[PATCH v5 21/23] reset: starfive: jh71x0: Support discontiguous reset IDs

[Changhuang Liang]

The reset IDs exposed to consumers of the StarFive JHB100 reset
controllers do not map one-to-one to the hardware reset bits.

Add struct jh71x0_reset_info, which describes the number of resets, the
assert/status register offsets and, for discontiguous controllers, a
table mapping reset IDs to hardware bits. Add
reset_starfive_jh71x0_register_with_info() to register such a
controller, and translate the reset ID in the update and status
callbacks when a map is provided.

Existing users of reset_starfive_jh71x0_register() are unaffected.

Signed-off-by: Changhuang Liang <changhuang.liang@xxxxxxxxxxxxxxxx>
---
 .../reset/starfive/reset-starfive-jh71x0.c    | 99 ++++++++++++++++---
 .../reset/starfive/reset-starfive-jh71x0.h    | 19 ++++
 2 files changed, 107 insertions(+), 11 deletions(-)

diff --git a/drivers/reset/starfive/reset-starfive-jh71x0.c b/drivers/reset/starfive/reset-starfive-jh71x0.c
index 29ce3486752f..fd1c755a0017 100644
--- a/drivers/reset/starfive/reset-starfive-jh71x0.c
+++ b/drivers/reset/starfive/reset-starfive-jh71x0.c
@@ -14,6 +14,8 @@
 
 #include "reset-starfive-jh71x0.h"
 
+#define JH71X0_RESET_ID_INVALID	ULONG_MAX
+
 struct jh71x0_reset {
 	struct reset_controller_dev rcdev;
 	/* protect registers against concurrent read-modify-write */
@@ -21,6 +23,11 @@ struct jh71x0_reset {
 	void __iomem *assert;
 	void __iomem *status;
 	const u32 *asserted;
+
+	/* Only exists in reset controllers that use the
+	 * reset_starfive_jh71x0_register_with_info helper.
+	 */
+	const struct jh71x0_reset_info *info;
 };
 
 static inline struct jh71x0_reset *
@@ -29,19 +36,40 @@ jh71x0_reset_from(struct reset_controller_dev *rcdev)
 	return container_of(rcdev, struct jh71x0_reset, rcdev);
 }
 
+static unsigned long
+jh71x0_reset_id_to_hw_id(const struct jh71x0_reset_map *map, unsigned int nr_resets,
+			 unsigned long reset_id)
+{
+	for (u32 i = 0; i < nr_resets; i++) {
+		if (map[i].reset_id == reset_id)
+			return map[i].hw_id;
+	}
+
+	return JH71X0_RESET_ID_INVALID;
+}
+
 static int jh71x0_reset_update(struct reset_controller_dev *rcdev,
 			       unsigned long id, bool assert)
 {
 	struct jh71x0_reset *data = jh71x0_reset_from(rcdev);
-	unsigned long offset = id / 32;
-	u32 mask = BIT(id % 32);
-	void __iomem *reg_assert = data->assert + offset * sizeof(u32);
-	void __iomem *reg_status = data->status + offset * sizeof(u32);
-	u32 done = data->asserted ? data->asserted[offset] & mask : 0;
-	u32 value;
-	unsigned long flags;
+	unsigned long offset, flags;
+	void __iomem *reg_assert;
+	void __iomem *reg_status;
+	u32 mask, done, value;
 	int ret;
 
+	if (data->info && data->info->discontiguous) {
+		id = jh71x0_reset_id_to_hw_id(data->info->map, data->info->nr_resets, id);
+		if (id == JH71X0_RESET_ID_INVALID)
+			return -EINVAL;
+	}
+
+	offset = id / 32;
+	mask = BIT(id % 32);
+	reg_assert = data->assert + offset * sizeof(u32);
+	reg_status = data->status + offset * sizeof(u32);
+	done = data->asserted ? data->asserted[offset] & mask : 0;
+
 	if (!assert)
 		done ^= mask;
 
@@ -89,10 +117,20 @@ static int jh71x0_reset_status(struct reset_controller_dev *rcdev,
 			       unsigned long id)
 {
 	struct jh71x0_reset *data = jh71x0_reset_from(rcdev);
-	unsigned long offset = id / 32;
-	u32 mask = BIT(id % 32);
-	void __iomem *reg_status = data->status + offset * sizeof(u32);
-	u32 value = readl(reg_status);
+	void __iomem *reg_status;
+	unsigned long offset;
+	u32 mask, value;
+
+	if (data->info && data->info->discontiguous) {
+		id = jh71x0_reset_id_to_hw_id(data->info->map, data->info->nr_resets, id);
+		if (id == JH71X0_RESET_ID_INVALID)
+			return -EINVAL;
+	}
+
+	offset = id / 32;
+	mask = BIT(id % 32);
+	reg_status = data->status + offset * sizeof(u32);
+	value = readl(reg_status);
 
 	if (!data->asserted)
 		return !(value & mask);
@@ -132,3 +170,42 @@ int reset_starfive_jh71x0_register(struct device *dev, struct device_node *of_no
 	return devm_reset_controller_register(dev, &data->rcdev);
 }
 EXPORT_SYMBOL_GPL(reset_starfive_jh71x0_register);
+
+int reset_starfive_jh71x0_register_with_info(struct device *dev, struct device_node *of_node,
+					     void __iomem *assert, void __iomem *status,
+					     const u32 *asserted,
+					     const struct jh71x0_reset_info *info,
+					     struct module *owner)
+{
+	struct jh71x0_reset *data;
+	int ret;
+
+	if (info->discontiguous && (!info->map || !info->nr_resets))
+		return dev_err_probe(dev, -EINVAL,
+				     "discontiguous controller without a valid ID map\n");
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->rcdev.ops = &jh71x0_reset_ops;
+	data->rcdev.owner = owner;
+	data->rcdev.nr_resets = info->nr_resets;
+	data->rcdev.dev = dev;
+	data->rcdev.of_node = of_node;
+
+	spin_lock_init(&data->lock);
+	data->assert = assert;
+	data->status = status;
+	data->asserted = asserted;
+	data->info = info;
+
+	ret = devm_reset_controller_register(dev, &data->rcdev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register reset controller\n");
+
+	dev_info(dev, "Registered %u resets\n", data->rcdev.nr_resets);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(reset_starfive_jh71x0_register_with_info);
diff --git a/drivers/reset/starfive/reset-starfive-jh71x0.h b/drivers/reset/starfive/reset-starfive-jh71x0.h
index db7d39a87f87..36f198139602 100644
--- a/drivers/reset/starfive/reset-starfive-jh71x0.h
+++ b/drivers/reset/starfive/reset-starfive-jh71x0.h
@@ -6,9 +6,28 @@
 #ifndef __RESET_STARFIVE_JH71X0_H
 #define __RESET_STARFIVE_JH71X0_H
 
+struct jh71x0_reset_map {
+	unsigned long reset_id;
+	unsigned long hw_id;
+};
+
+struct jh71x0_reset_info {
+	unsigned int nr_resets;
+	unsigned int assert_offset;
+	unsigned int status_offset;
+	bool discontiguous;
+	const struct jh71x0_reset_map *map;
+};
+
 int reset_starfive_jh71x0_register(struct device *dev, struct device_node *of_node,
 				   void __iomem *assert, void __iomem *status,
 				   const u32 *asserted, unsigned int nr_resets,
 				   struct module *owner);
 
+int reset_starfive_jh71x0_register_with_info(struct device *dev, struct device_node *of_node,
+					     void __iomem *assert, void __iomem *status,
+					     const u32 *asserted,
+					     const struct jh71x0_reset_info *info,
+					     struct module *owner);
+
 #endif /* __RESET_STARFIVE_JH71X0_H */
-- 
2.25.1