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-rw-r--r--drivers/sh/clk/cpg.c77
-rw-r--r--include/linux/sh_clk.h6
2 files changed, 38 insertions, 45 deletions
diff --git a/drivers/sh/clk/cpg.c b/drivers/sh/clk/cpg.c
index 29ee5f7072a4..06537f2b2fb8 100644
--- a/drivers/sh/clk/cpg.c
+++ b/drivers/sh/clk/cpg.c
@@ -14,6 +14,8 @@
#include <linux/io.h>
#include <linux/sh_clk.h>
+#define CPG_CKSTP_BIT BIT(8)
+
static unsigned int sh_clk_read(struct clk *clk)
{
if (clk->flags & CLK_ENABLE_REG_8BIT)
@@ -122,6 +124,30 @@ static int sh_clk_div_set_rate(struct clk *clk, unsigned long rate)
return 0;
}
+static int sh_clk_div_enable(struct clk *clk)
+{
+ sh_clk_write(sh_clk_read(clk) & ~CPG_CKSTP_BIT, clk);
+ return 0;
+}
+
+static void sh_clk_div_disable(struct clk *clk)
+{
+ unsigned int val;
+
+ val = sh_clk_read(clk);
+ val |= CPG_CKSTP_BIT;
+
+ /*
+ * div6 clocks require the divisor field to be non-zero or the
+ * above CKSTP toggle silently fails. Ensure that the divisor
+ * array is reset to its initial state on disable.
+ */
+ if (clk->flags & CLK_MASK_DIV_ON_DISABLE)
+ val |= clk->div_mask;
+
+ sh_clk_write(val, clk);
+}
+
/*
* div6 support
*/
@@ -174,44 +200,20 @@ static int sh_clk_div6_set_parent(struct clk *clk, struct clk *parent)
return 0;
}
-static int sh_clk_div6_enable(struct clk *clk)
-{
- unsigned long value;
- int ret;
-
- ret = sh_clk_div_set_rate(clk, clk->rate);
- if (ret == 0) {
- value = sh_clk_read(clk);
- value &= ~0x100; /* clear stop bit to enable clock */
- sh_clk_write(value, clk);
- }
- return ret;
-}
-
-static void sh_clk_div6_disable(struct clk *clk)
-{
- unsigned long value;
-
- value = sh_clk_read(clk);
- value |= 0x100; /* stop clock */
- value |= clk->div_mask; /* VDIV bits must be non-zero, overwrite divider */
- sh_clk_write(value, clk);
-}
-
static struct sh_clk_ops sh_clk_div6_clk_ops = {
.recalc = sh_clk_div_recalc,
.round_rate = sh_clk_div_round_rate,
.set_rate = sh_clk_div_set_rate,
- .enable = sh_clk_div6_enable,
- .disable = sh_clk_div6_disable,
+ .enable = sh_clk_div_enable,
+ .disable = sh_clk_div_disable,
};
static struct sh_clk_ops sh_clk_div6_reparent_clk_ops = {
.recalc = sh_clk_div_recalc,
.round_rate = sh_clk_div_round_rate,
.set_rate = sh_clk_div_set_rate,
- .enable = sh_clk_div6_enable,
- .disable = sh_clk_div6_disable,
+ .enable = sh_clk_div_enable,
+ .disable = sh_clk_div_disable,
.set_parent = sh_clk_div6_set_parent,
};
@@ -325,17 +327,6 @@ static int sh_clk_div4_set_parent(struct clk *clk, struct clk *parent)
return 0;
}
-static int sh_clk_div4_enable(struct clk *clk)
-{
- sh_clk_write(sh_clk_read(clk) & ~(1 << 8), clk);
- return 0;
-}
-
-static void sh_clk_div4_disable(struct clk *clk)
-{
- sh_clk_write(sh_clk_read(clk) | (1 << 8), clk);
-}
-
static struct sh_clk_ops sh_clk_div4_clk_ops = {
.recalc = sh_clk_div_recalc,
.set_rate = sh_clk_div_set_rate,
@@ -346,16 +337,16 @@ static struct sh_clk_ops sh_clk_div4_enable_clk_ops = {
.recalc = sh_clk_div_recalc,
.set_rate = sh_clk_div_set_rate,
.round_rate = sh_clk_div_round_rate,
- .enable = sh_clk_div4_enable,
- .disable = sh_clk_div4_disable,
+ .enable = sh_clk_div_enable,
+ .disable = sh_clk_div_disable,
};
static struct sh_clk_ops sh_clk_div4_reparent_clk_ops = {
.recalc = sh_clk_div_recalc,
.set_rate = sh_clk_div_set_rate,
.round_rate = sh_clk_div_round_rate,
- .enable = sh_clk_div4_enable,
- .disable = sh_clk_div4_disable,
+ .enable = sh_clk_div_enable,
+ .disable = sh_clk_div_disable,
.set_parent = sh_clk_div4_set_parent,
};
diff --git a/include/linux/sh_clk.h b/include/linux/sh_clk.h
index 35a04f19fb53..50910913b268 100644
--- a/include/linux/sh_clk.h
+++ b/include/linux/sh_clk.h
@@ -69,6 +69,8 @@ struct clk {
#define CLK_ENABLE_REG_16BIT BIT(2)
#define CLK_ENABLE_REG_8BIT BIT(3)
+#define CLK_MASK_DIV_ON_DISABLE BIT(4)
+
#define CLK_ENABLE_REG_MASK (CLK_ENABLE_REG_32BIT | \
CLK_ENABLE_REG_16BIT | \
CLK_ENABLE_REG_8BIT)
@@ -173,7 +175,7 @@ int sh_clk_div4_reparent_register(struct clk *clks, int nr,
{ \
.enable_reg = (void __iomem *)_reg, \
.enable_bit = 0, /* unused */ \
- .flags = _flags, \
+ .flags = _flags | CLK_MASK_DIV_ON_DISABLE, \
.div_mask = SH_CLK_DIV6_MSK, \
.parent_table = _parents, \
.parent_num = _num_parents, \
@@ -187,7 +189,7 @@ int sh_clk_div4_reparent_register(struct clk *clks, int nr,
.enable_reg = (void __iomem *)_reg, \
.enable_bit = 0, /* unused */ \
.div_mask = SH_CLK_DIV6_MSK, \
- .flags = _flags, \
+ .flags = _flags | CLK_MASK_DIV_ON_DISABLE, \
}
int sh_clk_div6_register(struct clk *clks, int nr);