[PATCH v3 0/2] mailbox: Add support for bcm74110

[PATCH v3 0/2] mailbox: Add support for bcm74110

[justin.chen]

From: Justin Chen <justin.chen@broadcom.com>

The bcm74110 mailbox driver is used to communicate with
a co-processor for various power management and firmware
related tasks.

Justin Chen (2):
  dt-bindings: mailbox: Add support for bcm74110
  mailbox: Add support for bcm74110

 .../bindings/mailbox/brcm,bcm74110-mbox.yaml  |  65 ++
 drivers/mailbox/Kconfig                       |  10 +
 drivers/mailbox/Makefile                      |   2 +
 drivers/mailbox/bcm74110-mailbox.c            | 655 ++++++++++++++++++
 4 files changed, 732 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
 create mode 100644 drivers/mailbox/bcm74110-mailbox.c

-- 
2.34.1

[PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[justin.chen]

From: Justin Chen <justin.chen@broadcom.com>

Add devicetree YAML binding for brcmstb bcm74110 mailbox used
for communicating with a co-processor.

Signed-off-by: Justin Chen <justin.chen@broadcom.com>
---
v3
	Added list for interrupts.
	Corrected dts example. Fixed ordering and naming.

v2
        Renamed brcm,brcm_{tx|rx} to brcm,{tx|rx}.
        Removed brcm,shmem node. Not necessary to keep in dt.
        Fixed example and added scmi node.

 .../bindings/mailbox/brcm,bcm74110-mbox.yaml  | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml

diff --git a/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml b/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
new file mode 100644
index 000000000000..d6084ed23126
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/brcm,bcm74110-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM74110 Mailbox
+
+maintainers:
+  - Justin Chen <justin.chen@broadcom.com>
+  - Florian Fainelli <florian.fainelli@broadcom.com>
+
+description: Broadcom mailbox hardware first introduced with 74110
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm74110-mbox
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    items:
+      - description: RX doorbell and watermark interrupts
+      - description: TX doorbell and watermark interrupts
+
+  "#mbox-cells":
+    const: 2
+    description:
+      The first cell is channel type and second cell is shared memory slot
+
+  brcm,rx:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: RX Mailbox number
+
+  brcm,tx:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: TX Mailbox number
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - "#mbox-cells"
+  - brcm,rx
+  - brcm,tx
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    mailbox@a552000 {
+        compatible = "brcm,bcm74110-mbox";
+        reg = <0xa552000 0x1104>;
+        interrupts = <GIC_SPI 0x67 IRQ_TYPE_LEVEL_HIGH>,
+                     <GIC_SPI 0x66 IRQ_TYPE_LEVEL_HIGH>;
+        #mbox-cells = <0x2>;
+        brcm,rx = <0x7>;
+        brcm,tx = <0x6>;
+    };
-- 
2.34.1

[PATCH v3 2/2] mailbox: Add support for bcm74110

[justin.chen]

From: Justin Chen <justin.chen@broadcom.com>

The bcm74110 mailbox driver is used to communicate with
a co-processor for various power management and firmware
related tasks.

Signed-off-by: Justin Chen <justin.chen@broadcom.com>
---
v3
	No changes

v2
        Fixed minor formatting issues
        Fixed error check of platform_get_irq()
        Removed offsetted base iomem vars. Instead we just offset directly
        from base.
	Removed shmem variable. Hardcode it instead.

 drivers/mailbox/Kconfig            |  10 +
 drivers/mailbox/Makefile           |   2 +
 drivers/mailbox/bcm74110-mailbox.c | 655 +++++++++++++++++++++++++++++
 3 files changed, 667 insertions(+)
 create mode 100644 drivers/mailbox/bcm74110-mailbox.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index ed52db272f4d..6fe3356ddde5 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -330,4 +330,14 @@ config THEAD_TH1520_MBOX
 	  kernel is running, and E902 core used for power management among other
 	  things.
 
+config BCM74110_MAILBOX
+	tristate "Brcmstb BCM74110 Mailbox"
+	depends on ARCH_BRCMSTB || COMPILE_TEST
+	default ARCH_BRCMSTB
+	help
+	  Broadcom STB mailbox driver present starting with brcmstb bcm74110
+	  SoCs. The mailbox is a communication channel between the host
+	  processor and coprocessor that handles various power management task
+	  and more.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 9a1542b55539..eb2e8f55bd15 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -70,3 +70,5 @@ obj-$(CONFIG_QCOM_CPUCP_MBOX)	+= qcom-cpucp-mbox.o
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
 
 obj-$(CONFIG_THEAD_TH1520_MBOX)	+= mailbox-th1520.o
+
+obj-$(CONFIG_BCM74110_MAILBOX)	+= bcm74110-mailbox.o
diff --git a/drivers/mailbox/bcm74110-mailbox.c b/drivers/mailbox/bcm74110-mailbox.c
new file mode 100644
index 000000000000..04600f2b075e
--- /dev/null
+++ b/drivers/mailbox/bcm74110-mailbox.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Broadcom BCM74110 Mailbox Driver
+ *
+ * Copyright (c) 2025 Broadcom
+ */
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/mailbox_controller.h>
+#include <linux/bitfield.h>
+
+#define BCM_MBOX_BASE(sel)		((sel) * 0x40)
+#define BCM_MBOX_IRQ_BASE(sel)		(((sel) * 0x20) + 0x800)
+
+#define BCM_MBOX_CFGA			0x0
+#define BCM_MBOX_CFGB			0x4
+#define BCM_MBOX_CFGC			0x8
+#define BCM_MBOX_CFGD			0xc
+#define BCM_MBOX_CTRL			0x10
+#define  BCM_MBOX_CTRL_EN		BIT(0)
+#define  BCM_MBOX_CTRL_CLR		BIT(1)
+#define BCM_MBOX_STATUS0		0x14
+#define  BCM_MBOX_STATUS0_NOT_EMPTY	BIT(28)
+#define  BCM_MBOX_STATUS0_FULL		BIT(29)
+#define BCM_MBOX_STATUS1		0x18
+#define BCM_MBOX_STATUS2		0x1c
+#define BCM_MBOX_WDATA			0x20
+#define BCM_MBOX_RDATA			0x28
+
+#define BCM_MBOX_IRQ_STATUS		0x0
+#define BCM_MBOX_IRQ_SET		0x4
+#define BCM_MBOX_IRQ_CLEAR		0x8
+#define BCM_MBOX_IRQ_MASK_STATUS	0xc
+#define BCM_MBOX_IRQ_MASK_SET		0x10
+#define BCM_MBOX_IRQ_MASK_CLEAR		0x14
+#define  BCM_MBOX_IRQ_TIMEOUT		BIT(0)
+#define  BCM_MBOX_IRQ_NOT_EMPTY		BIT(1)
+#define  BCM_MBOX_IRQ_FULL		BIT(2)
+#define  BCM_MBOX_IRQ_LOW_WM		BIT(3)
+#define  BCM_MBOX_IRQ_HIGH_WM		BIT(4)
+
+#define BCM_LINK_CODE0			0xbe0
+#define BCM_LINK_CODE1			0xbe1
+#define BCM_LINK_CODE2			0xbe2
+
+enum {
+	BCM_MSG_FUNC_LINK_START = 0,
+	BCM_MSG_FUNC_LINK_STOP,
+	BCM_MSG_FUNC_SHMEM_TX,
+	BCM_MSG_FUNC_SHMEM_RX,
+	BCM_MSG_FUNC_SHMEM_STOP,
+	BCM_MSG_FUNC_MAX,
+};
+
+enum {
+	BCM_MSG_SVC_INIT = 0,
+	BCM_MSG_SVC_PMC,
+	BCM_MSG_SVC_SCMI,
+	BCM_MSG_SVC_DPFE,
+	BCM_MSG_SVC_MAX,
+};
+
+struct bcm74110_mbox_msg {
+	struct list_head		list_entry;
+#define BCM_MSG_VERSION_MASK		GENMASK(31, 29)
+#define  BCM_MSG_VERSION		0x1
+#define BCM_MSG_REQ_MASK		BIT(28)
+#define BCM_MSG_RPLY_MASK		BIT(27)
+#define BCM_MSG_SVC_MASK		GENMASK(26, 24)
+#define BCM_MSG_FUNC_MASK		GENMASK(23, 16)
+#define BCM_MSG_LENGTH_MASK		GENMASK(15, 4)
+#define BCM_MSG_SLOT_MASK		GENMASK(3, 0)
+
+#define BCM_MSG_SET_FIELD(hdr, field, val)			\
+	do {							\
+		hdr &= ~BCM_MSG_##field##_MASK;			\
+		hdr |= FIELD_PREP(BCM_MSG_##field##_MASK, val);	\
+	} while (0)
+
+#define BCM_MSG_GET_FIELD(hdr, field)				\
+		FIELD_GET(BCM_MSG_##field##_MASK, hdr)
+	u32				msg;
+};
+
+struct bcm74110_mbox_chan {
+	struct bcm74110_mbox		*mbox;
+	bool				en;
+	int				slot;
+	int				type;
+};
+
+struct bcm74110_mbox {
+	struct platform_device		*pdev;
+	void __iomem			*base;
+
+	int				tx_chan;
+	int				rx_chan;
+	int				rx_irq;
+	struct list_head		rx_svc_init_list;
+	spinlock_t			rx_svc_list_lock;
+
+	struct mbox_controller		controller;
+	struct bcm74110_mbox_chan	*mbox_chan;
+};
+
+#define BCM74110_OFFSET_IO_WRITEL_MACRO(name, offset_base)	\
+static void bcm74110_##name##_writel(struct bcm74110_mbox *mbox,\
+				     u32 val, u32 off)		\
+{								\
+	writel_relaxed(val, mbox->base + offset_base + off);	\
+}
+BCM74110_OFFSET_IO_WRITEL_MACRO(tx, BCM_MBOX_BASE(mbox->tx_chan));
+BCM74110_OFFSET_IO_WRITEL_MACRO(irq, BCM_MBOX_IRQ_BASE(mbox->rx_chan));
+
+#define BCM74110_OFFSET_IO_READL_MACRO(name, offset_base)	\
+static u32 bcm74110_##name##_readl(struct bcm74110_mbox *mbox,	\
+				   u32 off)			\
+{								\
+	return readl_relaxed(mbox->base + offset_base + off);	\
+}
+BCM74110_OFFSET_IO_READL_MACRO(tx, BCM_MBOX_BASE(mbox->tx_chan));
+BCM74110_OFFSET_IO_READL_MACRO(rx, BCM_MBOX_BASE(mbox->rx_chan));
+BCM74110_OFFSET_IO_READL_MACRO(irq, BCM_MBOX_IRQ_BASE(mbox->rx_chan));
+
+static inline struct bcm74110_mbox *bcm74110_mbox_from_cntrl(
+					struct mbox_controller *cntrl)
+{
+	return container_of(cntrl, struct bcm74110_mbox, controller);
+}
+
+static void bcm74110_rx_push_init_msg(struct bcm74110_mbox *mbox, u32 val)
+{
+	struct bcm74110_mbox_msg *msg;
+
+	msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
+	if (!msg)
+		return;
+
+	INIT_LIST_HEAD(&msg->list_entry);
+	msg->msg = val;
+
+	spin_lock(&mbox->rx_svc_list_lock);
+	list_add_tail(&msg->list_entry, &mbox->rx_svc_init_list);
+	spin_unlock(&mbox->rx_svc_list_lock);
+}
+
+static void bcm74110_rx_process_msg(struct bcm74110_mbox *mbox)
+{
+	struct device *dev = &mbox->pdev->dev;
+	struct bcm74110_mbox_chan *chan_priv;
+	struct mbox_chan *chan;
+	u32 msg, status;
+	int type;
+
+	do {
+		msg = bcm74110_rx_readl(mbox, BCM_MBOX_RDATA);
+		status = bcm74110_rx_readl(mbox, BCM_MBOX_STATUS0);
+
+		dev_dbg(dev, "rx: [{req=%lu|rply=%lu|srv=%lu|fn=%lu|length=%lu|slot=%lu]\n",
+			BCM_MSG_GET_FIELD(msg, REQ), BCM_MSG_GET_FIELD(msg, RPLY),
+			BCM_MSG_GET_FIELD(msg, SVC), BCM_MSG_GET_FIELD(msg, FUNC),
+			BCM_MSG_GET_FIELD(msg, LENGTH), BCM_MSG_GET_FIELD(msg, SLOT));
+
+		type = BCM_MSG_GET_FIELD(msg, SVC);
+		switch (type) {
+		case BCM_MSG_SVC_INIT:
+			bcm74110_rx_push_init_msg(mbox, msg);
+			break;
+		case BCM_MSG_SVC_PMC:
+		case BCM_MSG_SVC_SCMI:
+		case BCM_MSG_SVC_DPFE:
+			chan = &mbox->controller.chans[type];
+			chan_priv = chan->con_priv;
+			if (chan_priv->en)
+				mbox_chan_received_data(chan, NULL);
+			else
+				dev_warn(dev, "Channel not enabled\n");
+			break;
+		default:
+			dev_warn(dev, "Unsupported msg received\n");
+		}
+	} while (status & BCM_MBOX_STATUS0_NOT_EMPTY);
+}
+
+static irqreturn_t bcm74110_mbox_isr(int irq, void *data)
+{
+	struct bcm74110_mbox *mbox = data;
+	u32 status;
+
+	status = bcm74110_irq_readl(mbox, BCM_MBOX_IRQ_STATUS);
+
+	bcm74110_irq_writel(mbox, 0xffffffff, BCM_MBOX_IRQ_CLEAR);
+
+	if (status & BCM_MBOX_IRQ_NOT_EMPTY)
+		bcm74110_rx_process_msg(mbox);
+	else
+		dev_warn(&mbox->pdev->dev, "Spurious interrupt\n");
+
+	return IRQ_HANDLED;
+}
+
+static void bcm74110_mbox_mask_and_clear(struct bcm74110_mbox *mbox)
+{
+	bcm74110_irq_writel(mbox, 0xffffffff, BCM_MBOX_IRQ_MASK_SET);
+	bcm74110_irq_writel(mbox, 0xffffffff, BCM_MBOX_IRQ_CLEAR);
+}
+
+static int bcm74110_rx_pop_init_msg(struct bcm74110_mbox *mbox, u32 func_type,
+				    u32 *val)
+{
+	struct bcm74110_mbox_msg *msg, *msg_tmp;
+	unsigned long flags;
+	bool found = false;
+
+	spin_lock_irqsave(&mbox->rx_svc_list_lock, flags);
+	list_for_each_entry_safe(msg, msg_tmp, &mbox->rx_svc_init_list,
+				 list_entry) {
+		if (BCM_MSG_GET_FIELD(msg->msg, FUNC) == func_type) {
+			list_del(&msg->list_entry);
+			found = true;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&mbox->rx_svc_list_lock, flags);
+
+	if (!found)
+		return -EINVAL;
+
+	*val = msg->msg;
+	kfree(msg);
+
+	return 0;
+}
+
+static void bcm74110_rx_flush_msg(struct bcm74110_mbox *mbox)
+{
+	struct bcm74110_mbox_msg *msg, *msg_tmp;
+	LIST_HEAD(list_temp);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mbox->rx_svc_list_lock, flags);
+	list_splice_init(&mbox->rx_svc_init_list, &list_temp);
+	spin_unlock_irqrestore(&mbox->rx_svc_list_lock, flags);
+
+	list_for_each_entry_safe(msg, msg_tmp, &list_temp, list_entry) {
+		list_del(&msg->list_entry);
+		kfree(msg);
+	}
+}
+
+#define BCM_DEQUEUE_TIMEOUT_MS 30
+static int bcm74110_rx_pop_init_msg_block(struct bcm74110_mbox *mbox, u32 func_type,
+					  u32 *val)
+{
+	int ret, timeout = 0;
+
+	do {
+		ret = bcm74110_rx_pop_init_msg(mbox, func_type, val);
+
+		if (!ret)
+			return 0;
+
+		/* TODO: Figure out what is a good sleep here. */
+		usleep_range(1000, 2000);
+		timeout++;
+	} while (timeout < BCM_DEQUEUE_TIMEOUT_MS);
+
+	dev_warn(&mbox->pdev->dev, "Timeout waiting for service init response\n");
+	return -ETIMEDOUT;
+}
+
+static int bcm74110_mbox_create_msg(int req, int rply, int svc, int func,
+				    int length, int slot)
+{
+	u32 msg = 0;
+
+	BCM_MSG_SET_FIELD(msg, REQ, req);
+	BCM_MSG_SET_FIELD(msg, RPLY, rply);
+	BCM_MSG_SET_FIELD(msg, SVC, svc);
+	BCM_MSG_SET_FIELD(msg, FUNC, func);
+	BCM_MSG_SET_FIELD(msg, LENGTH, length);
+	BCM_MSG_SET_FIELD(msg, SLOT, slot);
+
+	return msg;
+}
+
+static int bcm74110_mbox_tx_msg(struct bcm74110_mbox *mbox, u32 msg)
+{
+	int val;
+
+	/* We can potentially poll with timeout here instead */
+	val = bcm74110_tx_readl(mbox, BCM_MBOX_STATUS0);
+	if (val & BCM_MBOX_STATUS0_FULL) {
+		dev_err(&mbox->pdev->dev, "Mailbox full\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(&mbox->pdev->dev, "tx: [{req=%lu|rply=%lu|srv=%lu|fn=%lu|length=%lu|slot=%lu]\n",
+		BCM_MSG_GET_FIELD(msg, REQ), BCM_MSG_GET_FIELD(msg, RPLY),
+		BCM_MSG_GET_FIELD(msg, SVC), BCM_MSG_GET_FIELD(msg, FUNC),
+		BCM_MSG_GET_FIELD(msg, LENGTH), BCM_MSG_GET_FIELD(msg, SLOT));
+
+	bcm74110_tx_writel(mbox, msg, BCM_MBOX_WDATA);
+
+	return 0;
+}
+
+#define BCM_MBOX_LINK_TRAINING_RETRIES	5
+static int bcm74110_mbox_link_training(struct bcm74110_mbox *mbox)
+{
+	int ret, retries = 0;
+	u32 msg = 0, orig_len = 0, len = BCM_LINK_CODE0;
+
+	do {
+		switch (len) {
+		case 0:
+			retries++;
+			dev_warn(&mbox->pdev->dev,
+				 "Link train failed, trying again... %d\n",
+				 retries);
+			if (retries > BCM_MBOX_LINK_TRAINING_RETRIES)
+				return -EINVAL;
+			len = BCM_LINK_CODE0;
+			fallthrough;
+		case BCM_LINK_CODE0:
+		case BCM_LINK_CODE1:
+		case BCM_LINK_CODE2:
+			msg = bcm74110_mbox_create_msg(1, 0, BCM_MSG_SVC_INIT,
+						       BCM_MSG_FUNC_LINK_START,
+						       len, BCM_MSG_SVC_INIT);
+			break;
+		default:
+			break;
+		}
+
+		bcm74110_mbox_tx_msg(mbox, msg);
+
+		/* No response expected for LINK_CODE2 */
+		if (len == BCM_LINK_CODE2)
+			return 0;
+
+		orig_len = len;
+
+		ret = bcm74110_rx_pop_init_msg_block(mbox,
+						     BCM_MSG_GET_FIELD(msg, FUNC),
+						     &msg);
+		if (ret) {
+			len = 0;
+			continue;
+		}
+
+		if ((BCM_MSG_GET_FIELD(msg, SVC) != BCM_MSG_SVC_INIT) ||
+		    (BCM_MSG_GET_FIELD(msg, FUNC) != BCM_MSG_FUNC_LINK_START) ||
+		    (BCM_MSG_GET_FIELD(msg, SLOT) != 0) ||
+		    (BCM_MSG_GET_FIELD(msg, RPLY) != 1) ||
+		    (BCM_MSG_GET_FIELD(msg, REQ) != 0)) {
+			len = 0;
+			continue;
+		}
+
+		len = BCM_MSG_GET_FIELD(msg, LENGTH);
+
+		/* Make sure sequence is good */
+		if (len != (orig_len + 1)) {
+			len = 0;
+			continue;
+		}
+	} while (1);
+
+	return -EINVAL;
+}
+
+static int bcm74110_mbox_tx_msg_and_wait_ack(struct bcm74110_mbox *mbox, u32 msg)
+{
+	int ret;
+	u32 recv_msg;
+
+	ret = bcm74110_mbox_tx_msg(mbox, msg);
+	if (ret)
+		return ret;
+
+	ret = bcm74110_rx_pop_init_msg_block(mbox, BCM_MSG_GET_FIELD(msg, FUNC),
+					     &recv_msg);
+	if (ret)
+		return ret;
+
+	/*
+	 * Modify tx message to verify rx ack.
+	 * Flip RPLY/REQ for synchronous messages
+	 */
+	if (BCM_MSG_GET_FIELD(msg, REQ) == 1) {
+		BCM_MSG_SET_FIELD(msg, RPLY, 1);
+		BCM_MSG_SET_FIELD(msg, REQ, 0);
+	}
+
+	if (msg != recv_msg) {
+		dev_err(&mbox->pdev->dev, "Found ack, but ack is invalid\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Each index points to 0x100 of HAB MEM. IDX size counts from 0 */
+#define BCM_MBOX_HAB_MEM_IDX_START	0x30
+#define BCM_MBOX_HAB_MEM_IDX_SIZE	0x0
+static int bcm74110_mbox_shmem_init(struct bcm74110_mbox *mbox)
+{
+	u32 msg = 0;
+	int ret;
+
+	msg = bcm74110_mbox_create_msg(1, 0, BCM_MSG_SVC_INIT,
+				       BCM_MSG_FUNC_SHMEM_STOP,
+				       0, BCM_MSG_SVC_INIT);
+	ret = bcm74110_mbox_tx_msg_and_wait_ack(mbox, msg);
+	if (ret)
+		return -EINVAL;
+
+	msg = bcm74110_mbox_create_msg(1, 0, BCM_MSG_SVC_INIT,
+				       BCM_MSG_FUNC_SHMEM_TX,
+				       BCM_MBOX_HAB_MEM_IDX_START,
+				       BCM_MBOX_HAB_MEM_IDX_SIZE);
+	ret = bcm74110_mbox_tx_msg_and_wait_ack(mbox, msg);
+	if (ret)
+		return -EINVAL;
+
+	msg = bcm74110_mbox_create_msg(1, 0, BCM_MSG_SVC_INIT,
+				       BCM_MSG_FUNC_SHMEM_RX,
+				       BCM_MBOX_HAB_MEM_IDX_START,
+				       BCM_MBOX_HAB_MEM_IDX_SIZE);
+	ret = bcm74110_mbox_tx_msg_and_wait_ack(mbox, msg);
+	if (ret)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int bcm74110_mbox_init(struct bcm74110_mbox *mbox)
+{
+	int ret = 0;
+
+	/* Disable queues tx/rx */
+	bcm74110_tx_writel(mbox, 0x0, BCM_MBOX_CTRL);
+
+	/* Clear status & restart tx/rx*/
+	bcm74110_tx_writel(mbox, BCM_MBOX_CTRL_EN | BCM_MBOX_CTRL_CLR,
+			   BCM_MBOX_CTRL);
+
+	/* Unmask irq */
+	bcm74110_irq_writel(mbox, BCM_MBOX_IRQ_NOT_EMPTY, BCM_MBOX_IRQ_MASK_CLEAR);
+
+	ret = bcm74110_mbox_link_training(mbox);
+	if (ret) {
+		dev_err(&mbox->pdev->dev, "Training failed\n");
+		return ret;
+	}
+
+	return bcm74110_mbox_shmem_init(mbox);
+}
+
+static int bcm74110_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct bcm74110_mbox_chan *chan_priv = chan->con_priv;
+	u32 msg;
+
+	switch (chan_priv->type) {
+	case BCM_MSG_SVC_PMC:
+	case BCM_MSG_SVC_SCMI:
+	case BCM_MSG_SVC_DPFE:
+		msg = bcm74110_mbox_create_msg(1, 0, chan_priv->type, 0,
+					       128 + 28, chan_priv->slot);
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	return bcm74110_mbox_tx_msg(chan_priv->mbox, msg);
+}
+
+static int bcm74110_mbox_chan_startup(struct mbox_chan *chan)
+{
+	struct bcm74110_mbox_chan *chan_priv = chan->con_priv;
+
+	chan_priv->en = true;
+
+	return 0;
+}
+
+static void bcm74110_mbox_chan_shutdown(struct mbox_chan *chan)
+{
+	struct bcm74110_mbox_chan *chan_priv = chan->con_priv;
+
+	chan_priv->en = false;
+}
+
+static const struct mbox_chan_ops bcm74110_mbox_chan_ops = {
+	.send_data = bcm74110_mbox_send_data,
+	.startup = bcm74110_mbox_chan_startup,
+	.shutdown = bcm74110_mbox_chan_shutdown,
+};
+
+static void bcm74110_mbox_shutdown(struct platform_device *pdev)
+{
+	struct bcm74110_mbox *mbox = dev_get_drvdata(&pdev->dev);
+	u32 msg;
+
+	msg = bcm74110_mbox_create_msg(1, 0, BCM_MSG_SVC_INIT,
+				       BCM_MSG_FUNC_LINK_STOP,
+				       0, 0);
+
+	bcm74110_mbox_tx_msg_and_wait_ack(mbox, msg);
+
+	/* Even if we don't receive ACK, lets shut it down */
+
+	bcm74110_mbox_mask_and_clear(mbox);
+
+	/* Disable queues tx/rx */
+	bcm74110_tx_writel(mbox, 0x0, BCM_MBOX_CTRL);
+
+	/* Flush queues */
+	bcm74110_rx_flush_msg(mbox);
+}
+
+static struct mbox_chan *bcm74110_mbox_of_xlate(struct mbox_controller *cntrl,
+						const struct of_phandle_args *p)
+{
+	struct bcm74110_mbox *mbox = bcm74110_mbox_from_cntrl(cntrl);
+	struct device *dev = &mbox->pdev->dev;
+	struct bcm74110_mbox_chan *chan_priv;
+	int slot, type;
+
+	if (p->args_count != 2) {
+		dev_err(dev, "Invalid arguments\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	type = p->args[0];
+	slot = p->args[1];
+
+	switch (type) {
+	case BCM_MSG_SVC_PMC:
+	case BCM_MSG_SVC_SCMI:
+	case BCM_MSG_SVC_DPFE:
+		if (slot > BCM_MBOX_HAB_MEM_IDX_SIZE) {
+			dev_err(dev, "Not enough shared memory\n");
+			return ERR_PTR(-EINVAL);
+		}
+		chan_priv = cntrl->chans[type].con_priv;
+		chan_priv->slot = slot;
+		chan_priv->type = type;
+		break;
+	default:
+		dev_err(dev, "Invalid channel type: %d\n", type);
+		return ERR_PTR(-EINVAL);
+	};
+
+	return &cntrl->chans[type];
+}
+
+static int bcm74110_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bcm74110_mbox *mbox;
+	int i, ret;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->pdev = pdev;
+	platform_set_drvdata(pdev, mbox);
+
+	mbox->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->base))
+		return dev_err_probe(dev, PTR_ERR(mbox->base), "Failed to iomap\n");
+
+	ret = of_property_read_u32(dev->of_node, "brcm,tx", &mbox->tx_chan);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to find tx channel\n");
+
+	ret = of_property_read_u32(dev->of_node, "brcm,rx", &mbox->rx_chan);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to find rx channel\n");
+
+	mbox->rx_irq = platform_get_irq(pdev, 0);
+	if (mbox->rx_irq < 0)
+		return mbox->rx_irq;
+
+	INIT_LIST_HEAD(&mbox->rx_svc_init_list);
+	spin_lock_init(&mbox->rx_svc_list_lock);
+	bcm74110_mbox_mask_and_clear(mbox);
+
+	ret = devm_request_irq(dev, mbox->rx_irq, bcm74110_mbox_isr,
+			       IRQF_NO_SUSPEND, pdev->name, mbox);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to request irq\n");
+
+	mbox->controller.ops = &bcm74110_mbox_chan_ops;
+	mbox->controller.dev = dev;
+	mbox->controller.num_chans = BCM_MSG_SVC_MAX;
+	mbox->controller.of_xlate = &bcm74110_mbox_of_xlate;
+	mbox->controller.chans = devm_kcalloc(dev, BCM_MSG_SVC_MAX,
+					      sizeof(*mbox->controller.chans),
+					      GFP_KERNEL);
+	if (!mbox->controller.chans)
+		return -ENOMEM;
+
+	mbox->mbox_chan = devm_kcalloc(dev, BCM_MSG_SVC_MAX,
+				       sizeof(*mbox->mbox_chan),
+				       GFP_KERNEL);
+	if (!mbox->mbox_chan)
+		return -ENOMEM;
+
+	for (i = 0; i < BCM_MSG_SVC_MAX; i++) {
+		mbox->mbox_chan[i].mbox = mbox;
+		mbox->controller.chans[i].con_priv = &mbox->mbox_chan[i];
+	}
+
+	ret = devm_mbox_controller_register(dev, &mbox->controller);
+	if (ret)
+		return ret;
+
+	ret = bcm74110_mbox_init(mbox);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct of_device_id bcm74110_mbox_of_match[] = {
+	{ .compatible = "brcm,bcm74110-mbox", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, bcm74110_mbox_of_match);
+
+static struct platform_driver bcm74110_mbox_driver = {
+	.driver = {
+		.name = "bcm74110-mbox",
+		.of_match_table = bcm74110_mbox_of_match,
+		},
+	.probe = bcm74110_mbox_probe,
+	.shutdown = bcm74110_mbox_shutdown,
+};
+module_platform_driver(bcm74110_mbox_driver);
+
+MODULE_AUTHOR("Justin Chen <justin.chen@braodcom.com>");
+MODULE_DESCRIPTION("BCM74110 mailbox driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[Krzysztof Kozlowski]

On 05/04/2025 00:20, justin.chen@broadcom.com wrote:
> +
> +maintainers:
> +  - Justin Chen <justin.chen@broadcom.com>
> +  - Florian Fainelli <florian.fainelli@broadcom.com>
> +
> +description: Broadcom mailbox hardware first introduced with 74110
> +
> +properties:
> +  compatible:
> +    enum:
> +      - brcm,bcm74110-mbox
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    minItems: 1

Third version of patchset, third entirely different code.

Decide finally what is the hardware and send binding matching it.
Hardware did not change last one week three times.

Drop minItems or explain why this is flexible on the same SoC or between
boards using same SoC. You can always point me to upstream DTS, which
would solve many questions.

> +    items:
> +      - description: RX doorbell and watermark interrupts
> +      - description: TX doorbell and watermark interrupts
> +


Best regards,
Krzysztof

Re: [PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[Justin Chen]

On 4/6/25 5:27 AM, Krzysztof Kozlowski wrote:
> On 05/04/2025 00:20, justin.chen@broadcom.com wrote:
>> +
>> +maintainers:
>> +  - Justin Chen <justin.chen@broadcom.com>
>> +  - Florian Fainelli <florian.fainelli@broadcom.com>
>> +
>> +description: Broadcom mailbox hardware first introduced with 74110
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - brcm,bcm74110-mbox
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    minItems: 1
> 
> Third version of patchset, third entirely different code.
> 
> Decide finally what is the hardware and send binding matching it.
> Hardware did not change last one week three times.
> 
> Drop minItems or explain why this is flexible on the same SoC or between
> boards using same SoC. You can always point me to upstream DTS, which
> would solve many questions.
> 

We do not have an upstream DTS. We have a scripting engine that 
generates a DTS and we distribute DTBs to our customers. The example 
from v2 of my patch was copied from said generated DTS.

Apologies as I navigate through the different yaml keywords here. The HW
isn't changing, I am just struggling with representing the HW using the
different keywords. And the different implications of using said keywords.

Here is what I have for v4.
      items:
        - description: RX doorbell and watermark interrupts
        - description: TX doorbell and watermark interrupts
+    description:
+      RX interrupts are required to notify the host of pending messages. TX
+      interrupts are optional. The TX doorbell interrupt is not used by the
+      host, but watermark interrupts may be used to notify a host 
waiting on
+      a full out queue.

Thanks,
Justin

>> +    items:
>> +      - description: RX doorbell and watermark interrupts
>> +      - description: TX doorbell and watermark interrupts
>> +
> 
> 
> Best regards,
> Krzysztof

Re: [PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[Krzysztof Kozlowski]

On 07/04/2025 22:57, Justin Chen wrote:


> from v2 of my patch was copied from said generated DTS.
> 
> Apologies as I navigate through the different yaml keywords here. The HW
> isn't changing, I am just struggling with representing the HW using the
> different keywords. And the different implications of using said keywords.
> 
> Here is what I have for v4.
>       items:
>         - description: RX doorbell and watermark interrupts
>         - description: TX doorbell and watermark interrupts
> +    description:
> +      RX interrupts are required to notify the host of pending messages. TX
> +      interrupts are optional. The TX doorbell interrupt is not used by the
> +      host, but watermark interrupts may be used to notify a host 
> waiting on
> +      a full out queue.
What does it mean optional? Board decides on SoC connections? Given SoC
is fixed isn't it?

Best regards,
Krzysztof

Re: [PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[Justin Chen]

On 4/7/25 11:05 PM, Krzysztof Kozlowski wrote:
> On 07/04/2025 22:57, Justin Chen wrote:
> 
> 
>> from v2 of my patch was copied from said generated DTS.
>>
>> Apologies as I navigate through the different yaml keywords here. The HW
>> isn't changing, I am just struggling with representing the HW using the
>> different keywords. And the different implications of using said keywords.
>>
>> Here is what I have for v4.
>>        items:
>>          - description: RX doorbell and watermark interrupts
>>          - description: TX doorbell and watermark interrupts
>> +    description:
>> +      RX interrupts are required to notify the host of pending messages. TX
>> +      interrupts are optional. The TX doorbell interrupt is not used by the
>> +      host, but watermark interrupts may be used to notify a host
>> waiting on
>> +      a full out queue.
> What does it mean optional? Board decides on SoC connections? Given SoC
> is fixed isn't it?
> 

Maybe I misunderstand optional here. We have optional from the SoC 
perspective and optional from a driver perspective. I was thinking if we 
have a HW feature that the software may choose to use, it is considered 
optional. If that is not the correct understanding, I can make 
adjustments. I will remove minItems, which from understanding, means 
both IRQs are required.

Thanks,
Justin

> Best regards,
> Krzysztof

Re: [PATCH v3 1/2] dt-bindings: mailbox: Add support for bcm74110

[Krzysztof Kozlowski]

On 10/04/2025 20:44, Justin Chen wrote:
> 
> 
> On 4/7/25 11:05 PM, Krzysztof Kozlowski wrote:
>> On 07/04/2025 22:57, Justin Chen wrote:
>>
>>
>>> from v2 of my patch was copied from said generated DTS.
>>>
>>> Apologies as I navigate through the different yaml keywords here. The HW
>>> isn't changing, I am just struggling with representing the HW using the
>>> different keywords. And the different implications of using said keywords.
>>>
>>> Here is what I have for v4.
>>>        items:
>>>          - description: RX doorbell and watermark interrupts
>>>          - description: TX doorbell and watermark interrupts
>>> +    description:
>>> +      RX interrupts are required to notify the host of pending messages. TX
>>> +      interrupts are optional. The TX doorbell interrupt is not used by the
>>> +      host, but watermark interrupts may be used to notify a host
>>> waiting on
>>> +      a full out queue.
>> What does it mean optional? Board decides on SoC connections? Given SoC
>> is fixed isn't it?
>>
> 
> Maybe I misunderstand optional here. We have optional from the SoC 
> perspective and optional from a driver perspective. I was thinking if we 
> have a HW feature that the software may choose to use, it is considered 
> optional. If that is not the correct understanding, I can make 

Both meanings are considered. Optional for driver means hardware has it
but also has default values and driver implementations can work without
it on these defaults, e.g. some property configuring registers like
min/max regulator voltages.
Optional for hardware means it can really be "not connected" on some
hardwares/boards, e.g. some pins are grounded. The "interrupts" do not
really fit into the first category, so they could be optional only if
your hardware really allows this interrupt to be missing (or such
hardware exists).

> adjustments. I will remove minItems, which from understanding, means 
> both IRQs are required.

Best regards,
Krzysztof