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

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

[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):
  mailbox: Add support for bcm74110 mailbox
  dt-bindings: mailbox: Add devicetree binding for bcm74110 mbox

 .../bindings/mailbox/brcm,bcm74110-mbox.yaml  |  68 ++
 drivers/mailbox/Kconfig                       |  10 +
 drivers/mailbox/Makefile                      |   2 +
 drivers/mailbox/bcm74110-mailbox.c            | 661 ++++++++++++++++++
 4 files changed, 741 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
 create mode 100644 drivers/mailbox/bcm74110-mailbox.c

-- 
2.34.1

[PATCH 1/2] mailbox: Add support for bcm74110 mailbox

[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>
---
 drivers/mailbox/Kconfig            |  10 +
 drivers/mailbox/Makefile           |   2 +
 drivers/mailbox/bcm74110-mailbox.c | 661 +++++++++++++++++++++++++++++
 3 files changed, 673 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..9d5896725704
--- /dev/null
+++ b/drivers/mailbox/bcm74110-mailbox.c
@@ -0,0 +1,661 @@
+// 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;
+};
+
+#define BCM_MBOX_SLOT_SIZE		0x100
+struct bcm74110_mbox {
+	struct platform_device		*pdev;
+	void __iomem			*base;
+
+	/* TX */
+	int				tx_chan;
+	void __iomem			*base_tx;
+
+	/* RX */
+	int				rx_chan;
+	int				rx_irq;
+	void __iomem			*base_rx;
+	void __iomem			*base_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;
+	int				shmem_offset;
+	int				shmem_size;
+};
+
+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 = readl_relaxed(mbox->base_rx + BCM_MBOX_RDATA);
+		status = readl_relaxed(mbox->base_rx + 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 = readl_relaxed(mbox->base_rx_irq + BCM_MBOX_IRQ_STATUS);
+
+	writel_relaxed(0xffffffff, mbox->base_rx_irq + 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)
+{
+	writel_relaxed(0xffffffff, mbox->base_rx_irq + BCM_MBOX_IRQ_MASK_SET);
+	writel_relaxed(0xffffffff, mbox->base_rx_irq + 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 = readl_relaxed(mbox->base_tx + 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));
+
+	writel_relaxed(msg, mbox->base_tx + 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;
+}
+
+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,
+				       mbox->shmem_offset / BCM_MBOX_SLOT_SIZE,
+				       (mbox->shmem_size / BCM_MBOX_SLOT_SIZE) - 1);
+	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,
+				       mbox->shmem_offset / BCM_MBOX_SLOT_SIZE,
+				       (mbox->shmem_size / BCM_MBOX_SLOT_SIZE) - 1);
+	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 */
+	writel_relaxed(0x0, mbox->base_tx + BCM_MBOX_CTRL);
+
+	/* Clear status & restart tx/rx*/
+	writel_relaxed(BCM_MBOX_CTRL_EN | BCM_MBOX_CTRL_CLR,
+		       mbox->base_tx + BCM_MBOX_CTRL);
+
+	/* Unmask irq */
+	writel_relaxed(BCM_MBOX_IRQ_NOT_EMPTY, mbox->base_rx_irq +
+		       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 */
+	writel_relaxed(0x0, mbox->base_tx + 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_SLOT_SIZE) - 1 > mbox->shmem_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");
+
+	ret = of_property_read_u32_index(dev->of_node, "brcm,shmem", 0,
+					 &mbox->shmem_offset);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get shmem offset\n");
+
+	ret = of_property_read_u32_index(dev->of_node, "brcm,shmem", 1,
+					 &mbox->shmem_size);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get shmem size\n");
+
+	mbox->rx_irq = platform_get_irq(pdev, 0);
+	if (mbox->rx_irq <= 0)
+		return dev_err_probe(dev, -EINVAL, "Failed to get irq\n");
+
+	mbox->base_tx = mbox->base + BCM_MBOX_BASE(mbox->tx_chan);
+	mbox->base_rx = mbox->base + BCM_MBOX_BASE(mbox->rx_chan);
+	mbox->base_rx_irq = mbox->base + BCM_MBOX_IRQ_BASE(mbox->rx_chan);
+
+	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;
+
+	dev_info(dev, "Mailbox inited with %d channels\n", BCM_MSG_SVC_MAX);
+
+	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@broadcom.com>");
+MODULE_DESCRIPTION("BCM74110 mailbox driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

[PATCH 2/2] dt-bindings: mailbox: Add devicetree binding for bcm74110 mbox

[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>
---
 .../bindings/mailbox/brcm,bcm74110-mbox.yaml  | 68 +++++++++++++++++++
 1 file changed, 68 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..139728a35303
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
@@ -0,0 +1,68 @@
+# 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 Driver
+
+maintainers:
+  - Justin Chen <justin.chen@broadcom.com>
+  - Florian Fainelli <florian.fainelli@broadcom.com>
+
+description: Broadcom mailbox driver first introduced with 74110
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm74110-mbox
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  "#mbox-cells":
+    const: 2
+    description:
+      The first cell is channel type and second cell is shared memory slot
+
+  brcm,mbox_tx:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Mailbox transmit doorbell
+
+  brcm,mbox_rx:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Mailbox receive doorbell
+
+  brcm,mbox_shmem:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    maxItems: 2
+    description: Mailbox shared memory region and size
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - "#mbox-cells"
+  - brcm,mbox_tx
+  - brcm,mbox_rx
+  - brcm,mbox_shmem
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+        brcm_pmc_mailbox: brcm_pmc_mailbox@a552000 {
+                #mbox-cells = <2>;
+                compatible = "brcm,bcm74110-mbox";
+                reg = <0xa552000 0x1100>;
+                brcm,mbox_tx = <0x6>;
+                brcm,mbox_rx = <0x7>;
+                brcm,mbox_shmem = <0x3000 0x400>;
+                interrupts = <0x0 0x67 0x4>;
+                interrupt-parent = <&intc>;
+        };
-- 
2.34.1

Re: [PATCH 2/2] dt-bindings: mailbox: Add devicetree binding for bcm74110 mbox

[Krzysztof Kozlowski]

On 27/03/2025 23:16, justin.chen@broadcom.com wrote:
> 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>

Bindings are before users, see DT submitting patches.

> ---
>  .../bindings/mailbox/brcm,bcm74110-mbox.yaml  | 68 +++++++++++++++++++
>  1 file changed, 68 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..139728a35303
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
> @@ -0,0 +1,68 @@
> +# 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 Driver

Driver as Linux driver? Drop, bindings describe hardware.

> +
> +maintainers:
> +  - Justin Chen <justin.chen@broadcom.com>
> +  - Florian Fainelli <florian.fainelli@broadcom.com>
> +
> +description: Broadcom mailbox driver first introduced with 74110

Same comments.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - brcm,bcm74110-mbox
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  "#mbox-cells":
> +    const: 2
> +    description:
> +      The first cell is channel type and second cell is shared memory slot
> +
> +  brcm,mbox_tx:

No underscores. See DTS coding style.

> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Mailbox transmit doorbell

Why is this needed in DT? How many instances do you have in one SoC?
Where is the SoC DTS?

> +
> +  brcm,mbox_rx:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Mailbox receive doorbell
> +
> +  brcm,mbox_shmem:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    maxItems: 2
> +    description: Mailbox shared memory region and size

No, use existing properties, e.g. memory region.

> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - "#mbox-cells"
> +  - brcm,mbox_tx
> +  - brcm,mbox_rx
> +  - brcm,mbox_shmem
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +        brcm_pmc_mailbox: brcm_pmc_mailbox@a552000 {

Use indentation we expect. See writing schema, example-schema.

> +                #mbox-cells = <2>;
> +                compatible = "brcm,bcm74110-mbox";

Fix order, see DTS coding style.



Best regards,
Krzysztof

Re: [PATCH 1/2] mailbox: Add support for bcm74110 mailbox

[Krzysztof Kozlowski]

On 27/03/2025 23:16, justin.chen@broadcom.com wrote:
> +static int bcm74110_mbox_init(struct bcm74110_mbox *mbox)
> +{
> +	int ret = 0;
> +
> +	/* Disable queues tx/rx */
> +	writel_relaxed(0x0, mbox->base_tx + BCM_MBOX_CTRL);
> +
> +	/* Clear status & restart tx/rx*/
> +	writel_relaxed(BCM_MBOX_CTRL_EN | BCM_MBOX_CTRL_CLR,
> +		       mbox->base_tx + BCM_MBOX_CTRL);
> +
> +	/* Unmask irq */
> +	writel_relaxed(BCM_MBOX_IRQ_NOT_EMPTY, mbox->base_rx_irq +
> +		       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);
> +}
> +
> +
> +

Just one blank line




> +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");
> +
> +	ret = of_property_read_u32_index(dev->of_node, "brcm,shmem", 0,
> +					 &mbox->shmem_offset);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get shmem offset\n");
> +
> +	ret = of_property_read_u32_index(dev->of_node, "brcm,shmem", 1,
> +					 &mbox->shmem_size);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get shmem size\n");
> +
> +	mbox->rx_irq = platform_get_irq(pdev, 0);
> +	if (mbox->rx_irq <= 0)


That's not correct check: look at help for this function.

> +		return dev_err_probe(dev, -EINVAL, "Failed to get irq\n");
> +
> +	mbox->base_tx = mbox->base + BCM_MBOX_BASE(mbox->tx_chan);
> +	mbox->base_rx = mbox->base + BCM_MBOX_BASE(mbox->rx_chan);
> +	mbox->base_rx_irq = mbox->base + BCM_MBOX_IRQ_BASE(mbox->rx_chan);

And all this suggests DT properties are not correct. Why would you
offset base? What is the memory layout of all your mbox controllers?

> +
> +	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;
> +
> +	dev_info(dev, "Mailbox inited with %d channels\n", BCM_MSG_SVC_MAX);

Drop, drivers are supposed to be silent on success.



Best regards,
Krzysztof

Re: [PATCH 2/2] dt-bindings: mailbox: Add devicetree binding for bcm74110 mbox

[Justin Chen]

On 3/28/25 12:31 AM, Krzysztof Kozlowski wrote:
> On 27/03/2025 23:16, justin.chen@broadcom.com wrote:
>> 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>
> 
> Bindings are before users, see DT submitting patches.
> 
>> ---
>>   .../bindings/mailbox/brcm,bcm74110-mbox.yaml  | 68 +++++++++++++++++++
>>   1 file changed, 68 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..139728a35303
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mailbox/brcm,bcm74110-mbox.yaml
>> @@ -0,0 +1,68 @@
>> +# 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 Driver
> 
> Driver as Linux driver? Drop, bindings describe hardware.
> 
>> +
>> +maintainers:
>> +  - Justin Chen <justin.chen@broadcom.com>
>> +  - Florian Fainelli <florian.fainelli@broadcom.com>
>> +
>> +description: Broadcom mailbox driver first introduced with 74110
> 
> Same comments.
> 
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - brcm,bcm74110-mbox
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  "#mbox-cells":
>> +    const: 2
>> +    description:
>> +      The first cell is channel type and second cell is shared memory slot
>> +
>> +  brcm,mbox_tx:
> 
> No underscores. See DTS coding style.
> 

Acked. I already had this fixed in the driver, but not in the doc. Woops!

>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description: Mailbox transmit doorbell
> 
> Why is this needed in DT? How many instances do you have in one SoC?
> Where is the SoC DTS?
> 

We have 3 possible instances in our current SoC. We currently only 
implement one. arm,scmi. But more will come in the future. I'll put a 
sample arm,scmi node as an example consumer in v2.

>> +
>> +  brcm,mbox_rx:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description: Mailbox receive doorbell
>> +
>> +  brcm,mbox_shmem:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    maxItems: 2
>> +    description: Mailbox shared memory region and size
> 
> No, use existing properties, e.g. memory region.
> 

This is a region from the on chip memory. I will rename to be clear. It 
lies in a different address space as reserved-memory. I can still use 
memory region if you prefer, but I will need to manually strip the 
offset in my driver as the API agreed upon with the FW is an offset from 
the beginning of on chip memory. IMHO this makes things unnecessarily 
complicated.

>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - interrupts
>> +  - "#mbox-cells"
>> +  - brcm,mbox_tx
>> +  - brcm,mbox_rx
>> +  - brcm,mbox_shmem
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +
>> +        brcm_pmc_mailbox: brcm_pmc_mailbox@a552000 {
> 
> Use indentation we expect. See writing schema, example-schema.
> 
>> +                #mbox-cells = <2>;
>> +                compatible = "brcm,bcm74110-mbox";
> 
> Fix order, see DTS coding style.
> 
> 
> 

Thanks for the review.
Justin

> Best regards,
> Krzysztof

Re: [PATCH 2/2] dt-bindings: mailbox: Add devicetree binding for bcm74110 mbox

[Krzysztof Kozlowski]

On 28/03/2025 19:36, Justin Chen wrote:
>>> +    const: 2
>>> +    description:
>>> +      The first cell is channel type and second cell is shared memory slot
>>> +
>>> +  brcm,mbox_tx:
>>
>> No underscores. See DTS coding style.
>>
> 
> Acked. I already had this fixed in the driver, but not in the doc. Woops!

So this did not even work and you did not test DTS.

Where is the DTS?

> 
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>> +    description: Mailbox transmit doorbell
>>
>> Why is this needed in DT? How many instances do you have in one SoC?
>> Where is the SoC DTS?
>>
> 
> We have 3 possible instances in our current SoC. We currently only 
> implement one. arm,scmi. But more will come in the future. I'll put a 
> sample arm,scmi node as an example consumer in v2.

No. Post your DTS instead.

> 
>>> +
>>> +  brcm,mbox_rx:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>> +    description: Mailbox receive doorbell
>>> +
>>> +  brcm,mbox_shmem:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>> +    maxItems: 2
>>> +    description: Mailbox shared memory region and size
>>
>> No, use existing properties, e.g. memory region.
>>
> 
> This is a region from the on chip memory. I will rename to be clear. It 

memory? so reserved region is for what? Not memory?

If this is memory, then reserved region. If this is not memory, but
MMIO, then you have reg for that.


Best regards,
Krzysztof