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authorMike Looijmans <mike.looijmans@topic.nl>2018-06-04 08:34:39 +0300
committerStephen Boyd <sboyd@kernel.org>2018-06-29 20:59:40 +0300
commite8f127caf63ad29e2b4cb01894b97730384ad1ab (patch)
tree9507fd512e94d81abf542ec3b636c3c2b29e80d5 /drivers/clk/clk-si514.c
parentce397d215ccd07b8ae3f71db689aedb85d56ab40 (diff)
downloadlinux-e8f127caf63ad29e2b4cb01894b97730384ad1ab.tar.xz
clk-si514, clk-si544: Implement prepare/unprepare/is_prepared operations
This adds prepare/unprepare/is_prepared functionality to the drivers for the SI544 and SI514 chips, allowing the clock output to be disabled when the clock is not in use. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/clk-si514.c')
-rw-r--r--drivers/clk/clk-si514.c38
1 files changed, 37 insertions, 1 deletions
diff --git a/drivers/clk/clk-si514.c b/drivers/clk/clk-si514.c
index 09b6718956bd..153b3a2b5857 100644
--- a/drivers/clk/clk-si514.c
+++ b/drivers/clk/clk-si514.c
@@ -74,6 +74,33 @@ static int si514_enable_output(struct clk_si514 *data, bool enable)
SI514_CONTROL_OE, enable ? SI514_CONTROL_OE : 0);
}
+static int si514_prepare(struct clk_hw *hw)
+{
+ struct clk_si514 *data = to_clk_si514(hw);
+
+ return si514_enable_output(data, true);
+}
+
+static void si514_unprepare(struct clk_hw *hw)
+{
+ struct clk_si514 *data = to_clk_si514(hw);
+
+ si514_enable_output(data, false);
+}
+
+static int si514_is_prepared(struct clk_hw *hw)
+{
+ struct clk_si514 *data = to_clk_si514(hw);
+ unsigned int val;
+ int err;
+
+ err = regmap_read(data->regmap, SI514_REG_CONTROL, &val);
+ if (err < 0)
+ return err;
+
+ return !!(val & SI514_CONTROL_OE);
+}
+
/* Retrieve clock multiplier and dividers from hardware */
static int si514_get_muldiv(struct clk_si514 *data,
struct clk_si514_muldiv *settings)
@@ -235,12 +262,17 @@ static int si514_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct clk_si514 *data = to_clk_si514(hw);
struct clk_si514_muldiv settings;
+ unsigned int old_oe_state;
int err;
err = si514_calc_muldiv(&settings, rate);
if (err)
return err;
+ err = regmap_read(data->regmap, SI514_REG_CONTROL, &old_oe_state);
+ if (err)
+ return err;
+
si514_enable_output(data, false);
err = si514_set_muldiv(data, &settings);
@@ -255,12 +287,16 @@ static int si514_set_rate(struct clk_hw *hw, unsigned long rate,
/* Applying a new frequency can take up to 10ms */
usleep_range(10000, 12000);
- si514_enable_output(data, true);
+ if (old_oe_state & SI514_CONTROL_OE)
+ si514_enable_output(data, true);
return err;
}
static const struct clk_ops si514_clk_ops = {
+ .prepare = si514_prepare,
+ .unprepare = si514_unprepare,
+ .is_prepared = si514_is_prepared,
.recalc_rate = si514_recalc_rate,
.round_rate = si514_round_rate,
.set_rate = si514_set_rate,