| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1528090479-20861-1-git-send-email-mike.looijmans@topic.nl>
Date: Mon, 4 Jun 2018 07:34:39 +0200
From: Mike Looijmans <mike.looijmans@...ic.nl>
To: linux-clk@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, mturquette@...libre.com,
sboyd@...nel.org, Mike Looijmans <mike.looijmans@...ic.nl>
Subject: [PATCH] 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@...ic.nl>
---
drivers/clk/clk-si514.c | 38 +++++++++++++++++++++++++++++++++++++-
drivers/clk/clk-si544.c | 39 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 75 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/clk-si514.c b/drivers/clk/clk-si514.c
index 09b6718..153b3a2 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,
diff --git a/drivers/clk/clk-si544.c b/drivers/clk/clk-si544.c
index e972ffb..f8ed9d9 100644
--- a/drivers/clk/clk-si544.c
+++ b/drivers/clk/clk-si544.c
@@ -86,6 +86,34 @@ static int si544_enable_output(struct clk_si544 *data, bool enable)
SI544_OE_STATE_ODC_OE, enable ? SI544_OE_STATE_ODC_OE : 0);
}
+static int si544_prepare(struct clk_hw *hw)
+{
+ struct clk_si544 *data = to_clk_si544(hw);
+
+ return si544_enable_output(data, true);
+}
+
+static void si544_unprepare(struct clk_hw *hw)
+{
+ struct clk_si544 *data = to_clk_si544(hw);
+
+ si544_enable_output(data, false);
+}
+
+static int si544_is_prepared(struct clk_hw *hw)
+{
+ struct clk_si544 *data = to_clk_si544(hw);
+ unsigned int val;
+ int err;
+
+ err = regmap_read(data->regmap, SI544_REG_OE_STATE, &val);
+ if (err < 0)
+ return err;
+
+ return !!(val & SI544_OE_STATE_ODC_OE);
+}
+
+
/* Retrieve clock multiplier and dividers from hardware */
static int si544_get_muldiv(struct clk_si544 *data,
struct clk_si544_muldiv *settings)
@@ -273,6 +301,7 @@ static int si544_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct clk_si544 *data = to_clk_si544(hw);
struct clk_si544_muldiv settings;
+ unsigned int old_oe_state;
int err;
if (!is_valid_frequency(data, rate))
@@ -282,6 +311,10 @@ static int si544_set_rate(struct clk_hw *hw, unsigned long rate,
if (err)
return err;
+ err = regmap_read(data->regmap, SI544_REG_OE_STATE, &old_oe_state);
+ if (err)
+ return err;
+
si544_enable_output(data, false);
/* Allow FCAL for this frequency update */
@@ -303,12 +336,16 @@ static int si544_set_rate(struct clk_hw *hw, unsigned long rate,
/* Applying a new frequency can take up to 10ms */
usleep_range(10000, 12000);
- si544_enable_output(data, true);
+ if (old_oe_state & SI544_OE_STATE_ODC_OE)
+ si544_enable_output(data, true);
return err;
}
static const struct clk_ops si544_clk_ops = {
+ .prepare = si544_prepare,
+ .unprepare = si544_unprepare,
+ .is_prepared = si544_is_prepared,
.recalc_rate = si544_recalc_rate,
.round_rate = si544_round_rate,
.set_rate = si544_set_rate,
--
1.9.1
Powered by blists - more mailing lists