clk: divider: read-only divider can propagate rate change
When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the
register shall be left un-touched, but it does not mean the clock
should stop rate propagation if CLK_SET_RATE_PARENT is set
This is properly handled in qcom clk-regmap-divider but it was not in
the generic divider
To fix this situation, introduce a new helper function
divider_ro_round_rate, on the same model as divider_round_rate.
Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-By: David Lechner <david@lechnology.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 3c98d26..b6234a5 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -342,19 +342,43 @@ long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
}
EXPORT_SYMBOL_GPL(divider_round_rate_parent);
+long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
+ unsigned long rate, unsigned long *prate,
+ const struct clk_div_table *table, u8 width,
+ unsigned long flags, unsigned int val)
+{
+ int div;
+
+ div = _get_div(table, val, flags, width);
+
+ /* Even a read-only clock can propagate a rate change */
+ if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+ if (!parent)
+ return -EINVAL;
+
+ *prate = clk_hw_round_rate(parent, rate * div);
+ }
+
+ return DIV_ROUND_UP_ULL((u64)*prate, div);
+}
+EXPORT_SYMBOL_GPL(divider_ro_round_rate_parent);
+
+
static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_divider *divider = to_clk_divider(hw);
- int bestdiv;
/* if read only, just return current value */
if (divider->flags & CLK_DIVIDER_READ_ONLY) {
- bestdiv = clk_readl(divider->reg) >> divider->shift;
- bestdiv &= clk_div_mask(divider->width);
- bestdiv = _get_div(divider->table, bestdiv, divider->flags,
- divider->width);
- return DIV_ROUND_UP_ULL((u64)*prate, bestdiv);
+ u32 val;
+
+ val = clk_readl(divider->reg) >> divider->shift;
+ val &= clk_div_mask(divider->width);
+
+ return divider_ro_round_rate(hw, rate, prate, divider->table,
+ divider->width, divider->flags,
+ val);
}
return divider_round_rate(hw, rate, prate, divider->table,
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index cb18526..210a890 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -420,6 +420,10 @@ long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
unsigned long rate, unsigned long *prate,
const struct clk_div_table *table,
u8 width, unsigned long flags);
+long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
+ unsigned long rate, unsigned long *prate,
+ const struct clk_div_table *table, u8 width,
+ unsigned long flags, unsigned int val);
int divider_get_val(unsigned long rate, unsigned long parent_rate,
const struct clk_div_table *table, u8 width,
unsigned long flags);
@@ -780,6 +784,17 @@ static inline long divider_round_rate(struct clk_hw *hw, unsigned long rate,
rate, prate, table, width, flags);
}
+static inline long divider_ro_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate,
+ const struct clk_div_table *table,
+ u8 width, unsigned long flags,
+ unsigned int val)
+{
+ return divider_ro_round_rate_parent(hw, clk_hw_get_parent(hw),
+ rate, prate, table, width, flags,
+ val);
+}
+
/*
* FIXME clock api without lock protection
*/