[v3,3/4] reset-controller: ti: introduce a new reset handler

Crystal Guo
2020-08-17T02:52:01Z

Introduce ti_syscon_reset() to integrate assert and deassert together.
If some modules need do serialized assert and deassert operations
to reset itself, reset_control_reset can be called for convenience.

Such as reset-qcom-aoss.c, it integrates assert and deassert together
by 'reset' method. MTK Socs also need this method to perform reset.

Signed-off-by: Crystal Guo <crystal.guo@mediatek.com>
---
drivers/reset/reset-ti-syscon.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
index a2635c21db7f..08289342f9af 100644
--- a/drivers/reset/reset-ti-syscon.c
+++ b/drivers/reset/reset-ti-syscon.c
@@ -15,6 +15,7 @@
* GNU General Public License for more details.
*/

+#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -56,6 +57,7 @@ struct ti_syscon_reset_data {
struct regmap *regmap;
struct ti_syscon_reset_control *controls;
unsigned int nr_controls;
+ unsigned int reset_duration_us;
};

#define to_ti_syscon_reset_data(rcdev) \
@@ -89,7 +91,7 @@ static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,
mask = BIT(control->assert_bit);
value = (control->flags & ASSERT_SET) ? mask : 0x0;

- return regmap_update_bits(data->regmap, control->assert_offset, mask, value);
+ return regmap_write_bits(data->regmap, control->assert_offset, mask, value);
}

/**
@@ -120,7 +122,7 @@ static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,
mask = BIT(control->deassert_bit);
value = (control->flags & DEASSERT_SET) ? mask : 0x0;

- return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);
+ return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);
}

/**
@@ -158,9 +160,26 @@ static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
!(control->flags & STATUS_SET);
}

+static int ti_syscon_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
+ int ret;
+
+ ret = ti_syscon_reset_assert(rcdev, id);
+ if (ret)
+ return ret;
+
+ if (data->reset_duration_us)
+ usleep_range(data->reset_duration_us, data->reset_duration_us * 2);
+
+ return ti_syscon_reset_deassert(rcdev, id);
+}
+
static const struct reset_control_ops ti_syscon_reset_ops = {
.assert = ti_syscon_reset_assert,
.deassert = ti_syscon_reset_deassert,
+ .reset = ti_syscon_reset,
.status = ti_syscon_reset_status,
};

@@ -204,6 +223,9 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
controls[i].flags = be32_to_cpup(list++);
}

+ of_property_read_u32(pdev->dev.of_node, "reset-duration-us",
+ &data->reset_duration_us);
+
data->rcdev.ops = &ti_syscon_reset_ops;
data->rcdev.owner = THIS_MODULE;
data->rcdev.of_node = np;