sh: clkfwk: Introduce a div_mask for variable div types.

This plugs in a div_mask for the clock and sets it up for the existing
div6/4 cases. This will make it possible to support other div types, as
well as share more div6/4 infrastructure.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/sh/clk/cpg.c

@@ -111,7 +111,7 @@ static unsigned long sh_clk_div6_recalc(struct clk *clk)
 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 			     table, NULL);
 
-	idx = sh_clk_read(clk) & 0x003f;
+	idx = sh_clk_read(clk) & clk->div_mask;
 
 	return clk->freq_table[idx].frequency;
 }
@@ -159,7 +159,7 @@ static int sh_clk_div6_set_rate(struct clk *clk, unsigned long rate)
 		return idx;
 
 	value = sh_clk_read(clk);
-	value &= ~0x3f;
+	value &= ~clk->div_mask;
 	value |= idx;
 	sh_clk_write(value, clk);
 	return 0;
@@ -185,7 +185,7 @@ static void sh_clk_div6_disable(struct clk *clk)
 
 	value = sh_clk_read(clk);
 	value |= 0x100; /* stop clock */
-	value |= 0x3f; /* VDIV bits must be non-zero, overwrite divider */
+	value |= clk->div_mask; /* VDIV bits must be non-zero, overwrite divider */
 	sh_clk_write(value, clk);
 }
 
@@ -295,7 +295,7 @@ static unsigned long sh_clk_div4_recalc(struct clk *clk)
 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 			     table, &clk->arch_flags);
 
-	idx = (sh_clk_read(clk) >> clk->enable_bit) & 0x000f;
+	idx = (sh_clk_read(clk) >> clk->enable_bit) & clk->div_mask;
 
 	return clk->freq_table[idx].frequency;
 }
@@ -338,7 +338,7 @@ static int sh_clk_div4_set_rate(struct clk *clk, unsigned long rate)
 		return idx;
 
 	value = sh_clk_read(clk);
-	value &= ~(0xf << clk->enable_bit);
+	value &= ~(clk->div_mask << clk->enable_bit);
 	value |= (idx << clk->enable_bit);
 	sh_clk_write(value, clk);
 

include/linux/sh_clk.h

@@ -30,6 +30,10 @@ struct sh_clk_ops {
 	long (*round_rate)(struct clk *clk, unsigned long rate);
 };
 
+#define SH_CLK_DIV_MSK(div)	((1 << (div)) - 1)
+#define SH_CLK_DIV4_MSK		SH_CLK_DIV_MSK(4)
+#define SH_CLK_DIV6_MSK		SH_CLK_DIV_MSK(6)
+
 struct clk {
 	struct list_head	node;
 	struct clk		*parent;
@@ -51,6 +55,7 @@ struct clk {
 	unsigned int		enable_bit;
 	void __iomem		*mapped_reg;
 
+	unsigned int		div_mask;
 	unsigned long		arch_flags;
 	void			*priv;
 	struct clk_mapping	*mapping;
@@ -145,6 +150,7 @@ static inline int __deprecated sh_clk_mstp32_register(struct clk *clks, int nr)
 	.enable_reg = (void __iomem *)_reg,			\
 	.enable_bit = _shift,					\
 	.arch_flags = _div_bitmap,				\
+	.div_mask = SH_CLK_DIV4_MSK,				\
 	.flags = _flags,					\
 }
 
@@ -167,6 +173,7 @@ int sh_clk_div4_reparent_register(struct clk *clks, int nr,
 {								\
 	.enable_reg = (void __iomem *)_reg,			\
 	.flags = _flags,					\
+	.div_mask = SH_CLK_DIV6_MSK,				\
 	.parent_table = _parents,				\
 	.parent_num = _num_parents,				\
 	.src_shift = _src_shift,				\
@@ -177,6 +184,7 @@ int sh_clk_div4_reparent_register(struct clk *clks, int nr,
 {								\
 	.parent		= _parent,				\
 	.enable_reg	= (void __iomem *)_reg,			\
+	.div_mask	= SH_CLK_DIV6_MSK,			\
 	.flags		= _flags,				\
 }