clk: Add 16bit register access for clk-divider.

Some SoC use 16bit-word register. And required 16bit-word access.
This changes add 16-bit access mode.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 00e035b..16026bb 100644 (file)
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -141,7 +141,10 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
        struct clk_divider *divider = to_clk_divider(hw);
        unsigned int val;
 
-       val = clk_readl(divider->reg) >> divider->shift;
+       if (divider->flags & CLK_DIVIDER_WORD_REG)
+               val = clk_readw(divider->reg) >> divider->shift;
+       else
+               val = clk_readl(divider->reg) >> divider->shift;
        val &= div_mask(divider->width);
 
        return divider_recalc_rate(hw, parent_rate, val, divider->table,
@@ -403,7 +406,10 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
                val &= ~(div_mask(divider->width) << divider->shift);
        }
        val |= value << divider->shift;
-       clk_writel(val, divider->reg);
+       if (divider->flags & CLK_DIVIDER_WORD_REG)
+               clk_writew(val, divider->reg);
+       else
+               clk_writel(val, divider->reg);
 
        if (divider->lock)
                spin_unlock_irqrestore(divider->lock, flags);

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index da95258..34f1455 100644 (file)
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -369,6 +369,8 @@ struct clk_div_table {
  * CLK_DIVIDER_MAX_AT_ZERO - For dividers which are like CLK_DIVIDER_ONE_BASED
  *     except when the value read from the register is zero, the divisor is
  *     2^width of the field.
+ * CLK_DIVIDER_WORD_REG - The driver use 16-bit access function for register.
+ *     Usally 32-bit access.
  */
 struct clk_divider {
        struct clk_hw   hw;
@@ -389,6 +391,7 @@ struct clk_divider {
 #define CLK_DIVIDER_ROUND_CLOSEST      BIT(4)
 #define CLK_DIVIDER_READ_ONLY          BIT(5)
 #define CLK_DIVIDER_MAX_AT_ZERO                BIT(6)
+#define CLK_DIVIDER_WORD_REG           BIT(7)
 
 extern const struct clk_ops clk_divider_ops;
 extern const struct clk_ops clk_divider_ro_ops;
@@ -791,6 +794,16 @@ static inline void clk_writel(u32 val, u32 __iomem *reg)
 
 #endif /* platform dependent I/O accessors */
 
+static inline u32 clk_readw(u32 __iomem *reg)
+{
+       return readw(reg);
+}
+
+static inline void clk_writew(u32 val, u32 __iomem *reg)
+{
+       writew(val, reg);
+}
+
 #ifdef CONFIG_DEBUG_FS
 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
                                void *data, const struct file_operations *fops);