sh: clkfwk: Support variable size accesses for div4/div6 clocks.

This follows the MSTP clock change and implements variable access size
support for the rest of the CPG clocks, too. Upcoming SH-2A support has
need of this for 16-bit div4 clocks, while others will follow.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/sh/clk/cpg.c

@@ -14,32 +14,35 @@
 #include <linux/io.h>
 #include <linux/sh_clk.h>
 
-static int sh_clk_mstp_enable(struct clk *clk)
+static unsigned int sh_clk_read(struct clk *clk)
 {
 	if (clk->flags & CLK_ENABLE_REG_8BIT)
-		iowrite8(ioread8(clk->mapped_reg) & ~(1 << clk->enable_bit),
-			 clk->mapped_reg);
+		return ioread8(clk->mapped_reg);
 	else if (clk->flags & CLK_ENABLE_REG_16BIT)
-		iowrite16(ioread16(clk->mapped_reg) & ~(1 << clk->enable_bit),
-			  clk->mapped_reg);
-	else
-		iowrite32(ioread32(clk->mapped_reg) & ~(1 << clk->enable_bit),
-			  clk->mapped_reg);
+		return ioread16(clk->mapped_reg);
 
+	return ioread32(clk->mapped_reg);
+}
+
+static void sh_clk_write(int value, struct clk *clk)
+{
+	if (clk->flags & CLK_ENABLE_REG_8BIT)
+		iowrite8(value, clk->mapped_reg);
+	else if (clk->flags & CLK_ENABLE_REG_16BIT)
+		iowrite16(value, clk->mapped_reg);
+	else
+		iowrite32(value, clk->mapped_reg);
+}
+
+static int sh_clk_mstp_enable(struct clk *clk)
+{
+	sh_clk_write(sh_clk_read(clk) & ~(1 << clk->enable_bit), clk);
 	return 0;
 }
 
 static void sh_clk_mstp_disable(struct clk *clk)
 {
-	if (clk->flags & CLK_ENABLE_REG_8BIT)
-		iowrite8(ioread8(clk->mapped_reg) | (1 << clk->enable_bit),
-			 clk->mapped_reg);
-	else if (clk->flags & CLK_ENABLE_REG_16BIT)
-		iowrite16(ioread16(clk->mapped_reg) | (1 << clk->enable_bit),
-			  clk->mapped_reg);
-	else
-		iowrite32(ioread32(clk->mapped_reg) | (1 << clk->enable_bit),
-			  clk->mapped_reg);
+	sh_clk_write(sh_clk_read(clk) | (1 << clk->enable_bit), clk);
 }
 
 static struct sh_clk_ops sh_clk_mstp_clk_ops = {
@@ -88,7 +91,7 @@ static unsigned long sh_clk_div6_recalc(struct clk *clk)
 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
 			     table, NULL);
 
-	idx = ioread32(clk->mapped_reg) & 0x003f;
+	idx = sh_clk_read(clk) & 0x003f;
 
 	return clk->freq_table[idx].frequency;
 }
@@ -114,10 +117,10 @@ static int sh_clk_div6_set_parent(struct clk *clk, struct clk *parent)
 	if (ret < 0)
 		return ret;
 
-	value = ioread32(clk->mapped_reg) &
+	value = sh_clk_read(clk) &
 		~(((1 << clk->src_width) - 1) << clk->src_shift);
 
-	iowrite32(value | (i << clk->src_shift), clk->mapped_reg);
+	sh_clk_write(value | (i << clk->src_shift), clk);
 
 	/* Rebuild the frequency table */
 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
@@ -135,10 +138,10 @@ static int sh_clk_div6_set_rate(struct clk *clk, unsigned long rate)
 	if (idx < 0)
 		return idx;
 
-	value = ioread32(clk->mapped_reg);
+	value = sh_clk_read(clk);
 	value &= ~0x3f;
 	value |= idx;
-	iowrite32(value, clk->mapped_reg);
+	sh_clk_write(value, clk);
 	return 0;
 }
 
@@ -149,9 +152,9 @@ static int sh_clk_div6_enable(struct clk *clk)
 
 	ret = sh_clk_div6_set_rate(clk, clk->rate);
 	if (ret == 0) {
-		value = ioread32(clk->mapped_reg);
+		value = sh_clk_read(clk);
 		value &= ~0x100; /* clear stop bit to enable clock */
-		iowrite32(value, clk->mapped_reg);
+		sh_clk_write(value, clk);
 	}
 	return ret;
 }
@@ -160,10 +163,10 @@ static void sh_clk_div6_disable(struct clk *clk)
 {
 	unsigned long value;
 
-	value = ioread32(clk->mapped_reg);
+	value = sh_clk_read(clk);
 	value |= 0x100; /* stop clock */
 	value |= 0x3f; /* VDIV bits must be non-zero, overwrite divider */
-	iowrite32(value, clk->mapped_reg);
+	sh_clk_write(value, clk);
 }
 
 static struct sh_clk_ops sh_clk_div6_clk_ops = {
@@ -198,7 +201,7 @@ static int __init sh_clk_init_parent(struct clk *clk)
 		return -EINVAL;
 	}
 
-	val  = (ioread32(clk->mapped_reg) >> clk->src_shift);
+	val  = (sh_clk_read(clk) >> clk->src_shift);
 	val &= (1 << clk->src_width) - 1;
 
 	if (val >= clk->parent_num) {
@@ -268,7 +271,7 @@ 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 = (ioread32(clk->mapped_reg) >> clk->enable_bit) & 0x000f;
+	idx = (sh_clk_read(clk) >> clk->enable_bit) & 0x000f;
 
 	return clk->freq_table[idx].frequency;
 }
@@ -286,15 +289,15 @@ static int sh_clk_div4_set_parent(struct clk *clk, struct clk *parent)
 	 */
 
 	if (parent->flags & CLK_ENABLE_ON_INIT)
-		value = ioread32(clk->mapped_reg) & ~(1 << 7);
+		value = sh_clk_read(clk) & ~(1 << 7);
 	else
-		value = ioread32(clk->mapped_reg) | (1 << 7);
+		value = sh_clk_read(clk) | (1 << 7);
 
 	ret = clk_reparent(clk, parent);
 	if (ret < 0)
 		return ret;
 
-	iowrite32(value, clk->mapped_reg);
+	sh_clk_write(value, clk);
 
 	/* Rebiuld the frequency table */
 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
@@ -311,10 +314,10 @@ static int sh_clk_div4_set_rate(struct clk *clk, unsigned long rate)
 	if (idx < 0)
 		return idx;
 
-	value = ioread32(clk->mapped_reg);
+	value = sh_clk_read(clk);
 	value &= ~(0xf << clk->enable_bit);
 	value |= (idx << clk->enable_bit);
-	iowrite32(value, clk->mapped_reg);
+	sh_clk_write(value, clk);
 
 	if (d4t->kick)
 		d4t->kick(clk);
@@ -324,13 +327,13 @@ static int sh_clk_div4_set_rate(struct clk *clk, unsigned long rate)
 
 static int sh_clk_div4_enable(struct clk *clk)
 {
-	iowrite32(ioread32(clk->mapped_reg) & ~(1 << 8), clk->mapped_reg);
+	sh_clk_write(sh_clk_read(clk) & ~(1 << 8), clk);
 	return 0;
 }
 
 static void sh_clk_div4_disable(struct clk *clk)
 {
-	iowrite32(ioread32(clk->mapped_reg) | (1 << 8), clk->mapped_reg);
+	sh_clk_write(sh_clk_read(clk) | (1 << 8), clk);
 }
 
 static struct sh_clk_ops sh_clk_div4_clk_ops = {