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

[Crystal Guo]

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....@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;
-- 
2.18.0