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-rw-r--r--drivers/clk/clk-divider.c189
1 files changed, 155 insertions, 34 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 8ea11b444528..a9204c69148d 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -30,18 +30,89 @@
#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
#define div_mask(d) ((1 << (d->width)) - 1)
+#define is_power_of_two(i) !(i & ~i)
+
+static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
+{
+ unsigned int maxdiv = 0;
+ const struct clk_div_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->div > maxdiv)
+ maxdiv = clkt->div;
+ return maxdiv;
+}
+
+static unsigned int _get_maxdiv(struct clk_divider *divider)
+{
+ if (divider->flags & CLK_DIVIDER_ONE_BASED)
+ return div_mask(divider);
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ return 1 << div_mask(divider);
+ if (divider->table)
+ return _get_table_maxdiv(divider->table);
+ return div_mask(divider) + 1;
+}
+
+static unsigned int _get_table_div(const struct clk_div_table *table,
+ unsigned int val)
+{
+ const struct clk_div_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->val == val)
+ return clkt->div;
+ return 0;
+}
+
+static unsigned int _get_div(struct clk_divider *divider, unsigned int val)
+{
+ if (divider->flags & CLK_DIVIDER_ONE_BASED)
+ return val;
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ return 1 << val;
+ if (divider->table)
+ return _get_table_div(divider->table, val);
+ return val + 1;
+}
+
+static unsigned int _get_table_val(const struct clk_div_table *table,
+ unsigned int div)
+{
+ const struct clk_div_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->div == div)
+ return clkt->val;
+ return 0;
+}
+
+static unsigned int _get_val(struct clk_divider *divider, u8 div)
+{
+ if (divider->flags & CLK_DIVIDER_ONE_BASED)
+ return div;
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ return __ffs(div);
+ if (divider->table)
+ return _get_table_val(divider->table, div);
+ return div - 1;
+}
static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
- unsigned int div;
+ unsigned int div, val;
- div = readl(divider->reg) >> divider->shift;
- div &= div_mask(divider);
+ val = readl(divider->reg) >> divider->shift;
+ val &= div_mask(divider);
- if (!(divider->flags & CLK_DIVIDER_ONE_BASED))
- div++;
+ div = _get_div(divider, val);
+ if (!div) {
+ WARN(1, "%s: Invalid divisor for clock %s\n", __func__,
+ __clk_get_name(hw->clk));
+ return parent_rate;
+ }
return parent_rate / div;
}
@@ -52,6 +123,26 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
*/
#define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1)
+static bool _is_valid_table_div(const struct clk_div_table *table,
+ unsigned int div)
+{
+ const struct clk_div_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->div == div)
+ return true;
+ return false;
+}
+
+static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
+{
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ return is_power_of_two(div);
+ if (divider->table)
+ return _is_valid_table_div(divider->table, div);
+ return true;
+}
+
static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate)
{
@@ -62,10 +153,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
if (!rate)
rate = 1;
- maxdiv = (1 << divider->width);
-
- if (divider->flags & CLK_DIVIDER_ONE_BASED)
- maxdiv--;
+ maxdiv = _get_maxdiv(divider);
if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
parent_rate = *best_parent_rate;
@@ -82,6 +170,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
maxdiv = min(ULONG_MAX / rate, maxdiv);
for (i = 1; i <= maxdiv; i++) {
+ if (!_is_valid_div(divider, i))
+ continue;
parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
MULT_ROUND_UP(rate, i));
now = parent_rate / i;
@@ -93,9 +183,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
}
if (!bestdiv) {
- bestdiv = (1 << divider->width);
- if (divider->flags & CLK_DIVIDER_ONE_BASED)
- bestdiv--;
+ bestdiv = _get_maxdiv(divider);
*best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1);
}
@@ -115,24 +203,22 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
- unsigned int div;
+ unsigned int div, value;
unsigned long flags = 0;
u32 val;
div = parent_rate / rate;
+ value = _get_val(divider, div);
- if (!(divider->flags & CLK_DIVIDER_ONE_BASED))
- div--;
-
- if (div > div_mask(divider))
- div = div_mask(divider);
+ if (value > div_mask(divider))
+ value = div_mask(divider);
if (divider->lock)
spin_lock_irqsave(divider->lock, flags);
val = readl(divider->reg);
val &= ~(div_mask(divider) << divider->shift);
- val |= div << divider->shift;
+ val |= value << divider->shift;
writel(val, divider->reg);
if (divider->lock)
@@ -148,22 +234,11 @@ const struct clk_ops clk_divider_ops = {
};
EXPORT_SYMBOL_GPL(clk_divider_ops);
-/**
- * clk_register_divider - register a divider clock with the clock framework
- * @dev: device registering this clock
- * @name: name of this clock
- * @parent_name: name of clock's parent
- * @flags: framework-specific flags
- * @reg: register address to adjust divider
- * @shift: number of bits to shift the bitfield
- * @width: width of the bitfield
- * @clk_divider_flags: divider-specific flags for this clock
- * @lock: shared register lock for this clock
- */
-struct clk *clk_register_divider(struct device *dev, const char *name,
+static struct clk *_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 shift, u8 width,
- u8 clk_divider_flags, spinlock_t *lock)
+ u8 clk_divider_flags, const struct clk_div_table *table,
+ spinlock_t *lock)
{
struct clk_divider *div;
struct clk *clk;
@@ -178,7 +253,7 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
init.name = name;
init.ops = &clk_divider_ops;
- init.flags = flags;
+ init.flags = flags | CLK_IS_BASIC;
init.parent_names = (parent_name ? &parent_name: NULL);
init.num_parents = (parent_name ? 1 : 0);
@@ -189,6 +264,7 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
div->flags = clk_divider_flags;
div->lock = lock;
div->hw.init = &init;
+ div->table = table;
/* register the clock */
clk = clk_register(dev, &div->hw);
@@ -198,3 +274,48 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
return clk;
}
+
+/**
+ * clk_register_divider - register a divider clock with the clock framework
+ * @dev: device registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust divider
+ * @shift: number of bits to shift the bitfield
+ * @width: width of the bitfield
+ * @clk_divider_flags: divider-specific flags for this clock
+ * @lock: shared register lock for this clock
+ */
+struct clk *clk_register_divider(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width,
+ u8 clk_divider_flags, spinlock_t *lock)
+{
+ return _register_divider(dev, name, parent_name, flags, reg, shift,
+ width, clk_divider_flags, NULL, lock);
+}
+
+/**
+ * clk_register_divider_table - register a table based divider clock with
+ * the clock framework
+ * @dev: device registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust divider
+ * @shift: number of bits to shift the bitfield
+ * @width: width of the bitfield
+ * @clk_divider_flags: divider-specific flags for this clock
+ * @table: array of divider/value pairs ending with a div set to 0
+ * @lock: shared register lock for this clock
+ */
+struct clk *clk_register_divider_table(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width,
+ u8 clk_divider_flags, const struct clk_div_table *table,
+ spinlock_t *lock)
+{
+ return _register_divider(dev, name, parent_name, flags, reg, shift,
+ width, clk_divider_flags, table, lock);
+}