[PATCH v2] reset: hi6220: Add support for AO reset controller

From: John Stultz
Date: Mon Mar 02 2020 - 12:40:28 EST


From: Peter Griffin <peter.griffin@xxxxxxxxxx>

This is required to bring Mali450 gpu out of reset.

Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Cc: Peter Griffin <peter.griffin@xxxxxxxxxx>
Cc: Enrico Weigelt <info@xxxxxxxxx>
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
v2:
* Updated to v2 of Peter's patch from here:
https://lkml.org/lkml/2019/4/19/253
* Added a comment to explain ordering question brought
up on the list.
---
drivers/reset/hisilicon/hi6220_reset.c | 71 +++++++++++++++++++++++++-
1 file changed, 70 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/hisilicon/hi6220_reset.c b/drivers/reset/hisilicon/hi6220_reset.c
index 24e6d420b26b..a85ed276ab83 100644
--- a/drivers/reset/hisilicon/hi6220_reset.c
+++ b/drivers/reset/hisilicon/hi6220_reset.c
@@ -33,6 +33,7 @@
enum hi6220_reset_ctrl_type {
PERIPHERAL,
MEDIA,
+ AO,
};

struct hi6220_reset_data {
@@ -92,6 +93,67 @@ static const struct reset_control_ops hi6220_media_reset_ops = {
.deassert = hi6220_media_deassert,
};

+#define AO_SCTRL_SC_PW_CLKEN0 0x800
+#define AO_SCTRL_SC_PW_CLKDIS0 0x804
+
+#define AO_SCTRL_SC_PW_RSTEN0 0x810
+#define AO_SCTRL_SC_PW_RSTDIS0 0x814
+
+#define AO_SCTRL_SC_PW_ISOEN0 0x820
+#define AO_SCTRL_SC_PW_ISODIS0 0x824
+#define AO_MAX_INDEX 12
+
+static int hi6220_ao_assert(struct reset_controller_dev *rc_dev,
+ unsigned long idx)
+{
+ struct hi6220_reset_data *data = to_reset_data(rc_dev);
+ struct regmap *regmap = data->regmap;
+ int ret;
+
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_RSTEN0, BIT(idx));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_ISOEN0, BIT(idx));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_CLKDIS0, BIT(idx));
+ if (ret)
+ return ret;
+}
+
+static int hi6220_ao_deassert(struct reset_controller_dev *rc_dev,
+ unsigned long idx)
+{
+ struct hi6220_reset_data *data = to_reset_data(rc_dev);
+ struct regmap *regmap = data->regmap;
+ int ret;
+
+ /*
+ * It was suggested to disable isolation before enabling
+ * the clocks and deasserting reset, to avoid glitches.
+ * But this order is preserved to keep it matching the
+ * vendor code.
+ */
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_RSTDIS0, BIT(idx));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_ISODIS0, BIT(idx));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, AO_SCTRL_SC_PW_CLKEN0, BIT(idx));
+ if (ret)
+ return ret;
+}
+
+static const struct reset_control_ops hi6220_ao_reset_ops = {
+ .assert = hi6220_ao_assert,
+ .deassert = hi6220_ao_deassert,
+};
+
static int hi6220_reset_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
@@ -117,9 +179,12 @@ static int hi6220_reset_probe(struct platform_device *pdev)
if (type == MEDIA) {
data->rc_dev.ops = &hi6220_media_reset_ops;
data->rc_dev.nr_resets = MEDIA_MAX_INDEX;
- } else {
+ } else if (type == PERIPHERAL) {
data->rc_dev.ops = &hi6220_peripheral_reset_ops;
data->rc_dev.nr_resets = PERIPH_MAX_INDEX;
+ } else {
+ data->rc_dev.ops = &hi6220_ao_reset_ops;
+ data->rc_dev.nr_resets = AO_MAX_INDEX;
}

return reset_controller_register(&data->rc_dev);
@@ -134,6 +199,10 @@ static const struct of_device_id hi6220_reset_match[] = {
.compatible = "hisilicon,hi6220-mediactrl",
.data = (void *)MEDIA,
},
+ {
+ .compatible = "hisilicon,hi6220-aoctrl",
+ .data = (void *)AO,
+ },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, hi6220_reset_match);
--
2.17.1