diff options
| author | Mike Looijmans <mike.looijmans@topic.nl> | 2018-06-04 07:34:39 +0200 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2018-06-29 10:59:40 -0700 |
| commit | e8f127caf63ad29e2b4cb01894b97730384ad1ab (patch) | |
| tree | 9507fd512e94d81abf542ec3b636c3c2b29e80d5 /drivers/clk/clk-si514.c | |
| parent | ce397d215ccd07b8ae3f71db689aedb85d56ab40 (diff) | |
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.c | 38 |
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, |