[PATCH 0/4] mailbox: sprd: add UMS9230 support and fix interrupt handling

[PATCH 0/4] mailbox: sprd: add UMS9230 support and fix interrupt handling

[Otto Pflüger]

Add support for the new mailbox revision in UMS9230 and fix issues with
interrupt handling that were observed on this SoC.

Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
---
Otto Pflüger (4):
      dt-bindings: mailbox: sprd: add compatible for UMS9230
      mailbox: sprd: clear delivery flag before handling TX done
      mailbox: sprd: add support for mailbox revision 2
      mailbox: sprd: mask interrupts that are not handled

 .../devicetree/bindings/mailbox/sprd-mailbox.yaml  |   1 +
 drivers/mailbox/sprd-mailbox.c                     | 117 ++++++++++++++++-----
 2 files changed, 89 insertions(+), 29 deletions(-)
---
base-commit: f417b7ffcbef7d76b0d8860518f50dae0e7e5eda
change-id: 20250926-ums9230-mailbox-6a6e50486032

Best regards,
-- 
Otto Pflüger <otto.pflueger@abscue.de>

[PATCH 1/4] dt-bindings: mailbox: sprd: add compatible for UMS9230

[Otto Pflüger]

Add a compatible string for the mailbox controller found in the UMS9230
SoC.

Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
---
 Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml b/Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml
index b526f9c0c272b566688748302b5d939773d9932a..bf6ab4e7050cb75657977b9a07aaeb8191183510 100644
--- a/Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml
+++ b/Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml
@@ -16,6 +16,7 @@ properties:
     enum:
       - sprd,sc9860-mailbox
       - sprd,sc9863a-mailbox
+      - sprd,ums9230-mailbox
 
   reg:
     items:

-- 
2.50.0

[PATCH 2/4] mailbox: sprd: clear delivery flag before handling TX done

[Otto Pflüger]

If there are any pending messages in the mailbox queue, they are sent
as soon as a TX done event arrives from the driver. This may trigger a
new delivery interrupt while the previous one is still being handled.
If the delivery status is cleared after this, the interrupt is lost.
To prevent this from happening, clear the delivery status immediately
after checking it and before any new messages are sent.

Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
---
 drivers/mailbox/sprd-mailbox.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c
index ee8539dfcef549317f7b86321930bd6bef044598..9a3d388f76b78632ca08948e0fe0ad484aed23c3 100644
--- a/drivers/mailbox/sprd-mailbox.c
+++ b/drivers/mailbox/sprd-mailbox.c
@@ -166,6 +166,11 @@ static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
 		return IRQ_NONE;
 	}
 
+	/* Clear FIFO delivery and overflow status first */
+	writel(fifo_sts &
+	       (SPRD_INBOX_FIFO_DELIVER_MASK | SPRD_INBOX_FIFO_OVERLOW_MASK),
+	       priv->inbox_base + SPRD_MBOX_FIFO_RST);
+
 	while (send_sts) {
 		id = __ffs(send_sts);
 		send_sts &= (send_sts - 1);
@@ -181,11 +186,6 @@ static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
 			mbox_chan_txdone(chan, 0);
 	}
 
-	/* Clear FIFO delivery and overflow status */
-	writel(fifo_sts &
-	       (SPRD_INBOX_FIFO_DELIVER_MASK | SPRD_INBOX_FIFO_OVERLOW_MASK),
-	       priv->inbox_base + SPRD_MBOX_FIFO_RST);
-
 	/* Clear irq status */
 	writel(SPRD_MBOX_IRQ_CLR, priv->inbox_base + SPRD_MBOX_IRQ_STS);
 

-- 
2.50.0

[PATCH 3/4] mailbox: sprd: add support for mailbox revision 2

[Otto Pflüger]

Newer Unisoc SoCs such as UMS9230 include a new revision of the mailbox
IP with support for up to 16 channels. Since the new revision has a
similar register layout and many parts have remained unchanged, make the
driver support both revisions.

Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
---
 drivers/mailbox/sprd-mailbox.c | 103 ++++++++++++++++++++++++++++++++---------
 1 file changed, 82 insertions(+), 21 deletions(-)

diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c
index 9a3d388f76b78632ca08948e0fe0ad484aed23c3..26256581a76ad59785a1c87a34eb91f5985dc948 100644
--- a/drivers/mailbox/sprd-mailbox.c
+++ b/drivers/mailbox/sprd-mailbox.c
@@ -24,7 +24,8 @@
 #define SPRD_MBOX_IRQ_STS	0x18
 #define SPRD_MBOX_IRQ_MSK	0x1c
 #define SPRD_MBOX_LOCK		0x20
-#define SPRD_MBOX_FIFO_DEPTH	0x24
+#define SPRD_MBOX_FIFO_DEPTH	0x24 /* outbox only */
+#define SPRD_MBOX_IN_FIFO_STS2	0x24 /* inbox only, revision 2 */
 
 /* Bit and mask definition for inbox's SPRD_MBOX_FIFO_STS register */
 #define SPRD_INBOX_FIFO_DELIVER_MASK		GENMASK(23, 16)
@@ -32,8 +33,18 @@
 #define SPRD_INBOX_FIFO_DELIVER_SHIFT		16
 #define SPRD_INBOX_FIFO_BUSY_MASK		GENMASK(7, 0)
 
+/* Bit and mask definition for R2 inbox's SPRD_MBOX_FIFO_RST register */
+#define SPRD_INBOX_R2_FIFO_OVERFLOW_DELIVER_RST	GENMASK(31, 0)
+
+/* Bit and mask definition for R2 inbox's SPRD_MBOX_FIFO_STS register */
+#define SPRD_INBOX_R2_FIFO_DELIVER_MASK		GENMASK(15, 0)
+
+/* Bit and mask definition for SPRD_MBOX_IN_FIFO_STS2 register */
+#define SPRD_INBOX_R2_FIFO_OVERFLOW_MASK	GENMASK(31, 16)
+#define SPRD_INBOX_R2_FIFO_BUSY_MASK		GENMASK(15, 0)
+
 /* Bit and mask definition for SPRD_MBOX_IRQ_STS register */
-#define SPRD_MBOX_IRQ_CLR			BIT(0)
+#define SPRD_MBOX_IRQ_CLR			GENMASK(31, 0)
 
 /* Bit and mask definition for outbox's SPRD_MBOX_FIFO_STS register */
 #define SPRD_OUTBOX_FIFO_FULL			BIT(2)
@@ -52,8 +63,18 @@
 #define SPRD_OUTBOX_FIFO_IRQ_MASK		GENMASK(4, 0)
 
 #define SPRD_OUTBOX_BASE_SPAN			0x1000
-#define SPRD_MBOX_CHAN_MAX			8
-#define SPRD_SUPP_INBOX_ID_SC9863A		7
+#define SPRD_MBOX_R1_CHAN_MAX			8
+#define SPRD_MBOX_R2_CHAN_MAX			16
+
+enum sprd_mbox_version {
+	SPRD_MBOX_R1,
+	SPRD_MBOX_R2,
+};
+
+struct sprd_mbox_info {
+	enum sprd_mbox_version version;
+	unsigned long supp_id;
+};
 
 struct sprd_mbox_priv {
 	struct mbox_controller	mbox;
@@ -64,9 +85,11 @@ struct sprd_mbox_priv {
 	void __iomem		*supp_base;
 	u32			outbox_fifo_depth;
 
+	const struct sprd_mbox_info *info;
+
 	struct mutex		lock;
 	u32			refcnt;
-	struct mbox_chan	chan[SPRD_MBOX_CHAN_MAX];
+	struct mbox_chan	chan[SPRD_MBOX_R2_CHAN_MAX];
 };
 
 static struct sprd_mbox_priv *to_sprd_mbox_priv(struct mbox_controller *mbox)
@@ -154,22 +177,34 @@ static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
 {
 	struct sprd_mbox_priv *priv = data;
 	struct mbox_chan *chan;
-	u32 fifo_sts, send_sts, busy, id;
+	u32 fifo_sts, fifo_sts2, send_sts, busy, id;
 
 	fifo_sts = readl(priv->inbox_base + SPRD_MBOX_FIFO_STS);
 
+	if (priv->info->version == SPRD_MBOX_R2)
+		fifo_sts2 = readl(priv->inbox_base + SPRD_MBOX_IN_FIFO_STS2);
+
 	/* Get the inbox data delivery status */
-	send_sts = (fifo_sts & SPRD_INBOX_FIFO_DELIVER_MASK) >>
-		SPRD_INBOX_FIFO_DELIVER_SHIFT;
+	if (priv->info->version == SPRD_MBOX_R2) {
+		send_sts = fifo_sts & SPRD_INBOX_R2_FIFO_DELIVER_MASK;
+	} else {
+		send_sts = (fifo_sts & SPRD_INBOX_FIFO_DELIVER_MASK) >>
+			SPRD_INBOX_FIFO_DELIVER_SHIFT;
+	}
+
 	if (!send_sts) {
 		dev_warn_ratelimited(priv->dev, "spurious inbox interrupt\n");
 		return IRQ_NONE;
 	}
 
 	/* Clear FIFO delivery and overflow status first */
-	writel(fifo_sts &
-	       (SPRD_INBOX_FIFO_DELIVER_MASK | SPRD_INBOX_FIFO_OVERLOW_MASK),
-	       priv->inbox_base + SPRD_MBOX_FIFO_RST);
+	if (priv->info->version == SPRD_MBOX_R2) {
+		writel(SPRD_INBOX_R2_FIFO_OVERFLOW_DELIVER_RST,
+		       priv->inbox_base + SPRD_MBOX_FIFO_RST);
+	} else {
+		writel(fifo_sts & (SPRD_INBOX_FIFO_DELIVER_MASK | SPRD_INBOX_FIFO_OVERLOW_MASK),
+		       priv->inbox_base + SPRD_MBOX_FIFO_RST);
+	}
 
 	while (send_sts) {
 		id = __ffs(send_sts);
@@ -181,7 +216,11 @@ static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
 		 * Check if the message was fetched by remote target, if yes,
 		 * that means the transmission has been completed.
 		 */
-		busy = fifo_sts & SPRD_INBOX_FIFO_BUSY_MASK;
+		if (priv->info->version == SPRD_MBOX_R2)
+			busy = fifo_sts2 & SPRD_INBOX_R2_FIFO_BUSY_MASK;
+		else
+			busy = fifo_sts & SPRD_INBOX_FIFO_BUSY_MASK;
+
 		if (!(busy & BIT(id)))
 			mbox_chan_txdone(chan, 0);
 	}
@@ -295,7 +334,7 @@ static int sprd_mbox_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct sprd_mbox_priv *priv;
 	int ret, inbox_irq, outbox_irq, supp_irq;
-	unsigned long id, supp;
+	unsigned long id;
 	struct clk *clk;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -305,6 +344,10 @@ static int sprd_mbox_probe(struct platform_device *pdev)
 	priv->dev = dev;
 	mutex_init(&priv->lock);
 
+	priv->info = of_device_get_match_data(dev);
+	if (!priv->info)
+		return -EINVAL;
+
 	/*
 	 * Unisoc mailbox uses an inbox to send messages to the target
 	 * core, and uses (an) outbox(es) to receive messages from other
@@ -362,12 +405,12 @@ static int sprd_mbox_probe(struct platform_device *pdev)
 			return ret;
 		}
 
-		supp = (unsigned long) of_device_get_match_data(dev);
-		if (!supp) {
+		if (!priv->info->supp_id) {
 			dev_err(dev, "no supplementary outbox specified\n");
 			return -ENODEV;
 		}
-		priv->supp_base = priv->outbox_base + (SPRD_OUTBOX_BASE_SPAN * supp);
+		priv->supp_base = priv->outbox_base +
+			(SPRD_OUTBOX_BASE_SPAN * priv->info->supp_id);
 	}
 
 	/* Get the default outbox FIFO depth */
@@ -375,11 +418,15 @@ static int sprd_mbox_probe(struct platform_device *pdev)
 		readl(priv->outbox_base + SPRD_MBOX_FIFO_DEPTH) + 1;
 	priv->mbox.dev = dev;
 	priv->mbox.chans = &priv->chan[0];
-	priv->mbox.num_chans = SPRD_MBOX_CHAN_MAX;
 	priv->mbox.ops = &sprd_mbox_ops;
 	priv->mbox.txdone_irq = true;
 
-	for (id = 0; id < SPRD_MBOX_CHAN_MAX; id++)
+	if (priv->info->version == SPRD_MBOX_R2)
+		priv->mbox.num_chans = SPRD_MBOX_R2_CHAN_MAX;
+	else
+		priv->mbox.num_chans = SPRD_MBOX_R1_CHAN_MAX;
+
+	for (id = 0; id < priv->mbox.num_chans; id++)
 		priv->chan[id].con_priv = (void *)id;
 
 	ret = devm_mbox_controller_register(dev, &priv->mbox);
@@ -391,10 +438,24 @@ static int sprd_mbox_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct sprd_mbox_info sc9860_mbox_info = {
+	.version = SPRD_MBOX_R1,
+};
+
+static const struct sprd_mbox_info sc9863a_mbox_info = {
+	.version = SPRD_MBOX_R1,
+	.supp_id = 7,
+};
+
+static const struct sprd_mbox_info ums9230_mbox_info = {
+	.version = SPRD_MBOX_R2,
+	.supp_id = 6,
+};
+
 static const struct of_device_id sprd_mbox_of_match[] = {
-	{ .compatible = "sprd,sc9860-mailbox" },
-	{ .compatible = "sprd,sc9863a-mailbox",
-	  .data = (void *)SPRD_SUPP_INBOX_ID_SC9863A },
+	{ .compatible = "sprd,sc9860-mailbox", .data = &sc9860_mbox_info },
+	{ .compatible = "sprd,sc9863a-mailbox", .data = &sc9863a_mbox_info },
+	{ .compatible = "sprd,ums9230-mailbox", .data = &ums9230_mbox_info },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, sprd_mbox_of_match);

-- 
2.50.0

[PATCH 4/4] mailbox: sprd: mask interrupts that are not handled

[Otto Pflüger]

To reduce the amount of spurious interrupts, disable the interrupts that
are not handled in this driver.

Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
---
 drivers/mailbox/sprd-mailbox.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c
index 26256581a76ad59785a1c87a34eb91f5985dc948..565502904e1f296dff02e308d8b7f1e1ff2d1692 100644
--- a/drivers/mailbox/sprd-mailbox.c
+++ b/drivers/mailbox/sprd-mailbox.c
@@ -282,21 +282,19 @@ static int sprd_mbox_startup(struct mbox_chan *chan)
 		/* Select outbox FIFO mode and reset the outbox FIFO status */
 		writel(0x0, priv->outbox_base + SPRD_MBOX_FIFO_RST);
 
-		/* Enable inbox FIFO overflow and delivery interrupt */
-		val = readl(priv->inbox_base + SPRD_MBOX_IRQ_MSK);
-		val &= ~(SPRD_INBOX_FIFO_OVERFLOW_IRQ | SPRD_INBOX_FIFO_DELIVER_IRQ);
+		/* Enable inbox FIFO delivery interrupt */
+		val = SPRD_INBOX_FIFO_IRQ_MASK;
+		val &= ~SPRD_INBOX_FIFO_DELIVER_IRQ;
 		writel(val, priv->inbox_base + SPRD_MBOX_IRQ_MSK);
 
 		/* Enable outbox FIFO not empty interrupt */
-		val = readl(priv->outbox_base + SPRD_MBOX_IRQ_MSK);
+		val = SPRD_OUTBOX_FIFO_IRQ_MASK;
 		val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
 		writel(val, priv->outbox_base + SPRD_MBOX_IRQ_MSK);
 
 		/* Enable supplementary outbox as the fundamental one */
 		if (priv->supp_base) {
 			writel(0x0, priv->supp_base + SPRD_MBOX_FIFO_RST);
-			val = readl(priv->supp_base + SPRD_MBOX_IRQ_MSK);
-			val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
 			writel(val, priv->supp_base + SPRD_MBOX_IRQ_MSK);
 		}
 	}

-- 
2.50.0

Re: [PATCH 1/4] dt-bindings: mailbox: sprd: add compatible for UMS9230

[Krzysztof Kozlowski]

On Sat, Jan 10, 2026 at 04:43:35PM +0100, Otto Pflüger wrote:
> Add a compatible string for the mailbox controller found in the UMS9230
> SoC.
> 
> Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
> ---
>  Documentation/devicetree/bindings/mailbox/sprd-mailbox.yaml | 1 +
>  1 file changed, 1 insertion(+)

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Re: [PATCH 0/4] mailbox: sprd: add UMS9230 support and fix interrupt handling

[Jassi Brar]

On Sat, Jan 10, 2026 at 9:44 AM Otto Pflüger <otto.pflueger@abscue.de> wrote:
>
> Add support for the new mailbox revision in UMS9230 and fix issues with
> interrupt handling that were observed on this SoC.
>
> Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
> ---
> Otto Pflüger (4):
>       dt-bindings: mailbox: sprd: add compatible for UMS9230
>       mailbox: sprd: clear delivery flag before handling TX done
>       mailbox: sprd: add support for mailbox revision 2
>       mailbox: sprd: mask interrupts that are not handled
>
>  .../devicetree/bindings/mailbox/sprd-mailbox.yaml  |   1 +
>  drivers/mailbox/sprd-mailbox.c                     | 117 ++++++++++++++++-----
>  2 files changed, 89 insertions(+), 29 deletions(-)
> ---
> base-commit: f417b7ffcbef7d76b0d8860518f50dae0e7e5eda
> change-id: 20250926-ums9230-mailbox-6a6e50486032
>
Applied to mailbox/for-next
Thanks
Jassi