7e59253..16e4df2 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -512,15 +512,14 @@ static inline const char *of_clk_get_parent_name(struct device_node *np,
* for improved portability across platforms
*/
-static inline u32 clk_readl(u32 __iomem *reg)
-{
- return readl(reg);
-}
+struct clk_reg_ops {
+ u32 (*clk_readl)(u32 __iomem *reg);
+ void (*clk_writel)(u32 val, u32 __iomem *reg);
+};
-static inline void clk_writel(u32 val, u32 __iomem *reg)
-{
- writel(val, reg);
-}
+u32 clk_readl(u32 __iomem *reg);
+void clk_writel(u32 val, u32 __iomem *reg);
+int clk_register_reg_ops(struct clk_reg_ops *ops);
#endif /* CONFIG_COMMON_CLK */
#endif /* CLK_PROVIDER_H */
--
1.7.9.5
--
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