Add mtk-vcp-mailbox driver to support the communication with
VCP remote microprocessor.

Signed-off-by: Jjian Zhou <jjian.zhou@mediatek.com>
---
 drivers/mailbox/Kconfig                 |   9 ++
 drivers/mailbox/Makefile                |   2 +
 drivers/mailbox/mtk-vcp-mailbox.c       | 168 ++++++++++++++++++++++++
 include/linux/mailbox/mtk-vcp-mailbox.h |  32 +++++
 4 files changed, 211 insertions(+)
 create mode 100644 drivers/mailbox/mtk-vcp-mailbox.c
 create mode 100644 include/linux/mailbox/mtk-vcp-mailbox.h

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 02432d4a5ccd..c28bdb855663 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -294,6 +294,15 @@ config MTK_CMDQ_MBOX
 	  critical time limitation, such as updating display configuration
 	  during the vblank.
 
+config MTK_VCP_MBOX
+	tristate "MediaTek VCP Mailbox Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  Say yes here to add support for the MediaTek VCP mailbox driver.
+	  The mailbox implementation provides access from the application
+	  processor to Video Companion Processor Unit.
+	  If unsure say N.
+
 config ZYNQMP_IPI_MBOX
 	tristate "Xilinx ZynqMP IPI Mailbox"
 	depends on ARCH_ZYNQMP && OF
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 98a68f838486..07278871d254 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX)	+= mtk-adsp-mailbox.o
 
 obj-$(CONFIG_MTK_CMDQ_MBOX)	+= mtk-cmdq-mailbox.o
 
+obj-$(CONFIG_MTK_VCP_MBOX)	+= mtk-vcp-mailbox.o
+
 obj-$(CONFIG_ZYNQMP_IPI_MBOX)	+= zynqmp-ipi-mailbox.o
 
 obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
diff --git a/drivers/mailbox/mtk-vcp-mailbox.c b/drivers/mailbox/mtk-vcp-mailbox.c
new file mode 100644
index 000000000000..a2a80d124e50
--- /dev/null
+++ b/drivers/mailbox/mtk-vcp-mailbox.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 MediaTek Corporation. All rights reserved.
+ * Author: Jjian Zhou <jjian.zhou.@mediatek.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/mtk-vcp-mailbox.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct mtk_vcp_mbox {
+	struct mbox_controller mbox;
+	void __iomem *base;
+	struct device *dev;
+	const struct mtk_vcp_mbox_cfg *cfg;
+	struct mtk_ipi_info ipi_recv;
+	struct mbox_chan chans;
+};
+
+struct mtk_vcp_mbox_cfg {
+	u32 set_in;
+	u32 clr_out;
+};
+
+static irqreturn_t mtk_vcp_mbox_irq_thread(int irq, void *data)
+{
+	struct mtk_vcp_mbox *priv = data;
+
+	/* get irq status */
+	priv->ipi_recv.irq_status = readl(priv->base + priv->cfg->clr_out);
+
+	__ioread32_copy(priv->ipi_recv.msg, priv->base, MBOX_SLOT_MAX_SIZE / 4);
+
+	mbox_chan_received_data(&priv->chans, &priv->ipi_recv);
+
+	/* clear irq status */
+	writel(priv->ipi_recv.irq_status, priv->base + priv->cfg->clr_out);
+
+	return IRQ_HANDLED;
+}
+
+static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller *mbox,
+					    const struct of_phandle_args *sp)
+{
+	if (sp->args_count)
+		return NULL;
+
+	return &mbox->chans[0];
+}
+
+static int mtk_vcp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mtk_vcp_mbox *priv = chan->con_priv;
+	struct mtk_ipi_info *ipi_info = data;
+	u32 status;
+
+	if (!ipi_info->msg) {
+		dev_err(priv->dev, "msg buffer is NULL.\n");
+		return -EINVAL;
+	}
+
+	status = readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index);
+	if (status) {
+		dev_warn(priv->dev, "mailbox IPI %d is busy.\n", ipi_info->id);
+		return -EBUSY;
+	}
+
+	if (ipi_info->slot_ofs + ipi_info->len > MBOX_SLOT_MAX_SIZE)
+		return -EINVAL;
+	__iowrite32_copy(priv->base + ipi_info->slot_ofs, ipi_info->msg,
+			 ipi_info->len);
+
+	writel(BIT(ipi_info->index), priv->base + priv->cfg->set_in);
+
+	return 0;
+}
+
+static bool mtk_vcp_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct mtk_ipi_info *ipi_info = chan->active_req;
+	struct mtk_vcp_mbox *priv = chan->con_priv;
+
+	return !(readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index));
+}
+
+static const struct mbox_chan_ops mtk_vcp_mbox_chan_ops = {
+	.send_data	= mtk_vcp_mbox_send_data,
+	.last_tx_done	= mtk_vcp_mbox_last_tx_done,
+};
+
+static int mtk_vcp_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_vcp_mbox *priv;
+	struct mbox_controller *mbox;
+	int ret, irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->chans.con_priv = priv;
+	mbox = &priv->mbox;
+	mbox->dev = dev;
+	mbox->ops = &mtk_vcp_mbox_chan_ops;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = true;
+	mbox->of_xlate = mtk_vcp_mbox_xlate;
+	mbox->num_chans = 1;
+	mbox->chans = &priv->chans;
+
+	priv->ipi_recv.msg = devm_kzalloc(dev, MBOX_SLOT_MAX_SIZE, GFP_KERNEL);
+	if (!priv->ipi_recv.msg)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->cfg = of_device_get_match_data(dev);
+	if (!priv->cfg)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_threaded_irq(dev, irq, NULL,
+					mtk_vcp_mbox_irq_thread, IRQF_ONESHOT,
+					dev_name(dev), priv);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return devm_mbox_controller_register(dev, &priv->mbox);
+}
+
+static const struct mtk_vcp_mbox_cfg mt8196_cfg = {
+	.set_in		= 0x100,
+	.clr_out	= 0x10c,
+};
+
+static const struct of_device_id mtk_vcp_mbox_of_match[] = {
+	{ .compatible = "mediatek,mt8196-vcp-mbox", .data = &mt8196_cfg },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_vcp_mbox_of_match);
+
+static struct platform_driver mtk_vcp_mbox_driver = {
+	.probe		= mtk_vcp_mbox_probe,
+	.driver = {
+		.name	= "mtk_vcp_mbox",
+		.of_match_table = mtk_vcp_mbox_of_match,
+	},
+};
+module_platform_driver(mtk_vcp_mbox_driver);
+
+MODULE_AUTHOR("Jjian Zhou <jjian.zhou@mediatek.com>");
+MODULE_DESCRIPTION("MTK VCP Mailbox Controller");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mailbox/mtk-vcp-mailbox.h b/include/linux/mailbox/mtk-vcp-mailbox.h
new file mode 100644
index 000000000000..143fb0d06e30
--- /dev/null
+++ b/include/linux/mailbox/mtk-vcp-mailbox.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/*
+ * Copyright (c) 2025 MediaTek Inc.
+ */
+
+#ifndef __MTK_VCP_MAILBOX_H__
+#define __MTK_VCP_MAILBOX_H__
+
+#define MBOX_SLOT_MAX_SIZE	0x100 /* mbox max slot size */
+
+/**
+ * struct mtk_ipi_info - mailbox message info for mtk-vcp-mailbox
+ * @msg: The share buffer between IPC and mailbox driver
+ * @len: Message length
+ * @id: This is for identification purposes and not actually used
+ *	by the mailbox hardware.
+ * @index: The signal number of the mailbox message.
+ * @slot_ofs: Data slot offset.
+ * @irq_status: Captures incoming signals for the RX path.
+ *
+ * It is used between IPC with mailbox driver.
+ */
+struct mtk_ipi_info {
+	void *msg;
+	u32 len;
+	u32 id;
+	u32 index;
+	u32 slot_ofs;
+	u32 irq_status;
+};
+
+#endif
-- 
2.45.2

Il 26/09/25 11:05, Jjian Zhou ha scritto:
> Add mtk-vcp-mailbox driver to support the communication with
> VCP remote microprocessor.
> 
> Signed-off-by: Jjian Zhou <jjian.zhou@mediatek.com>
> ---
>   drivers/mailbox/Kconfig                 |   9 ++
>   drivers/mailbox/Makefile                |   2 +
>   drivers/mailbox/mtk-vcp-mailbox.c       | 168 ++++++++++++++++++++++++
>   include/linux/mailbox/mtk-vcp-mailbox.h |  32 +++++
>   4 files changed, 211 insertions(+)
>   create mode 100644 drivers/mailbox/mtk-vcp-mailbox.c
>   create mode 100644 include/linux/mailbox/mtk-vcp-mailbox.h
> 
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 02432d4a5ccd..c28bdb855663 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -294,6 +294,15 @@ config MTK_CMDQ_MBOX
>   	  critical time limitation, such as updating display configuration
>   	  during the vblank.
>   
> +config MTK_VCP_MBOX
> +	tristate "MediaTek VCP Mailbox Support"
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	help
> +	  Say yes here to add support for the MediaTek VCP mailbox driver.
> +	  The mailbox implementation provides access from the application
> +	  processor to Video Companion Processor Unit.
> +	  If unsure say N.
> +
>   config ZYNQMP_IPI_MBOX
>   	tristate "Xilinx ZynqMP IPI Mailbox"
>   	depends on ARCH_ZYNQMP && OF
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 98a68f838486..07278871d254 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX)	+= mtk-adsp-mailbox.o
>   
>   obj-$(CONFIG_MTK_CMDQ_MBOX)	+= mtk-cmdq-mailbox.o
>   
> +obj-$(CONFIG_MTK_VCP_MBOX)	+= mtk-vcp-mailbox.o
> +
>   obj-$(CONFIG_ZYNQMP_IPI_MBOX)	+= zynqmp-ipi-mailbox.o
>   
>   obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
> diff --git a/drivers/mailbox/mtk-vcp-mailbox.c b/drivers/mailbox/mtk-vcp-mailbox.c
> new file mode 100644
> index 000000000000..a2a80d124e50
> --- /dev/null
> +++ b/drivers/mailbox/mtk-vcp-mailbox.c
> @@ -0,0 +1,168 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2025 MediaTek Corporation. All rights reserved.
> + * Author: Jjian Zhou <jjian.zhou.@mediatek.com>
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/mailbox/mtk-vcp-mailbox.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +struct mtk_vcp_mbox {
> +	struct mbox_controller mbox;
> +	void __iomem *base;
> +	struct device *dev;
> +	const struct mtk_vcp_mbox_cfg *cfg;
> +	struct mtk_ipi_info ipi_recv;
> +	struct mbox_chan chans;
> +};
> +
> +struct mtk_vcp_mbox_cfg {
> +	u32 set_in;
> +	u32 clr_out;

u16 is enough for both register offsets, at least for now - and I suspect it's
going to be enough forever.

> +};
> +
> +static irqreturn_t mtk_vcp_mbox_irq_thread(int irq, void *data)
> +{
> +	struct mtk_vcp_mbox *priv = data;
> +
> +	/* get irq status */
> +	priv->ipi_recv.irq_status = readl(priv->base + priv->cfg->clr_out);
> +
> +	__ioread32_copy(priv->ipi_recv.msg, priv->base, MBOX_SLOT_MAX_SIZE / 4);
> +
> +	mbox_chan_received_data(&priv->chans, &priv->ipi_recv);
> +
> +	/* clear irq status */
> +	writel(priv->ipi_recv.irq_status, priv->base + priv->cfg->clr_out);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller *mbox,
> +					    const struct of_phandle_args *sp)
> +{
> +	if (sp->args_count)
> +		return NULL;
> +
> +	return &mbox->chans[0];
> +}
> +
> +static int mtk_vcp_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> +	struct mtk_vcp_mbox *priv = chan->con_priv;
> +	struct mtk_ipi_info *ipi_info = data;
> +	u32 status;
> +
> +	if (!ipi_info->msg) {
> +		dev_err(priv->dev, "msg buffer is NULL.\n");
> +		return -EINVAL;
> +	}
> +
> +	status = readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index);

status = readl(priv->base + priv->cfg->set_in);
if (status & BIT(ipi_info->index) {
  ....
}

> +	if (status) {
> +		dev_warn(priv->dev, "mailbox IPI %d is busy.\n", ipi_info->id);
> +		return -EBUSY;
> +	}
> +
> +	if (ipi_info->slot_ofs + ipi_info->len > MBOX_SLOT_MAX_SIZE)
> +		return -EINVAL;
> +	__iowrite32_copy(priv->base + ipi_info->slot_ofs, ipi_info->msg,
> +			 ipi_info->len);
> +
> +	writel(BIT(ipi_info->index), priv->base + priv->cfg->set_in);
> +
> +	return 0;
> +}
> +
> +static bool mtk_vcp_mbox_last_tx_done(struct mbox_chan *chan)
> +{
> +	struct mtk_ipi_info *ipi_info = chan->active_req;
> +	struct mtk_vcp_mbox *priv = chan->con_priv;
> +
> +	return !(readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index));
> +}
> +
> +static const struct mbox_chan_ops mtk_vcp_mbox_chan_ops = {
> +	.send_data	= mtk_vcp_mbox_send_data,
> +	.last_tx_done	= mtk_vcp_mbox_last_tx_done,
> +};
> +
> +static int mtk_vcp_mbox_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mtk_vcp_mbox *priv;
> +	struct mbox_controller *mbox;
> +	int ret, irq;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->dev = dev;
> +	priv->chans.con_priv = priv;
> +	mbox = &priv->mbox;
> +	mbox->dev = dev;
> +	mbox->ops = &mtk_vcp_mbox_chan_ops;
> +	mbox->txdone_irq = false;
> +	mbox->txdone_poll = true;
> +	mbox->of_xlate = mtk_vcp_mbox_xlate;
> +	mbox->num_chans = 1;
> +	mbox->chans = &priv->chans;
> +
> +	priv->ipi_recv.msg = devm_kzalloc(dev, MBOX_SLOT_MAX_SIZE, GFP_KERNEL);
> +	if (!priv->ipi_recv.msg)
> +		return -ENOMEM;
> +
> +	priv->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	priv->cfg = of_device_get_match_data(dev);
> +	if (!priv->cfg)
> +		return -EINVAL;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +

Please set the driver data before requesting the interrupt: what happens if the
ISR is run before having driver data available otherwise?! :-)

> +	ret = devm_request_threaded_irq(dev, irq, NULL,
> +					mtk_vcp_mbox_irq_thread, IRQF_ONESHOT,
> +					dev_name(dev), priv);
> +	if (ret < 0)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	return devm_mbox_controller_register(dev, &priv->mbox);
> +}
> +
> +static const struct mtk_vcp_mbox_cfg mt8196_cfg = {
> +	.set_in		= 0x100,
> +	.clr_out	= 0x10c,
> +};
> +
> +static const struct of_device_id mtk_vcp_mbox_of_match[] = {
> +	{ .compatible = "mediatek,mt8196-vcp-mbox", .data = &mt8196_cfg },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, mtk_vcp_mbox_of_match);
> +
> +static struct platform_driver mtk_vcp_mbox_driver = {
> +	.probe		= mtk_vcp_mbox_probe,
> +	.driver = {
> +		.name	= "mtk_vcp_mbox",
> +		.of_match_table = mtk_vcp_mbox_of_match,
> +	},
> +};
> +module_platform_driver(mtk_vcp_mbox_driver);
> +
> +MODULE_AUTHOR("Jjian Zhou <jjian.zhou@mediatek.com>");
> +MODULE_DESCRIPTION("MTK VCP Mailbox Controller");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mailbox/mtk-vcp-mailbox.h b/include/linux/mailbox/mtk-vcp-mailbox.h
> new file mode 100644
> index 000000000000..143fb0d06e30
> --- /dev/null
> +++ b/include/linux/mailbox/mtk-vcp-mailbox.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
> +/*
> + * Copyright (c) 2025 MediaTek Inc.
> + */
> +
> +#ifndef __MTK_VCP_MAILBOX_H__
> +#define __MTK_VCP_MAILBOX_H__
> +
> +#define MBOX_SLOT_MAX_SIZE	0x100 /* mbox max slot size */

Please, change this definition to MTK_VCP_MBOX_SLOT_MAX_SIZE

Cheers,
Angelo

> +
> +/**
> + * struct mtk_ipi_info - mailbox message info for mtk-vcp-mailbox
> + * @msg: The share buffer between IPC and mailbox driver
> + * @len: Message length
> + * @id: This is for identification purposes and not actually used
> + *	by the mailbox hardware.
> + * @index: The signal number of the mailbox message.
> + * @slot_ofs: Data slot offset.
> + * @irq_status: Captures incoming signals for the RX path.
> + *
> + * It is used between IPC with mailbox driver.
> + */
> +struct mtk_ipi_info {
> +	void *msg;
> +	u32 len;
> +	u32 id;
> +	u32 index;
> +	u32 slot_ofs;
> +	u32 irq_status;
> +};
> +
> +#endif

On Mon, 2025-09-29 at 12:33 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Il 26/09/25 11:05, Jjian Zhou ha scritto:
> > Add mtk-vcp-mailbox driver to support the communication with
> > VCP remote microprocessor.
> > 
> > Signed-off-by: Jjian Zhou <jjian.zhou@mediatek.com>
> > ---
> >   drivers/mailbox/Kconfig                 |   9 ++
> >   drivers/mailbox/Makefile                |   2 +
> >   drivers/mailbox/mtk-vcp-mailbox.c       | 168
> > ++++++++++++++++++++++++
> >   include/linux/mailbox/mtk-vcp-mailbox.h |  32 +++++
> >   4 files changed, 211 insertions(+)
> >   create mode 100644 drivers/mailbox/mtk-vcp-mailbox.c
> >   create mode 100644 include/linux/mailbox/mtk-vcp-mailbox.h
> > 
> > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> > index 02432d4a5ccd..c28bdb855663 100644
> > --- a/drivers/mailbox/Kconfig
> > +++ b/drivers/mailbox/Kconfig
> > @@ -294,6 +294,15 @@ config MTK_CMDQ_MBOX
> >         critical time limitation, such as updating display
> > configuration
> >         during the vblank.
> > 
> > +config MTK_VCP_MBOX
> > +     tristate "MediaTek VCP Mailbox Support"
> > +     depends on ARCH_MEDIATEK || COMPILE_TEST
> > +     help
> > +       Say yes here to add support for the MediaTek VCP mailbox
> > driver.
> > +       The mailbox implementation provides access from the
> > application
> > +       processor to Video Companion Processor Unit.
> > +       If unsure say N.
> > +
> >   config ZYNQMP_IPI_MBOX
> >       tristate "Xilinx ZynqMP IPI Mailbox"
> >       depends on ARCH_ZYNQMP && OF
> > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> > index 98a68f838486..07278871d254 100644
> > --- a/drivers/mailbox/Makefile
> > +++ b/drivers/mailbox/Makefile
> > @@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX) += mtk-adsp-mailbox.o
> > 
> >   obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
> > 
> > +obj-$(CONFIG_MTK_VCP_MBOX)   += mtk-vcp-mailbox.o
> > +
> >   obj-$(CONFIG_ZYNQMP_IPI_MBOX)       += zynqmp-ipi-mailbox.o
> > 
> >   obj-$(CONFIG_SUN6I_MSGBOX)  += sun6i-msgbox.o
> > diff --git a/drivers/mailbox/mtk-vcp-mailbox.c
> > b/drivers/mailbox/mtk-vcp-mailbox.c
> > new file mode 100644
> > index 000000000000..a2a80d124e50
> > --- /dev/null
> > +++ b/drivers/mailbox/mtk-vcp-mailbox.c
> > @@ -0,0 +1,168 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2025 MediaTek Corporation. All rights reserved.
> > + * Author: Jjian Zhou <jjian.zhou.@mediatek.com>
> > + */
> > +
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mailbox_controller.h>
> > +#include <linux/mailbox/mtk-vcp-mailbox.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +
> > +struct mtk_vcp_mbox {
> > +     struct mbox_controller mbox;
> > +     void __iomem *base;
> > +     struct device *dev;
> > +     const struct mtk_vcp_mbox_cfg *cfg;
> > +     struct mtk_ipi_info ipi_recv;
> > +     struct mbox_chan chans;
> > +};
> > +
> > +struct mtk_vcp_mbox_cfg {
> > +     u32 set_in;
> > +     u32 clr_out;
> 
> u16 is enough for both register offsets, at least for now - and I
> suspect it's
> going to be enough forever.

OK. I change u32 to u16 in the next version.

> 
> > +};
> > +
> > +static irqreturn_t mtk_vcp_mbox_irq_thread(int irq, void *data)
> > +{
> > +     struct mtk_vcp_mbox *priv = data;
> > +
> > +     /* get irq status */
> > +     priv->ipi_recv.irq_status = readl(priv->base + priv->cfg-
> > >clr_out);
> > +
> > +     __ioread32_copy(priv->ipi_recv.msg, priv->base,
> > MBOX_SLOT_MAX_SIZE / 4);
> > +
> > +     mbox_chan_received_data(&priv->chans, &priv->ipi_recv);
> > +
> > +     /* clear irq status */
> > +     writel(priv->ipi_recv.irq_status, priv->base + priv->cfg-
> > >clr_out);
> > +
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller
> > *mbox,
> > +                                         const struct
> > of_phandle_args *sp)
> > +{
> > +     if (sp->args_count)
> > +             return NULL;
> > +
> > +     return &mbox->chans[0];
> > +}
> > +
> > +static int mtk_vcp_mbox_send_data(struct mbox_chan *chan, void
> > *data)
> > +{
> > +     struct mtk_vcp_mbox *priv = chan->con_priv;
> > +     struct mtk_ipi_info *ipi_info = data;
> > +     u32 status;
> > +
> > +     if (!ipi_info->msg) {
> > +             dev_err(priv->dev, "msg buffer is NULL.\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     status = readl(priv->base + priv->cfg->set_in) &
> > BIT(ipi_info->index);
> 
> status = readl(priv->base + priv->cfg->set_in);
> if (status & BIT(ipi_info->index) {
>   ....
> }

OK.

> 
> > +     if (status) {
> > +             dev_warn(priv->dev, "mailbox IPI %d is busy.\n",
> > ipi_info->id);
> > +             return -EBUSY;
> > +     }
> > +
> > +     if (ipi_info->slot_ofs + ipi_info->len > MBOX_SLOT_MAX_SIZE)
> > +             return -EINVAL;
> > +     __iowrite32_copy(priv->base + ipi_info->slot_ofs, ipi_info-
> > >msg,
> > +                      ipi_info->len);
> > +
> > +     writel(BIT(ipi_info->index), priv->base + priv->cfg->set_in);
> > +
> > +     return 0;
> > +}
> > +
> > +static bool mtk_vcp_mbox_last_tx_done(struct mbox_chan *chan)
> > +{
> > +     struct mtk_ipi_info *ipi_info = chan->active_req;
> > +     struct mtk_vcp_mbox *priv = chan->con_priv;
> > +
> > +     return !(readl(priv->base + priv->cfg->set_in) &
> > BIT(ipi_info->index));
> > +}
> > +
> > +static const struct mbox_chan_ops mtk_vcp_mbox_chan_ops = {
> > +     .send_data      = mtk_vcp_mbox_send_data,
> > +     .last_tx_done   = mtk_vcp_mbox_last_tx_done,
> > +};
> > +
> > +static int mtk_vcp_mbox_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct mtk_vcp_mbox *priv;
> > +     struct mbox_controller *mbox;
> > +     int ret, irq;
> > +
> > +     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +     if (!priv)
> > +             return -ENOMEM;
> > +
> > +     priv->dev = dev;
> > +     priv->chans.con_priv = priv;
> > +     mbox = &priv->mbox;
> > +     mbox->dev = dev;
> > +     mbox->ops = &mtk_vcp_mbox_chan_ops;
> > +     mbox->txdone_irq = false;
> > +     mbox->txdone_poll = true;
> > +     mbox->of_xlate = mtk_vcp_mbox_xlate;
> > +     mbox->num_chans = 1;
> > +     mbox->chans = &priv->chans;
> > +
> > +     priv->ipi_recv.msg = devm_kzalloc(dev, MBOX_SLOT_MAX_SIZE,
> > GFP_KERNEL);
> > +     if (!priv->ipi_recv.msg)
> > +             return -ENOMEM;
> > +
> > +     priv->base = devm_platform_ioremap_resource(pdev, 0);
> > +     if (IS_ERR(priv->base))
> > +             return PTR_ERR(priv->base);
> > +
> > +     priv->cfg = of_device_get_match_data(dev);
> > +     if (!priv->cfg)
> > +             return -EINVAL;
> > +
> > +     irq = platform_get_irq(pdev, 0);
> > +     if (irq < 0)
> > +             return irq;
> > +
> 
> Please set the driver data before requesting the interrupt: what
> happens if the
> ISR is run before having driver data available otherwise?! :-)
> 

OK, I put the "platform_set_drvdata(pdev, priv)" between 
"of_device_get_match_data(dev)" and "platform_get_irq(pdev, 0)".

Do you want me to submit a new version right now?

> > +     ret = devm_request_threaded_irq(dev, irq, NULL,
> > +                                     mtk_vcp_mbox_irq_thread,
> > IRQF_ONESHOT,
> > +                                     dev_name(dev), priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     platform_set_drvdata(pdev, priv);
> > +
> > +     return devm_mbox_controller_register(dev, &priv->mbox);
> > +}
> > +
> > +static const struct mtk_vcp_mbox_cfg mt8196_cfg = {
> > +     .set_in         = 0x100,
> > +     .clr_out        = 0x10c,
> > +};
> > +
> > +static const struct of_device_id mtk_vcp_mbox_of_match[] = {
> > +     { .compatible = "mediatek,mt8196-vcp-mbox", .data =
> > &mt8196_cfg },
> > +     {},
> > +};
> > +MODULE_DEVICE_TABLE(of, mtk_vcp_mbox_of_match);
> > +
> > +static struct platform_driver mtk_vcp_mbox_driver = {
> > +     .probe          = mtk_vcp_mbox_probe,
> > +     .driver = {
> > +             .name   = "mtk_vcp_mbox",
> > +             .of_match_table = mtk_vcp_mbox_of_match,
> > +     },
> > +};
> > +module_platform_driver(mtk_vcp_mbox_driver);
> > +
> > +MODULE_AUTHOR("Jjian Zhou <jjian.zhou@mediatek.com>");
> > +MODULE_DESCRIPTION("MTK VCP Mailbox Controller");
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/linux/mailbox/mtk-vcp-mailbox.h
> > b/include/linux/mailbox/mtk-vcp-mailbox.h
> > new file mode 100644
> > index 000000000000..143fb0d06e30
> > --- /dev/null
> > +++ b/include/linux/mailbox/mtk-vcp-mailbox.h
> > @@ -0,0 +1,32 @@
> > +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
> > +/*
> > + * Copyright (c) 2025 MediaTek Inc.
> > + */
> > +
> > +#ifndef __MTK_VCP_MAILBOX_H__
> > +#define __MTK_VCP_MAILBOX_H__
> > +
> > +#define MBOX_SLOT_MAX_SIZE   0x100 /* mbox max slot size */
> 
> Please, change this definition to MTK_VCP_MBOX_SLOT_MAX_SIZE

OK.
> 
> Cheers,
> Angelo
> 
> > +
> > +/**
> > + * struct mtk_ipi_info - mailbox message info for mtk-vcp-mailbox
> > + * @msg: The share buffer between IPC and mailbox driver
> > + * @len: Message length
> > + * @id: This is for identification purposes and not actually used
> > + *   by the mailbox hardware.
> > + * @index: The signal number of the mailbox message.
> > + * @slot_ofs: Data slot offset.
> > + * @irq_status: Captures incoming signals for the RX path.
> > + *
> > + * It is used between IPC with mailbox driver.
> > + */
> > +struct mtk_ipi_info {
> > +     void *msg;
> > +     u32 len;
> > +     u32 id;
> > +     u32 index;
> > +     u32 slot_ofs;
> > +     u32 irq_status;
> > +};
> > +
> > +#endif
> 
> 

Il 30/09/25 04:59, Jjian Zhou (周建) ha scritto:
> On Mon, 2025-09-29 at 12:33 +0200, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>
>>
>> Il 26/09/25 11:05, Jjian Zhou ha scritto:
>>> Add mtk-vcp-mailbox driver to support the communication with
>>> VCP remote microprocessor.
>>>
>>> Signed-off-by: Jjian Zhou <jjian.zhou@mediatek.com>
>>> ---
>>>    drivers/mailbox/Kconfig                 |   9 ++
>>>    drivers/mailbox/Makefile                |   2 +
>>>    drivers/mailbox/mtk-vcp-mailbox.c       | 168
>>> ++++++++++++++++++++++++
>>>    include/linux/mailbox/mtk-vcp-mailbox.h |  32 +++++
>>>    4 files changed, 211 insertions(+)
>>>    create mode 100644 drivers/mailbox/mtk-vcp-mailbox.c
>>>    create mode 100644 include/linux/mailbox/mtk-vcp-mailbox.h
>>>
>>> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
>>> index 02432d4a5ccd..c28bdb855663 100644
>>> --- a/drivers/mailbox/Kconfig
>>> +++ b/drivers/mailbox/Kconfig
>>> @@ -294,6 +294,15 @@ config MTK_CMDQ_MBOX
>>>          critical time limitation, such as updating display
>>> configuration
>>>          during the vblank.
>>>
>>> +config MTK_VCP_MBOX
>>> +     tristate "MediaTek VCP Mailbox Support"
>>> +     depends on ARCH_MEDIATEK || COMPILE_TEST
>>> +     help
>>> +       Say yes here to add support for the MediaTek VCP mailbox
>>> driver.
>>> +       The mailbox implementation provides access from the
>>> application
>>> +       processor to Video Companion Processor Unit.
>>> +       If unsure say N.
>>> +
>>>    config ZYNQMP_IPI_MBOX
>>>        tristate "Xilinx ZynqMP IPI Mailbox"
>>>        depends on ARCH_ZYNQMP && OF
>>> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
>>> index 98a68f838486..07278871d254 100644
>>> --- a/drivers/mailbox/Makefile
>>> +++ b/drivers/mailbox/Makefile
>>> @@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX) += mtk-adsp-mailbox.o
>>>
>>>    obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
>>>
>>> +obj-$(CONFIG_MTK_VCP_MBOX)   += mtk-vcp-mailbox.o
>>> +
>>>    obj-$(CONFIG_ZYNQMP_IPI_MBOX)       += zynqmp-ipi-mailbox.o
>>>
>>>    obj-$(CONFIG_SUN6I_MSGBOX)  += sun6i-msgbox.o
>>> diff --git a/drivers/mailbox/mtk-vcp-mailbox.c
>>> b/drivers/mailbox/mtk-vcp-mailbox.c
>>> new file mode 100644
>>> index 000000000000..a2a80d124e50
>>> --- /dev/null
>>> +++ b/drivers/mailbox/mtk-vcp-mailbox.c
>>> @@ -0,0 +1,168 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Copyright (c) 2025 MediaTek Corporation. All rights reserved.
>>> + * Author: Jjian Zhou <jjian.zhou.@mediatek.com>
>>> + */
>>> +
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/mailbox_controller.h>
>>> +#include <linux/mailbox/mtk-vcp-mailbox.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/slab.h>
>>> +
>>> +struct mtk_vcp_mbox {
>>> +     struct mbox_controller mbox;
>>> +     void __iomem *base;
>>> +     struct device *dev;
>>> +     const struct mtk_vcp_mbox_cfg *cfg;
>>> +     struct mtk_ipi_info ipi_recv;
>>> +     struct mbox_chan chans;
>>> +};
>>> +
>>> +struct mtk_vcp_mbox_cfg {
>>> +     u32 set_in;
>>> +     u32 clr_out;
>>
>> u16 is enough for both register offsets, at least for now - and I
>> suspect it's
>> going to be enough forever.
> 
> OK. I change u32 to u16 in the next version.
> 
>>
>>> +};
>>> +
>>> +static irqreturn_t mtk_vcp_mbox_irq_thread(int irq, void *data)
>>> +{
>>> +     struct mtk_vcp_mbox *priv = data;
>>> +
>>> +     /* get irq status */
>>> +     priv->ipi_recv.irq_status = readl(priv->base + priv->cfg-
>>>> clr_out);
>>> +
>>> +     __ioread32_copy(priv->ipi_recv.msg, priv->base,
>>> MBOX_SLOT_MAX_SIZE / 4);
>>> +
>>> +     mbox_chan_received_data(&priv->chans, &priv->ipi_recv);
>>> +
>>> +     /* clear irq status */
>>> +     writel(priv->ipi_recv.irq_status, priv->base + priv->cfg-
>>>> clr_out);
>>> +
>>> +     return IRQ_HANDLED;
>>> +}
>>> +
>>> +static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller
>>> *mbox,
>>> +                                         const struct
>>> of_phandle_args *sp)
>>> +{
>>> +     if (sp->args_count)
>>> +             return NULL;
>>> +
>>> +     return &mbox->chans[0];
>>> +}
>>> +
>>> +static int mtk_vcp_mbox_send_data(struct mbox_chan *chan, void
>>> *data)
>>> +{
>>> +     struct mtk_vcp_mbox *priv = chan->con_priv;
>>> +     struct mtk_ipi_info *ipi_info = data;
>>> +     u32 status;
>>> +
>>> +     if (!ipi_info->msg) {
>>> +             dev_err(priv->dev, "msg buffer is NULL.\n");
>>> +             return -EINVAL;
>>> +     }
>>> +
>>> +     status = readl(priv->base + priv->cfg->set_in) &
>>> BIT(ipi_info->index);
>>
>> status = readl(priv->base + priv->cfg->set_in);
>> if (status & BIT(ipi_info->index) {
>>    ....
>> }
> 
> OK.
> 
>>
>>> +     if (status) {
>>> +             dev_warn(priv->dev, "mailbox IPI %d is busy.\n",
>>> ipi_info->id);
>>> +             return -EBUSY;
>>> +     }
>>> +
>>> +     if (ipi_info->slot_ofs + ipi_info->len > MBOX_SLOT_MAX_SIZE)
>>> +             return -EINVAL;
>>> +     __iowrite32_copy(priv->base + ipi_info->slot_ofs, ipi_info-
>>>> msg,
>>> +                      ipi_info->len);
>>> +
>>> +     writel(BIT(ipi_info->index), priv->base + priv->cfg->set_in);
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static bool mtk_vcp_mbox_last_tx_done(struct mbox_chan *chan)
>>> +{
>>> +     struct mtk_ipi_info *ipi_info = chan->active_req;
>>> +     struct mtk_vcp_mbox *priv = chan->con_priv;
>>> +
>>> +     return !(readl(priv->base + priv->cfg->set_in) &
>>> BIT(ipi_info->index));
>>> +}
>>> +
>>> +static const struct mbox_chan_ops mtk_vcp_mbox_chan_ops = {
>>> +     .send_data      = mtk_vcp_mbox_send_data,
>>> +     .last_tx_done   = mtk_vcp_mbox_last_tx_done,
>>> +};
>>> +
>>> +static int mtk_vcp_mbox_probe(struct platform_device *pdev)
>>> +{
>>> +     struct device *dev = &pdev->dev;
>>> +     struct mtk_vcp_mbox *priv;
>>> +     struct mbox_controller *mbox;
>>> +     int ret, irq;
>>> +
>>> +     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>> +     if (!priv)
>>> +             return -ENOMEM;
>>> +
>>> +     priv->dev = dev;
>>> +     priv->chans.con_priv = priv;
>>> +     mbox = &priv->mbox;
>>> +     mbox->dev = dev;
>>> +     mbox->ops = &mtk_vcp_mbox_chan_ops;
>>> +     mbox->txdone_irq = false;
>>> +     mbox->txdone_poll = true;
>>> +     mbox->of_xlate = mtk_vcp_mbox_xlate;
>>> +     mbox->num_chans = 1;
>>> +     mbox->chans = &priv->chans;
>>> +
>>> +     priv->ipi_recv.msg = devm_kzalloc(dev, MBOX_SLOT_MAX_SIZE,
>>> GFP_KERNEL);
>>> +     if (!priv->ipi_recv.msg)
>>> +             return -ENOMEM;
>>> +
>>> +     priv->base = devm_platform_ioremap_resource(pdev, 0);
>>> +     if (IS_ERR(priv->base))
>>> +             return PTR_ERR(priv->base);
>>> +
>>> +     priv->cfg = of_device_get_match_data(dev);
>>> +     if (!priv->cfg)
>>> +             return -EINVAL;
>>> +
>>> +     irq = platform_get_irq(pdev, 0);
>>> +     if (irq < 0)
>>> +             return irq;
>>> +
>>
>> Please set the driver data before requesting the interrupt: what
>> happens if the
>> ISR is run before having driver data available otherwise?! :-)
>>
> 
> OK, I put the "platform_set_drvdata(pdev, priv)" between
> "of_device_get_match_data(dev)" and "platform_get_irq(pdev, 0)".
> 
> Do you want me to submit a new version right now?

Yes, please.

Cheers,
Angelo